Suggested by National Semiconductor in documentation from the 90s, this circuit uses a switched regulator of the time. The circuit is suitable for NiCad battery charges.
This circuit triggers a remote doorbell when the phone rings. The circuit is for the 110 V mains...
This circuit uses na Unijunction Transistor (UJT) to produce a modulation tone for several...
This circuit was found in a Popular Electronics from April 1993. It is a voltage regulator circuit...