This simple continuity tester consists of an oscillator found in the 1983 Electronics Experimenter Special projects magazine. The circuit is powered by a single battery.
An interesting and versatile filter circuit, suggested by National Semiconductor is the one shown...
Found in na 1970 EDN this circuit has a parallel regulation providing a symmetrical output of 15 V....
This circuit was found in an American magazine 73 for radio amateurs of the 80s. It is an...