Post a schematic!
My questions are :- Is it really useful to put a bypass capacitor on the other board just before the TIP transistor gate to ensure that the gate always receive a clean power ?
- Does bypass capacitor are standard capacitor ? I mean I can use a normal ceramic capacitor ? Because I have seen some website selling specially named "bypass capacitor".
- To produce drops with the solenoid valve I have to put it on for short amount of time (like 50-60ms), then wait desired delay between drops and so on .. Would a capacitor apply lag to this process has it have to charge himself ? While it's charging the power won't reach the transistor gate, right ?
- And the last one, how do I calculate the size of a bypass capacitor ? I am by example thinking to add one on the 12v DC of the solenoid as it is provided by a very old power supply.
More important is a diode across the solenoid, and some surge protection.