changing outputs: IGBT's to logic level

[ZoLtaR]

I have few units with 4 and 6 IGBT onboards. I want to use them on 5 and 6 cyl engines with active VAG cops. Do I have to send them back to hungary to convert IGBTs to logic level, or is there some method to do it myself just changing driver on board?

[[email protected]]

If you are comfortable with a soldering iron - you'll see when you open the case that the IGBTs that have not been populated have a wire link between two of their pads - this is the logic level set-up.  You need just use that.

Rob

[ZoLtaR]

Thanks rob for very fast reply! I'm pretty comfortable with soldering iron, this shouldn't be a problem. Thanks, maybe do you have some picture of pcb how do they look and what should I look for? From the words you wrote I understand that I will have to add a wire between IGBT pads and then those outputs become logic-level outputs? Or I misunderstood something..

And second thing, as we know VAG active cops works much better via stepper outputs, but how to use them in 5 cyl engine? It's possible to use them in such an application?

[[email protected]]

When you open the ECU you will see how the wire link will work as they are linked from the factory if the IGBT is not populated.
You could do what Hilly did to drive his VAG coils: http://www.vemssupport.com/forum/index.php/topic,217.msg2015.html#msg2015
I don't have the details for the chip but basically they're driven by the IGBT's driver and push 12V out.  I don't have the part number to hand though.

[ZoLtaR]

I removed IGBT's and made wire links as you adviced but now I'm getting no spark from outputs where I have removed IGBT's. Controller was originally 6 IGBTs + 2 logic levels. I'm getting spark from outputs there were "original" logic, but no spark from outputs which was IGBTs previously. Do I have to do something more or broke something?  :-[

[peter_jensen]

You have solder 2 resisters marked 511 parallel to the one´s there already it mounted. Look at the 2 logic level you have and make the new ons looking same way.

The resistors is a current limiter for not fray the preamp ic. When mounting one more resistor in parallel you double the current. The new resistor should be near 500 ohm. 

Hope that’s the problem.

Peter 
Vems.dk

[ZoLtaR]

I made them like the originally ones. Removed IGBTs from board, and made wire link between two points like the originally one. Maybe I miss something ? I will try to make a photo of board today and place it here. How can I check with DVM if outputs are ok and working fine?

[MWfire]

You need to have +5V when output is ON.

[ZoLtaR]

Measure between logiclevel output and GND (pin 26 ) ?

[MWfire]

ign output and gnd(like pin 22 or 23)

[ZoLtaR]

Ok I have checked outputs. I have a ~5,68V on every output that is logic level now. But when I go to menu ignition outputs visual and enable test mode, spark on plugs jumps only on the outputs there were "originally" logic levels (pin 11 and 12). The others that were IGBTs previously (pins 10, 24, 33, 35) the spark doesn't want to jump on the plug. Plug is mounted directly into VAG cops and grounded with thick wire to engine ground. What is going on? Why every output shows 5V and spark is only at the two of them? I don't get it.

[MWfire]

vag coils need lot of current for ignition. Check resistors on gate of ign outputs.

[ZoLtaR]

Could you explain more precisly (maybe with some board picturE) where should I search for those resistors? Or how to measure if something is missing?

[MWfire]

http://www.vems.hu/files/genboardv3/v3.3/v33_top.pdf
look resistor r122 r123 r92 r64...
On "stock" vems (non audi vag cop) are 500ohm or similar. But you need more current for vag cop, so there is near every resistor free pad to add one more parrallel resistor(you have it in rescue kit). So add one more 500ohm resistor per output.

[ZoLtaR]

I hope I understood correctly. The yellow ones are the existing 500ohm resistors (or no resistors at all where were IGBTs outputs previously?). The orange ones are the extra 500ohm resistors that I have to mount on board?