Because I’m old school, I wanted to build a Garage Door Closing circuit without relying on integrated configurations (555 timer etc) to keep it simplistic. The circuit closes the garage door after two ...

Use the potentiometer for setting the timing period within these intervals. For the 0.3 second to 10 minutes timer version the potentiometer is 100kΩ, R1 = 9.1kΩ, R2 = 910kΩ, R3 = 220kkΩ and C1 = ...

We often marvel at the many things a 555 can do. But [Zafer Yildiz] shows us that it can even take the place of a PCB. You’ll see what we mean in the video below. The timer relay circuit is built ...

Relays usually are driven using optocouplers, which offer isolation between analog and digital grounds to ensure that switching currents in the relay coils do not affect the noise margin of the ...