Paul & Sabrina's cheap DIY 144v motor controller

[exrdega]

I live in a hilly area. Pulled 400amps plus for several 12-15 seconds. No problem at all. I feel like the cat that ate the canary driving this electric vehicle. No gas, no noise. SWEET!!!
Its quite cool here around 0 deg C today. Cooling is not a issue.

[Dwffy]

Hey you guys, I've got a new problem for you to solve for me, nothing blow up this time, but it is frustrating. My controller has been working flawlessly in my Ranger p/u for a month now. Two nights ago I was trying to demonstrate my ev to a friend. I turned on the ignition which powers all the ignition circuits that are normal for a car plus it puts 12 v to the controller. This starts a 7 sec timer which inhibits the main contactor for that perion. IE can't engage main battery pack until the pre-charge is done. I'm using a 40watt 120volt light as a pre-charge resistor so I can visually see the beast charging up.
I'm using 10-12v batteries in series 5 up front 5 behind the seats. Once the pre-charge relay finishes its work I can then engage the main contactor which is 12volt operating.
So I pressd the main push button to engage the contactor.. Contactor engages but that is all that happens. Push the accelerator and nothing happens. Normally at that time the motor stars whirring. This time, nada. So I press the accelerator harder thinking that perhaps my wonderful home made pot was not working properly. Still nothing. I walk to the front of the vehicle standing by the front wheel lean across the fender and manually pull the accelerator cable to max throttle. That is exactly what it did, it went to max throttle and when I released the cable it stayed there revving and by now turning at some impossible revs. So I rush to the main emergency cut-off lever and pull the plug and all goes quiet. My friend by now had lost all interest in any electrical form of transport what so ever. How ever I had not so I reconnected the power again, turned the ignition on, waited for the pre-charge thingy to do its thing and pressed the main contactor button once more. Ready now for anything. Pressed the accelerator again. No responce, gave it full throttle, no responce released the throttle and gave it full once more and everything bust forth into action again. Releasing the throttle does not help. Emergency shut-off again.
I then proceed to remove the controller expecting to see lots of char-burnt stock inside. To my utter amazement it all looked absolutely perfect inside. Put it on the bench and with about 60 volts of batteries etc hooked it al up to a 90 volt motor I have lying aroung the workshop, connected a 5k pot up and, walla, everything works as smooth as ever. Revs up slows down you name it it does it. I boxed it all up put it back on the vehicle and tried it once more. All working perfectly. Went to bed a happy man ready to go for my ride tomorrow. (had great dreams about setting new world speed records for EV's etc). Tomorrow comes, I climb happily into my fine steed push the appropriate buttons and proceed to glide silently out of my garage. All that happened was a frightening roar from the motor which necessitated my emergency proceedure , which I now have down to about .05 seconds flat. Went through the whole proceedure once more to get the same dismal results. I now have the controller back on the work bench once more where it is working flawlessly again..............
Any ideas from all you great gurus of electricity out there.
So now you need not say it is quiet on the western front any more!!!!
That's all Folks...........

[mrbigh]

Originally Posted by Dwffy

Any ideas from all you great gurus of electricity out there.
So now you need not say it is quiet on the western front any more!!!!
That's all Folks...........

Hi, first thing I would properly check is your "Pot Box", or the potentiometer is acting funny or the connections to/from the controller.

[jmcginley]

Hey Paul,

My truck ran flawlessly on 120 v today! Previously it was running on 48 v. Kidney stone passed without incident!

John

[MPaulHolmes]

Hi Dwffy. Are you able to see what the error LED is doing during this process? Have you gotten RTD Explorer working? You can download it from Adam Brunette's website, but I can never remember where it is! Makes me mad. It would help to see some useful information about things like throttle, current, pwm duty, and all that stuff. It will make errors easier to determine.



In my searching I did find Adam's wedding album! You wife is way too cute, and your wedding cake looks really tasty. Is there any way that you saved a piece? Even if it's only a small one, that's fine. I could pay for shipping.

[Dwffy]

Hi again,
I don't know what an RTD Explorer is it sounds like a program. No I cant see the lights but I will re-instal the controller with the cover removed. I will also try it with another pot when it is installed. When that is done I will post again.
Paul, why would you want cake, I thought you were guzzling down pink stuff.....Ha.Ha.

[MPaulHolmes]

You don't actually need RTD Explorer. All you really need is a computer with a serial port to hook up to the controller, but RTD Explorer is much more user friendly. 19200 8N1 are the settings. You can have it stream data on the screen, so you can see the actual value of the throttle and everything else. Using the serial port makes it a lot easier to debug. I'd talk to adam on here about RTD Explorer. I only tried it once and it was pretty easy, but I didn't have a laptop until very recently, so I don't really know how to use it. He's the expert.

The main reason I need lots of pepto bismal is because I have no self control with cake.

[Dwffy]

Ok I'm back again,
I tried checking all the connections and all seemed ok. I disconnected the pot and connected up another one and hand operated it. Worked ok.
Switched the system off and on several times to check. All seems to be ok now. I guess it was "pot" after all. I used a cheapie pot from one of the local dealers. Very small and low wattage. I will replace it with a new sturdy one and see how that goes. I did notice once while I was blipping the throttle with the old pot connected and main power off, just the 12 volts to the controller, the orange or yellow light started to flash and I had to switch off the power and back on again before it worked. Seems like we've got this one nailed then. Thanks very much for you help again, you guys are a great help.

It's a tough life when all you can get to eat is cake..............

[mrbigh]

Make sure that the new pot is LINEAR and not logarithmic.

[MPaulHolmes]

Let that be a lesson to all you kids out there. Stay away from pot. haha.