This circuit was obtained in an American documentation of 1964. The transistors are of the time. The circuit includes a counter circuit.
This circuit was obtained from Radio Electronics from the 90s. The infrared sensor is of an...
This circuit is from the 1993 Motorola Linear Interface ICs. The circuit must use symmetrical power...
This circuit was found in the magazine of radio amateurs 73 in a 90's edition. The components are...