# Amps, Watts Coulombs



## bjfreeman (Dec 7, 2011)

An Amp specifies how much Flow of electrons there is in One sec.
The amount of electrons that flow are stated in Coulombs.
There are two important values in what is above.
1) to have Amps there must be a closed Circuit with a Charge Differential. Electrons must be moving.
2)the measurement of Amps is in Seconds.

Consider that you open a faucet to fill a container for one sec. that is the equivalent of Amps and the amount for the sake of discussion is 1 Amp.
Now you open the faucet at the same rate for an hour (3600 sec) can you see the amount of electrons that have came out of the Faucet? it will be 3600 times as much as one sec.
It is important to keep this in mind when talking about amps.

1 Amp that Comes from, or creates Charge Differential of 1 Volt will Generated Work and or Heat equivalent to 1 Watt for 1 Second. I use Watt second to denote we are talking about the amount of watts expended base on time.

Keeping in mind that we are talking about electron flow, if you have 1 amp for 1 hour, that is from or generates a Charge differential of 1 volt, and it flows for 3600 second, you will expend 3600 Watts or 1 watt hour.

So if you have a Battery that is rated at 100 Ah and has a charge Differential of 3 Volts. lets say you have a flow of 100 amps for one hour.
This is not the same electrons for the whole hour so you will have 360,000 amps in one hour. At 3 Volts you will have expended 1,080,000 Watts or 300 watt hour.


----------



## palmer_md (Jul 22, 2011)

bjfreeman said:


> ... if you have 1 amp for 1 hour, that is from or generates a Charge differential of 1 volt, and it flows for 3600 second, you will expend *3600 Watts or 1 watt hour*.
> 
> So if you have a Battery that is rated at 100 Ah and has a charge Differential of 3 Volts. lets say you have a flow of 100 amps for one hour.
> This is not the same electrons for the whole hour so you will have 360,000 amps in one hour. At 3 Volts you will have expended *1,080,000 Watts or 100 watt hour*.


I think you mean 300 watt-hour.


----------



## bjfreeman (Dec 7, 2011)

palmer_md said:


> I think you mean 300 watt-hour.


Yes I did, Math is not my strong point, caught it when I reread the post.


----------



## major (Apr 4, 2008)

bjfreeman said:


> An Amp specifies how much Flow of electrons there is in One sec.
> ........2)the measurement of Amps is in Seconds.


bj,

This is where you are wrong. An Ampere is a unit of current. Current is the flow of charge. Charge is measured in the units of Coulombs (C). An Ampere is defined as the flow on one Coulomb for one second but is a rate therefore Ampere = Coulomb per second or A = C/s. As such the term "Amps" has no time frame associated with it. It is an instantaneous quantity. A point. You can't have a container of Amps and store it. Unlike the charge where you can have a container of charge and store it.

The measurement of Amps is NOT in seconds. Just as the measurement of flow (gpm) is NOT in minutes. These are rates and time independent.

You have the same problem with Watts. Power (watts) is a rate. So it makes no sense to say:


> At 3 Volts you will have expended 1,080,000 Watts or 100 watt hour.


 You cannot "expend" a quantity of Watts. You can expend a quantity of Watt hours and at any instant in time the rate at which you do that is measured in Watts.

major

Ref: http://www.diyelectriccar.com/forums/showpost.php?p=276010&postcount=4


----------



## bjfreeman (Dec 7, 2011)

Your funny.
tell me how you achive a charge in a physical world?
another way to ask is what physicaly flows through a wire?

till we are on the same page we can not go further.


----------



## major (Apr 4, 2008)

bjfreeman said:


> Your funny.


That's beside the point. I saw no humor in my post.



> tell me how you achive a charge in a physical world?


I say charges have always existed. All we can do is moved them around. And a moving charge represents a current.



> another way to ask is what physicaly flows through a wire?


Charge.


----------



## bjfreeman (Dec 7, 2011)

major said:


> That's beside the point. I saw no humor in my post.
> 
> 
> 
> ...


All the books I have read are able to define a Charge in a physical world.
they define them as either an negative charge create by an electron or a positive charge defined by a proton.

So I am defining a Charge in modern electrical term as Negative an electron.
I laughed because I was saying the same thing. but you can not see that.
So Tell me why is there a Negative Post and Positive post but No Charge post, not meaning a charger.


----------



## bjfreeman (Dec 7, 2011)

I started started out reading he ARRL handbook when I was 12.
I have designed and built many electronic system in my 70 years.
I have taught and communicated electronics since I was 17. I have had no problem with the way I communicate, as I have done here.
I have a FCC First Class license since I was 20.

When your dealing with electronic you need to know the State of a charge otherwise you will blow up a lot of components.
It is no possible to design using just a Charge


----------



## EVfun (Mar 14, 2010)

Seems you have already started the thread for me... 


EVfun said:


> kilowatt *hours*
> 
> In the example given by JRP3 there are 300 watt hours available (3 volts times 100 amp-hours.) You can use that in the form of 900 watts for 20 minutes or 30 watts for 10 hours.
> 
> ...





bjfreeman said:


> Not quite.
> start a thread on Amps and Watts and I will repsond.
> but for this thread I will only respond to posts about traction motor as a generator.


Please explain what is "not quite" right about that. 

1 amp at 1 volt for 1 second is a 1 joule or 1 watt-second. 1 amp at 1 volt for one hour is 3600 joules or 3600 watt-seconds or 1 watt hour. 10 amps at 1 volt for 6 minutes is 10 watts for 0.1 hour, or 1 watt-hour. 10 watts is the measure of power, 1 watt-hour is the energy expended upon completion of those 6 minutes.


----------



## bjfreeman (Dec 7, 2011)

EVfun said:


> Seems you have already started the thread for me...
> 
> 
> 
> ...


Do you agree with the post 1 here?


----------



## EVfun (Mar 14, 2010)

bjfreeman said:


> Do you agree with the post 1 here?


No, let me correct it for you:


> Keeping in mind that we are talking about electron flow, if you have 1 amp for 1 hour, that is from or generates a Charge differential of 1 volt, and it flows for 3600 second, you will expend 3600 Watt *seconds* or 1 watt hour.
> 
> So if you have a Battery that is rated at 100 Ah and has a charge Differential of 3 Volts. lets say you have a flow of 100 amps for one hour.
> This is not the same electrons for the whole hour so you will have 360,000 amp *seconds* in one hour. At 3 Volts you will have expended 1,080,000 Watt *seconds* or 300 watt hour.


I will point out that listing the amp seconds per hour is bit redundant. In common english "for" typically means to multiply while "in" generally indicates division. There are 3600 seconds in an hour (H = 3600 * S) so I could write that as follows:

360,000A * S / 3600 * S

which can be reduced to:

360,000A / 3600

which further reduces to:

100A

So I can conclude that you have 100 amps flowing if you move 360,000 amps seconds in 1 hour.


----------



## Sunking (Aug 10, 2009)

bjfreeman said:


> An Amp specifies how much Flow of electrons there is in One sec.


No wonder you are so confused, you do not even understand what an AMP, Volt, Ohm, or Watt is. Therefore you have no chance or clue how it relates to time and energy used.

Your first step is to learn simple 6th grade algebra, then study the 12 formulas of Ohm's Law. In the USA that takes 24 years or public school, or 30 minutes anywhere else.


----------



## JRP3 (Mar 7, 2008)

bjfreeman said:


> I have taught and communicated electronics since I was 17. I have had no problem with the way I communicate, as I have done here.


I guess you can't see it but you've had quite a large problem communicating here. YOU may not have a problem with your communication skills but I assure you the same is not true for those with whom you are trying to communicate. Just to be fair, is English your second language? Or do you have some disability?


----------



## Gary B (Jun 2, 2011)

JRP3 said:


> I guess you can't see it but you've had quite a large problem communicating here. YOU may not have a problem with your communication skills but I assure you the same is not true for those with whom you are trying to communicate. Just to be fair, is English your second language? Or do you have some disability?


Hello, JRP3 - Not to be unkind. - - - if you live long enough, you TOO may have a "disability" (called Alzheimer's). - It's onset is very gradual and the person suffering it (you, someday, maybe) may not be very much aware of it. - However, such a disability should not prevent one from pursuing what interests them, within their capabilities. - It is desirable (in my mind) to be kind to "people" first. Then worry about who is the most knowledgeable or experienced or on top of the pile. - Who is on top of the pile today will be (definitely) UNDER the pile when their time comes. - People, certainly, are different. Some pound their chests. Some just smile. Gary B.


----------



## JRP3 (Mar 7, 2008)

I was asking an honest question. I realize that many who post here speak another language, or may indeed have some sort of problem, I wanted to know what we are dealing with. I think it was a valid question to ask of someone who seems to think they are communicating well when the opposite is true.


----------



## Gary B (Jun 2, 2011)

JRP3 said:


> I was asking an honest question. I realize that many who post here speak another language, or may indeed have some sort of problem, I wanted to know what we are dealing with. I think it was a valid question to ask of someone who seems to think they are communicating well when the opposite is true.


We are off thread at this point. But, basically, i agree with you. - For me, it's a question of how to do that in a way that is not offensive or aggressive. Even given that, some people are more easily offended or defensive than others. Who's to determine the crossing of that line? - People are different. - Best to you.

Gary B.


----------



## Duncan (Dec 8, 2008)

Hi Guys

The root cause of the problem is in the "language" - specifically the units used

The problem is Ampere seconds - correctly Coulombs 
this leads into Ampere Hours - 3600 Coulombs

Ampere Hours leads into Watt hours - it's a slippery slope!
and back to Watt Seconds

The correct unit for energy is the Joule - a Watt Second is a mongrel! 
a Watt Hour is a bigger mongrel!

If everybody used the correct units all of this would go away - and I could while away the hours shooting the pigs flying over my paddock


----------



## EVfun (Mar 14, 2010)

A Watt Hour is a bigger mongrel? Electricity is sold by the kWh in the USA. That would be 1000 watt hours. Does that mean kWh is some type of mongrel too? Many of us measure our EVs energy consumption in watt hours per mile.


----------



## Duncan (Dec 8, 2008)

EVfun said:


> A Watt Hour is a bigger mongrel? Electricity is sold by the kWh in the USA. That would be 1000 watt hours. Does that mean kWh is some type of mongrel too? Many of us measure our EVs energy consumption in watt hours per mile.



Yep - it's an even bigger mongrel!

And it's worse than that - things like BTU's (British Thermal Units) Horsepower and Slugs were developed from pre-scientific measurements 
So there is some excuse for their eccentricities

Watt seconds 
Watt hours
Kilowatt hours

Are just plain mongrels, 

There was already a correct unit available but some lazy buggers started using Ampere hours and the whole thing started going to hell from that point

It will probably take hundreds of years to fix it 

And yes we buy electricity in Kwhrs here as well


----------



## tomofreno (Mar 3, 2009)

I think you are a bit pedantic Duncan. True, Joule is the unit of energy in the mks system, but it is equally true that it is equal a Watt-second by definition of a Watt. None of this seems to be such a big deal, and evfun already pointed out that Watt-second is a Joule in his first post in this thread.



Duncan said:


> Hi Guys
> 
> The root cause of the problem is in the "language" - specifically the units used
> 
> ...


----------



## bjfreeman (Dec 7, 2011)

EVfun said:


> No, let me correct it for you:
> 
> 
> I will point out that listing the amp seconds per hour is bit redundant. In common english "for" typically means to multiply while "in" generally indicates division. There are 3600 seconds in an hour (H = 3600 * S) so I could write that as follows:
> ...


using my explanation of Charge flow show how what you said fits.


----------



## bjfreeman (Dec 7, 2011)

Sunking said:


> No wonder you are so confused, you do not even understand what an AMP, Volt, Ohm, or Watt is. Therefore you have no chance or clue how it relates to time and energy used.
> 
> Your first step is to learn simple 6th grade algebra, then study the 12 formulas of Ohm's Law. In the USA that takes 24 years or public school, or 30 minutes anywhere else.


Yes you use Ohms and Kirchhoff law do define Static relationships in a circuit.
However once you have a complete circuit you have flow.
Here are some references from the web. Saves me typing

The SI unit of charge, the coulomb, "is the quantity of electricity carried in 1 _second_ by a current of _1 ampere_".

An _ampere_-hour or _amp_-hour (symbol Ah , A·h, A h) is a unit of electric charge, with sub-units milliampere-hour (mAh) and milliampere _second_ (mAs).

_One_ amp represents a rate of electron flow of 1 coulomb of electrons per _second

So I would say you missed some things.
_


----------



## bjfreeman (Dec 7, 2011)

JRP3 said:


> I guess you can't see it but you've had quite a large problem communicating here. YOU may not have a problem with your communication skills but I assure you the same is not true for those with whom you are trying to communicate. Just to be fair, is English your second language? Or do you have some disability?


there is another conditiion of those that don't know they don't know. everyone has this condition I find the younger ones have it more.

To answer you question, I am selective group dyslexic. I could not write so anyone could read till I was 40. and arithmetic still gives me problems so i use a calculator.


----------



## EVfun (Mar 14, 2010)

bjfreeman said:


> The SI unit of charge, the coulomb, "is the quantity of electricity carried in 1 _second_ by a current of _1 ampere_".
> 
> _One_ amp represents a rate of electron flow of 1 coulomb of electrons per _second_


The first quote makes it clear that 1 Coulomb = 1 amp second.

The second quote, in math since that is my style:
(where A is amp, C is Coulomb, S is second)

1A = 1C/S

since C = A*S

1A = 1AS/S

which reduces to

1A = 1A

That is so true it's obvious. 

I have yet to figure out your "charge flow" explanation. From what I can make of it you seem to be saying that one Amp is one Coulomb and one Watt is one Joule -- but that is wrong. Perhaps you can explain it with math?


----------



## bjfreeman (Dec 7, 2011)

EVfun said:


> The first quote makes it clear that 1 Coulomb = 1 amp second.
> 
> The second quote, in math since that is my style:
> (where A is amp, C is Coulomb, S is second)
> ...


you left out the time factor of electron flow which does not happen in static calculations. Hence the explanation of the amount of electrons the will pass a point in a complete circuit based on time.
you can not mix static circuit calculation with electron flow and time based calculations, which is why I wrote the fist post the way I did.


----------



## tomofreno (Mar 3, 2009)

I have added some comments, indicated by >>>, to your original text bj:

An Amp specifies how much Flow of electrons there is in One sec.
The amount of electrons that flow are stated in Coulombs.
There are two important values in what is above.
1) to have Amps there must be a closed Circuit with a Charge Differential. Electrons must be moving.
2)the measurement of Amps is in Seconds.

>>> The amount of charge is stated in Coulombs. The amount of charge flowing is given in Amperes. One Ampere is one Coulomb/second. The charge on an electron is 1.6 e10^-19 Coulomb. One Ampere is one Coulomb per second, or 6.25 e10^18 electrons per second.

Consider that you open a faucet to fill a container for one sec. that is the equivalent of Amps and the amount for the sake of discussion is 1 Amp.
Now you open the faucet at the same rate for an hour (3600 sec) can you see the amount of electrons that have came out of the Faucet? it will be 3600 times as much as one sec.
It is important to keep this in mind when talking about amps.

>>>In this metaphor the water molecules represent charge, measured in Coulomb, and the measurement of flow of charge is Coulomb per second, or Ampere. The charge on an electron is 1.6 e10^-19 Coulomb. One Ampere is 1 Coulomb per second, or 6.25 e10^18 electrons per second. If these flow through a potential difference of 1 Volt, that is 1 Watt or 1 Joule/second of power, energy per time.

1 Amp that Comes from, or creates Charge Differential of 1 Volt will Generated Work and or Heat equivalent to 1 Watt for 1 Second. I use Watt second to denote we are talking about the amount of watts expended base on time.

>>> Volt is work per charge, Volt = Joule/Coulomb. One Joule of work is expended to raise the potential of one Coulomb of charge one Volt. One Ampere flowing through a potential difference of 1 Volt is one Watt, energy per time. An Ampere is one Coulomb/second, so this is 1 Volt-Coulomb/second, but one Volt is one Joule/Coulomb, so we have one Joule/second (energy/time), which is one Watt.

Keeping in mind that we are talking about electron flow, if you have 1 amp for 1 hour, that is from or generates a Charge differential of 1 volt, and it flows for 3600 second, you will expend 3600 Watts or 1 watt hour.

>>> Well, you can't have it both ways, Watt is a unit of power, or energy per time, and Watt-hour is a unit of energy. 1 Watt-hour is correct. Or, you could say 3600 Watt-seconds, but not 3600 Watt, since you are taking the product of 1 Volt, 1 Ampere, and 3600 seconds, or 3600 Coulomb of charge falling through a potential of one Volt. A Volt is a Joule/Coulomb, so we have 3600 Joule = 3600 Watt-seconds, or 1 Watt-hour.

So if you have a Battery that is rated at 100 Ah and has a charge Differential of 3 Volts. lets say you have a flow of 100 amps for one hour.
This is not the same electrons for the whole hour so you will have 360,000 amps in one hour. At 3 Volts you will have expended 1,080,000 Watts or 300 watt hour.

>>> You will have discharged 360,000 Ampere-seconds of charge, or 360,000 Coulomb through a potential of 1 Volt, so the work done by the 1 Volt potential on the charge was 360,000 Joule, or Watt-seconds if you prefer. At 3 Volt potential difference and 100 Ampere for 1 hour you will have discharged 360,000 Coulomb of charge, and the 3 Volt potential did work on the charge in the amount of 1,080,000 Joule.


----------



## bjfreeman (Dec 7, 2011)

tomofreno said:


> I have added some comments, indicated by >>>, to your original text bj:
> 
> An Amp specifies how much Flow of electrons there is in One sec.
> The amount of electrons that flow are stated in Coulombs.
> ...


I am slow on math so will respond to that later.

we disagree on one point
Power is defined as the rate at which work is done upon an object. Like all rate quantities, power is a time-based quantity. Power is related to how fast a job is done. Two identical jobs or tasks can be done at different rates - one slowly or and one rapidly. The work is the same in each case (since they are identical jobs) but the power is different. The equation for power shows the importance of time:
*Power = Work / time*​ *P = W / t*​


----------



## Duncan (Dec 8, 2008)

Hi Tomofreno

A bit pedantic
1. ostentatious in one's learning. 
2. overly concerned with minute details or formalisms, especially in teaching.

I don't think so, 
When the correct units are used a lot of issues become so much clearer 

This and related threads are about a confusion that causes people to obtain silly answers 

The welding comment that Aerosmith? made 24,000 joules per inch is a sensible number 6.6 Joules per inch is not

So long as people talk about watts per second we are going to have silly answers

When a writer puts a point in the wrong place - who cares

When an engineer does the same - things break


----------



## EVfun (Mar 14, 2010)

bjfreeman said:


> you left out the time factor of electron flow [snip]


Yes, because Amps don't have a time factor. 1 amp for 1 hour is 1 amp hour. 1 amp for 1 second is 1 amp second, better known as 1 Coulomb. 1 amp for 6 days is 144 amp hours. 12 amps for 5 hours is 60 amp hours (a full charge for my small pack.) Coulombs has a time factor. Coulomb/second (Coulombs divided by seconds) is amps.

1 Coulomb (1 amp second) is approximately 6,241,500,000,000,000,000 (6.2415 * 10^18) electrons moving past a point. It could be in the form of 1/2 that many for 2 seconds or twice than many for a 1/2 second.

You have a rate of electron flow and a length of time for them to flow. Amps is rate and time is... well... time.


----------



## EVfun (Mar 14, 2010)

21,600,000 Joules is an awkward way to refer to my battery pack. 6kWh is so much easier, especially since the USA isn't on the metric system. Joules are apt to get me a blank stare. Watt seconds are the same thing, but won't draw a blank stare because they can relate that to kWh.


----------



## bjfreeman (Dec 7, 2011)

EVfun said:


> Yes, because Amps don't have a time factor. 1 amp for 1 hour is 1 amp hour. 1 amp for 1 second is 1 amp second, better known as 1 Coulomb. 1 amp for 6 days is 144 amp hours. 12 amps for 5 hours is 60 amp hours (a full charge for my small pack.) Coulombs has a time factor. Coulomb/second (Coulombs divided by seconds) is amps.
> 
> 1 Coulomb (1 amp second) is approximately 6,241,500,000,000,000,000 (6.2415 * 10^18) electrons moving past a point. It could be in the form of 1/2 that many for 2 seconds or twice than many for a 1/2 second.
> 
> You have a rate of electron flow and a length of time for them to flow. Amps is rate and time is... well... time.


is not a per second a time factor?
Rate as in the number of electrons per second, yes.
if 1 Coulomb passes a point in 1 sec then 2 *coulombs *will pass in 2 second.
otherwise you do not have 1 amp per second, which is the rate of flow.


----------



## Duncan (Dec 8, 2008)

bjfreeman said:


> Rate as in the number of electrons per second, yes.
> if 1 Coulomb passes a point in 1 sec then 2 *coulombs *will pass in 2 second.
> otherwise you do not have 1 amp per second, which is the rate of flow.



You are doing it again!

*1 amp per second* is nonsense like Gallons per minute per minute


----------



## EVfun (Mar 14, 2010)

Amp per second (A/S) has no meaning. Amp second (A*S) does have a meaning, 1 amp second equals 1 Coulomb. Coulombs do not equal amps.

From The Standard Electrical Dictionary 2008:


> *Ampere*
> The practical unit of electric current strength. It is the measure of
> the current produced by an electro-motive force of one volt through a
> resistance of one ohm. In electric quantity it is the rate of one
> ...


----------



## tomofreno (Mar 3, 2009)

bjfreeman said:


> I am slow on math so will respond to that later.
> 
> we disagree on one point
> Power is defined as the rate at which work is done upon an object. Like all rate quantities, power is a time-based quantity. Power is related to how fast a job is done. Two identical jobs or tasks can be done at different rates - one slowly or and one rapidly. The work is the same in each case (since they are identical jobs) but the power is different. The equation for power shows the importance of time:
> *Power = Work / time*​ *P = W / t*​


We don't disagree. That is what I said:


> If these flow through a potential difference of 1 Volt, that is 1 Watt or 1 Joule/second of power, energy per time.


I think it would help if you took the time to read through what I wrote.


----------



## tomofreno (Mar 3, 2009)

Duncan said:


> Hi Tomofreno
> 
> A bit pedantic
> 1. ostentatious in one's learning.
> ...


The error was not attributable to using Watt-second rather than Joule.


----------



## bjfreeman (Dec 7, 2011)

EVfun said:


> 21,600,000 Joules is an awkward way to refer to my battery pack. 6kWh is so much easier, especially since the USA isn't on the metric system. Joules are apt to get me a blank stare. Watt seconds are the same thing, but won't draw a blank stare because they can relate that to kWh.


you bring up an awareness that I need input on. Has the schools in the USA 
gone to metric.
when I reply I look at the location so I respond to the way those in the location will know what I am saying. It seems that either we have a lot of Brits in the US that were taught metric or the schools in the US have finally caught up the metric system. I can do both.
I will just specify I am using US or Metric


----------



## bjfreeman (Dec 7, 2011)

EVfun said:


> Amp per second (A/S) has no meaning. Amp second (A*S) does have a meaning, 1 amp second equals 1 Coulomb. Coulombs do not equal amps.
> 
> From The Standard Electrical Dictionary 2008:


Wow I can see why we don't understand each other. I am using the values that no longer exist in the current understanding.
However I find the water analogy is the same one I used in the original post, on this thread.

The whole point is most forget that Amp Second, which is what I was trying to define in my antiquainted way.

so I guess I will re-educated myself in the way people say the things I now, since most don't know the way I have used for decades.
I use _The Communications Handbook by Ieee press dated 2000_


----------



## bjfreeman (Dec 7, 2011)

Duncan said:


> You are doing it again!
> 
> *1 amp per second* is nonsense like Gallons per minute per minute


so how do you respond to
1 Coulomb (1 amp second) is approximately 6,241,500,000,000,000,000 (6.2415 * 10^18) electrons moving past a point. It could be in the form of 1/2 that many for 2 seconds or twice than many for a 1/2 second.


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> you bring up an awareness that I need input on. Has the schools in the USA
> gone to metric.
> when I reply I look at the location so I respond to the way those in the location will know what I am saying. It seems that either we have a lot of Brits in the US that were taught metric or the schools in the US have finally caught up the metric system. I can do both.
> I will just specify I am using US or Metric


We have been using metric, more specifically SI, in US Science classes for at least 30 years. When I started teaching HS Physics I didn't even give conversion factors for things. I would just hold up a meter stick and say this is a meter long. When asked how long a meter was I would say, pointing to the ends of the stick, "from here to here." I didn't want my students to be stuck with the myth that to use metric one has to convert. Just learn the new system and scrap the conversions between measurement systems. If you really need to move between systems it can easily be looked up and done later.

Back to this thread's main topic. There is some misconception about that a static value is, a change in a value over time, and a change in a value over time over time. A very common one I encounter is the concept of distance, the concept of how quickly distance (position really) is changing, and the concept of how quickly the rate of change of position is changing. Using SI units this would relate to, meters (m), meters/second (m/s), and meters/second/second (m/s/s or m/s^2) or position, speed (rate), acceleration, respectively.

Amps is a rate so is analogous to speed which means that Amps/second would be an acceleration, a rate of change of Amps. This is not a meaningless unit as some said but it is referred to, IIRC, as a slew rate in the Evnetics controllers to define how quickly the current is ramped up. I have a similar parameter in my Sevcon controller except that I enter a time unit to tell the controller how long to take to go from 0A to 400A for example. If I set the time unit to 0.5sec in my controller this would be a slew rate of 400A/0.5s = 800A/s. A very reasonable unit of measure.

In any case, if the units were mathematically written out in this discussion so that the proper dimensional analysis or unit analysis could be shown it would be obvious to everyone why the Watts/second would or would not be applicable. It would also show why BJ's comment, "if 1 Coulomb passes a point in 1 sec then 2 *coulombs *will pass in 2 second.
otherwise you do not have 1 amp per second, which is the rate of flow" doesn't make sense. It is true that if 1 Coulomb passes a point in 1 second that 2 Coulombs will pass in 2 sec, assuming no change in rate. But it is not going to be a rate of 1 amp per second because an amp is already a rate like speed is a rate. Dividing by another time unit makes it an acceleration unit or a rate of change of rate. An Amp = 1 Coulomb/sec so to say an Amp/sec is to say a Coulomb/sec/sec or C/s^2 which is an acceleration.

BJ's comment would be correct if the second sentence said "otherwise you do not have 1 amp, which is a rate of flow." Note that if 1 Coulomb paasses a point in 1 sec by definition this is a rate of 1 amp. In 2 seconds then we can calculate the amount of charge that was moved in that time as follows: (1 amp)(2 sec) = 2 amp-seconds or it could be done this way: (1 amp)(2 sec) = (1 Coulomb/sec)(2 sec) = 2 Coulombs.

Keep the units, do the math, go back to the definition of the derived units you are using if needed and it will all work and make sense. This is something that has not changed over time and is not dependent on what system of units you are working with.


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> so how do you respond to
> 1 Coulomb (1 amp second) is approximately 6,241,500,000,000,000,000 (6.2415 * 10^18) electrons moving past a point. It could be in the form of 1/2 that many for 2 seconds or twice than many for a 1/2 second.


My previous comment addresses this but I'll do it again for the record.

1 Coulomb = 1 amp second now divide both sides by 1 second

1 Coulomb / second = (1 amp second)/second Simplify each side 

1 Coulomb/second = 1 amp

Now for the "1/2 that many for 2 seconds" would mean that the rate was 1/2 Amp or 1/2 Coulomb/sec. Just multiply by 2 sec and you get 1 Coulomb. (1/2 Amp)(2 Sec) = 1 amp second = (1 Coulomb/sec)(sec) = 1 Coulomb

And for the "twice than many for a 1/2 second" would mean that the rate was 2 Amp or 2 Coulombs/sec. Just multiply by 1/2 sec and you get the same 1 Coulomb. (2 amp)(1/2 sec) = 1 amp second = (1 Coulomb/sec)(sec) = 1 Coulomb

Simple, isn't it?


----------



## Duncan (Dec 8, 2008)

tomofreno said:


> The error was not attributable to using Watt-second rather than Joule.


No it was attributable to using Ampere Hours in place of Amps


----------



## bjfreeman (Dec 7, 2011)

Duncan said:


> No it was attributable to using Ampere Hours in place of Amps


so how do you express the flow of a amp for an hour?

note I am in learning mode an really want answers so I can learn.
if you have a reference that will help I will be glad to spend time to update my knowledge.


----------



## EVfun (Mar 14, 2010)

bjfreeman said:


> you bring up an awareness that I need input on. Has the schools in the USA
> gone to metric.


As of the 1980's High Schools around the country where still teaching primarily in US Customary units. Grams had made significant inroads in science classes. Math classes often used story problems with mixed units to make everyone comfortable with the metric system, and conscious of the need to not mix units. The USA has not officially converted to SI units.


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> so how do you express the flow of a amp for an hour?


No different than expressing driving 80km/h for an hour. Remember that amp already has the /time unit in it so just say the flow or current was at an amp for an hour for a total charge transfer of 1 Ah. This would be more akin to saying a speed of 20m/s for an hour and saying the distance traveled was 20m/s*h. Now if we gave a name to m/s, say a BJF then we could say that the speed was 20 BJF and that was kept for an hour so the distance was 20 BJF*hours.

FWIW, when I started taking Physics classes I found initially that it was helpful to have a reference sheet of the various units of measure and what they were derived from. That list would include things such as A=C/s, or W=J/s, or N=kg*m/s^2, etc.


----------



## EVfun (Mar 14, 2010)

bjfreeman said:


> so how do you express the flow of a amp for an hour?


That would be an amp hour. I think the confusion is from a common (bad) habit of using "per." It is not an amp per hour (A/H) but an amp for an hour (A*H.) It is not division but multiplication (rate times time.)

The amp has no ties to time. It could flow for a second or a week. You can measure it at any instant and know the amps. Only together with the time it flows can you know the amp hours.


----------



## bjfreeman (Dec 7, 2011)

EVfun said:


> That would be an amp hour. I think the confusion is from a common (bad) habit of using "per." It is not an amp per hour (A/H) but an amp for an hour (A*H.) It is not division but multiplication (rate times time.)
> 
> The amp has no ties to time. It could flow for a second or a week. You can measure it at any instant and know the amps. Only together with the time it flows can you know the amp hours.


so how would you express flow of an amp for 20 minutes?


----------



## EVfun (Mar 14, 2010)

bjfreeman said:


> so how would you express flow of an amp for 20 minutes?


1/3 amp hour.


----------



## bjfreeman (Dec 7, 2011)

GizmoEV said:


> No different than expressing driving 80km/h for an hour. Remember that amp already has the /time unit in it so just say the flow or current was at an amp for an hour for a total charge transfer of 1 Ah. This would be more akin to saying a speed of 20m/s for an hour and saying the distance traveled was 20m/s*h. Now if we gave a name to m/s, say a BJF then we could say that the speed was 20 BJF and that was kept for an hour so the distance was 20 BJF*hours.
> 
> FWIW, when I started taking Physics classes I found initially that it was helpful to have a reference sheet of the various units of measure and what they were derived from. That list would include things such as A=C/s, or W=J/s, or N=kg*m/s^2, etc.


yes I have those in my mind for decades. But what is new is how people interpret what is written.
that is something new and I have to learn.


----------



## bjfreeman (Dec 7, 2011)

EVfun said:


> 1/3 amp hour.


is it common to use decimal instead of fractions?
does the expression of amp-hour infer more power used than in one second in most peoples mind, or do they assume it is still equivalent of 1 amp, if you get what I mean.


----------



## Duncan (Dec 8, 2008)

Hi Guys

The unit Ampere Hour is a mongrel - the correct unit would be Coulombs - 
3.6 Kilo Coulombs - 3.6kC

The same way the Watt Hour should be Joules - 3.6 Kilo Joules - 3.6kJ

If the correct units are used confusion is reduced

_so how would you express flow of an amp for 20 minutes? _

That would be 1 x 20(minutes) x 60(seconds) = 1200 Coulombs - 1.2Kilo Coulombs - 1.2kC

It would be a lot easier - and in about 200 years maybe people will be consistent in their units - but I would not bet on it!



Hi GizmoEv

I can see how a slew rate of amperes per second would apply to a situation in power electronics but its still a funny unit

would Coulombs per second per second not be more consistent with the rest of the SI system?


----------



## bjfreeman (Dec 7, 2011)

Duncan said:


> Hi Guys
> 
> The unit Ampere Hour is a mongrel - the correct unit would be Coulombs -
> 3.6 Kilo Coulombs - 3.6kC
> ...


It would help for a newbie for this forum that it is stated that Metrics are preferred. But it should not be considered wrong for those that are not use to metric be allowed to express their units, without be chastised.


----------



## Duncan (Dec 8, 2008)

bjfreeman said:


> It would help for a newbie for this forum that it is stated that Metrics are preferred. But it should not be considered wrong for those that are not use to metric be allowed to express their units, without be chastised.



As far as I am concerned you are welcome to use imperial units if you wish

however if you are using Amperes, Coulombs, Watts I would expect you to use them correctly 

What are the non metric electrical units? - Frogs Legs / acre?


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> yes I have those in my mind for decades. But what is new is how people interpret what is written.
> that is something new and I have to learn.


Well, it hasn't changed for over 30 years and I have no trouble properly interpreting what was written even before you were born. I don't see what you think has changed in the interpretation. I showed the math to support what many of us have said. That part hasn't changed at all. Do the unit analysis and you will see what we are trying to convey.


----------



## bjfreeman (Dec 7, 2011)

Duncan said:


> Hi Guys
> 
> The unit Ampere Hour is a mongrel - the correct unit would be Coulombs -
> 3.6 Kilo Coulombs - 3.6kC
> ...


----------



## Duncan (Dec 8, 2008)

bjfreeman said:


> Duncan said:
> 
> 
> > Hi Guys
> ...


----------



## EVfun (Mar 14, 2010)

bjfreeman said:


> is it common to use decimal instead of fractions?
> does the expression of amp-hour infer more power used than in one second in most peoples mind, or do they assume it is still equivalent of 1 amp, if you get what I mean.


I tried to use the decimal number, but I ran out of 3's 

Yes, use of decimal numbers would be more common. Carefully chosen fractions can mean exactly the same thing (like Coulomb and amp second.)


----------



## GizmoEV (Nov 28, 2009)

Duncan said:


> Hi Guys
> 
> The unit Ampere Hour is a mongrel - the correct unit would be Coulombs -
> 3.6 Kilo Coulombs - 3.6kC
> ...


Mathematically both are correct units. The issue isn't Ah vs. Coulombs it is using those units correctly in the first place.




Duncan said:


> Hi GizmoEv
> 
> I can see how a slew rate of amperes per second would apply to a situation in power electronics but its still a funny unit
> 
> would Coulombs per second per second not be more consistent with the rest of the SI system?


Yes it is a funny unit but not any funnier than acceleration units like 10mi/h/s. I can even change the slew rate of my vehicle on the fly, just vary the rate at which throttle is applied. 

As for the SI system, I don't think c/s^2 would be any more consistent when it defines Kg as the standard unit for mass when all the rest use the base unit.


----------



## bjfreeman (Dec 7, 2011)

GizmoEV said:


> Well, it hasn't changed for over 30 years and I have no trouble properly interpreting what was written even before you were born. I don't see what you think has changed in the interpretation. I showed the math to support what many of us have said. That part hasn't changed at all. Do the unit analysis and you will see what we are trying to convey.


Not sure you guess my age but I was 40, 30 years a go. and have been on electronics for 30 years by then.
however that does mean I want to start a flame war on understanding.
I am just trying to understand what you guys mean now.


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> My understanding is Joules express energy capable and to be converted to flow would be Joules per second.
> if I am correct how would you express Joules to show that it is flowing as compared just being stored?


This is like saying, "How would you express miles to show that you are moving?" In miles per hour. The per time unit is what makes it obvious that it is a rate based on time. Some units "hide" the time component like Watts because it is more convenient and maybe also to remember past scientists.


----------



## bjfreeman (Dec 7, 2011)

Duncan said:


> bjfreeman said:
> 
> 
> > Joules per second is (are?) Watts
> ...


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> Not sure you guess my age but I was 40, 30 years a go. and have been on electronics for 30 years by then.
> however that does mean I want to start a flame war on understanding.
> I am just trying to understand what you guys mean now.


Yes, I know from another post about how old you are. That is why I stated it the way I did. I can interpret things written well before your parents were thought of so I'm confused at what you think has changed in how people interpret things. Yes I had to change from using angstroms to nm for measuring wavelengths of light when I went from HS to College but that was probably more because of the age of the physics book I had in HS than anything else.


----------



## EVfun (Mar 14, 2010)

Duncan said:


> The unit Ampere Hour is a mongrel - the correct unit would be Coulombs -
> 3.6 Kilo Coulombs - 3.6kC
> 
> The same way the Watt Hour should be Joules - 3.6 Kilo Joules - 3.6kJ
> ...


Since the USA has not adopted SI units as its standard wouldn't amp hours and watt hours be equally correct in the USA? Since a Joule is a watt second and a Coulomb is an amp second I don't think it will cause any Mars orbiters to crash. Perhaps when both of us are billed for home electricity use in MJ instead of kWh the world will be ready for Joules. And really, are you not mentally relabeling Coulombs to Amp Seconds when you determine amps based on Coulombs and time?


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> Duncan said:
> 
> 
> > The same way the Watt Hour should be Joules - 3.6 Kilo Joules - 3.6kJ
> ...


1 Watt = 1 Joule per second or W=J/s

1 Watt hour = 1 Wh = 1 J/s*h = (1 J/s*h)(60min/h)(60s/min) = 3600J = 3.6kJ

1 Joule per hour 1 J/h = (1 J/h)(1 h/60min)(1 min/60sec) = 1/3600 J/s = 1/3600 Watts

What you are missing is how the units cancel. Write out the lines above in fraction form with all the "per" units underneath the fraction and all the other units above. You will see that for every unit which appears above and below it can be crossed out. You are then left with the proper units. This is called dimensional analysis or unit analysis.


----------



## Duncan (Dec 8, 2008)

bjfreeman said:


> Duncan said:
> 
> 
> > The same way the Watt Hour should be Joules - 3.6 Kilo Joules - 3.6kJ
> ...


----------



## major (Apr 4, 2008)

bjfreeman said:


> what am I missing?


Everything we've been telling you 



bjfreeman said:


> to me Watt hours is Jules per hour not kj.


A (Watt hour) is a unit of energy.

A Joule is a unit of energy.

(Joules per hour) would be power.

Energy is not the same as power.

A number of Watt hours can be converted to a number using units of kJ because both Wh and kJ are units of energy. 1 Wh = 3.6 kJ.

Similarly power can be expressed with the units of Watts or kilowatts or horsepower. 1000 W = 1 kW = 1.34 hp.

Joules per hour would also be a unit of power but rarely used. 1 J/h = 0.00028 W. This would also equal 0.00000037 hp.

This does relate back to what got me started with you. That was your use of Watts per second (W/s). Would you ever use the units of hp/s (horsepower per second)? 

I hope we are making progress here 

major


----------



## bjfreeman (Dec 7, 2011)

major said:


> Everything we've been telling you
> 
> 
> 
> ...


yes the difference between Joule Energy and Joule Power is time since time represents flow. So Joules is energy Joule per Second or Joule second is Power.
My problem still is how, in writing, do you distinguish between Power and energy, related to Joules.
and how do you communicate that so many joules (power) have been used over time compared to Joules Stored?
it may be clear to you but I can not see the correlation, in writing.
what units of Joules would you use to calculate a choke or Boost Coil?
milliJoules?
and yes a watt hour stored is energy and watt-hour can all be power when applied to complete circuit.


----------



## major (Apr 4, 2008)

bj,

We've been telling you the answers in very precise language for the past week or two. But here I will tell you again.



bjfreeman said:


> yes the difference between Joule Energy and Joule Power is time since time represents flow.


Joule is a unit of energy. NOT power. There is no such thing as "Joule Power".

Power uses the unit of Watt.

The relationship between power and energy is one Watt = 1 Joule per second, 1W = 1J/s.



> So Joules is energy


 Yes.


> Joule per Second or Joule second is Power.


 "Joule per second" is power, "Joule second" is a meaningless term and I never want to hear or see it used again.



> My problem still is how, in writing, do you distinguish between Power and energy, related to Joules.


It is easy. When writing about power use the units of Watts. When writing about energy use the units of Joules. You'll help yourself by never referring to power in terms of Joules what-so-ever.



> and how do you communicate that so many joules (power)


 "joules (power)" is nonsense.


> have been used over time compared to Joules Stored?


 Energy used over a time period is still energy and expressed in Joules. Just like energy stored is expressed in Joules. It is the rate of energy which is power (watts) and that is the rate at which energy is used, not the amount of energy used.



> it may be clear to you but I can not see the correlation, in writing.
> what units of Joules


Joules are the unit.



> would you use to calculate a choke or Boost Coil?
> milliJoules?


If you're talking about the energy stored by a coil then use Joules. MilliJoule is just 1/1000th of a Joule.



> and yes a watt hour stored is energy


 Yes.


> and watt-hour can all be power when applied to complete circuit


 No. A Watt hour can never be power. A Watt hour will always be energy. A Watt hour of energy can be dissipated in a circuit and the rate at which it is dissipated or the rate at which the energy is used is expressed in Watts and is power.

Regards,

major


----------



## bjfreeman (Dec 7, 2011)

so how do you respond to
The terms power and energy are frequently confused. Power is the rate at which energy is generated or consumed.

http://en.wikipedia.org/wiki/Watt#Confusion_of_watts.2C_watt-hours.2C_and_watts_per_hour


----------



## major (Apr 4, 2008)

bjfreeman said:


> so how do you respond to
> The terms power and energy are frequently confused. Power is the rate at which energy is generated or consumed.


Exactly. That is what I have told you multiple times.


----------



## Jan (Oct 5, 2009)

Done. But you have to admit, it was funny, after all your effort.


----------



## Lordwacky (Jan 28, 2009)

As an person with a BS in Physics, a MS in Applied energy Sciences and who has been a R&D Engineer in electronics/Solar for over 6 years..... This Topic makes me want to curl up in a ball an cry.

the ability for you people to sit and bicker and argue is amazing. 

You should all be running for the republican presidential nomination.

You all know what you know, some you know what you don't know, but most of you don’t. 

BJ, with all due respect to your overwhelming experience in electronics. As major has pointed out, you are either mistaken, or unable to adequately communicate your understanding of the basic underlying physical principles involved. 

Please re read major’s posts and try to understand what he and a few of the others are tyring to communicate to you. What is the point of this forum if you continue to refuse to listen to and learn from each other.


----------



## bjfreeman (Dec 7, 2011)

j


major said:


> Exactly. That is what I have told you multiple times.


 I can tell you did not read the link. it contradict much of what you said.
Power has a time factor in it, here is called rate, like I said and Energy does not.
You can also use Current, Flow.
Some measurement with a time factor is rate.
You can also use movement.
Another point that was shown is energy is lower case kj where Power is uppercase MJ


----------



## bjfreeman (Dec 7, 2011)

Lordwacky said:


> As an person with a BS in Physics, a MS in Applied energy Sciences and who has been a R&D Engineer in electronics/Solar for over 6 years..... This Topic makes me want to curl up in a ball an cry.
> 
> the ability for you people to sit and bicker and argue is amazing.
> 
> ...


There are learned people and there are educated people.
learned person can spit back exactly what they learned every time.
and educated person can apply what they learned in different ways because they understand the principals.
As Thomas Edison once said, I am glad I was not taught in public schools, so I did not learn what I could not know.


----------



## major (Apr 4, 2008)

bjfreeman said:


> Another point that was shown is energy is lower case kj where Power is uppercase MJ


bj,

I read the Wikipedia reference some time ago. I just re-read it now. Your quote above shows that you do not understand what it says and you still don't understand what I have been telling you or what these other members who have been kind enough to chime in and say, which is the same thing I have been telling you. Even Lordwacky agrees with us and tells you that you are mistaken. What more can we do? 

Back to your quote above. kj is kilojoule which is 1000 Joules which is a unit for energy.

MJ is megajoule which is 1,000,000 Joules which is a unit for energy. 

Neither is for power.

Maybe Wikipedia got sloppy with capitalization, I don't know. I like to use the upper case for the J in Joules because it is a person's name. Convention uses upper case M for Mega (times a million) and lower case m for milli (1/1000th). Typically lower case is used for k meaning kilo (times 1000).

Regards,

major


----------



## bjfreeman (Dec 7, 2011)

major said:


> bj,
> 
> I read the Wikipedia reference some time ago. I just re-read it now. Your quote above shows that you do not understand what it says and you still don't understand what I have been telling you or what these other members who have been kind enough to chime in and say, which is the same thing I have been telling you. Even Lordwacky agrees with us and tells you that you are mistaken. What more can we do?
> 
> ...


 It is obvious that you and I will not agree.
So enjoy your forum, I really don't have any more time to put into this.


----------



## major (Apr 4, 2008)

bjfreeman said:


> It is obvious that you and I will not agree.
> So enjoy your forum, I really don't have any more time to put into this.


bj,

It is really not about agreeing with me. It is about you learning something; something about energy and power which would be essential in your endeavors with the HEV project. 

Good luck,

major


----------



## mmark666 (Feb 21, 2009)

Major, 

I guess you need the following:

SCNR


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> It is obvious that you and I will not agree.
> So enjoy your forum, I really don't have any more time to put into this.


And that you will not agree with what has been standard for longer than two of your lifetimes!

Oh, and I was not educated in public schools until after I earned my BA in Physics. Oh, and I have applied all of what we have been talking about outside of the classroom too. Go back and reread what many of us have been telling you and what the Wikipedia article you referenced said and you will see that we and it agree. As for capitalization of unit multipliers you might want to go read what the proper use of them is too. In fact, if you scroll up the page you referenced you will see that what major said about that is correct too.


----------



## Coulomb (Apr 22, 2009)

I'll have a belated go at this.



bjfreeman said:


> Power has a time factor in it, here is called rate, like I said and Energy does not.


I'd be cautious about statements like that. Certainly, power is the rate of doing work, but sometimes you don't care about the total energy flow at all. For example, you have a 12 V battery and a 6 ohm resistive load; two amps flows, and the resistor dissipates 2*12 = 24 watts. How much energy does the resistor add to the total heat of the room after 10 minutes? Well, it happens to be 10 * 60 * 24 = 14400 Joules, or 14.4 kJ. But the total energy provided by a resistor isn't of great interest. It heats the room a little, but it's negligible, so we just don't care.

So in this case, we don't care that the power is actually the rate of doing work. We care more about the power dissipated by the resistor; it means that if we use a 20 W resistor it will overheat. In fact, we'd need a big heatsink on a 25 W resistor to keep it cool; better use a 50 W resistor. There, the power is useful; we get to choose the right component.

But sometimes we do care about the total energy. Suppose the 2 amps was instead flowing *into* the battery, charging it. Now we're charging at the rate of 24 Watts, and we do care how long we continue charging, and how much energy ends up in the battery. Suppose it's an 18 Ah (amp-hour) battery; it is capable of storing 18 amp-hours of energy. We know that if it is empty, it will take us 9 hours to charge with 2 amps. Ignoring the change in voltage of the battery, that means that at the rate of 24 Watts, it will take us about 9 hours to completely charge the battery. At the end of the charge, we will have added 18 amp-hours to the battery, or equivalently, 216 Watt-hours (Wh). We care about the power, because we know a 5 Watt charger won't charge the battery in 9 hours, and we know that a 50 Watt charger could do it in about half the time. We can even get an estimate of what it will cost us (in terms of electricity usage) to charge the battery. We know we will transfer 216 Wh of energy (at the rate of 24 watts, but that's irrelevant here) to the battery. Our 24 W battery charger might be 80% efficient. So that means we need 216/0.8 = 270 Wh of energy from the wall; that's the same as 0.27 kWh. Suppose electricity costs 20c per kWh; it will cost us 0.27 * $0.20 = $0.054, or 5.4 cents. This time, energy was a useful quantity for us, as well as power.



> You can also use Current, Flow.


Right. It is true that current is the rate of flow of charge. However, for most purposes, we don't care about the total amount of charge that has been transferred. I suspect that this is the root of your problems; you see some variables as rates, and some as static, but in fact many quantities are the rates (mathematically, derivatives) of others.

Let's go back to the 12 V battery and 6 ohm resistor I used above. Two amps are flowing, so two Coulombs are passing through the resistor per second. How many coulombs have passed in 10 minutes? Again, we can work it out, but really, we don't care. We can't see the individual electrons, which have the charge on them. We haven't stored the charge in a capacitor or battery, so we can't do anything with the charge. In fact, the charge just moves around in a circuit, so the net change of charge on our circuit after 10 minutes is nothing.

You might be tempted to say that current is a rate quantity, and charge is not. Let's put an ammeter in the circuit. The amp meter should read 2.0 while the load is connected to the battery. The current would be constant. But now let's replace the 6 ohm resistor by a motor, or some other load whose current isn't constant. Suppose that the current ramps up linearly (smoothly) from zero to 4 amps over 5 seconds. We could say that the current is increasing (over that time) by 4/5 = 0.8 amps per second. Oh no! Is current now a rate quantity? Well, sometimes it is, some times it is not.

Suppose we want to know what a sensible fuse is for the motor circuit. Do we use charge or current? Well, it happens that fuses are sensitive to instantaneous current (well, they actually respond to the integral of current with time, but let's pretend that we have a very fast blowing, ideal fuse). We could possibly work it out from considerations of the total amount of charge transferred over a certain time, but it's much easier to use the current in this case. We know the current varies over the range of 0-4 Amps, so a 5 Amp fuse would work out well.

Does this mean that charge is a useless concept? No, there are a few applications where the charge stored in a device (e.g. the reverse bias junction of a diode, or the gate-source capacitance of a Field Effect Transistor).

Can we say that current is never a rate quantity? Not really; sometimes it has a constant ramp rate. In AC circuits, instantaneous current is varying all the time, and sometimes we need to take that into account.



> Some measurement with a time factor is rate.


As I point out above, it doesn't really make sense to categorize some variables as rates and some as non-rates. It depends on the application.



> You can also use movement.


I don't know what your point is here, but movement is a good example of rates, as others have stated. An object has a position (relative to some origin). If it is moving, it has a velocity (the rate of change of that movement with time). If the velocity is changing, the object has an acceleration, the rate of change of velocity with respect to time. If that acceleration is not constant, there can be a rate of change of acceleration as well; it can keep going for ever. We can say that the acceleration is the second derivative (the derivative is just the instantaneous slope; it can be defined in maths) of position (since it is the rate of change of the rate of change of position, all with respect to time). There can also be derivatives with respect to other variables; not all derivatives are with respect to time. However, time is the more common variable to take derivatives with respect to, and we have a special name for the derivative with respect to time: the rate.

[ Edit: even if the velocity of an object is constant, it still could be said to have an acceleration; it just happens to be zero at the moment. But again, do we really care about the acceleration of an object if it's always zero? ]



> Another point that was shown is energy is lower case kj where Power is uppercase MJ


Well, this is complete nonsense. As others have pointed out, whether the unit itself has an upper or lower case depends on whether the unit is the name of a person or not. So Volts, Amps (technically Amperes), Watts, and Joules are all upper case, but meters, kilograms, seconds and hours are all lower case. So power might be measured in kW (kilo-Watts), and energy might be measured in Wh (Watt-hours). Power is NEVER measured in Joules (J) or MegaJoules (MJ).

It's important to get the case of the multiplier correct; mJ are milliJoules (1/1000 of one Joule), but MJ are MegaJoules (1000000 Joules). So the difference between mJ and MJ is a billion times. Same with mA and MA (milliAmps, like the current in a LED, and megaAmps, like the current in a lightning strike, or perhaps a fault current in a very high power transmission line).

Perhaps one last example (I promise!) will help. Let's consider two amps flowing into a 12 V battery for 9 hours. Over the course of the nine hours, we will get 18 amp-hours, or 216 watt-hours. But you can't say that the power (24 watts) and the energy (216 Wh) are the same thing, or equivalent in any way. In fact, half way (at the 4.5 hour point), we have charged the battery with only half the energy, so at the half way point, the power is still 24 Watts (we're assuming that the current and voltage are steady, so the power, which is their product, is also steady), but the energy transferred so far is only half the eventual total, or 108 Wh. So during the charging process, the power is steady, but the energy transferred is ramping up. If we had a current meter (ammeter) and an energy meter, the ammeter reading would be steady, but the energy meter would be ramping up. If it was a spinning disk type meter, the disk would be spinning, and the numbers would be changing.

But of course, totally constant current and voltage is not typical when charging the battery. The battery voltage will go up as the battery charges, and the current will probably taper off towards the end of the charge. Even so, at any instant, the power transferred will be the rate at which the stored energy is increased. [ Edit: that's the principle that we can use to make predictions about the behavior of a circuit. ]

BJF, sometimes I think that your problem is that you consider single units of time in your examples (e.g. one second or one hour), so the energy (number of Joules transferred) in your example is numerically the same as the power (the rate of energy transfer in Watts), so you tend to think of Joules and Watts as the same thing, because over unit time, they have the same numeric value. But remember that if you are transferring at a rate of 24 Watts, even though 24 Joules are transferred over one second, it's only at the *end* of that second that the numeric quantities happen to coincide. In other words, at a rate of 24 Watts of energy transfer, the energy transferred is 24 Joules at the *end* of one second, but half way through that second only 12 Joules are transferred. And of course, after 2 seconds, 48 Joules are transferred, and so on.


----------



## bjfreeman (Dec 7, 2011)

Coulomb:
appreciate you post. I am glad you can see what I was saying.
However I said as much in all my post but a different way. the Problem I have is most here can not see that, yet I can see what they say is similar.
I get the feeling I am talking to a lot of learned people that are not educated.
anyway I don't have time to buck head here. So far I have not received anything helpful in the areas I am working. I take that back the open-source charger gave me an Idea of how to package my System. But I can get that type of inspiration just lurking.
Since I am able to get what I want working, I will spend time doing that.


----------



## bjfreeman (Dec 7, 2011)

GizmoEV said:


> And that you will not agree with what has been standard for longer than two of your lifetimes!
> 
> Oh, and I was not educated in public schools until after I earned my BA in Physics. Oh, and I have applied all of what we have been talking about outside of the classroom too. Go back and reread what many of us have been telling you and what the Wikipedia article you referenced said and you will see that we and it agree. As for capitalization of unit multipliers you might want to go read what the proper use of them is too. In fact, if you scroll up the page you referenced you will see that what major said about that is correct too.


 Strange you picked up this line.
You have been one I considered could see it both ways.


----------



## major (Apr 4, 2008)

bjfreeman said:


> You have been one I considered could see it both ways.


Both ways  That would be the right way and the wrong way. We are talking about physics. It is an exact science. And it has convention in the units and nomenclature which are used by all in the field. The definitions of Mega, milli, Ampere, Joule and Watt are not open to interpretation.


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> Strange you picked up this line.
> You have been one I considered could see it both ways.


If you think this response it too long then just read major's response.

When standard definitions are used there is no leeway in interpreting them or using them. Sometimes minor things are changed like around the time I was in HS dm was used for decimeter and Dm was used for dekameter but has been changed to dam for dekameter. That or my recollection is wrong on that. It makes more sense to me to use lower case letters for unit mulitipliers when they are less than 1 and capital letters when they are greater than 1 but I don't get to choose that. I'm only one vote among thousands. Just like you, you don't have the freedom to change definitions to fit your view unless you get the whole scientific community to agree.

Just like your speedometer doesn't read miles or kilometers. Just because most speed limit signs I have seen in the US say things like SPEED 55 MILES, doesn't mean that speed is measured in miles and so is distance. The sign is actually saying that I'm supposed to floor it for 55 miles! like I stated before, if a new unit was made up in place of mi/h or km/h so that the time unit was embedded in it, then speed could be written without showing the time unit. The time unit is still there, however. Adding another one would just either cancel it out or change the unit to an acceleration value, depending on if the time unit were multiplied or divided, respectively.


----------



## bjfreeman (Dec 7, 2011)

GizmoEV said:


> If you think this response it too long then just read major's response.
> 
> When standard definitions are used there is no leeway in interpreting them or using them. Sometimes minor things are changed like around the time I was in HS dm was used for decimeter and Dm was used for dekameter but has been changed to dam for dekameter. That or my recollection is wrong on that. It makes more sense to me to use lower case letters for unit mulitipliers when they are less than 1 and capital letters when they are greater than 1 but I don't get to choose that. I'm only one vote among thousands. Just like you, you don't have the freedom to change definitions to fit your view unless you get the whole scientific community to agree.
> 
> Just like your speedometer doesn't read miles or kilometers. Just because most speed limit signs I have seen in the US say things like SPEED 55 MILES, doesn't mean that speed is measured in miles and so is distance. The sign is actually saying that I'm supposed to floor it for 55 miles! like I stated before, if a new unit was made up in place of mi/h or km/h so that the time unit was embedded in it, then speed could be written without showing the time unit. The time unit is still there, however. Adding another one would just either cancel it out or change the unit to an acceleration value, depending on if the time unit were multiplied or divided, respectively.


Good example for educated against learned.


----------



## bjfreeman (Dec 7, 2011)

my


major said:


> Both ways  That would be the right way and the wrong way. We are talking about physics. It is an exact science. And it has convention in the units and nomenclature which are used by all in the field. The definitions of Mega, milli, Ampere, Joule and Watt are not open to interpretation.


There are 3 types of people
the Doers will take the step by step direction and do them correctly.
There are the Dreamers that come up with the Ideas the doers do.
The Problem is the Dreamers can not communicated in terms the doers understand
so the third person is one that can take the Dreamers Idea and make it so the Doers can do it.
My mistake was interpreting DIY as doers. Now I know this board is Mostly dreamers.


----------



## EVfun (Mar 14, 2010)

bjfreeman said:


> There are 3 types of people
> the Doers will take the step by step direction and do them correctly.
> There are the Dreamers that come up with the Ideas the doers do.
> The Problem is the Dreamers can not communicated in terms the doers understand
> so the third person is one that can take the Dreamers Idea and make it so the Doers can do it.


Did you just dream that up?


----------



## major (Apr 4, 2008)

bjfreeman said:


> my
> There are 3 types of people
> the Doers will take the step by step direction and do them correctly.
> There are the Dreamers that come up with the Ideas the doers do.
> ...


Do you drive your self-converted EV or HEV daily like several of the members who responded on this thread?

I suppose most of the thousands who view this board are dreamers. A lot of them are doers and build an EV. Visit our DIY garage http://www.diyelectriccar.com/garage/ and see over 300 examples. Some of us who have knowledge try to share to help those doers and dreamers.

You seem to just dream about being right when you could do something about it and learn the right way and become educated.

Regards,

major


----------



## JRP3 (Mar 7, 2008)

bjfreeman said:


> The Problem is the Dreamers can not communicated in terms the doers understand


This is priceless.  You still don't realize that you are the one not communicating clearly.


----------



## bjfreeman (Dec 7, 2011)

major said:


> Do you drive your self-converted EV or HEV daily like several of the members who responded on this thread?


More Monthly to dump tanks some 15 miles away. City and Freeway driving.
looking forward to going to RV rallies starting in April, now that mom has passed. Been Tied to this area since 1998 when I came here to take care of my parents.


----------



## Duncan (Dec 8, 2008)

Hi JRP3

I think Bjf has communicated very well,

The message is simple - don't believe anything he says!


----------



## bjfreeman (Dec 7, 2011)

Duncan said:


> Hi JRP3
> 
> I think Bjf has communicated very well,
> 
> The message is simple - don't believe anything he says!


sound like a plan.
been there many times.


----------



## major (Apr 4, 2008)

bjfreeman said:


> More Monthly to dump tanks some 15 miles away. City and Freeway driving.


Hi bj,

Remember this from your first post here? 



bjfreeman said:


> This is my introduction......So why am I posting here.
> Well I think we can help each other since some can take the traction motor and drive a 1 ton 4 wheel.
> If you have suggestion or question please post. Nothing is propretary.


Please tell us about the traction motor you are using for these dump runs. We are also interested in the controller.

Thanks in advance,

major


----------



## bjfreeman (Dec 7, 2011)

major said:


> Hi bj,
> 
> Remember this from your first post here?
> 
> ...


from the comments about right and wrong from you and the last one from the thread


> but I'm afraid I'm going to be in the "disbeliever" camp until I see numbers to back it up. Though that's my usual stance on these kinds of things.


I see no common ground for further discussion.
To Get pictures would require putting the 30 foot on a hoist and pulling everything out from under the bus. When we start the next phase I will make sure to have many pictures.
I rather put my time into productive areas like the new board set.
once I have the documentation completed and reviewed I will share it.


----------



## major (Apr 4, 2008)

bjfreeman said:


> from the comments about right and wrong from you and the last one from the thread
> 
> 
> 
> ...


Hey bj,

Those are not my words. And I am not demanding pictures for proof. A picture would be nice since it is worth a 1000 words. But I'd just like a simple description for starters. It is the motor and control systems which interest me about your project more than anything else and you claimed a desire to share that. I come from electric motor roots. I've worked with Swiger Coil and been at their Cleveland shop. Did they build the motor you're presently running?

Regards,

major


----------



## major (Apr 4, 2008)

bjfreeman said:


> from the comments about right and wrong from you and the last one from the thread
> I see no common ground for further discussion.


And you told me: 


bjfreeman said:


> and part of our problems is you don't understand Electricity.


 If we all agreed it would be a boring discussion, wouldn't it?

You don't have to be a PhD in physics to build a functioning EV. This forum is proof of that


----------



## bjfreeman (Dec 7, 2011)

major said:


> And you told me:
> You don't have to be a PhD in physics to build a functioning EV. This forum is proof of that


Yes I got that definite view.
so I will take my non PHD knowledge and continue.
Your statement is exactly what Thomas Edison was referring to when he stated the formal schools teach what you can not know.


----------



## major (Apr 4, 2008)

bjfreeman said:


> Yes I got that definite view.
> so I will take my non PHD knowledge and continue.
> Your statement is exactly what Thomas Edison was referring to when he stated the formal schools teach what you can not know.


Cool. So tell us about your motor and controller.


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> Good example for educated against learned.


BJ, If I started changing the meaning of all the words we used and started trying to get you to follow my new definitions of them would you call that useful for communicating? Of course not! There are standard definitions of things including units of measure so that there can be ACCURATE communication. That is both educated and learned. You are a classic case of, "My mind is made up, don't confuse me with the facts!" Just because you are in your 70s doesn't automatically make you more knowledgeable than any one younger than you. It also doesn't give you license to change the definition of accepted units from the scientific community. This thread is not about what can or can't be invented or applied.

This thread is ENTIRELY about what the scientific community has agreed the different units are and what they mean. Many of us have given numerous examples and shown mathematically why what we said is true is true but you stubbornly refuse to accept that OR prove from the base set of definitions why what you are saying is right.

I ask again, go back to the base definitions and support what you are saying is true.


----------



## bjfreeman (Dec 7, 2011)

GizmoEV said:


> BJ, If I started changing the meaning of all the words we used and started trying to get you to follow my new definitions of them would you call that useful for communicating? Of course not! There are standard definitions of things including units of measure so that there can be ACCURATE communication. That is both educated and learned. You are a classic case of, "My mind is made up, don't confuse me with the facts!" Just because you are in your 70s doesn't automatically make you more knowledgeable than any one younger than you. It also doesn't give you license to change the definition of accepted units from the scientific community. This thread is not about what can or can't be invented or applied.
> 
> This thread is ENTIRELY about what the scientific community has agreed the different units are and what they mean. Many of us have given numerous examples and shown mathematically why what we said is true is true but you stubbornly refuse to accept that OR prove from the base set of definitions why what you are saying is right.
> 
> I ask again, go back to the base definitions and support what you are saying is true.


 I agree my Mind is made up.
I also though can read what is written in “scientific” and comprehend.
I can show you book after book written the way I sayit.
The problem now is I have used up more time on this than I have gain from it.
So I am cutting my losses and continuing to put my time where it counts.
Delivering product.


----------



## GizmoEV (Nov 28, 2009)

bjfreeman said:


> I can show you book after book written the way I sayit.


Well so far you haven't done that. All the references you have shown have supported what the rest of us have been saying.

It is possible to still design products and NOT understand the proper use of the units, as long as you are consistent in your misuse of them. Just don't expect anyone else to agree with your misuse. As long as you use standard convention when communicating to the rest of the world and only the misuse in your own mind and own personally kept info there will be no problem.

If you are gong to contribute, however, you owe it to those trying to understand what you are saying to use the standard convention of things. Just like I think it is dumb to use dam for the abbreviation for dekameter rather than Dm I still follow the standard convention in my use and teaching so every one is on the "same page."


----------



## major (Apr 4, 2008)

bjfreeman said:


> I can show you book after book written the way I sayit.


Please provide those references for us. Names and authors or ISBN. I may have copies in my library as I collect old engineering and physics texts.


----------



## bjfreeman (Dec 7, 2011)

major said:


> Please provide those references for us. Names and authors or ISBN. I may have copies in my library as I collect old engineering and physics texts.


plain and simple no more time will be devoted to this forum.
Have a good year.


----------



## major (Apr 4, 2008)

Duncan said:


> The message is simple - don't believe anything he says!


I'm starting to think Duncan hit the nail on the head  How long would it take for bj to type a couple of those book titles? We try to help a guy out and this is the thanks we get. I can't figure out why bj came to this forum in the first place. Oh well


----------



## major (Apr 4, 2008)

bjfreeman said:


> I also though can read what is written in “scientific” and comprehend.
> I can show you book after book written the way I sayit.
> The problem now is I have used up more time on this than I have gain from it.
> So I am cutting my losses and continuing to put my time where it counts.


Where your time counts? Like this  
http://www.diyelectriccar.com/forums/showpost.php?p=276952&postcount=5 

You can't post up one of the titles to the "book after book" which you can show me?


----------



## dtbaker (Jan 5, 2008)

major said:


> I'm starting to think Duncan hit the nail on the head  How long would it take for bj to type a couple of those book titles? We try to help a guy out and this is the thanks we get. I can't figure out why bj came to this forum in the first place. Oh well


perhaps his real name is/was 'Rational'.....


----------

