This circuit is from an article in Radio Electronics magazine from October 1958. The circuit is for testing electrolytics that operate at high voltages depending on the source.
This low-frequency oscillator was found in a 1963 documentation. Capacitors determine frequency. The...
This circuit uses a triac to detect the level of a reservoir, and a sensitive SCR connected to the...
Found in a 1964 Electronic Design this circuit compares two signals by providing the inverse of the...