This circuit was obtained from a 1967 GE SCR manual. The SCRs must be rated for the wattage of the controlled heating element.
This circuit is used in transceivers, enabling input selection by diode switching through polarity...
This configuration was found in an American publication from the 90s. Operators admit equivalents just...
This circuit was found in an Italian magazine Elettronica Prática of 1977. The transistors can be...