This circuit uses an optical coupler to indicate a phone call through a lamp. The circuit is from a Hands-On Electronics from the 90s. The lamp must be incandescent.
This circuit, which in our times would be called a shield, can also be used with other loads. The...
This converter converts signals from the 50 MHz band to the AM band, making it possible to receive...
Other operational amplifiers series, such as the MC34072, MC34074, MC35071, MC35072, MC35074 d...