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.
The purpose of this circuit is to match two operational amplifiers that operate with different...
This low current circuit is suitable for powering the previous circuit and other strobe lamp...
The LEDs act as diodes, so if good they will show the same characteristic curve. Arrangment shown...