Paul & Sabrina's cheap DIY 144v motor controller

[Weisheimer]

Originally Posted by snakub

Does anyone have a board lying around maybe you could do some testing like I did and tell me what measurements you got?

My spare board was not a populated as I thought....
But I'll share some thoughts.

Originally Posted by snakub

I still think the issue is in the control board here are some oddities that I found while measuring components while they were on the board.

I would take the control board to the bench and test it.
Do you have an o'scope available? It would be quite helpful.
If you can't test it there, mail it to Columbus and I'll promptly test
it and send it back to you.

Originally Posted by snakub

D8 and D9 are not backwards but I couldn't test them properly either when I measured them with the multimeter positive to positive negative to negative I got 7.3k both ways.

Your multimeter should have a diode test. It will read about .7v one direction and 0L when the leads are reversed.
The multimeter has to provide at least enough voltage to overcome the diode threshold. If you have already tested it with that scale, then the diodes are faulty.
They are not located in a place where I would expect them to fail from an external fault, so I expect them to be OK.

Originally Posted by snakub

R18 measured 2.2k but I looked at it and the color code was definitely Orange black red 100 percent sure.

It is probably fine, the other components are causing that reading.

Originally Posted by snakub

Maybe I have to take these parts off to get a proper measurement?

Yes, in theory, but other than your diode measurements, they seem
OK to me.

[Thalass]

Awesome stuff, Jack.

[wakinyantanka]

Originally Posted by jackbauer

wakinyantanka can you post the part number?

Yes it's a Hitachi MBN1200GS12AW 1200v 1200A module. I am actually looking at two of them.
Thanks.

[jackbauer]

The problem with such large slightly dated modules is not their ability to handle power but their ability to switch fast. Comparing the hitachi module to the fuji 1mbi800U4B-120 that i'm using in the car right now:
Fuji:
ton typ = 0.32us
toff typ = 0.41us

Hitachi :
ton typ = 0.8us
toff typ = 1.4us

So from the above switching losses would be quite high.The hitachi also has a higher gate capacitance at 112nf vs 90nf for the fuji. this would require more gate drive.

I'm not saying it won't work just that its not all about the Vce and Ic when it comes to igbts.

[wakinyantanka]

Originally Posted by jackbauer

The problem with such large slightly dated modules is not their ability to handle power but their ability to switch fast. Comparing the hitachi module to the fuji 1mbi800U4B-120 that i'm using in the car right now:
Fuji:
ton typ = 0.32us
toff typ = 0.41us

Hitachi :
ton typ = 0.8us
toff typ = 1.4us

So from the above switching losses would be quite high.The hitachi also has a higher gate capacitance at 112nf vs 90nf for the fuji. this would require more gate drive.

I'm not saying it won't work just that its not all about the Vce and Ic when it comes to igbts.

Thanks Jack that's what I needed to know. What about these types of igbts: EUPEC 1U/1200A/1200V IGBT Module, FZ1200R12KL4C ?

[Tired2]

Paul, or anyone else who might know...

I built my over current section for my "spin off" of the ReVolt I'm building... I have tested the circuit on a breadboard, and it works with my 3.3v conversion and logic. I'm at the point where I need to feed in a PWM signal and simulate an over current condition, then start toggling the reset pin to turn the drives back on.

My questions:

1) I need to toggle the pin from low to high for a small amount of time to reset the overcurrent condition... what is the ReVolt's phase relationship between PWM and the overcurrent clear signal? Also, when in the PWM's cycle do you toggle that pin, and how long does it stay high? (I imagine the time is not critical, just that the NAND has time to react)...
It is possible the reset is not PWM aligned in any meaningful way... It seems like it would work at any phase, but you might cut a duty cycle in half when it re-enables the gate drive.

2) On a related note, what have you found to be the amount of "dead time" that you leave the PWM output off for? I seem to remember reading it a few times, but I'm not sure what the final value was set to. The dead time should be long enough to let the current fall back below the threshold, but short enough to not make the motor action jerky.

Thanks.

[jackbauer]

wakinyantanka , again just looking at ton and toff in the datasheet at 0.54us and 1.05us respectively you can see its a much better choice. Its a *little* long in the turn off but i'd live with it..........

[MPaulHolmes]

I made a driver board based on the BG2A board from Powerex. I haven't sent it in yet. It can drive dual 1200v 1200amp igbts no problem. Powerex says it works for anything they sell. It's just a bit over $100 in parts (including the price of the board). There are 2 drivers/power supplies. Here's a picture of it:



It drives to +15v and down to around -8v for shutoff.

This would work well for mosfets too. It might be a better choice for the SR controller, due to the absurdly awesome drivers.

[mrbigh]

OMG!!!
we are getting closer to the SR controller board completion.............

[mrbigh]

Originally Posted by MPaulHolmes

It drives to +15v and down to around -8v for shutoff.

This would work well for mosfets too. It might be a better choice for the SR controller, due to the absurdly awesome drivers.

Paul, do you care to share the part numbers of U1, U2 and the 2 large integrators in the right hand side of the board so I can read the Tech spec's about them?