This circuit has an interface for a multimeter or electronic voltmeter. We found it in a 90s Electronic Engineering. The sensor is an unusual component today.
This circuit was designed to power the previous circuits of the wireless sound system, but it can...
This circuit is from the documentation of Radio Shack 1975. It can be mounted with 12 V relays,...
This circuit is suggested by the Optoelectronics Sourcebook by Texas Instruments when AC signals...