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.
Found in an Elektor from the 90s, this circuit is used with analog TV signals. The components are...
This circuit was found on an application note from Linear Technology of the 1990s. The source must...
We found this high input impedance, low output impedance amplification stage in the October 1993...