This circuit is from a 90's documentation. The circuit is simple, as it uses only two transistors, and the control is done by pressure switches. The indication is done by LEDs.
This circuit uses two light-activated SCRs or LASCRs, uncommon components today. The power depends on...
This type of configuration can be seen elsewhere in this section. This is from a 1965 General...
Crystals from 100 kHz to 1 MHz can be used in this 1957 Raytheon circuit. 4 can have values...