Found in a 1968 Electronics World, this circuit uses components from the era. In this circuit, a small incandescent lamp is activated when it gets dark.
This receiver for infrared remote control was found in the Philips Databook of 1990, The circuit...
Found in an English publication from the 1980s, this circuit uses components that are still common...
This circuit was found in Maxim's documentation from the 90's. The frequency of the circuit is...