Digital timer II

74HC00, 74HC191

Here's a digital timer using a counter IC. It can count clock pulses with a separation of one second and give an output when the 10 pulses are counted up.

The schematic shows you that U1 is the oscillator that generates the clock pulses at intervals of one second, and U2 is the counter whose output is displayed by LED 2.

When you set the slide switch up, the counter keeps counting the pulses continuously. When it is set to down, the counter lights up LED 2 on counting the 10th pulse, then stops.

When you finish the wiring, turn power ON with the slide switch up, LED 1 blinks ON and OFF at intervals of one second and LED 2 lights up in 10 seconds (when the 10th pulse is counted). The timer repeats this operation over and over again so long as you keep the slide switch up.








Recherche personnalisée