# Controller number 4... and counting



## CPLTECH (Sep 14, 2007)

Thanks for sharing. Hopefully others will heed your advice at your expense. Sorry.
Your experience sounds so similar to mine I posted 1½ yr ago.
It is so sad that within that time frame they still have no clue.

Curtis 1231 144V


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## dimitri (May 16, 2008)

Have you considered a Lemon Law? I'm not a lawyer, but I think it should be possible to open a case in small claims court against these "businessmen". Send them a demanding letter first, maybe they'll decide to settle and refund your money before it goes to court.

As for replacement, unfortunately you have conflicting requirements of "good" and "cheap", not sure you will find what you want unless you are willing to build it yourself, but even that usually ends up not so cheap once you count all the blown parts and tools you had to buy to put it all together.


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## Coley (Jul 26, 2007)

Small claims court is just a waste of your time and money.

Get a real lawyer to write the letter.

I had a recipient of the small claims letter walk into the shop and, with a smile, told me wipe my butt with it.

The court said that he owed the bill and since he didn't show up, I was told to hire a lawyer and sue him......

Lots of wasted time and money.........


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## etischer (Jun 16, 2008)

have they done a failure analysis on the previously burned up controllers? 

Surely this is not a sustainable solution for them, so they need to find the root cause, or issue you a refund. 

Are you misapplying the controller? Is it under sized for your application? Are you providing ample cooling? Is your motor and wiring in good health?


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## kittydog42 (Sep 18, 2007)

I used to sell Logisystems controllers. They were not worth the hassle. Almost every unit I purchased had to be returned for repair, some multiple times. I was able to secure two refunds from them, eventually. One was because I refused to pay on an invoice that was due on another controller. The other time, I purchased a WarpCore and Netgain gave me the refund after two repair attempts. Pressure the company that sold the controller to you to take care of the problem. Part of the responsibility of selling products is to support the products to the extent that they can. In this case, what they can do is use their leverage to force Logisystems to do the right thing. The dealer can't just take the $350 markup on the controller and expect you to deal directly with Logisystems. In fact, I am surprised that Logisystems isn't getting on the dealer for not being the intermediary in all of this, as it ultimately makes them look bad and the only one who comes out okay is the dealer.


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## evsource (Mar 23, 2009)

kittydog42 said:


> I used to sell Logisystems controllers. They were not worth the hassle. Almost every unit I purchased had to be returned for repair, some multiple times. The dealer can't just take the $350 markup on the controller and expect you to deal directly with Logisystems. In fact, I am surprised that Logisystems isn't getting on the dealer for not being the intermediary in all of this, as it ultimately makes them look bad and the only one who comes out okay is the dealer.


We've had our share of Logisystems problems, and no longer carry them either. We try to help out with a discount on a more reliable design for our customers that have had problems. 

Since you've been a dealer, and with your comments, would you *really* provide a full refund to the customer, no matter how many controllers you had sold? Let's say you sold 50 controllers at $1200 each over a year's period. The initial response from customers was favorable, so you kept selling them. A couple come back with problems, but for the most part, they work out for customers. Then, after several months, the failure rate starts to increase. You pull the product line. Let's say 25 of the 50 controllers end up coming back. Where are you going to pull out the $30k in a low profit-margin EV business to refund all the customers out of your own pocket?

I'm a little biased, but I don't think the anger and frustration should be directed at the dealers. The manufacturer needs to solve the problem. That's why there is a manufacturer's warranty. I once had an air compressor that went bad after about 6 uses over about a 4 month period. I bought it from Lowes. When I went to have it repaired at the designated service center, I found out that the company that had manufactured it had gone out of business. So I was stuck with it. I went to Lowes to see what I could do about getting a new compressor. The manager decided to just eat it, and gave me credit towards a new compressor. Did he have to do that? He could have told me sorry, and there would have been nothing I could have done. Would I have been mad? I'm sure I would have been frustrated. Would the store have done the same thing for every customer that had this problem? Probably not, it depended on the manager. Fact is, Lowes is big enough that they have the wherewithal to do something like this. I have sucked up stuff before on smaller items to make a customer happy. But if I tried to take the place of the controller manufacturer for defective controllers, I would be out of business. Where the manufacturer is still around to "fix" problems, they should be the place that handles it. I can't see how it would be in their interests to continue sending out defective product if they know they'll just see it back again. Hopefully they pick up on this trend, hire someone to get to the root of the problem if necessary, and get people permanently back on the road.


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## JRP3 (Mar 7, 2008)

With the huge number of Logisystems problems and their inability to fix them, it's pretty obvious they simply do not know what they are doing, or they just don't care.


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## voltmatic automaton (Nov 2, 2008)

Thanks for the varied responses. I believe the controller they sent me will be my last. I have no intention of keeping this back and forth thing going. Instead I think i'll keep it as an emergency backup....last ditch effort etc.

What I may do is actually open it up and see what kind of setup is inside. If i find a dead gerbil then we'll know what the problem is.
It may be possible to replace certain parts with better quality/performance parts.
Since Logisystems doesn't seem to be on top of this I think I may take a look.
And since I'm not going to see any of my money returned at least I can learn something.

I toyed with the idea of selling it for about $500, but with the history of these controllers and no warranty it really would not be fair to the buyer,
I'll just keep it on the back burner.

Now , I'm looking forward to my Zilla to come in


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## Guest (Apr 13, 2010)

Are they still actually selling them? I thought that the word was out to not buy any more. It did not take many dead logisystem controllers to get me off that band wagon. When they don't fix the issue but only put a band aid on the issues then they are setting themselves up for failure. Fix the issue and make the controller reliable. 

Pete 

I never see the owner posting to help quell the issues we all have with multi faulty units even ones that were supposed to have been fixed.


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## kittydog42 (Sep 18, 2007)

evsource said:


> Since you've been a dealer, and with your comments, would you *really* provide a full refund to the customer, no matter how many controllers you had sold? Let's say you sold 50 controllers at $1200 each over a year's period. The initial response from customers was favorable, so you kept selling them. A couple come back with problems, but for the most part, they work out for customers. Then, after several months, the failure rate starts to increase. You pull the product line. Let's say 25 of the 50 controllers end up coming back. Where are you going to pull out the $30k in a low profit-margin EV business to refund all the customers out of your own pocket?


In my case, yes. But I only sold 6-8 total and of those only 2 actually requested refunds. For the others with problems (which was nearly all of them), I was their advocate and they never had to contact Logisystems directly. 

If I had sold 50, my response may have been different. It would have been hard to support them all so actively.


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## Quasar (May 5, 2010)

voltmatic automaton said:


> What I may do is actually open it up and see what kind of setup is inside. If i find a dead gerbil then we'll know what the problem is.
> It may be possible to replace certain parts with better quality/performance parts.
> Since Logisystems doesn't seem to be on top of this I think I may take a look.
> And since I'm not going to see any of my money returned at least I can learn something.


Did you ever open it up? I did mine and I'd be interested to compare notes.


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## voltmatic automaton (Nov 2, 2008)

no i haven't opened it up. i was pondering how to get the case open, i wanted to try mounting a new heatsink design on it.

unfortunately my plans are on hold because the replacement controller i ordered from ev components is up in the air since the company went south....

i hesitate to open the controller as it may be the only one i have for a while...then again i'm still not using it for fear it'll blow up..catch-22 yes?

did you find anything particularly noteworthy or changeable inside yours?

and how did you open the seals on it?

look forward to your response.


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## Quasar (May 5, 2010)

They didn't make it easy to get inside.
The bottom plate is glued in place, but a couple of screwdrivers and a hammer will remove it. Take it off first.
The 8 Silicone rubber spots on the top of the heatsink cover the heads of screws that secure the whole innards to the heatsink. Dig out the silicone and remove the screws. The heatsink still won't fall off as it has some plastic insulators going through the holes, but it will lever off quite easily.
The only thing holding it together now is the end plates which are moulded resin and hence stick to the Al case, but a bit of tapping and levering will spring them free. You should then be able to remove the whole assembly from the case.
The control board is attached to the side of the power board by simply soldering the pins of a couple of right-angle connectors through the board. Its easy enough to remove it, but you need some de-soldering wick or a really good solder sucker and make sure you free each pin completely, else you risk pulling the thru-hole plating out.
Once you have it apart, you can see if it uses MOSFETs or IGBTs. Apparently the older ones used MOSFETs.
Note the insulating sheet between the top of the Al plate heat spreader and the inside of the case. The screws holding the heatsink plate on are "live" - hence the silicone rubber covering the heads.
You could mount a decent sized bit of finned heat sink to the existing heatsink plate with a bit of drilling and tapping.

If you do decide to take it apart, I can tell you how to modify the controller board to get the current sensing working properly and also fit a thermistor so it senses temperature properly. It has a place to connect one but they just fit a fixed resistor. I tried shorting out said resistor to simulate a very hot thermistor and the PWM frequency dropped from about 13.6 kHz down to 4 kHz, so I know it works OK.


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## voltmatic automaton (Nov 2, 2008)

Getting ready to open up the controller, I am going to need some advice on what to add/change etc.
I would change the whole board provided its more or less a swap out part similar to the open revolt board.
Post a reply or email me so i can get the particulars
thanks!


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## Quasar (May 5, 2010)

voltmatic automaton said:


> Getting ready to open up the controller, I am going to need some advice on what to add/change etc.
> I would change the whole board provided its more or less a swap out part similar to the open revolt board.
> Post a reply or email me so i can get the particulars
> thanks!


The OpenRevolt board is too big to do a straight swap. I had thought about re-laying it to fit, but that is one of those projects that will have to wait until I get a few other tasks out of the way. I'll get some photos of the thing and stick them up here so you can see what you are in for.


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## voltmatic automaton (Nov 2, 2008)

well i pulled apart the controller... bye bye warranty, not that i would ever see my money again anyway.

so , i have some pics of the controller innards. anyone see or notice anything unusual?

in my experience anything producing so much heat has a lot of thermal conductive product to guide the heat.

there is nothing to seal any of the heat conductive surfaces in the controller, there is the light green paperish stuff but i think thats more for a dielectric than heat conduction.

plus the heat sink parts aren't polished or give any impression of being high contact surface areas...

what do you think?

plus , am i looking at mosfets or IGBTs?


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## voltmatic automaton (Nov 2, 2008)

oh, and to pull the controller apart i used a heat gun along the seams on the bottom, starting at one corner and prying it apart. worked really well !


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## Quasar (May 5, 2010)

voltmatic automaton said:


> well i pulled apart the controller... bye bye warranty, not that i would ever see my money again anyway.
> 
> 
> plus , am i looking at mosfets or IGBTs?
> ...


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## voltmatic automaton (Nov 2, 2008)

I checked my board, from the description you gave me there ARE 2 empty holes in that area of the board. Looks like it doesn't have the right parts either.

can you tell me what parts i need to install there?


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## 9852 (Jan 17, 2010)

as someone who just bought an LS controller 2 months ago, I get what you are saying about no current sensing, but if I have an amp gauge and my controller is 700 amps, cant I monitor the current with my gauge anyway, I just ask because I will be using my LS controller as the primary controller for my car, but if it does go away I have a curtis as a spare so i dont get stranded, but I want to give it every oppertunity to work properly in my car.


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## Quasar (May 5, 2010)

billhac said:


> as someone who just bought an LS controller 2 months ago, I get what you are saying about no current sensing, but if I have an amp gauge and my controller is 700 amps, cant I monitor the current with my gauge anyway, I just ask because I will be using my LS controller as the primary controller for my car, but if it does go away I have a curtis as a spare so i dont get stranded, but I want to give it every oppertunity to work properly in my car.


To properly protect the controller, it needs to monitor the current on a cycle by cycle basis and terminate the drive pulse if the current reaches the max. Your amp gauge will only read the "average" current and the peak current will be much higher. For example, if your meter reads 500A and the PWM duty cycle is only 50%, the peak current will be 1000A.


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## Quasar (May 5, 2010)

voltmatic automaton said:


> I checked my board, from the description you gave me there ARE 2 empty holes in that area of the board. Looks like it doesn't have the right parts either.
> 
> can you tell me what parts i need to install there?


Yes, I can do that. Give me a little time to draw it up properly and get a couple of photos and I'll post the details on here.


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## voltmatic automaton (Nov 2, 2008)

Thanks for your help, 

If I can at least make the Logisystems more reliable then I'll have a working vehicle while waiting for the EVComponents nightmare to sort itself out.

this controller thing is the single biggest money pit i have experienced in the conversion. unfortunately some guys at work are yanking my chain for the 'flop' that the car is so far, things are just tough all over when you're a DIYer

Hope you'll post soon,

Thanks Again!


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## 9852 (Jan 17, 2010)

thanks for the clarification. I do see where it should sense current. but it sounds to me like you have worked that out, so If I could just get mine open I might be interested in learning what components to install for current sensing too.


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## 9852 (Jan 17, 2010)

I feel your pain with work freinds. but if I had spent a bit more money the first time, my car would still be taking me to work now. Instead IM waiting for LS to fix mine, but In the mean time I bought a curtis to get the car back on the road. Oh what's that saying? hind sight is 20/20.


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## Tesseract (Sep 27, 2008)

Quasar said:


> To properly protect the controller, it needs to monitor the current on a cycle by cycle basis and terminate the drive pulse if the current reaches the max.


Depends on what you mean here... a desaturation detection circuit is technically a cycle-by-cycle limiter, but it has a rather coarse trip point so it usually only kicks in during an extreme overload. The motor current should otherwise be regulated by a proper feedback loop. See below.



Quasar said:


> Your amp gauge will only read the "average" current and the peak current will be much higher. For example, if your meter reads 500A and the PWM duty cycle is only 50%, the peak current will be 1000A.


Yeah, your amp gauge will definitely average out the current, but the _peak_ current through the switch will only be the input current divided by the duty cycle if the load is purely resistive (i.e. - no inductance). The presence of an inductor - like, say, a motor  - results in the current being integrated, or averaged over time, so that the resulting current waveform is a sawtooth riding on top of a DC level.

The peak to peak variation of the sawtooth is inversely proportional to the amount of inductance, so this does mean there is a minimum amount of inductance required to keep the peak current below the maximum the switch can tolerate. In selecting the inductor for a switching power supply the ripple current is targeted to be 40% of the average current. This means the switch current goes 20% above the average and 20% below the average during each cycle. In a motor controller not only do you not get a say in how much inductance there is - it's whatever is in the motor! - but you also don't get much control over the pack voltage (the rate of current rise is proportional to that, too)! 

I don't know what the minimum inductance would be for the Logi, but it looks like it wouldn't matter, anyway, since there doesn't appear to be either a functioning average current control loop nor desat detection! 

I really try to refrain from commenting on controllers these days - I do have an obvious bias after all  - but if the Logis really don't have a temperature sensor, desat detection, or any means of measuring and regulating the output current (i.e. - throttle directly controls duty cycle) then every last one of them will blow up.

The Curtis 1221/1231 measures the voltage drop across the MOSFET during the on time to regulate current. It's very sloppy because Rds[on] varies with temperature - usually 1.5x higher with a 50C rise - but at least it is a resistance. The on drop, of Vce[sat], of an IGBT, though, behaves like a diode so it increases by 60mV for every _decade_ of current increase! For example, if there is 1.20V of drop at 300A there would only be 1.26V of drop at 3000A (assuming you didn't come out of saturation, or _desaturate_). 

You simply cannot regulate current in an IGBT controller by looking at Vce[sat]. 

Finally, how thick is the copper on that PCB? I mean, you can make PCBs that will carry several hundred amps - I've done it, no problem - but you have to be very careful about the width of the traces and the thickness of the copper plating. Oh, and always remember that the vias connecting layers will likely be 1oz. Cu unless you are prepared to pay a hideous premium to start off with a lower Cu thickness and have the board "plated up" more than 1oz. 4oz. copper (140um) here would still be too small. A 1" wide trace this thick can carry ~100A with a 37C temp rise. How wide are the traces leading to the bus bars on that board?


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## Quasar (May 5, 2010)

voltmatic automaton said:


> Thanks for your help,
> 
> If I can at least make the Logisystems more reliable then I'll have a working vehicle while waiting for the EVComponents nightmare to sort itself out.
> 
> ...


Well, I'll see if I can upload a diagram!

Tried to, but I don't know where it went.

If you can find it, the top diagram shows the controller as supplied. The diode is driven by an open-collector comparator and there is no pull-up resistor. The comparator is driven (off) by the gate drive signal, delayed 5 uS, presumably to allow time for the IGBTs to turn on and the current to start to rise. This means that the anode end of the diode is floating and the only signal appearing on the comparator input is what is coupled through the diode capacitance - very little! So this is why I say the "current" sensing can't work. You should note that the voltage across the IGBT rises fairly linearly with current, once the thing gets above a volt and a bit - seems like it is proportional to current from about 1.8v up.
I noted that there was a resistor missing on the circuit board, R30, and it connects the drive comparator output to the + supply, 10V. So I inserted a 4k7 resistor and lo and behold, very nice looking pulses appeared at the diode anode and hence the input to the second comparator, but they had quite a spike on the leading edge. This spike triggered the comparator which in turn terminates the gate drive pulse, so the thing wouldn't work - all I got out was 5 uS pulses due to the above mentioned delay. Nothing ventured, nothing gained, so I inserted the 1K/.01 uF cap as in the lower diagram to act as a low pass filter and this removed the spike quite nicely. The thing then started to behave properly and I could terminate the gate drive pulse quite nicely at different levels by adjusting the reference voltage pot. I set it up with a single IGBT on the bench so I didn't need hundreds of amps through the thing to see what was happening.

Next thing I looked at was the gate drive. The 24 IGBTs each has a 200 ohm gate drive resistor and this is surprisingly large. One normally tries to drive as much gate current into (and out of) these things as possible to minimise the switching times and hence the switching losses.
The TC4420 gate driver is capable of 6A and the supply voltage is 15V so the effective gate resistance could be as low as 2.5 ohms, which would give 60 ohms for each device. I wondered if they deliberately slowed it down to try and minimise the switching spikes that were ruining the current sense when all the bits were connected. So I paralled each gate resistor with another 200 ohm one to bring it down to 100 ohms and this significantly reduced the switching times and I didn't see any worse spikes on the current sense circuit, so that's what I am using now.

Looking at the Curtis 123 circuit diagram, I see that the LS thing has lots of stuff the same and there is a thermistor shown on the end of the board. But mine just has a 50K fixed resistor soldered across the pins where the thermistor should go. I shorted out that resistor while it was running and the PWM frequency dropped from 13.6 kHz to 4 kHz, so I surmise it is doing what it should.
I connected the thermistor I had from the OpenRevolt board to it and that works OK although I have only heated it up with the soldering iron so far to see if it works.

So that summarises what I have done to make the thing work properly. It should be pretty blow-up proof now.

Interestingly enough, the circuit board has a zero ohm link fitted between the comparator input and the sense wirer from the diode - it looks as if there was a diode there once as it uses a square pad for one end. I took this link out and that's where the 1K resistor goes, quite handily. The .01u cap is soldered direct to the comparator pins on the bottom of the board. ie the - input and gnd.

I hope this gives you enough info to see what I have done and try it for yourself.


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## Quasar (May 5, 2010)

Tesseract said:


> Yeah, your amp gauge will definitely average out the current, but the _peak_ current through the switch will only be the input current divided by the duty cycle if the load is purely resistive (i.e. - no inductance). The presence of an inductor - like, say, a motor  - results in the current being integrated, or averaged over time, so that the resulting current waveform is a sawtooth riding on top of a DC level.
> 
> 
> The on drop, of Vce[sat], of an IGBT, though, behaves like a diode so it increases by 60mV for every _decade_ of current increase! For example, if there is 1.20V of drop at 300A there would only be 1.26V of drop at 3000A (assuming you didn't come out of saturation, or _desaturate_).
> ...


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## Tesseract (Sep 27, 2008)

Quasar said:


> Yes, I was oversimplifying to make the point.


Fine, but your oversimplification led to a grossly incorrect conclusion. Not that I can say much, because...



Quasar said:


> I don't see why you say an IGBT behaves like a diode. Here's the output characteristic and you can see it is quite linear.


...yep, it does look linear, because I totally neglected the contribution of from the equivalent collector resistance. If you look where the graph starts you see that conduction loss is a diode drop plus an "ohmic" loss, which comes from the collector resistance times current. This resistance is much lower than a MOSFETs drain-source resistance but it still totally swamps the relatively modest logarithmic increase of the diode drop so my characterization was inaccurate. Got me on that one


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## voltmatic automaton (Nov 2, 2008)

thanks for the information. I understand some of the technical stuff (i really am doing classes for this)
to get me off the ground fast though can you give me an idea of the parts/ part numbers and suppliers for the parts used?

a picture of the alterations would be really handy too.

just post what you can, it will make life so much better,

thanks again for everything you've been willing to share.


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## Quasar (May 5, 2010)

Tesseract said:


> Fine, but your oversimplification led to a grossly incorrect conclusion. Not that I can say much, because...
> 
> 
> 
> ...yep, it does look linear, because I totally neglected the contribution of from the equivalent collector resistance. If you look where the graph starts you see that conduction loss is a diode drop plus an "ohmic" loss, which comes from the collector resistance times current. This resistance is much lower than a MOSFETs drain-source resistance but it still totally swamps the relatively modest logarithmic increase of the diode drop so my characterization was inaccurate. Got me on that one



Its not "grossly incorrect" - the point is that the peak current will be much higher than the current read by the meter. How much higher depends on the inductance, resistance and time as you point out.

And I wasn't trying to "get" anyone, just to keep things simple and straightforward for the other poor suckers, like me, who wasted good money on a piece of junk.


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## Quasar (May 5, 2010)

voltmatic automaton said:


> thanks for the information. I understand some of the technical stuff (i really am doing classes for this)
> to get me off the ground fast though can you give me an idea of the parts/ part numbers and suppliers for the parts used?
> 
> a picture of the alterations would be really handy too.
> ...


Here's a couple of rather poor pictures. The two resistors on the right are: the top one is the 1K with one end going to the square pad, the bottom one is the 50K in lieu of the thermistor. I put it back as I didn't have a spare thermistor.
The 4k7 resistor is in the middle, between the ics. You will know where it goes because yours will have a couple of holes!
The resistors are just metal film, 1 or 2 or 5%, 1/4 or 1/3 watt. I took them out of my junk box and your local electronics shop should be able to supply them. The capacitor likewise. I used a plastic one because that's what I had, but a ceramic one - 50V - would do just fine.
Ignore the blue wires, they're there for some testing.
The "brown" bit of track is where it burnt the coating off!

After looking at the bottom picture, I realised it doesn't show where I had to cut the track, so I've done another one.
See next!


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## Quasar (May 5, 2010)

This picture, I have tidied it up and it shows where the track was cut and the wire put on to replace it. I stood the cap up so you can see. The white mark just to the left of the "x" is the cut.
Ignore the previous photo.


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## ngrimm (Oct 19, 2007)

"Looking at the Curtis 123 circuit diagram, I see that the LS thing has lots of stuff the same and there is a thermistor shown on the end of the board. But mine just has a 50K fixed resistor soldered across the pins where the thermistor should go. I shorted out that resistor while it was running and the PWM frequency dropped from 13.6 kHz to 4 kHz, so I surmise it is doing what it should.
I connected the thermistor I had from the OpenRevolt board to it and that works OK although I have only heated it up with the soldering iron so far to see if it works."

I think this has been discussed before but does reducing the frequency from 13.6 to 4 khz in case of over temp add much protection other than making it squeal like a pig? Just curious.


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## Quasar (May 5, 2010)

ngrimm said:


> "Looking at the Curtis 123 circuit diagram, I see that the LS thing has lots of stuff the same and there is a thermistor shown on the end of the board. But mine just has a 50K fixed resistor soldered across the pins where the thermistor should go. I shorted out that resistor while it was running and the PWM frequency dropped from 13.6 kHz to 4 kHz, so I surmise it is doing what it should.
> I connected the thermistor I had from the OpenRevolt board to it and that works OK although I have only heated it up with the soldering iron so far to see if it works."
> 
> I think this has been discussed before but does reducing the frequency from 13.6 to 4 khz in case of over temp add much protection other than making it squeal like a pig? Just curious.


I think that if most of the heat is generated by switching losses, then dropping the frequency will produce less heat. I didn't actually check to see if the "on" time stayed the same - if it did that would really cut the power back.
I've had enough fiddling with the fool thing and now I have built an OpenRevolt controller, it runs the risk of becoming the world's most expensive door stop.
As I have said before, I may do a new layout for the OpenRevolt and stick that controller into it. I think it would be pretty robust then and maybe even saleable! Or someone offer me a few hundred dollars for it as is.


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## voltmatic automaton (Nov 2, 2008)

okay so afetr reading the posts and getting the pics i am ready with a shopping list of parts 

only one question left, where is the cap soldered to?
i understand its to the ic input and ground but if you could tell me the pins from the bottom side of the board as a reference i can get on it.

for example the ic has 8 pins.
from the bottom side of the board would i solder the top left to the bottom right ...etc. plus if i'm not too far mistaken capacitors have a + - which leg goes to which pin?

i was going to ask about the type of thermistor, but if the open revolt spec works i'll just look for that one.

the pics are a HUGE help.

as an aside----and just so you know, having opened the thread and getting feedback i realise that some people on the forum feel the need to nail down every esoteric concept they know as far as engineering, calculating etc. 
i actually appreciate it when someone can bring things into the domain of the layman. i'm not asking questions on the forum to give people the opportunity to parade their considerabe knowledge and make me or others like me feel like an idiot for asking.
so thanks much quasar for your straightforward approach.


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## Quasar (May 5, 2010)

voltmatic automaton said:


> okay so afetr reading the posts and getting the pics i am ready with a shopping list of parts
> 
> only one question left, where is the cap soldered to?
> i understand its to the ic input and ground but if you could tell me the pins from the bottom side of the board as a reference i can get on it.
> ...


The capacitor is .01uF - might have 103 printed on it - and a 50V one is plenty big enough. Looking at the bottm of the board, pin 1 of the ic is the square pad and pin 4 is ground. Pins 2 and 6 are joined together and the cap goes between pins 2 and 4. Doesn't matter which way round as it will not be a polarised type. The track leading off to the left from the top pad of what will be the 1K resistor is cut. It goes to one of the "vacant" pads which now will have the 4K7 resistor. Then you need to place a piece of wire linking that pad back to the square pad end of the 1K resistor.

The thermistor from the OpenRevolt worked OK on mine, but any with a resistance at 25 deg C of 15K or greater and a resistance at 100 deg C of as small as possible should be OK.

Also, here's a picture showing some of the extra gate drive resistors I fitted to the power section. These are 200 ohms, same as the ones on the top side of the board and they are simply soldered across the existing ones, paralleling them to make an effective resistance of 100 ohms. You need one per IGBT.


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## voltmatic automaton (Nov 2, 2008)

i am having trouble comparing your instructions with your pictures.
I may be missing something.
i used the picture you put up and put what i think are the numbers for the pin out.

let me know if these are right please.

you specified putting a wire on 2 & 6

then a cap on 2 & 4

but the picture looks different, please advise

thanks again


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## Quasar (May 5, 2010)

voltmatic automaton said:


> i am having trouble comparing your instructions with your pictures.
> I may be missing something.
> i used the picture you put up and put what i think are the numbers for the pin out.
> 
> ...


You have the pin numbers correct. Pins 2 and 6 are already connected together by a copper track. The capacitor goes between pins 6 (and hence also pin 2) and 4.
Throw away this picture and look at the later one that I sent as it shows where the wire goes. The blue wire. 
It goes from what was the top empty pad down to the bottom pad of the 1K resistor (which replaces the zero ohm link).


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## 9852 (Jan 17, 2010)

ok, I think that i can follow that. thanks for all of your info. I havent started on my LS controller, because I haven't got it back from them but after reading this post Im willing to give it a try I mean what can happen it wont work, thats bound to happen anyway, so what the hell.


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## Quasar (May 5, 2010)

billhac said:


> ok, I think that i can follow that. thanks for all of your info. I havent started on my LS controller, because I haven't got it back from them but after reading this post Im willing to give it a try I mean what can happen it wont work, thats bound to happen anyway, so what the hell.


You're welcome.
Can't make it any worse!
The lack of proper current sensing and also thermal protection is a sure way to blow them up. What really puzzles me is that they are still sending the things out in this state, because its not too hard to make the design a lot more robust.
They never replied to any of my communications and that makes me think they really have no idea of what they are doing.


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## voltmatic automaton (Nov 2, 2008)

well i got the cap, and resistors in place, just waiting for the thermistor to arrive in a few days.
that gives me time to get a better heatsink from somewhere.

the devices are indeed IGBTs. had to figure out the part number for that.

you had shown the gate drive resistors you installed, are those a necessity for these alterations to work or is it an added margin of reliability?

i also noticed that the IGBTs have no interfacing material against the heatsink bar, would it be worth the time to apply some or just leave as is?

you know you could always offer upgrade services to anyone with an LS controller, maybe make some cash back that way !


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## Quasar (May 5, 2010)

voltmatic automaton said:


> well i got the cap, and resistors in place, just waiting for the thermistor to arrive in a few days.
> that gives me time to get a better heatsink from somewhere.
> 
> the devices are indeed IGBTs. had to figure out the part number for that.
> ...


The extra gate drive resistors are not essential but fitting them should reduce the power dissipation quite a bit by speeding up the switching times.
The IGBTs don't need any material between them and the heat sink, in fact they make better contact with nothing there. I put thermal grease under mine but I was fitting new ones. I don't think its worth undoing them all to do that.

Good luck, be interested to hear how it goes as my car now uses the OpenRevolt controller and it is very smooth.

I'm not interested in doing upgrades - I wouldn't have put the details of what to do on here if I was!


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## 9852 (Jan 17, 2010)

well i appreciate the info and i will be trying to repair/ upgrade mine as soon as i get it back.


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## dexion (Aug 22, 2009)

One thing ive been curious about if the controller doesnt sense current, how does the current limiting twiddle work?
It works on my controller fine. I have it set to a max of 400 motor amps and it wont go alick over 400 motor amps. Do they use a different method (or is that not what you are talking about when you say no over-current sensing.)


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## 9852 (Jan 17, 2010)

well mine dont have any adjustment pots, so i can see how it wont work, maybe they do different things for different models.


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## dexion (Aug 22, 2009)

Sorry i should have put the question is for quasar. But that may also be why mine is still kicking since I can adjust the current via a pot (and 2 other adjustments (ramp and max motor voltage) which definately do something when I mess with them.)


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## voltmatic automaton (Nov 2, 2008)

DOH!!!!!!!!!

okay so i did the refit Quasar suggested and everything was good, i was able to back the car out of the drive way, crawl down the road...etc
but since a crawl wasn't going to do i got out and made a couple of adjustments to the ramp, current etc.

guess what i DIDN'T DO ???

i didn't shut off the main breaker, and while fiddling with the current sensitivity pot i touched the case of the controller.

THUNKK!!

the motor made a big lunge and the breaker tripped.

heres what i DO know.

the motor is fine, i tested with a small battery and it turns with no issues.

the controller is the problem...well DUH!

i hooked up a battery, a throttle pot and motor as a small test bed. i hooked the battery in last and as soon as it was hooked, the little motor i was using kicked up.
the throttle is good and i didn't mess with anything so i suspect a short has developed since i messed with the control board with the power on.
so the power side of the controller seems good enough to want to pull all the juice from the pack in the car until the circuit breaker trips.

so then i should be looking for a bad component on the control board???

no components are outwardly damaged, no burns, carbon or anything. i have a multimeter, so if anyone can suggest a component to look at as the primary suspect let me know.

if it helps, i decided to test my controller with the normal wiring as used in a car setup which leads to immediate and full power just by hooking up the battery.

just to rule something out though i removed the wire that is used for the KSI. this time when i hooked up the battery there was no activity. so i guess something is working correctly there.

please let me have your advice gents


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## voltmatic automaton (Nov 2, 2008)

also tried just hooking in the KSI without the throttle potbox wiring, again the motor comes on immediately, so then the control board becomes active and throws the power board into 100% as soon as its got any power.

i am wondering, as long as im looking at all this, the control board from paulandsbrina looks like it may work, i have the power side prebuilt from logisystems along with its IGBTs.

do you think its possible to wire it to the openrevolt board? if so how much trouble would it be?

it may be les work to build a more reliable control board than to keep messing with this one.
plus tracking down the bad component could take forever given that i don't know what i'm looking for... i thought it would be as simple as find a shorted cap or blown resistor..not so


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## dexion (Aug 22, 2009)

one other thing to try (be careful) is to short across the throttle pot inputs (at the controller) does the motor stop spinning?

Does the motor stop spinning without the pot connected but ksi on?


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## voltmatic automaton (Nov 2, 2008)

The motor continues to turn with no pot connected.

when i connect the pot and move the throttle from min to max, theres no effect on the motor, it just keeps running.

I will try shorting the throttle inputs to see what happens.

I'm still fairly sure the problem lies with the control board, not the power board.


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## Wirecutter (Jul 26, 2007)

*Slight OT: Re: Controller number 4... and counting*

I've been away, so I missed a lot of this thread as it developed. I'm very interested, since I have a Logisystems controller that I haven't had a chance to install yet. 

First, I'd like to thank Voltsmatic, Quasar, and Tesseract for a very informative and educational thread. My general level of knowledge of controller workings is in the "enough to be dangerous" range, but I actually understand everything being said here. Thanks again!

Now then - question from the Peanut Gallery: My LS is only a 48v 700A version, and might not have much in common with the higher voltage controllers discussed here so far. Its intended use is to upgrade a gokart, so I'm not at risk of getting stranded on the way to work. It also appears to be potted. DOH!

I'm seeking anyone with experience removing potting from a controller in order to fix/upgrade. I have _some_ experience, and I have a gallon or so of a very expensive chemical used for removal of potting. I actually tried it out on a fried Sevcon controller. It works on Sevcon's potting, but unfortunately, also on the packages of all the semiconductors. DOH!

Has anyone penetrated this seemingly impenetrable barrier? Thanks in advance.

-M


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## 9852 (Jan 17, 2010)

*Re: Slight OT: Re: Controller number 4... and counting*



Wirecutter said:


> I've been away, so I missed a lot of this thread as it developed. I'm very interested, since I have a Logisystems controller that I haven't had a chance to install yet.
> 
> First, I'd like to thank Voltsmatic, Quasar, and Tesseract for a very informative and educational thread. My general level of knowledge of controller workings is in the "enough to be dangerous" range, but I actually understand everything being said here. Thanks again!
> 
> ...


 yes, some where inthis thread I think they talk about heating the controller up and then levering the heat sink off then the rest is easy to get off (supposedly, I havn't tried yet). I will be working on mine also as soon as it gets back to me. I will "FIX" it. a wise man once told me that there are 2 ways to fix something,1 is to fix it so it works, and the other is to fix it so it never works again, with LS, either way works for me.


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## voltmatic automaton (Nov 2, 2008)

I'm sure my ignorance is showing but what is 'potting' ?

I believe the reference to heat and then prying open the controller earlier in the thread was mine.
I initialy tried just a screwdriver and hammer but it looked like too much damage was happening to the aluminum casing.
I used a heat gun and slowly worked it up and down one seam of the controllers base to soften up the glue holding it together. I then used a pry bar (screwdriver will work) to pry it apart a little bit. The glue itself is epoxy-like and will release on the other side once one side is free (it will crack like hard candy)

other than that...


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## Quasar (May 5, 2010)

voltmatic automaton said:


> also tried just hooking in the KSI without the throttle potbox wiring, again the motor comes on immediately, so then the control board becomes active and throws the power board into 100% as soon as its got any power.
> 
> i am wondering, as long as im looking at all this, the control board from paulandsbrina looks like it may work, i have the power side prebuilt from logisystems along with its IGBTs.
> 
> ...


Yes, very sad!
The KSI input controls a transistor "switch" that turns on the power to most of the electronics on the control board. Sounds like you have probably blown one of the comparators - not easy to find without an oscilloscope.

The OpenRevolt board will drive the LS power stage quite happily. The US version has 10 gate drive resistors that connect to the gates of the MOSFETs. You leave these out and just put a wire link from the driver output on the OpenRevolt board to the "bus" on the LS power board that drives all the IGBT gates (That's a track that runs right around the perimeter). And run a short, heavy ground wire as well. That's actually two of the pins in the 3-pin connector. Ignore the other pin. Of course you need a 12V supply to the OpenRevolt board, but that gate drive and ground are the only two connections you need between the boards. You can ignore the 7-pin connector.
The OpenRevolt board is too big to fit into the LS case though.
And you need to mount the current sensor on the M- busbar. It just slips over and you can stick it down with some hot melt glue, but that won't fit in the case either.

Why some LS things work and some don't is a mystery, but I guess they are different - different bits get left out, or not, as the case may be. I've only seen inside one of them and I have no desire to ever see another.


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## 9852 (Jan 17, 2010)

well I think I can beat that, I have never seen inside one of them and from reading this thread (and countless others) I dont want to either. I was half ready to rip mine open provided i ever get it back, but now, I think its trash can food.


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## JRP3 (Mar 7, 2008)

voltmatic automaton said:


> I'm sure my ignorance is showing but what is 'potting' ?


Potting is when you encase all the components in goop, probably epoxy. Makes them waterproof, and hard to fix.


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## voltmatic automaton (Nov 2, 2008)

Thank you for the definition of 'potting' ...learn something new every day 

as for tracking down the bad component...this is what i did..and i may have found it...hope springs eternal.

i think its one of the 8 leg i.c. 
the way i checked was to desolder the control board. then i set my multimeter to check current, dc amps.

i would wire everything like normal. then connect the pins from the 3 prong connector to their native control board hole using the multi meter.
using this i was able to start the motor i'm using, increase its speed by moving to the next pin up, then back down and then finally off.

the part i suspect is marked TC4420 EPA.

hopefully i'll know by tomorrow.

if this doesn't work then i'm going to get the open revolt control board.

i think this sounds like the making of a good plan.


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## Quasar (May 5, 2010)

voltmatic automaton said:


> Thank you for the definition of 'potting' ...learn something new every day
> 
> as for tracking down the bad component...this is what i did..and i may have found it...hope springs eternal.
> 
> ...


The TC4420 is the IGBT gate driver chip.
Farnell stock them.
I'm surprised that you managed to damage that one!
Actually, when I think about it, that chip is probably OK and you are just turning the gate drive on and off with your multimeter.
You can try disabling the current sensing altogether by shorting across that capacitor you added. That will turn it off and you can then see if the speed control pot varies your test motor. If it does, the most likely blown chip is one of the other 8-pin ones at the end of the board.


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## voltmatic automaton (Nov 2, 2008)

p6ke20a-tp

thats the part number of the ONE component i can't get.

you can probably guess that the part i replaced on the failed control board didn't fix the problem...oh well.

So now i'm building the open revolt control board...every part has been found except the one mentioned above.

edit... never mind the 'tp' is a component storage description, found that part.

now i have to find this one FQU17P06TU

BAH !!!


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## Quasar (May 5, 2010)

voltmatic automaton said:


> p6ke20a-tp
> 
> thats the part number of the ONE component i can't get.
> 
> ...


The P6K... is a transient voltage suppressor used to eliminate spikes from the car's 12V system. It'll work without that, but highly recommended to fit one as soon as you get one.
The FQU.... is a p-channel MOSFET that is used to switch the main contactor under timed control of the microprocessor. It isn't needed either as you can close the main contactor manually - which is better anyway.

The recommended power up sequence is to apply the 12V first and also the main battery power via the pre-charge resistor, then close the main contactor.

I do it slightly differently in that I supply the main battery volts via the precharge resistor (across the main contactor), then switch on the 12V supply and close the main contactor at the same time. Works for me!

You can save a bit of hassle if you buy the microprocessor already programmed.


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## voltmatic automaton (Nov 2, 2008)

good to know...i did see the wisdom in buying the preprogrammed chip, i really can't justify spending MORE time learning to program something and then upload the code (even though they have that on the wiki site)

i do have a laptop and have every intention of going into the chip and checking out the parameters, but thats a step further down the road.

the only part i would be short is the FQ....whatsit.

meanwhile the power setup in the car is such that the contactor and controller fans are controlled seperately. i turn the key to ACC and the fans come on plus all the 12V stuff, once i turn to ON the main contactor engages. ithink this sequence will work out well.

i do have a precharge resistor installed permanently across the contactor.
hopefully this will not be too difficult to wire in once the board is complete.

more on this as i get the parts and start building.

thanks folks!!


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## 9852 (Jan 17, 2010)

well, I finaly got my logisystems controller back, I would love to do this repair, but right now I just dont have the time, Im goint to give it one more shoot giving it every chance for success. I bolted a large heat sink to the bottom of my assembly and used heat sink compound, then bolted the controller back on the assembly, and I have 2 high output fans on top. now i also upgreded the controller from 48-72 to 72-120, because Iv heard that with the newer ones people are having good luck, if they run it at a lower voltage than what they are rated for. so here we go again, LS #2


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## voltmatic automaton (Nov 2, 2008)

Alrighty... have the control board ready from the Open Revolt design. All parts are soldered in place save for the GR resistors and the Q1 component.

Quasar you said that at the moment Q1 isn't critical, i do have it on back order so it should be here in about 3 weeks.

Anyway, how about attaching this board to the power assembly from the Logisystems?
How would I do that?

So far as i can see theres the J1 5 lead connector and theres the J2 3 pin connector, theres also the J3 4 lead connector but i didn't install a onnector so theres just holes.

From the instructions it looks like the J2 is for the serial cable connection. Other than that i can't really tell what the other connectors are respinsible for.

If you can advise me on what to connect where i would appreciate it. I plan to make the serial connection for J2, th shouldn't be a problem....but what about those other connections?


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## captain stone (Dec 21, 2010)

voltmatic automaton said:


> So Logisystems sent me a replacement for the third controller they sent. I opened the box took the thing out and flipped it over to inspect it... rattle...rattle...
> 
> I called them up, stating there was a tiny rattle inside, long story short my request for a refund on the unit was denied. Logiystems does not refund.
> 
> ...


 Yea I have the same problem. what i understand is IF you get it back keep it and upgrade it yourself with better parts or use an open revolt controller.I think its a mom and pop outfit Jim is the tech and his wife the answering service, on a walmart answering machine with a caller id so they dont have to talk to people they owe!!!


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