This circuit can generate signals of different frequencies, switched by a DC voltage. The frequencies are determined by the crystals. The circuit is from a 90s American documentation.
This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...
This circuit for modeling was found in a 1980s documentation. The SCR can be the TIC106 and the...
This circuit allows you to use the parallel PC interface to control LEDs. The circuit was found in...