This plug-in control was found in General Electric documentation from the 1970s. The SCR can be the TIC106 mounted on a heatsink. The circuit can be changed to the 220 V network.
This small general purpose and RF transistor tester appeared in a February 1958 Radio Electronics...
The MC4741 integrated circuit consists of four operational amplifiers similar to the 741 in a...
We found this touch control on a Popular Electronics from 1970. The circuit makes use of an...