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 circuit has several features, such as timing to activate and deactivate, in addition to a...
The 4528 is a dual-retriggerable monostable that needs only the timing network formed by R and C...
This circuit from a 1978 American publication is used on vintage vehicles that still have contact...