Found in a Popular Electronics from the 90s, this circuit checks the presence of voltage on a common telephone line. This check can also be done with a multimeter.
The presented circuit makes use of two hybrid modules (see articles on the website) to drive a...
With this simple tester you can measure the gain of an NPN or PNP transistor. The instrument can...
This circuit amplifies signals only in the frequency range determined by the double T. The circuit is...