We found this circuit in an English publication from 1969. The circuit uses transistors from the time and can operate at frequencies up to 300 MHz. Observe the waveforms of the obtained signal.
This is a circuit published in the patent section of the April 1961 Radio Electronics magazine. The...
In the original version of this 1987 circuit, the loads are lamps, but it can be adapted to drive a...
This simple circuit indicates, through an LED, when the water level of a filter (or other kind of...