Found in a European magazine from the 90s, this circuit emits beeps that are several seconds apart to indicate that a device is on. The transducer is a ceramic or crystal capsule.
This circuit drives two-color LEDs at a speed that is set in the 100k pot. The circuit can be...
The circuit shown was found in a 1967 RCA manual. Modern equivalent components can be used. The...
Indicated for automotive applications, this circuit was found in the November 1980 issue of Radio...