With this circuit it is possible to use a pair of old telephones in a wired communication system. The circuit is from a Popular Electronics from the 90s.
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....