I have some questions about a circuit I'm using for an upcoming art piece.
I've been using the following circuit schematic that discharges current from a wound coil every time a magnet pendulum swings above the coil to keep it in 'perpetual' oscillation. It works just fine as it is and it pulls about 100 mA for the short duration of the discharge pulse.
I wanted to make around 50 of these circuits on the same power supply that are each 'enabled' using simple voltage controlled switches via an Arduino (5 V logic signals.) I've designed a simple low-side (edit: high-side) switch using an NPN and PNP transistor in order to be able to control the 9V (VCC) source from the 5V logic signal.
While testing this with two circuits (see diagram) and two Arduino logic signals (one for EN1 and one for EN2,) it works as intended as long as one circuit is disabled and another one is enabled.
When both are enabled, magnet swings over either coil will trigger coil discharges (LEDs light up) across both circuits. I think intuitively it makes sense because when both switches are open, current is pulled from the 9V source to both of the circuits since they're in parallel and it doesn't know how to discriminate .
I'm trying to figure out a way to isolate the circuits from one another in order to use the same source. My plan B is to use separate voltage sources (batteries) for each circuit but I'd much rather be able to use just a few large power supplies that can be shared throughout the 50 circuits.
Does anybody see any glaring errors or misunderstandings? Does anybody have any advice on what I might be able to do to?