This circuit emits a warning sound when night falls. The circuit is from a Hands On Electronics from the 90s. The Sensor is a common LDR and R6 adjusts the trigger point.
I got this circuit from Hands-On Electronics, 1988. The American magazine no longer exists, but...
This circuit is from a April 1991 Popular Electronics. The magazine no longer exists, but the...
With this circuit it is possible to accelerate the triggering of a relay. The capacitor can have...