This automatic brightness control that uses an LDR as a sensor, was found in American documentation from the 1980s. Resistors in series with LEDs depend on the desired current.
This circuit was found in a Popular Electronics from April 1993. It is a voltage regulator circuit for...
Suggested by American documentation from the 90s, this circuit has separate controls for the...
This circuit was obtained from an Electronics World magazine from 1992. The circuit provides an...