Direction of flyback diode??

[Arthur]

Hi

Two of my fets have already died. I'm not sure if I have the direction of my flyback diode correctly. I used the picture from Rob's guide. Wikipedia flyback info tells me the other way around. It's now mounted so the current can go from + to pin 23 and blocked from 23 to +?

[rob@vems.co.uk]

Flyback protects the ECU against reverse voltage - FETs will be killed by excess current.

[Arthur]

Oké

So I need to switch it around than. It should block from + to pin 23?

[rob@vems.co.uk]

No, what I'm saying is that if your flyback was wrong, you'd have a dead ecu rather than a dead FET

[Arthur]

Oké sorry

But i'm still confused. What direction does the current of the closing injectorcoil flow? To groud(fet) or to +. So how should the diode be?

[rob@vems.co.uk]

Check page6 of this: http://ftp.ni.com/support/measure/manuals/323605a.pdf
It explains better than I ever could.
Hope this helps.

[Arthur]

Oké

I'll try and work my way trough that. I found an other shematic drawing on wiki that was helpful. My ts-diode is correct afterall. I think I found the problem. The ground of fet was dodgy. So you're right aboud one thing. After checking ground you should check ground and than ground, in that order!