When no current flows by the base of a transistor it is off and a also an LED in its collector. Otherwise, when a current flows by the base of a transistor it is on, and a LED placed in its collectors bright. Connecting the base of a transistor to the collector of another when can have a double control for two LEDs. When one transistor is on the other remain off and vice-versa. This is the circuit simulated here. A switch controlling the first transistor also control the second. When one LED is on, the other is off. The control can be mad by the key “space”. This is a logic circuit such as the ones fount in computers and called inverters. One LED represents the input and the other the output. When the input is “1” (LED on) the output is off (LED off) and vice versa.
Simulation:
To download the simulation files and Netlist - click here (msb0057.zip)
