Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

Merry Christmas and Kwanzaa!

Interesting Kwanzaa facts:

1. Kwanzaa means "first" in kiswahili.
2. It goes back THOUSANDS of years, all the way to 1966 A.D., where it was invented at California State University.
4. I can't think of any more interesting Kwanzaa facts.

Hey! I'm almost done with the 1000 amp controller! Well, not really, but I just wanted to say that to make a couple people feel better.

[jackbauer]

Whats the chances of getting the controller to operate with a 0-5v signal from a hall effect throttle such as this unit:
Throttle Foot 0-5V Hall Effect Type,JCTH,EV Throttle Foot 0-5V Hall Effect Type,Chennic Technology Co.,Ltd.

[MPaulHolmes]

How does a hall effect throttle work? Like if You had one lead hooked up to the A/D input, and one lead hooked to ground, when you hit the throttle, does the wire connected to the A/D input vary from x to y (0 to 5v or whatever)?

[Weisheimer]

Originally Posted by MPaulHolmes

How does a hall effect throttle work? Like if You had one lead hooked up to the A/D input, and one lead hooked to ground, when you hit the throttle, does the wire connected to the A/D input vary from x to y (0 to 5v or whatever)?

Yes, that is what it does with the Curtis hall effect foot pedal.
I think that the Chennic one is the same.

[MPaulHolmes]

Great! I'll add that to the board. I hear they are more reliable than potentiometers.

[duncan]

Hi Guys
I have my Christmas present (controller kit) and I am plucking up the courage to start work
(the boss says I have some other work to do first)

As part of the preparation is it a good idea to tin the copper buss bars?

I thought that I had read it somewhere - on the Australian site?
But I can't find the reference

Should I tin?

[MPaulHolmes]

I ordered some tinnit bright tin plate, and it turned out really splotchy and looked like crap, but maybe a lousy tinning job is better than nothing? At any rate, it would probably only be necessary to tin the spots where you bolt the bus bars to the motor cable (right at the tips). If you just sand the bars just a bit with some fine sand paper during assembly, that should be fine because you have to put that silver conductive epoxy on them before bolting them to the power board, and that epoxy stuff keeps out the oxygen and basically glues most of the bar to the power board.

[jpirkola]

Originally Posted by MPaulHolmes

Great! I'll add that to the board. I hear they are more reliable than potentiometers.

While on this subject a couple of questions,

First question;
When you say you will "add it to the board," are you talking hardware or softwear?

If it's software, can be loaded in by us using Adams program or does it need to be done at your end?

Next question;
I'm using a Alltrax right now in the tractor that the P&S controller will go into. The Alltrax has a handy input pin called 1/2 speed reverse. What it does is reduce power through out the entire throttle movement. I have no idea how they do it.

I can say it is very useful in two ways.
Even at 48 volt,s the tractor will wheelie violently in third (top) gear when full throttle is applied. You can be sure 15 mph is scarry on a garden tractor as well. I can't imagine what it will be like at 120 or 144 volts. I always start a new driver out on half speed for a while.
Then there is backing up to the weight transfer sled to have the chain hooked. I find it a lot easier and smoother to use 1/2 speed in tight spots with people behind me.
Finally there is loading.

Barring Paul or someone saying all you need to do is add this wire to this pin and program this, I was wondering if a simple switch or relay to add in a resistor parallel to the throttle signal line. So instead of 5k ohms for full throttle it would be 2500 or maybe even less.

Doable?

Finally Is there an official Open Re Volt decal I can put on the controller cover/

Be glad to purchase a few if there is.

If you don't have instock decals do you have artwork I can take in and have something made up.

Have a great New Year,
Jim

[jpirkola]

Originally Posted by duncan

Hi Guys
I have my Christmas present (controller kit) and I am plucking up the courage to start work.

Don't worry as long as your soldering skills are good, it will go well. I just finished assembling my kit and then learned something after the fact. Paul may have already notified you of this, but better to be safe. Check with him anyway just to be sure.

The heat transfer material you put between the heat spredder bar and the mosfets or diodes has peeloffs on both sides. It's not really apparent (at least it wasn't to me).

It's a fairly easy fix I'm told and it does look that way.

Hope this save you some time.

Jim

[harlequin2]

Originally Posted by duncan

Hi Guys
I have my Christmas present (controller kit) and I am plucking up the courage to start work
(the boss says I have some other work to do first)

As part of the preparation is it a good idea to tin the copper buss bars?

I thought that I had read it somewhere - on the Australian site?
But I can't find the reference

Should I tin?

Yes!
Its a good idea to solder the bus bars to the board as well instead of relying on just the bolt pressure.
I did it by using the big burner on our gas cooktop (when my wife wasn't home!). I coated the pcb area with flux, tinned it with a big old plumbers iron and kept it handy, then heated the bus bars (one at a time) on the gas burner until they were hot enough to melt solder. I then tinned the bus bar and while it was still really hot, squashed it down onto the pcb - I stuck a couple of bolts through the board holes first to ensure the alignment was correct. I then held a fair bit of pressure on the bus bar to keep it flat while it cooled.
The bus bar acted like a big soldering iron and melted the tinning on the pcb, so you just keep it squashed until the solder sets.