Using the 4001 integrated circuit, this latching relay can employ any general-purpose transistor. The power supply is according to the relay with voltage up to 12 V.
This old slide projector control circuit was found in an 80s Hands On. The circuit uses modern...
In the figure we have a circuit that uses unusual components, being indicated for low frequency...
The sensor of this circuit found in Popular Electronics can be formed by a piece of fabric between two...