This circuit was found in the Linear Applications Handbook of the National Semiconductor of 1994. Some of the components used are not easy to obtain, but equivalents can be used.
This circuit allows frequencies between 1.8 and 30 MHz to pass. Data for the coils is provided next to...
The first configuration we show is a flip-flop that can be triggered using two push buttons of the...
With each touch on S1, an output of 4017 is activated, this in sequence 3, 2, 4, etc. These...