This is a precision half-wave rectifier, suggested by Texas Instruments. Diodes are commonly used, and resistors can have signal values. The power supply must be symmetrical.
This defrost alarm starts from an interesting idea. A small magnet on an ice stone is trapped at the...
Found in the Radio Experimenter Handbook in a 1986 edition, this circuit warns when the car's high...
This interesting emitter-coupled circuit was found in the May 1970 issue of Radio Electronics...