This circuit was found in a Motorola documentation from the 90s. The transistor used is uncommon today. The output power is 1 W.
This contact or reed switch actuation was found in a 1964 Electronic Design. The circuit can be...
This is the previous version, but with a simplification given by the use of the 7404 and 7408...
In the figure we present a circuit of a microphone signal conditioner using the SSM2167 integrated...