Found in a 1980s publication, this circuit can be modified to use modern components and operate at lower voltages. The power supply does not have to be symmetrical.
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...