Circuit diagrams and schematics - Electronic projects

This simple logic probe has both LEDs on with no signal at the input but due to the nor gates connected to the probe, indicates correctly when a high or low signal is present. It also works correctly for pulse trains. Normally both LEDs are forward biased and therefore on, powered by the 12V supply. [...]

This is Logic Digital Tester Circuit. It uses the level input about 5V and use the integrated circuit LM324. Be Main Part electronics perform Drive All LED. Then use Current very low about 10mA by have potentiometer be formed fine the value threshold give just right with the level logic digital both of 3 the [...]

This circuit is a Logic Probe. It indicates the logic state of the node of any TTL logic circuit. To do that, we have to supply the probe with the same power of the circuit that we want to analyse: same Vcc and same GND. To check the logic level, we must connect the “Test” [...]