Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

Holy cow! Thank you for posting that surplus site. I had gotten two 4 ounce pcbs awhile back from wherewolf, but I didn't know where he bought it from. Since then, I bought some 3 ounce pcb. I don't have any of the 4 ounce left that is unetched. I did Ben's with a piece, and the other piece is called for for someone that was helping me a whole bunch with the hardware side. I didn't know digikey had it. Maybe I can order it from them, just to make sure it's thick enough? I think I'll do that. I'll check the thickness of the 4 ounce stuff when I get back from picking up the foster kids. They are spicy meatballs!

[Wherewolf]

If you look at digikey for 4 oz double sided boards they will all show no-stock with big lead times. They special order them only. If we want to save big money, we can order a custom 24x24 or 24x36 "6 oz" double sided copper, and have it cut up (or not if it's easier to mill whole) and probably still wind up around $16.00 a board. It's been some time since my research, but that's close. I can dig back through my notes at some point and pull quotes that I received when we get closer.

Wherewolf

[dlaing]

I'm really looking forward to seeing the new code.
The compiler will be optimizing all math with powers of 2 to be bit shifts, 1 clock cycle vs lots of cycles.
Because the ADC is going fast now, could we have the throttle and temperature checks happen in the time between current checks . You could put the temp and throttle into the interrupt when the current finishes. The ADC should easily be finished before the next current read. Then we can always check the current.

[MPaulHolmes]

OK, I'm watching my son tonight while my wife goes to see Star Trek with her girlfriends. (Ya, sort of dorky, huh? hehe) So, I'll have to test the software in the car tomorrow. I tried it today and nothing happened. I had cranked up the optimizations all the way, and had a million changes. I probably should have just left it at no optimizations at first. I got greedy. I took out the controller and have it sitting on top of my oscilloscope in the garage. I'll just keep testing the software by looking at the PWM signal. Once I get that working, I'll stick it in the car. I think there is MORE than enough time to slow down the A/D conversions to improve accuracy. It really is much better now. Very expandable. You can do a lot when you aren't just sitting doing nothing waiting for a conversion to finish!

I've had some sleepless nights because of the 3 ounce copper pcb. I'm pretty sure that it will be fine, but I'm not sure. That 6 ounce copper is sounding really good.

[JayC]

Originally Posted by Wherewolf

If you look at digikey for 4 oz double sided boards they will all show no-stock with big lead times. They special order them only. If we want to save big money, we can order a custom 24x24 or 24x36 "6 oz" double sided copper, and have it cut up (or not if it's easier to mill whole) and probably still wind up around $16.00 a board. It's been some time since my research, but that's close. I can dig back through my notes at some point and pull quotes that I received when we get closer.

Wherewolf

What about this 25 shts Copper Clad Laminate, FR-4, .060, 8 x 12, 3oz
price: US $40.00

[blackpanther-st]

Paul, are your buss bars still solid copper? if so you could tin the path on the PCB and then preheat the buss bar with a torch and lay it on the path, hot. if done rite it should solder well to the PCB and give excellent conduction with only a short path to your components.

[MPaulHolmes]

That's a good idea, Blackpanther! I don't have a blow torch, but maybe I could improvise?

JayC, that is a seriously good deal! I'm pretty sure 3 ounce would be fine. However, I think I'm going to order a couple 4 ounce pieces for the trial. I'll test the 3 ounce stuff in my car I think.

My oscilloscope broke. The screen doesn't stay on anymore. It is acting really weird. It was only about $120 and lasted for 5 months or so. Not too bad I guess. That's my eyes and ears, so that's sort of bad. hehe. Also, I think that old control section is acting weird again too. I may not be able to test the new software in the car with this old control section. It's behaving really strange. Maybe I can just send the software to that one place, but I don't know how to "commit" to send it. I don't see that as an option. Maybe people can look over the code and make sure everything seems basically OK. I think I need a new control section before test driving it, though. boohoo.

[dlaing]

Maybe I can just send the software to that one place, but I don't know how to "commit" to send it. I don't see that as an option. Maybe people can look over the code and make sure everything seems basically OK. I think I need a new control section before test driving it, though. boohoo.

Paul, if you have already checked out the code, you should see the same files as here: /trunk - Open ReVolt - Trac
Then you move your code, c and project files, into the directory you want. Add the files to svn, and then commit your changes.
If this doesn't help, where are you running into problems?

[blackpanther-st]

Paul I hear you about the Oscilloscope, I am hoping I can get mine working again. I got the horizontal amp fixed and then the vertical amp quit. I cant complain though I'ts an antique 50 KHZ audio scope with tubes. proly 1960's erea.

[adamj12b]

Hey Paul,

A simple way to solder the bus bars to the board would be to add the solder to the board, rub some rosin on the rail and lay it on the the spot to be soldered to and then place it in the hot oven. Keep an eye on it, and take it out carefully when the solder melts. A heat gun would work as well, or heating the buss bar on the grill and then placing it on the solder.

Just thinking out loud. lol

-Adam