Magnetti Marelli BKL3B on MS3X

[LanciaDan]

Magnetti Marelli BKL3B

I'm going to assemble my first Megasquirt III with ms3x this winter or spring but i'm still orientating what parts i can use (learning as i go along). The plan is to drive 2 ignition modules (BKL3B) with the ms3x 0-5v spark outputs to control 2 wasted spark coils, but i have found little information about this module.
After some experimenting it looks like (i might be wrong) that the module fires the coil as soon as the signal pin is grounded and charges the coil as soon as the input is "open". Signal pin itself gives a voltage of around 7v if connected to nothing.
I wonder if other ignition modules work like this? I thought they received a 5 volt signal?

I assume it will work if the 0 volt of the ms3x spark output is grounded but i don’t wont to damage the Megasquirt.

I do have some oscilloscope readings if that helps.

Thanks.

[flycat]

I have used it on Lancia Delta engine, it works with 0-5v signal of MS3X

Bye, Luca

[LanciaDan]

Great, thanks!

Some more information if someone comes across this module:

After some more testing it appears this module controls charging of the coil and keeps it from burning. It will will lower the current / voltage after a few milliseconds and “wait” until the signal wire (6) is grounded. If this does not happen within about 1.5 sec. it will shut down ,and fire the spark-plug. This is tested with just grounding the signal wire by hand and leaving it unconnected to charge the coil..

But using my cheap signal generator it fires the spark plug just fine but charging of the coil does not correspond with the signal given. I will test this with the MS3X as soon as I soldered everything together and see what happens.

Pins in the picture:
1: Negative side of coil
2: Ground
3: ? - Is connected at the ECU in my car. Probably ground for the signal wire.
4: Power
5: ? - Gives 7V, not connected in my car. Maybe to power a Hall sensor?
6: Signal wire. - Gives its own voltage. (Low current, about 4 mA shorted.)