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.
Obtained from a 1996 documentation, this circuit uses common components and has a voltage gain of 200...
This precision circuit can provide timings from 0.2 milliseconds to 3 minutes accurately. The...
Found in RCA documentation from the 90s, this bass and treble control uses an operational...