I raised this as one of my points on this other thread but it was too many questions at once, and most of it has fallen by the wayside now anyway.
So I thought I would address this one question again. My aim is to achieve a little bit of engine braking with the throttle closed, similar to a petrol bike. The Mecatecno I tried had this.
Having studied the information on konrad's website, I'm proposing to use the microswitch in the Domino throttle to feed about 1 volt into the PRB connector. I'll use the PRB/FRB Y-piece to actually make the connection at that end, meaning of course that the FRB won't work, but that doesn't matter. To get the 1 volt, I'm hoping to pick up 5 volts from the feed to the throttle (or maybe the lighting DC/DC converter) and use a converter like this https://www.amazon.co.uk/gp/product/B07DK6WN63/ref=pe_4074371_1338459331_em_1p_1_lm. Does that make sense, konrad?
If that's all OK, my only issue now is to understand the wiring colours. According to konrad's website, the main wires from the throttle are blue, white and black but I've got a connector marked T1 going into the throttle connector that has red, black and blue. The standard (non-EM) version of the throttle has blue, white and black, and the micro-switch wires are both green. However I've got a connector marked T2 that has white, brown and yellow.
If I ever manage to sort out the conundrum above, I also intend to add an on/off switch on the handlebars to switch the engine braking on and off.
Any thoughts?