This circuit was found in RCA documentation from the 90s. It consists of a power control for a load based on a thermocouple. The integrated circuits are uncommon today.
In the figure we have a circuit of a dimmer for fluorescent lamps. The circuit is from...
This receiver was found in a documentation by Gernsback from 1960. The circuit uses high impedance...
This generator is more complete than the previous one, being able to generate pulses as indicated...