# Upconvert 32 volts to 72 volts



## Guest (Aug 1, 2010)

What are you using as a 32 volt DC generator? At what speed is the generator putting out 32 volts and 500 amps? 

Pete


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## Biostudent (Jul 13, 2010)

> Jack & Heintz G32 Aircraft DC Generator
> 
> Believed to be a starting unit. Labeled "For Ground Power Use Only"
> Appears to be refurbished and not used since
> ...


Opps its 30 volts.


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## Guest (Aug 1, 2010)

Mine are not Jack Heinz but I have two. Used to power a VW. With Regen 

You will need to find out what the output voltage is and at what rpm and amperage before you can move forward for converting to 72 volts. It should be possible to convert to 72 volts. Actually it will be more than 72 volts but you need to know what that generator puts out. 

Pete


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## Guest (Aug 1, 2010)

These are not your normal SepEx motors.


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## Duncan (Dec 8, 2008)

Hi Biostudent

What are you using to drive your generator?
You do know you will need something to spin its input shaft before you can take any power off it?

And NO you can't drive it off your wheels or your D&D motor


Assuming that you are driving this with an IC engine - the easiest way of increasing the voltage is to spin it faster!
Basically if you can double the speed of the generator you can double the voltage
Be careful something may not like the excess speed!


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## Biostudent (Jul 13, 2010)

Duncan said:


> Hi Biostudent
> 
> What are you using to drive your generator?
> You do know you will need something to spin its input shaft before you can take any power off it?
> ...


I don't know about doubling the speed of it. I am assuming the 30 volts is in the 4000-8000 rpm range. But I haven't tested it yet. I am in the mists of getting ready to move so I am trying to plan at this point. Maybe I can hook up a drill to it and spin it around. Any tool for this?

The engine is a 14.5hp Lawn mower engine.


> 14.5 hp Tecumseh Enduro Industrial/commercial
> Family#STP49OUI62RA
> MOD.#0HV17 2040602A





> And NO you can't drive it off your wheels or your D&D motor


Not sure what you mean. I can't connect directly to wheels? is that what you mean?

So if my controller was set up for regen...that would pretty much be the answer...as long as I get the power up to 72 volts?


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## Guest (Aug 1, 2010)

The generator can do 8000 with no problem and will do 3 or 4 K all day long. The issue is what will the generator actually put out at the speeds he wants to use. That will determine if he can up the voltage and half the amps to drive a smaller motor and or charge a 72 volt pack for further distance. The little DC generators are hell for stout and should put out 30 volts and a decent amount of amps at a decent rpm. I just don't know what that speed would be. Never tried yet. Some day I will use one for a generator. 

Pete


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## Guest (Aug 1, 2010)

It wont run with a standard SepEx controller. PM me. 

Pete


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## Duncan (Dec 8, 2008)

Hi Biostudent

There are ways of converting 30v DC to 72v DC but they are ugly

Is would be better if you had a good hard look at your generator to see if

(a) you can get AC out
(b) you can increase the voltage

It sounds as if over-speeding is not practicable (16,000rpm!) but have a look and see how it works inside


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## Guest (Aug 1, 2010)

What he has is a starter/generator. In starter mode (motor) it can go to 8000 rpm because turbine engines need that kind of speed to start. In generator mode I doubt its running at that speed. 

These motors don't do AC out as far as I am aware.

Pete


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## Guest (Aug 1, 2010)

Why would it be ugly to step up DC voltage? 

Pete


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## Biostudent (Jul 13, 2010)

So how do you know my motor is Sepex? I am sorry I didn't understand before you were referring to the motor since I never heard of a sepex motor before. It seems its better than a series motor since it has regen features. But, I don't know the horsepower of the sepex motor so it probably is to weak for my purposes. Not sure though.

I was thinking, would it be possible to take the current motor out and put in this sepex motor? I could then get a controller for the sepex motor. Then have the regen hooked up to the series motor which would be spun by the ICE. Getting the series motors output to 72V is something I am unsure of as well. Or if its even required. 

Or should I have a series motor and a series generator (or) sepex motor and a sepex generator? Meaning, should the types of motors be matched to simplify things. Keep in mind I am an amateur of electronic theory.

It would be nice to have built in regen!


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## Guest (Aug 2, 2010)

I am unsure of what you have in your vehicle right now but that Jack Heinz Generator motor is a special SepEx motor and will require a special setup to work properly. They can belt out a pretty good amount of power but they do not have as high of torque as a series motor. What they lack in torque they make up in rpm. You can't run your series motor with a sepex controller. It's just won't work. Did you have a look at my site? Look at the top right flick. It is a starter/generator like the Jack Heinz motor you have. It is a special SepEx motor and they are built to military specs which far exceeds the civilian specs for motors. These were built only for the aviation industry and military. They are all military spec. That is a good thing. What car again? What is your motor in your vehicle now? I know it's a D&D but what size? 8" 6" What?

http://greenev.zapto.org/electricvw/Electric_VW/Flicks.html


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## Biostudent (Jul 13, 2010)

here is my motors specs



48-72 VDC Series Motor
 9 HP @ 72V Continuous Rated *
65 Ft /Lbs Torque Peak
25 HP Peak
(Similar to the ADC #K91-4003 only longer for more power)
7/8" Single Shaft Base / Face-mounted
 6.7" Dia by 12.28" Long
 Actual Weight 62 lbs
Shipping Weight 70 lbs
I get it a controller is specific to the motor type in this case.


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