This circuit is from old American documentation, using a regulator integrated circuit that is uncommon today. The diodes can be 1N4002 and the transformer has a 500mA secondary.
This circuit is more sensitive than the previous one, triggering when a laser beam that hits the...
This circuit was obtained in a 1967 Electronics World. The components are still common today, the...
The simple touch of the fingers on a sensor causes this circuit to drive a motor that goes into...