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 was found in documentation from the 1980s. The transistor depends on the desired...
We found this circuit in a 1985 technical publication. The circuit uses PUTs to drive lamps....
This type of circuit, found in American documentation from the 1980s, triggers producing output...