This is a battery powered 3W power amplifier using germanium transistors. The circuit is from an English documentation from 1967. The transistors are from the time.
We found this circuit in an English magazine from 1976. The magazine no longer exists, but just...
I found this simple zener diodes voltage divider circuit in an old documentation. The resistor...
This circuit locks after a short touch on the sensor. The circuit can be powered by voltages from 5...