LED inverted

The inverted logic states are used in industry and technology in many circuits. Here we use two LEDs to demonstrate the invertion behavior of a transistor. If the push button is pressed, then the blue LED is on and the yellow LED is off. If the push button is released, the blue LED is off and the yellow LED is on. If the button is pressed a current ows into the blue LED and also into the base via the 100 k Ohm resistor. The Transistor is activated and current can ow between collector and emitter. The voltage at the collector therefore drops below the threshold voltage of the yellow LED which diminshes. If the button is in the release position, the base of the transistor is at the ground level, the transistor is off. The collector now can raise to a high level via the 1 kOhm resistor leading to the voltage source and the yellow LED is on.