We found this touch control on a Popular Electronics from 1970. The circuit makes use of an integrated of the time. It can be adapted to use modern equivalent components.
We found this circuit in a 1967 Japanese technical magazine. The transistors are made of germanium at...
The circuit presented was obtained in a technical documentation from National Semiconductor. The...
This high current switching stage was found in a 1967 EEE. The power transistor is from that time....