This old circuit from a documentation from the 70s disconnects a TV from a signal obtained on the TV itself, detecting when the tuned channel goes out of the air.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit can produce signals up to 100 kHz depending on C1 and R1 adjustment. The output has a...
This circuits shows how to use in operational amplifier as a basic voltmeter. Power supply must be...