Power Inverter for a Car (Diagnose + Repair)

[scampo77]

Re: Power Inverter for a Car (Diagnose + Repair)

In the board there are no shorts, did you want me to yank them out?

[ben7]

Re: Power Inverter for a Car (Diagnose + Repair)

In the board there are no shorts, did you want me to yank them out?

Take them out and check them with the diode check mode on your DMM. If you are not sure of the pinout, tell me what the transistor types are.

[ben7]

Re: Power Inverter for a Car (Diagnose + Repair)

Also another test, with the driver transistors still on the board, remove the IRF640's and turn the unit on. Make sure the HV DC bus is on, and measure the voltage from the gate pad (where each IRF640 mosfet gate pin was) to ground.

[scampo77]

Re: Power Inverter for a Car (Diagnose + Repair)

Q7,Q16 the outer ones are NPN KSP42
Q12,Q24 the inner ones are NPN PN222A

I built a transistor testing station i found here, (the third or fourth one down from the top)

http://www.kpsec.freeuk.com/components/tran.htm

I pulled all 4 out and put them in this circuit and all of them acted as an insulator (no LED light) untill I applied voltage to the base, then my LED lit up.

[ben7]

Re: Power Inverter for a Car (Diagnose + Repair)

Q7,Q16 the outer ones are NPN KSP42
Q12,Q24 the inner ones are NPN PN222A

I built a transistor testing station i found here, (the third or fourth one down from the top)

http://www.kpsec.freeuk.com/components/tran.htm

I pulled all 4 out and put them in this circuit and all of them acted as an insulator (no LED light) untill I applied voltage to the base, then my LED lit up.

Those are good, so it seems like the CD4013 flip flop(s) aren't switching, and we need to figure out if it is getting the correct input pulses. (or, no pulses at all!)