This is the receiver for the previous circuit found in the November 1991 Radio Electronics magazine. The frequency is 2.2 MHz determined by the coils.
September 2016 - It can be obtained from Mouser Electronics modules with 2.4 inch from 4D Systems...
We find this circuit in a 1980s documentation. The integrated circuit used is unusual today. The...
This circuit detects a light window using two operating systems. The circuit is from a July 1992...