Paul & Sabrina's cheap DIY 144v motor controller

[jackbauer]

Video here :

http://www.youtube.com/watch?v=nkZNFCsi-A4

Only took 15 hours to upload! Gotta love Irish broadband

[dave koller]

Yep, quite the flux-capacitor there!

[SEBART PL]

Originally Posted by SEBART PL

...
After my second set of mosfet failed, I have decided to put more of them in TO220 case
- I want to change IRFP4668PbF for irfb4115gpbf (150V 11mohm 70A ) 22 pieces

1. I want to ask is mic4451YN can manage those 22 mosfets? And do I need to change resistors gate parametrs ?

Data S:
mic4451YN http://www.micrel.com/_PDF/mic4451.pdf

OK I will try to reply by myself.
1HZ = 1s

1/16KHZ=0,0000625 sek=62500ns

or
625000x16000 we should get about 1s
so driver will be call for every 62500ns
I have cheked speed for my gate Capacitance ––– 5270 ––– pF x22=115940 pF it is around 50ns for mic4451 so it is enough couse driver "rest" for 62500ns-50ns-recovery time50ns
IS THIS POSITIVE THINKING ?
or
maybe driver fill up all the gates for 50ns and then transistors start - mosfet got 18ns for start so maybe this could turn ON them not at once???

Sorry for this basic questions but I wish to be an electronic.

Originally Posted by adamj12b

More isn't always better. having multip MOSFET drivers increases the chance of them being out of sync from each other turning switches on off microseconds before or after each other. Paul used one MOSFET driver because that was all that was needed to drive all of the MOSFETs. The total gate charge of all ten MOSFETs is still less than limit on one driver.

Adam

Adam, I have seen your Coguar ver.2 with two drivers why is that, what benefits system with this two drivers?

[MPaulHolmes]

What is around 50nS for the MIC4451?

[SEBART PL]

Originally Posted by MPaulHolmes

What is around 50nS for the MIC4451?

At the end of the data sheet I have found Diagrams Speed to Cappacity - please check attachment.

[MPaulHolmes]

Wouldn't it be around 200nS rise and fall times since it's over 100k picoFarad for the total gate capacitance?

[SEBART PL]

Originally Posted by MPaulHolmes

Wouldn't it be around 200nS rise and fall times since it's over 100k picoFarad for the total gate capacitance?

good point but
they guaranty at first page 62000 pF at 22ns so looks like drawing show this but axis X need to be amended couse in my opinion someone have eaten one zero

for instance ixys driver IXDD604PI has got similar diagram ... below... anyway 50 or 200ns is this badly change my situation if I put 22 mosfets?

[MPaulHolmes]

200nS is still really fast. I think it will be fine. You don't want it too fast, because then you'll get higher spikes on turnoff of the mosfets.

cyrusamory, the diode in the mosfet is generally not very good. It's there just as a side affect of the manufacturing process I think. I think it can be done, but it would have to be a separate mosfet being used as the freewheel diode.

[duncan]

Hi Paul
Re-assembled my controller,
Re-wired my car for the OpenRevolt
Switched it on
12v power - green and yellow LED's shining
Pre-charge - OK
Main contactor - OK

- No power to motor -
messed with throttle
0 Ohms to 4.85Kohms

NOTHING

Things I have done

I soldered an extra wire along all of the gate resistors - the schematic shows them all connected together - and I was not happy about all of the soldered joints to the board

The Thermistor connections on the board were damaged so I soldered the thermistor wires to R3 and R6

I was unhappy about the new MOSFET driver (the way it went into the board) so I checked continuity - all of the pins seemed to be connected

What do I do next??

At least it didn't go bang

[mora]

Connect your controller to a computer using RTD explorer and see what it says. Maybe there is a high pedal lockout or something similar going on?