Thank you @allObjects and @Robin for time you put into this :)
So indeed, all this time I thought that unlocking action is triggered by grounding MK. Analyzes of @allObjects shows that it should be KE. So I double-checked and you're right :) I was grounding KE and put wrong info in one of the first posts in this thread. To my defense this generator is installed in a place that is hard to get to, so I was relying on small mirror to read the labels.
In any case, it's definitely KE that is getting grounded.
I also did a bunch of measurements:
Is the voltmeter an analog needle type or a digital LCD type? Black ground and Red positive probes?
It's a digital LCD type, with black and red probes.
- The voltage drop on on R18 by measuring between MK and MASA. The voltage drop is 9.6V.
- The VAC between X1-1 and X1-2 (the black cables from the coil) and it's 13VAC.
- The drop between MU and MASA is 14V.
- The drop between KE and MASA is only 0.6V (this is what I need to pull-down to ground).
Does this information change anything in values of resistor or transistor type I should use ?
Today I got pulled into work and did not manage to do the shopping. Hopefully tomorrow I will go buy the missing parts :)
Thank you both for all your awesome help:)