Using an LDR, this Philips circuit directly activates a relay when light strikes the sensor. The relay is 45 V with 20k coil resistance. The 220 nF capacitor must be polyester for 400 V.
This electronic level or plumb indicator has two mercury switches as sensors. The indication is...
ON Semiconductor AMIS−3910XGEVB Evaluation Board demonstrates the features and capabilities of the...
This circuit is a version of the previous one, but with full wave control. The diodes must be...