This Power supply sources from 500 to 1,000 mA according the transformar and was found in a publication of the year 1958. The diodes can be now the 1N4004 and the transistor should be mounted on a heatsink.
This intercom uses transistors from the 60s. It was found in a Japanese publication at the time....
A The adjustable Q-factor rejector filter in the figure is based on two LM110. These integrated...
Found in Electronics Now this circuit can generate signals up to a few tens of Megahertz. The circuit...