This circuit was found in a 1967 Japanese documentation. It consists of a touch control system with two transistors from the time. The circuit uses a power source and sensitive relays.
This circuit is based on the DCP010515 integrated circuit found in the August 1998 issue of...
Found in a 90s Popular Electronics, this circuit aims to find the voltage of a zener diode up to...
The transistor used in this circuit is uncommon today, but equivalents can be used. The zener...