We found this circuit in a 1986 documentation. It uses only LEDs, batteries, resistors and the power supply which can consist of 4 batteries or a 9V battery. The basic circuit uses two-color LEDs.
This 1/2 hertz high selectivity filter was found in the December 1990 issue of Radio Electronics...
This circuit was found in the October 1994 issue of Electronics Now magazine. The 40446 IC is a...
This is one of many Morse code audio oscillators that can be found in this section. The circuit...