Found in a Popular Electronics from the 80's, this circuit makes use of a time integrated to control a relay in a timed way. R2 determines the activation time.
This ohmmeter can be made with a scrap milliammeter used for continuity tests or even resistance...
This circuit was found in the November 1992 issue of Radio Electronics magazine. The circuit has...
Found in an English Maplin documentation from 1983, this circuit generates separate frequency...