Paul & Sabrina's cheap DIY 144v motor controller

[madmike8]

Thanks for all the answers... I could build a mechanical throttle stop, but I'd prefer the software method I'm slowly building an electric T-Bucket that will weigh about 1000 pounds. I have a 7.2" Prestolite motor that I'm told that I should try to keep at 80v max. That's fine because I only need a 45 mph speed, but I'd like to to run a higher voltage to keep the battery amps lower.

[flores]

Wouldn't it be more efficient to advance the motor and use all the volts available?

[isaac_alaska]

usually the motor can't handle the RPM's cause by high apparent voltage

[MPaulHolmes]

First I forgot to mention! My wife just gave birth on Saturday. We left the house at around 3:40am, and got checked in to the hospital at 3:50, and she delivered at 4:30am. It was disturbingly close. haha.

I did a test of the new controller with the Bike permanent magnet motor at 24 volts and it has a voltage turnoff spike of about 1 volt overshoot per 17.5 amps. This is significantly less overshoot than the 500amp version. In the 500amp version, I believe Joe got a 25v spike at 180 amps. 1 volt of overshoot per 7.2 amps.

Joes test:

http://www.youtube.com/watch?v=vM8j_...2&feature=plcp

Video of my test coming soon...

[madmike8]

Congrats on the new kid!

[bjdEV]

congrats on the new addition to your family

[sawickm]

Originally Posted by MPaulHolmes

First I forgot to mention! My wife just gave birth on Saturday.

Congratulations Paul !!!

-Mark

[dave koller]

Originally Posted by MPaulHolmes

First I forgot to mention! My wife just gave birth on Saturday. ..

(PS - they know what causes that now..... )

[mrbigh]

Again, congratullations in the new addition to the family, GOD bless them all.

[MPaulHolmes]

Turn off is perfect, but turn ON has a bit of ringing, so I tried one driver per mosfet, and that was no help, so I reduced the gate resistor value to 5 Ohms, and that didn't help either. I don't know why that would help, but whatever. haha. So, I ordered some mica capacitors whose job is to smooth out very high frequencies. The ringing is at 25 MHz. We'll see what happens. But overall, every concern I had has been dealt with. I think it's actually going to work. Hurray! And it's easier to assemble.

EDIT: I actually just didn't know how to use my stupid oscilloscope. The lower gate resistors basically eliminated the ringing. Hurray! This is actually going to work! I don't THINK it's going to work! hahaha. Ben, as soon as I get it all spick and span, just you try and blow this sucker up. Hmm... is the other controller having any cold temperature issues?

I took it apart and reassembled the control board adn driver board like 4 times now to test different things to eliminate the ringing, so I might need a new driver board, but maybe not. There are a few little details that could change, but nothing major! I guess 5th times the charm.