This circuit was obtained in a Hobbyst Handbook from 1990. The circuit can be easily assembled since the SCR can be a TIC106 and the transistor a 2N30555.
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...