What You Need

I originally designed this project using a relay switch that we would have constructed part by part. This relay would have been used to turn on and off the power to the electric door latch. But after reviewing the potential safety hazards associated with improper wiring and handling of the circuit, I decided to take a safer, more conservative approach.

Instead of wrestling with the potentially jolting perils of accidental relay shocks, we will use a product specifically designed to address these concerns. Called the PowerSwitch Tail II, this simple switch houses a relay that can control standard 120V electrical devices. The relay can be energized via a 5V signal from a digital pin of a microcontroller board such as an Arduino ...

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