I am very new to electronics field. Especially to the digital electronics.
I am trying to make an AND gate circuit using transistors, switches and LED. I have tried the below circuit:
simulate this circuit – Schematic created using CircuitLab
But there is a problem when simulating this circuit.
SW1 | SW2 | LED OFF | OFF | OFF OFF | ON | 80% ON | OFF | 20% ON | ON | 100%
As you can see that above mentioned truth table is not AND Gate but it looks more like OR Gate. So, what is my mistake??
Q1), rather than driving it with an emitter follower. Also add a fairly strong pull down on their bases to ensure offness. In your current configuration, as soon as
SW2is on, some of
Q2's base current will flow through the LED and illuminate it. \$\endgroup\$