This commercial earphone receiver was manufactured in the 1960s in Japan. It was powered by a 9 V battery and the transistors were made of germanium.
The four gates of a 40111 IC are used in thes two-out circuit. The output chages their state in a...
This circuit was found in a 1980 publication. It uses only 3 easily obtainable transistors. It is a...
This circuit operates at a voltage of 1.3 V from a single mercury cell. We found in an old...