In the figure we have a stereo decoder from the 70's with pilot lamp for signal indication. The circuit employs a component of the time, which is uncommon today.
The simple circuit doubler shown here can source a voltage two times the one applied to the input. The...
This circuit is from an old American documentation using LEDs in the rectification. The circuit...
This circuit using an operational amplifier was found in old American documentation. It can be...