Found in an Electronics World of 1966, this circuit makes use of FETs of the time. Modern equivalents can be used. The high voltage supply suggests its use with tube amplifiers.
This circuit was found in a 1980s telecommunications publication. The circuit uses a diode bridge to...
This circuit is from an English magazine from 1980, but it can be easily assembled with more...
The indicated circuit is an intermittent one in which we use two 555 integrated ones, one as a low...