Using 555 integrated circuits, this alarm circuit was found in a 90s American documentation. The signal must be applied to a good audio amplifier.
This circuit is from an American 1964 documentation. Transistors of the time are used, but modern...
This oscillator produces a signal with a central frequency in 1 MHz. This frequency can be...
Found in an American documentation from 1968, this circuit senses the temperature through an...