This circuit serves as an audio output for AM or even FM radios and was found in a Radio Electronics magazine from March 1990. Note the supply voltages.
This circuit was found in Radio Electronics from the 90s. It uses a transconductance operational...
This circuit activates a relay at dawn. The relay can be used to sound an alarm, turn on a radio...
The circuit shown can be used in an audio link using visible light or IR. Any photo transistor can be...