After controlling the locos with my chosen ESCs works excellent now,
I turn myself to the question of operating functions from my transmitter like switching front & rear light on & off.
There are several electronic RC-switches available (I have only looked here in Germany).
While an ESC controls motor speed analogous to the transmitter stick movement,
such a RC-switch controls the switching status (on/off) of a lamp, a relay etc.
activated by the end-positions of a transmitter stick or a toggle switch on your transmitter.
I have bought a "Multi 2-channel switch" from Sol-Expert
As soon s Theodor found that the wires are nothing to eat, he went away to take a shower.
For the Spektrum receivers that I use,
I wouldn't need a BEC, because they have a wide voltage range between 3,5V - 9,6V,
and I use mainly 7,4V Lipo power in my models.
But in this case it is useful for the RC-switch.
Indeed this RC-switch it is not a real "switch" but two voltage sources you can separately activate from your transmitter.
Thus, using this "switch" for activating sound functions on a sound-module ( instead of a reed-switch )
you will need an additional relay that connects the corresponding output of the sound-module with "ground".
____________________ modelling in 1:22.5 on 32mm and 16.5mm track
Actual project: 7/8" scale on 45 mm track