Paul & Sabrina's cheap DIY 144v motor controller

[voltmatic automaton]

thanks for the great information , i had already pulled the resistor and found it was 200ohm.

i agree that just paralleling additional resisotrs is easier and less strain on the board...had that happen before. so i think what i'll do is get an upgraded cincon to 15 v and put low value resistors on the existing ones.

as for a laser temperature probe....no go...

but lets try the other stuff first...if theres still a problem then we'll see


thanks again,

let you know how it goes.

[MPaulHolmes]

The "typical" gate charge for 20 of those IGBTs would be about 2000nC. The revolt controller has a total typical gate charge of about 1600nC. Pretty close. I'm using a 12amp gate driver, but they also have a 14amp inverting driver that is a drop in replacement, but I think Digikey doesn't have any in stock. I would try going way smaller than 200 Ohms. Man, that's huge. I wonder why it was so big? I bet 30 Ohms would be fine.

[Weisheimer]

Originally Posted by MPaulHolmes

The "typical" gate charge for 20 of those IGBTs would be about 2000nC. The revolt controller has a total typical gate charge of about 1600nC. Pretty close. I'm using a 12amp gate driver, but they also have a 14amp inverting driver that is a drop in replacement, but I think Digikey doesn't have any in stock. I would try going way smaller than 200 Ohms. Man, that's huge. I wonder why it was so big? I bet 30 Ohms would be fine.

I agree with Paul on 30 ohms as the end goal. If you used a 15v supply,
That would drive the gate "on" in 250ns at .5 Amp peak gate current.
20 gates at .5 amp would be 10 amp peak gate drive required, so
the 12 amp gate driver should do that just fine.

VA, to get to 30.5 ohms, you could leave the 200 ohm resistors
on top and tack 36 ohm resistors on the bottom.

I think you should stick with the 12v supply and just put the resistors
in first. It won't turn on quite as fast as at 15v, but it would turn on
a heck of a lot faster (and run cooler!) than it is now.

Mark

[voltmatic automaton]

Thanks guys, i'll get the resistors and see what i can do. I would guess that if they are going parallel to the 200ohm resistors i can just solder the new ones onto the bottom side of the board where the original legs stick out, yes?

[MPaulHolmes]

I think that would be fine. I'm just wondering why they had such large gate resistance. I feel a tiny bit worried. Does a very slow turn on make it more likely that all of them share the current better? igbts can have thermal runaway in parallel. The hottest one draws more current, whereas mosfets get hot and then draw less current. And 20 of them in parallel. Why would Logisystems have 200 Ohm resistors? If all they had to do was stick in some 30 Ohm ones, and it would suddenly be a better controller, wouldn't they do that? Was their gate drive such that they couldn't do that?

You are a brave man, and I wish you the best of luck! hehe

[Weisheimer]

Why not get multiple values. They are less than a dime apiece and even
a hundred of each is less than 6 bucks per value. Perhaps an order for 200 ohm,
75 ohm, and 36 ohm would be a starting spot and begin by using the 200 ohm.
That has already been done by Quasar.

And yes, tack them onto the bottom of the board where the existing leads come out.

[Grimm]

Any more word on the surface mount controller? I've been holding off on building the old revision for about a month now. I'd be the first in line to buy one (or even test one if I ran out and bought my FB-4001A motor)

I don't know about the rest of you guys, but I think Paul needs a blog and a decent digital camera. Nobody updates the wiki until there's a fairly finished new version... I need the inside scoop on the beta testing!

[sawickm]

Originally Posted by Grimm

Any more word on the surface mount controller? I've been holding off on building the old revision for about a month now. I'd be the first in line to buy one

Grimm,

Adam was working on a SMT/PTH version of the Cougar a few months ago (see attached picture). I don't know what the status is of that PCB?

I'm not sure if Paul's SR controller is going to be SMT?



-Mark

[adamj12b]

Yes, I am still working on an SMD version, but it kinda got put on the back burner due to funding and some other projects that i needed to get done.

There were some design flaws in the 1st version that needed fixing, some parts needed to be better SMD equivalents and some parts I should have just left through hole. lol

I am working on those changes and the updated layout. These boards are ment to be used with my external driver boards as well. So they dont have the resistor hook ups on them, only 2 outputs, 1 for each driver board.

If somebody wanted to order me a board after I finish the design, it would greatly speed up the prototype. I have almost all the parts to stuff the board with (caps, resistors). I think it was like $24 for 1.

-Adam

[Grimm]

Originally Posted by adamj12b

Yes, I am still working on an SMD version, but it kinda got put on the back burner due to funding and some other projects that i needed to get done.

There were some design flaws in the 1st version that needed fixing, some parts needed to be better SMD equivalents and some parts I should have just left through hole. lol

I am working on those changes and the updated layout. These boards are ment to be used with my external driver boards as well. So they dont have the resistor hook ups on them, only 2 outputs, 1 for each driver board.

If somebody wanted to order me a board after I finish the design, it would greatly speed up the prototype. I have almost all the parts to stuff the board with (caps, resistors). I think it was like $24 for 1.

-Adam

So what are the advantages of the SR and SMD versions over the original, and can I combine the two? Also, if I fund the prototype board, does that mean I get to be the first beta tester (assuming the price isn't too high and I get my motor) I would love to have a semi-functional EV by the end of the summer.