When the voltage supplying the circuit falls below the zener value, the LED lights up, and if a low current buzzer is used, it is activated. The circuit is from a 1999 American publication.
This circuit produces a single pulse whose duration depends on the capacitor. The circuit is from an...
This circuit shows how a simple one-transistor stage can be used to Power high current loads from...
Using the well-known CK722 and also the CK721, this signal follower or tracer was found in Radio...