Paul & Sabrina's cheap DIY 144v motor controller

[duncan]

Hi Guys
A short update,
I now have a new shed with a roof and sides - no door yet!
And a Volt battery!

I have to sort out workbenches and sort out all my tools and junk then at long last I will be able to get back to work on my car

[MPaulHolmes]

A Volt battery!! Oh please oh please film your race.

[hamsterpower]

A little bit about liquid cooling as discussed above. The mineral oil used for "Fish tank" PCs is because the oil does not conduct so the boards/circuits go right in the fluid. That is not a concern here as the fluid loop is isolated mechanically. The fluid only contacts the chill plate.
The reservoir is important to maintain fluid level through out thermal expansion/contraction. Having air in the system can lead to bubbles at the pump and cavitation. Put the reservoir high in the system so you can bleed all the air out of the lines. I would bet this is a bigger problem for internal combustion engines with their larger temperature swings. Having a small reservoir is cheap insurance.

[thingstodo]

Originally Posted by hamsterpower

A little bit about liquid cooling as discussed above. The mineral oil used for "Fish tank" PCs is because the oil does not conduct so the boards/circuits go right in the fluid. That is not a concern here as the fluid loop is isolated mechanically. The fluid only contacts the chill plate.
The reservoir is important to maintain fluid level through out thermal expansion/contraction. Having air in the system can lead to bubbles at the pump and cavitation. Put the reservoir high in the system so you can bleed all the air out of the lines. I would bet this is a bigger problem for internal combustion engines with their larger temperature swings. Having a small reservoir is cheap insurance.

Excellent! I have been toying with the idea of submerging an IGBT-based controller in coolant - a less expensive version of the fish tank fluid - and circulating it through an external radiator. What has stopped me so far is whether the fluid will cause problems with the capacitors. They are open type electrolytics.

Using the non-water based coolant is less efficient heat transfer - so I've read - but having a coolant leak of water/glycol causes ... issues ... with the controller and the motor. I realize that the controller and the motor have to be water resistant - sealed and gasketed - to handle being in the engine bay, splashes, puddles ...

Just an idea I've been toying with ..

[MPaulHolmes]

We just got thingstodo's controller put together. It should be good to about 1400-1500amp peak, 350-400v. Here's a test at 24v on my golf cart:

https://www.youtube.com/watch?v=xXwJ...ature=youtu.be

[Astro]

Whoohoo...

That seemed to go too well.
I liked the bit where it all worked and then its like, what do we do now.

Also finally got to see the throttle control in use, i was starting to think it hadn't arrived.

Does the golf cart have a mechanical reverse or is it a battery polarity change?

Makes a neat little test bed for the controller.

Will the MGR motor fit in the golf cart? Now that would get it close to highway speeds.

[MPaulHolmes]

Astro, it's a 2 wire 0-5k pot that you sent. I think I had gotten confused several months ago and said it was a hall effect. Did you also get a 2 wire pot?

[thingstodo]

March 27 update on my DC controller.

Quick Summary

The controller is up and running, connected to my Warp 9 DC motor, and it rotates the motor clockwise as it should. There is some video, but I don't have it edited yet. I was so excited that I had to post right away (!!)

Details - for anyone who is interested ..

The controller is connected to my pack, reading 124V. I'm doing a manual pre-charge for paranoia's sake right now. There is also an extra gigavac contactor between the M+ output on the controller and the M+ terminal on the motor.

The serial cable that I got with my used cougar controller (that I blew up earlier in my testing) has the pins seated kinda of weird. I had tried this cable on the Cougar and it had not worked out. I straightened the pins and gently worked it onto the serial header on the DC controller board. When I power up the DC controller, it displays 'The Stinky Diaper Controller version 1.0' .. or something like that. It displays at 19200,n,8,1 no handshaking .. just like the Cougar used to.

Enter gets another line printed. Nothing that I type echoes for some reason ... I'll have to look up the commands again. For tomorrow.

Tomorrow I'd like to:
- wire in the throttle better
- get the configuration logged from the controller
- see if I can log data from both controllers at once
- figure out how to log the DC controller data

[Astro]

Originally Posted by MPaulHolmes

Astro, it's a 2 wire 0-5k pot that you sent. I think I had gotten confused several months ago and said it was a hall effect. Did you also get a 2 wire pot?

It was definitely meant to be a hall effect throttle. I had ordered one the same for myself earlier and i am sure it is hall effect. Will double check that. That was the whole reason for getting it, to remove any issues that may be caused by a noisy pot.
That makes me sad, here i thought i had gotten you something nice.

Here is the listing of the one that was sent to you from my eBay purchase history.
I will check mine and see what i received. I ordered the exact same item from the same seller 2 months prior to ordering yours.

[MPaulHolmes]

I'm actually very happy to have this, and it's extremely useful for me. Take the throttle you have and (if it's practical) power it up. It has a +5v and ground wire. Then, see what the voltage is at zero throttle and full throttle. I'll make sure your throttle is configured based on those numbers when I mail it to you. My guess is it is about 0.5v at zero throttle and around 4.5v at full throttle.