This circuit was found in the June 1991 issue of Radio Electronics magazine. The circuit uses two Hall effect sensors of the time. It can be assembled using modern equivalents.
September 2016 - It can be obtained from Mouser Electronics the new ADC AD7779 from Analog Devices with...
This relay time delay circuit was found in the October 1993 issue of Electronics Now magazine. The timing...
This circuit, which appears elsewhere in this section, is from a 1969 Electronic Experimenter...