Some questions have come up about driving logic gates... By default, EveryCircuit uses 0 V and 5 V to represent logical true and false. There are a few ways to deliver voltage to logic gate inputs:
1. Logic source produces 5 V and 0 V.
2. SPDT switch connected to 5 V and 0 V.
3. SPST switch with pull-down resistor.
A common mistake is to use an SPST switch, that simply disconnects a high voltage source without providing a low voltage.
