Found in old documentation, this circuit can generate pulses from 400 to 4000 Hz with active cycle control from 1% to 99%.
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...