I would like to create an inverter because I would like to have an inverse switch, that is: my circuit should only work when some signal current does NOT flow. This is even mechanic: When a certain switch is NOT set, I want no current to flow at all.
The only idea that I have right now is using an NPN transistor in parallel with my circuit, while the circuit has a higher resistance than the collector-emitter part of the transistor. I could then connect the switch to the base of the transistor. If closed, the main current flows through the emitter-collector. But the down sides clearly are that:
1) current flows, nonetheless
2) a certain current will flow, according to the resistance, through my circuit anyways
My circuit is battery-powered and I would like to not have the battery be consumed at all. I have a 3V coin cell and, without use, it should last weeks or months.
I do not need an electronic inverter, it could also be mechanically triggered (my application is that I have a box and I want to have LEDs glow when it is opened... when the box is closed, I can have contacts closed, i.e., a closed switch; but I cannot close a switch when the box is opened)
Any ideas welcome!