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 steady hand or nerve-rest or steady hand as called in the original English publication uses a...
When the sensor X1 is opened, the relay is energized. When waiting, the current drained is very...
This circuit is suggested by Motorola in its 1990 Linear Databook. The integrated circuit is no...