This circuit was found in a 90s Popular Electronics. The circuit operates in the range determined by L1. The integrated circuit used is uncommon today.
This circuit triggers a relay when the phone rings. An application is like remote doorbell. The circuit...
This simple CMOS circuit generates two-frequency signals for use as a signal injector. The circuit...
With a mains-rated transformer and 1:1 winding this benchtop circuit was found in the January 1995...