# open source controller burnt chip? help!



## Weisheimer (May 11, 2009)

It is an opto-isolator.
It shouldn't be too hard to replace it.
Cut the 4 legs off at the body and then de-solder it.
No schematic here to look at but will post a link to the part and describe the function as soon as I round up a schematic.
You might need to check some other components out too, but let's see what it does first...

Here is a link to the schematic:
https://files.secureserver.net/1sSGzSxxkzUU4E
It is an HCPL-817 opto-isolator and controls FET that turns on the CONTACTOR.

I recommend asking your question at Ecomodder.com on the Open-Revolt forum too.
http://ecomodder.com/forum/showthread.php/paul-sabrinas-cheap-diy-144v-motor-controller-6404.html

Here is a link to the Open Revolt Wiki:
http://ecomodder.com/wiki/index.php...ougar_500_Amp_DC_motor_controller_.28Rev2C.29


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## alvin (Jul 26, 2008)

I think this is the optocoupler between the microchip and Q1. That powers the contactor. That is the yellow wire in the photo.

The part number is HCPL-817-000E from mouser.

That should not stop the controller from working.

But there is a reason for the burn mark. 

Alvin


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## OMT (May 10, 2010)

hmm. well i found this issue because i noticed a burning smell in the garage, and a slight stream of smoke from the controller, but it worked a moment before(i just got in the car and revved it lightly to check if it works) then i noticed the smoke/smell and never tried it again so it could acctually be working because the odd thing is i dont even use the contactor yellow wire, and never have.

thanks for all the tips and help!!


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## PStechPaul (May 1, 2012)

It looks like the damage is on the output side of the optocoupler U9, which provides a 12 VDC gate drive for the contactor MOSFET Q1. There also appears to be a repaired or modified track from R8 to J1-5, which is the throttle pot. It also looks like the wires for J1 are soldered to component leads on the board, and perhaps a loose wire strand caused a short. The battery GND is isolated from the main PCB GND through a diode D1 and part of a common mode choke L1. There is a separate 12VDC circuit which seems to be gate drive for the MOSFETs.

I don't see any obvious circuit design problems, but a misconnection or short among the wires of the J1 terminal block could have caused a failure of U9, although more likely might be a failure of the MOSFET Q1. If the contactor does not have a commutation diode or snubber, it could create a destructive inductive spike that could destroy Q1 and the energy could have passed on to U9. It might be a good idea to put a diode like a 1N4004 across the contactor connections on the board. Also it would be a good idea to add a fuse to the contactor connection (Q1 drain).


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## OMT (May 10, 2010)

yes i forgot the reason now, because i cant see the undewrside of the board, but i most likely did it because i may have damaged the board by j1. im not sure. would you suggest buying a whole new control board and components. im good to solder, but limited in my circuit knowlege at the moment. i hope to someday catch up!


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## alvin (Jul 26, 2008)

You might cap the yellow wire and clip the legs off U9 and remove it. Then power up the board if the led's are on and not blinking it may be OK.

The pre charge would not work but the controller might. Q1 might be shorted so the yellow cable would always be hot.

When you power-up the board the LEM must be connected to the board or the LED will flash indicating a fault.

You might just check continuity for where it should be and where it should not be.


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## PStechPaul (May 1, 2012)

That is good advice. You may also want to scrub the area around the burnt component, using detergent and a stiff toothbrush or equivalent, rinse with clean water, dry thoroughly with a heat gun, and check carefully for any damaged traces. The black deposits from a failure such as this may consist of carbon from organic compounds such as plastics, as well as metallic deposits from vaporized copper, and both are conductive. 

When you reapply power to the board, it may be wise to use a 1/2 amp or so fuse in series with the supply in case there are other damaged components or shorts. Good luck!


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## OMT (May 10, 2010)

ok thanks guys! ill clip the legs off i guess and clean it with a soft brush. i have a strong feeling it still works because i never acctually tried it again after i noticed something went bad inside. ill let you guys know what happened next!

thanks again!


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## OMT (May 10, 2010)

Thanks guys! i took the advice and cut the legs off, and removed the sticky black junk with a toothbrush and water and i air dried it with my compressor. since i use a small relay to start my car up (12v) i think it blew because my chennic dc-dc converter blew! i emailed them twice, and both times they stopped responding when i asked for a replacement or compensation since it was only a few months old. anyways, im putting the controller housing and stuff back together and see if it can handle some amps! ill take pictures soon


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## OMT (May 10, 2010)

i cleaned the area, temporarily connected the power and pot lines and it spun the motor up in neutral!! i put it all back together, make sure the lights are both solid. yes ( they still are) but as my freind was dischrging the capacitor bank with the resistor when we were romoving it, he accidentally touched the +/- side on the + bus bar for the input. i didnt think it would ruin anything but sure enough. i reconnect the controller and ladi-da it doesnt work again. although both lights are solid. so im now removing it once again to check for any other fried components?


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## PStechPaul (May 1, 2012)

I offer the following as general advice on how to proceed with troubleshooting.

I'm not really familiar enough with the controller to give any more than general advice. You may be able to supply power to the board through a current limiting device like a light bulb or polyswitch fuse, and once you can get proper power supply voltages on the components you can check for overheated chips or improper voltages at various points. But even with a circuit diagram such troubleshooting is very difficult. If you can post some good photos of the entire PCB showing most of the tracks and the components with labels and values clearly visible, I might be able to give a few ideas. Other people may have more experience with this controller, or they may benefit from the information provided from further discussion.

OK, now that I found the schematic, here are the steps I would take:

Apply 12VDC through a current-limited source to J1-1 and J1-2
Check for 12VDC on pins 14 and 16 of the DC-DC converter. If the "power" LED D4 is lit, this is probably OK.
Check for 5VDC on U1-3 to U1-2 (GND).
Check for proper voltages and signals on U3 (ATMEGA) to GND.
Pin 1, RESET, 5VDC
Pins 9 or 10, 16 MHz clock signal
Pin 25 (Motor current) = 0 (you may need the hall effect sensor connected or short J3-2 to J3-3)
Pin 15 (Clear) should be low (0.5V or less)
Pin 14 (Overcurrent) should be low (I think)
U8B-7 (UV Fault) should be high
Attach a throttle pot from J1-4 to J1-5.
Adjust pot and observe PWM waveform at U3-15.
PWM waveform should also be observed on U6-5 and U7-6 (PWMOUT)
You can connect the limited current source +12VB to the B+ of the output bus, and connect a small load from B+ to M- to simulate a motor, and observe PWM signal from M- to B-
Be careful taking these measurements, but they should guide you to the area of the circuit that is malfunctioning. Then you might be able to use simple ohmmeter and diode tests to find a damaged component, or you may have to start replacing parts and hoping (before hopping) for joy!


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## OMT (May 10, 2010)

ok ill start seperating the two boards, i noticed gr10's wire seems to have been heated to a different reddish color


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## OMT (May 10, 2010)

where did you get that schimatic? i want to make sure i dont mess up any parts


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## OMT (May 10, 2010)

thanks for tall the help by the way!! im looking to eventually paint and sell the car to seave up for university im going to windsor for mech. eng


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## alvin (Jul 26, 2008)

OMT said:


> i cleaned the area, temporarily connected the power and pot lines and it spun the motor up in neutral!! i put it all back together, make sure the lights are both solid. yes ( they still are) but as my freind was dischrging the capacitor bank with the resistor when we were romoving it, he accidentally touched the +/- side on the + bus bar for the input. i didnt think it would ruin anything but sure enough. i reconnect the controller and ladi-da it doesnt work again. although both lights are solid. so im now removing it once again to check for any other fried components?


 
I am not sure what you mean by touched the +/- on the + bus bar.

There was a patch jumper on your board that connected R8 to J1 pin 5. That is where the 5 volts for the potentiometer comes from. It may have come loose.

You might power-up the board and see if by turning the "pot" the output of the driver is working. Test between any gate resistor (GR1-GR10) and PH1 or PH2. It should go to 12 volts I think.

https://files.secureserver.net/1sSGzSxxkzUU4E
This is the link for the schematic.


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## OMT (May 10, 2010)

ok well i checked the dc voltage on ph1 and ph2 zero , and between gr1 and gr10 also zero i was testing while pulling the throttle and it didnt change atall. is the control board the issue then? ive been considering ordering a whole new kit and fixing this one later but i am interested to see if i can fix it


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## alvin (Jul 26, 2008)

OMT said:


> ok well i checked the dc voltage on ph1 and ph2 zero , and between gr1 and gr10 also zero i was testing while pulling the throttle and it didnt change atall. is the control board the issue then? ive been considering ordering a whole new kit and fixing this one later but i am interested to see if i can fix it


Ph1 and Ph2 are ground and gr1-10 are the positive


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## OMT (May 10, 2010)

wow lol i misread your comment. thank you for being so patient and helping! ill give it a shot now


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## OMT (May 10, 2010)

ok i triied every single combonation possible, and nothing. with 0 throttle & about 85% still nothing. both yellow/green led are solid. but i noticed a pretty intense heat coming from the dc-dc! could this be the issue. its confusing because i got it to work and while putting it together a friend shorted B+ and B- while trying to discharge the cap bank D: and i hoped it was ok but no...


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## OMT (May 10, 2010)




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## OMT (May 10, 2010)

nothing seems fried or damaged atall. last time i powered just the control board when it was all together the dc-dc was pretty hot that was the only odd thing


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## OMT (May 10, 2010)

if someone is willing to fix it with me or arrange a deal i am willing to pay! i need to get the car on the road but i dont have any other measuring devices at the moment other than a volt/ohm meter :/


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## PStechPaul (May 1, 2012)

It would help if you could go through the troubleshooting steps I posted and show the voltages you get. A scope would help but just the DC levels should reveal where the problem is. The hot DC-DC converter indicates that the +12V DC supply is shorted or loaded down, most likely from the driver U7. If you have the power board disconnected then this is very likely, or it could be the gate protection TVS D6. 

If your friend accidentally discharged the capacitor bank to the PWMOUT connection, the most likely damage was incurred by the TVS, which may have saved the rest of the board from getting fried. You can just take an ohmmeter reading on it, and it is very likely shorted. It seems to be a 20V device. You could temporarily replace it with a 15V zener, or you may even just see if removing it restores the 12VDC and cools off the DC-DC. If not, then the driver and/or the DC-DC are probably toast, and anything else using the 12VDC power may be damaged. But there aren't very many sensitive components in that circuit.

I don't know where you are located but I'd be willing to take a look at the board if you can mail it to me. But it would be better if someone with more experience could help you with this.


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## OMT (May 10, 2010)

im in london ontario canada haha probably far away right?


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## PStechPaul (May 1, 2012)

Near Toronto, right? Probably 2 days by USPS express mail (flat rate box) to MD, but maybe longer to cross the border? If you pay postage both ways I'd be glad to look at it, but no guarantees. PM for address and other details if you wish. I won't charge anything except for any special parts I might need to fix it. 

Just looking at your photos of the MOSFET power board and the schematic, I am wondering how well the source and drain are connected to the bus bars, and I also question if the 30 ohm gate resistors are sized correctly. These MOSFETs (IRFP4668) have about 10 nF of gate capacitance which is a time constant of 300 nSec with 30 ohms. The device itself has delay, rise, and fall times of 100 nSec or less, and these parameters are tested with a 2.7 ohm gate resistor. Also of some concern is that there is no bleeder resistor or gate protection zener/TVS on the board, and your photos show the leads unsoldered and possibly susceptible to ESD from handling. MOSFETs are fairly rugged but I like to have at least a 1k-10k resistor directly from gate to source as a precaution.

The MIC4451 seems to be a good choice for the gate driver, with 12A peak current and delay/rise/fall times of 25-30 nSec. But I think the TVS D6, and the gate resistor R17, would be better placed on the MOSFET power board to maintain protection and keep the gates from floating when disconnected as you show. I doubt this has anything to do with your problem, but it seems like a design issue that might be discussed, especially as this is an open source controller.


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