The figure shows how to use the LM3914 bargraph with expanded scale. The circuit has two adjustments determining the extremes of the LED excitation scale.
One touch on S1 and the circuit turns on. With a tap on S2 it turns off. This is the purpose of...
Found in a magazine 73 for radio amateurs from the 90's, this transmitter sends location signals in...
This simple 3-transistor radio with earphone was found in a 1967 documentation. The circuit uses...