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 SANYO circuit has a typical input resistance of 1ook9 and excites a load with a resistance of 5.1k...
This circuit was obtained in a 1989 English magazine. Despite using a fixed 5 V regulator, it can...
We found this speed control for miniature cars in an American publication from the 70s. With...