Using a 4046 PLL this circuit recognizes a 1.6 to 1.8 kHz tone by driving an output LED. The circuit is from a Radio Electronics from December 1989.
This circuit is a handset receiver that picks up the signal emitted by a coil under the rug or...
Books and e-Books by Institute NCB 100 CIRCUITS - SHIELDS FOR ARDUINO FUN PROJECTS FOR THE...
This circuit for the logic control of the 555 in a power supply was found in the October 1989...