This light activated remote switch circuit could be operated using a flashlight beam and could eb used for toggling a specified load from a distance using an external light source such as a flashlight ...

Here is an ultra simple automatic light switch circuit for bedrooms. After construction, connect the input terminals of this circuit in parallel to the internal buzzer terminals of a Quartz-Alarm ...

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 ...