This simple power supply, which is equivalent to 2 AAA or AA batteries, was found in an Elektor from the 90's. The transformer has a 4.5 V secondary with a current of 50 mA or more.
This circuit with germanium transistors was found in documentation from the 50's. The transistors are...
The circuit presented was found in a documentation from the 1950s, generating a sinusoidal signal...
This circuit was originally indicated as a signal reinforcement step for the previous receiver...