This is the 1968 MR480 commercial cassette recorder circuit. The circuit was fully transistorized and powered by 4 large batteries. We found the diagram in a Japanese documentation of the time.
This 12V battery charging circuit automatically shuts off at the end of the charge. The disconnect...
We do not know exactly what sound a flying saucer makes, or if it makes a sound! But this is not...
This simple 1 transistor circuit was found in an American documentation from the 60's. The...