Found in a Popular Electronics from the 90s, this circuit activates a recorder for automatic recording of telephone calls. The circuit was used with old cassette recorders of the time.
June 2017 - New Honeywell MT MICROSWITCH Series can be ordered from Mouser Electronics for...
This two-transistor circuit was found in the January 1994 issue of Electronics Now. The circuit can...
This circuit is from American documentation from the 70s. Transistors are not common today, but...