Found in a 90s American documentation, this circuit that was used in cars of the time, detects low temperatures and light by activating a warning relay.
This low power circuit for the FM band was found in a spy book from the 90s. The tunnel diode is...
This circuit was found in Intersil's 1992 documentation consisting of a test for ADc0801 and...
We found this circuit in an old European documentation. Transistor TR1 can be BC548 and TR2 can be...