Question about COPs in Alfa Romeo TS engine.

[ZoLtaR]

Hi everybody. First of all I want to say hi to everyone, this is my first post in this forum. I'm not very experienced in VEMS installs, so please forgive me maybe stupid questions 

I ordered assembled 3.6 controller with 4+4 ignition outputs. I don't know exactly coil construction of TS engine and don't know how to drive it, +12 or 5V logic level ?

I made a simply drawing below and I'm wondering if it is correct? Should I drive this coils with +12v outputs or maybe some stepper outputs? Do I need to make some modifications on the loom with some diodes or something or just connect EC36 pins directly with - of the coils?



Thanks for help.
Regards
Lukasz

[jrussell]

If it's only 2 pins on the coil connector I will assume it's a passive coil. If that is truly the case, the way your diagram is laid out will work just fine.

[ZoLtaR]

Thanks for reply.

1) How to recognize if coil is active or passive?
2) Every 2 pin COPs are passive and need to be drive via +12v IGBTs outputs?
3) What about driving coils via stepper output? Is it better than standard high current ignition outputs? Could it be used with passive coils?

[rob@vems.co.uk]

1) It can be difficult - if there is an external igniter unit in the original car then the coil will be passive, you'd need to have the schematics for the system that the coil was originally designed for, or sit and be patient while measuring all of the resistances across the pins.
2) Yes, although you can have more pins on a coil and still have a passive
3) You would use the stepper to drive active coils if they don't fire with 5V logic outputs, connecting a 0.33Ohm coil to a stepper output will draw ~36.4A (12 / 0.33) the stepper can drive only 1A so you would get to replace a blown stepper driver chip.

[ZoLtaR]

Great. Thank you Rob for the comprehensive and fast answer.