This circuit was found in a 1967 General Electric manual. It shows a SCR control with unijunction and zener diode. The triac depends on the controlled load.
This circuit was found in an American publication from the 1980s. The circuit generates pulses from...
This circuit is from 1977 Radio Shack documentation. The frequency depends on the capacitor. The...
Found in a 1993 Electronics Experimenter Handbook, this circuit uses a multimeter to measure...