This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time and the frequency is determined by the crystal. The circuit operates at voltages from 3 to 9 V.
This circuit is from a 1954 transistors publication. The transistors are the CK722 among the first...
This sophisticated circuit of the coin-toss game was found in an American 1980s documentation. The circuit...
This windshield wiper interval was found in an old documentation. The SCR can be the C106 and the...