This circuit was found I a 1965 Radio Schack documentation. The transistors are from that time, admitting equivalents. The transformer has 500 ohm primary and secondary depending on the speaker.
This fast converter using operational was found in a 70s American documentation. The circuit can be...
This circuit uses two sensors that are placed at the intersection of a miniature railroad, causing the LED...
This RF wattmeter was found in an American 1980s documentation. The components are common and the...