This circuit was found in the February 1980 issue of Radio Electronics magazine. The digital circuit was shown in two parts, using 20 LEDs in a configuration with the LM3914.
We found this circuit in a 1998 documentation. It senses the passage of people or objects through an...
This circuit is from a Linear datasheet. The circuit provides a 5 m voltage with 40 mA from an AA...
We found this circuit in a 1995 paper. The reed switches are surrounded by a few coils of coarse...