Infrared modulated transmitter (CB7247E)

This simple Philips circuit from the 1960s can use any general-purpose transistor. The signal is modulated at 2.7 kHz.

Bicolor Sequential with LEDs (CB18783E)
This circuit drives two-color LEDs at a speed that is set in the 100k pot. The circuit can be...
Light operated switch (CB8278E)
The circuit shown was found in a 1967 RCA manual. Modern equivalent components can be used. The...
Light Control (CB24669E)
Indicated for automotive applications, this circuit was found in the November 1980 issue of Radio...