Found in old American documentation, this receiver receives modulated infrared signals and converts them into sound. The audio amplifier circuit can be replaced by a modern equivalent.
This circuit activates a buzzer when the voltage applied to the input falls below a preset value in...
This simple window comparator based on the well-known LM339 was found in the June 1998 issue of...
This circuit, which can act as a shield, was found in a 1990 PE Hobbyst Handbook. The circuit...