Paul & Sabrina's cheap DIY 144v motor controller

[MetroMPG]

Yay - congratulations! My little muppe... uh, mosfets worked!

I feel like a proud father. Who has shipped his children off into forced labour. Wait...

[MPaulHolmes]

Your children are going to work in terribly hot conditions, like 70 degC!!! hahaha! It's easy work, though, just turning on and off a "light switch", but they have to do it real fast, or else I'll punch them in the face... And you signed the papers!! hahaha! you will never see them alive again! haha! Maybe I'm being slightly over dramatic. They actually aren't really alive, so it's OK.

Ben and Sven, and Wen(dy), Darin's mosfets, are actually the most hard working of them all. Eric's dog mosfets are sort of lazy. They just like to be petted with static discharge resistant gloves.

[bennelson]

WhooooHoooo!

Great! Now I gotta make more battery cables!!!!


(Now upgrading car to 144V......)

Still gotta find some Ford Ranger Front Springs to fit to the back of my Metro!!!!!

[esoneson]

Originally Posted by MPaulHolmes

Eric's dog mosfets are sort of lazy. They just like to be petted with static discharge resistant gloves.

Lazy because there is nothing to do.....yet. Just turn up the amps and
they will spring into action! Yowza!

Great work Paul, your attention to detail is helping us all.
Can't wait to see what Ben can do with it (just don't break it, Ben ).

Eric, Jake and Emma

[Blue Bomber Man]

Looking forward to hearing about this bad boy in action. Would to hear about it's efficiency as well =)

[MPaulHolmes]

I tested it at 12v on the bike and everything worked perfectly!


I'll mess around a bit more at higher voltages, and check out the spikes, and then I'll put it in the car by this weekend, and take it for a drive.

A 144v 500amp bike controller! hahaha! It's nice, the pack voltage input range is 0v to 144v DC. So, let's say you have that controller, and all you have in your car are some 1.5v AA batteries. It would be perfectly fine to run the car on them. No problem! The top speed might not let you keep up with traffic though.

I have a slight concern about one of the mosfets. I checked the resistance across it from drain to source, and it read 500kOhms. It could have been because I was touching it or something and it was reading my resistance? All the others read OPEN CIRCUIT because the resistance was too high. It might be nothing, but I'm going to keep an eye on things. Worst case senario, I'll remove it, and leave it at 500 amp current limit, because I think the mosfets can take it.

[MPaulHolmes]

At 12v (on the bike), there are NO voltage spikes that I can see! If there are spikes, they are smaller in magnitude than about 0.1v!!! I'm getting the stuff ready outside right now to install it in the superbeetle. I think that layout is really good, and everything was as short as possible on the power section. Even the control board I think has just the right sized capacitors, because the signal from the fet driver has NO visible spikes either. Oh man! I don't want to get greedy, but if it stays this way, if someone wanted to live dangerously, I think 156v would be OK! haha! ya! Ben, carry that extra battery in your lap, or have your wife hold it, or put it in the glove compartment, or on the roof. Actually, maybe that's not a good idea. Let's just be happy with 144v, for now... duh duh duhhhhhh.....

[MazdaMatt]

Paul... were you checking the resistance across that mosfet with it out of the circuit? Otherwise you're just checking the same nodes at each mosfet and you touched your hands to it.

Great work! I'm not sure if happy-dancing is in order regarding voltage spikes. I think that the spikes are directly related to the motor power. Keep it REALLY easy for the first few run hours to make sure that things are happy before you start to pour on the juice.

Btw, is your throttle controll system a relation between pedal position and amperage?

[MPaulHolmes]

Hey! They were soldered already, so it was the same ones!!! Yahoo! That's right! Thanks Matt.

Happy dancing on standby for voltage spikes... hehe. I'll tote that big dang oscilloscope into the back of the car, jack up the back end, and run it to see how the spikes look then.

Yes. PWM DUTY is set based on current and throttle position, whichever is bigger.

Here are some pictures!



Monitoring M- to B- at 12v on bike.


Wow! What an ugly pile of crap! hahaha.

Thanks Matt!!!

[MazdaMatt]

That... is... *sniff*... SO... beautiful... gotta wipe a tear away.

I'm not quite sure what you mean by "whever is bigger". Can you PM me a code-snippet for your PWM control code? I'd be interested in reading it... I'd also like to get some feedback from your testing of what you think of how the pedal acts in low/high speed at low/high acceleration.