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 is a traditional double timer configuration with the 555 found in a 1987 documentation. The...
The amplifier presented is ideal for use in small monophonic sound systems, radios or televisions powered...
This variable voltage regulator circuit has a power stage capable of supplying currents up to 1 A....