This circuit was found in documentation from the 90s. The operational amplifier admits an equivalent. The circuit has frequency ranges up to 5kHz determined by R1.
This '80s circuit drives an infrared LED, producing a modulated signal. Modern higher power LEDs...
We found this circuit in the February 1987 issue of Radio Electronics magazine. It is based on an...
This simple 1 transistor circuit was found in an American documentation from the 60's. The...