Paul & Sabrina's cheap DIY 144v motor controller

[princeton]

OMG! Those are big caps!! You definitely won the p****** contest.

[Tired2]

OMG, I cannot say how happy I am to see the word "Today" on the most recent post. Almost at 400 pages! I think it was 250 when I started reading a few months ago. I felt like in swim lessons, when the teacher kept walking backwards in the pool while you tried to swim to them.

Thanks Paul for your help via email. Now that I read the whole thread I won't end up posting ideas for stuff that has already happened.

Paul - Did you already get a replacement scope? I have an extra analog 2 channel 20 year old one laying around. It works. It's yours if you want it, if not I'll hang on to it :P

I'm currently in the process of making my own rendition of the control circuitry.. point to point soldering the prototype .

I'll be driving large IGBT's in parallel in the final setup... more info on that later. I hope to post a sub-thread when I get a few more things ready to post.

I have some features in mind that are "extra" for my controller for drag racing purposes, and I refuse to learn PIC, so I'm basically borrowing some ReVolt concepts and putting my own "spin" on it.

Keep up the great work.

Oh, one feature request for ReVolt that I have come to love on my prototype controllers... I use a piezo buzzer to sound out various errors, for instance if throttle goes out of spec, it sounds 3 beeps on a loop... like:
___-_-_-______-_-_-______-_-_-___

I can easily tell what went wrong by looking at my error code file... This eats up a PWM channel, but I'm sure it could be done with something simple like a 555 you toggle power to, etc. Since the controller shuts down anyway, you can probably dedicate the cpu to run the piezo on an endless loop...

Anyway, my point is to have the error LED flash the number of times that denotes which error is active. It might already do that, but i do not recall people's "error report" posts including the number of blinks. Its easy to pass an error code to a function and use that as the counter for number of blinks. It might help with new users troubleshooting issues. With all the extra I/O coming up in the SR controller, you could dedicate 3 outs to a RGB LED so your errors could have pretty colors. I think phillips has a patent on denoting status via PWM RGB LED, but they don't enforce it. Bit Angle Modulation works and would not take a PWM chan, and avoids patent issues.

[mrbigh]

Originally Posted by Tired2

Keep up the great work.

Oh, one feature request for ReVolt that I have come to love on my prototype controllers... I use a piezo buzzer to sound out various errors, for instance if throttle goes out of spec, it sounds 3 beeps on a loop... like:
___-_-_-______-_-_-______-_-_-___

I can easily tell what went wrong by looking at my error code file... .

I like this idea of an external error code indicator interface...
It would be nice addition; Paul what do you think?
Imagine, almost a self troubleshooting of the SR ......

[jackbauer]

snakub , sound like you might have a driver problem. Can you scope the pwm pin on the micro?

[sawickm]

Originally Posted by Tired2

I have some features in mind that are "extra" for my controller for drag racing purposes, so I'm basically borrowing some ReVolt concepts and putting my own "spin" on it.

Tired2,

Good to hear from you about your ReVolt project for Drag Racing, I too am a fan of Performance EV !!!

I am anxious to hear more about your project

-Mark

[The Toecutter]

I took a look at snakub's truck today.

Earlier in the day, he had it on a lift. He had used a programmed arduino board as a temporary 'control' system and it worked perfectly fine. The rear wheels spun while it was on the lift, at 168V(battery; Exide Nautilus 12V flooded).

He took the arduino board off and put in the ReVolt control board. This time, it 'worked', and the yellow light was not blinking. On the lift, he accelerated, and then a transistor blew with very little throttle applied.

He then connected a 24V pack and ran it on the lift with the ReVolt logic board. It worked, although 250A was being drawn just to spin the wheels. We tried this at 36V, 48V, 60V, 84V, and 108V. After 108V, we discovered a bad battery that was reading 6 kohm resistance and removed it; at this volyage level, voltage of the pack was dropping to almost 0 with very light throttle. After removing this battery, current draw was very reasonable at 108V. We checked all connections and they were good.

At 156V, we measured the resting battery voltage at ~160V, and we ran the truck on the lift, and the rear wheels spun with no issue.

We then lowered the truck, put it in reverse, and backed it a few feet. Then we put it in second, and began going forward; a jerk ensued for about 1/3 a second and the transistors in the controller blew. The batteries also began to smell horrible and read ~80V at rest, for a 156Vnom pack.



I suspect that the control board, for whatever reason, is acting as an ON/OFF switch under load. Could this be indicative of a bad ATMEL microprocessor or faulty programming within? The power section of the controller used to work fine with the arduino board, but without all of the safety features that you want a PWM controller for(hence why he ordered the ReVolt logic board kit). I'm thinking that the ReVolt logic board is trying to tell the power section to output max current under load; the truck jerked somewhat violently to indicate this, and the transistors blew, along with the batteries being cooked(they are intended for like 250-300A) indicating that the overcurrent protection is not working.

The yellow light for the logic board, even after all of this, still comes on, as a solid yellow color.

[snakub]

snakub , sound like you might have a driver problem. Can you scope the pwm pin on the micro?

The base resistors to the Ks621k30 transistors were just bad I replaced them and then went on to have the calamity the toecutter described. This has all been very disappointing I only went two feet and the power board blew up!?? With the arduino even with the fet driver slamming the car forward the transistors didn't blow how then could the Paul and Sabrina board have over current protection?

[The Toecutter]

I'm thinking the Atmel is faulty(under the assumption that that plays a role in controlling the current limit and controller ramp function). The car seemed to have no ramp function at all. The FETs blew so fast in that 2 feet of travel that the in-car ammeter gauge didn't even register a spike in the current reading, and it was under very light throttle.

The Arduino used before it worked fine.

Perhaps the PCB board that snakub received just might be faulty... his is the only example I know of that had proper soldering, but still doesn't work. The vast majority of the ReVolts built seem to work fine. I wish we could solve this issue so that this truck could be back on the road. I would be extremely frustrated if I were in his position.

[jackbauer]

Couple of things i'd suggest doing at this stage. First would be to connect a laptop running rtd explorer to the controller and post the .csv file on here so as we can see whats actually going on with the micro. It could indeed be something as simple as a corrupt program. Secondly , can you post some pictures or video of your setup? Again that give people a better understanding of your setup with a view to offering better help.

[MPaulHolmes]

The microcontroller plays no role whatsoever in the overcurrent protection. It's a simple NAND circuit. Were you using a LEM HASS 300-S? Was it on M-? Was it facing the right direction? Overcurrent protection will not work at all if the correct current sensor isn't hooked up correctly. For the light not to be blinking just means the LEM at zero current outputs about 2.5v, and that throttle is in 0-5k range. It says nothing about if the LEM is pointing the right direction, or is on B+ instead of M-, or ... If everything to do with the current sensor was all correct, then another possibility is that there was a bad NAND chip, or there was a soldering problem with the nand. It also has to be a 74hc00 type of NAND. The overcurrent protection circuit is really pretty simple, and acts fast.
Can you post a picture of the soldering for the control board and how the LEM was hooked up, and the connection to the control board for the LEM?