This circuit monitors an old-style analog telephone line. We found it in the September 1991 issue of Radio Electronics magazine.
This circuit, which can generate voltages up to 25 V, was found in the December 1992 issue of...
In the figure we have the way to make the three-phase control of a motor using opto-diacs. The circuit is...
The circuit shown here uses a 4047 to produce three signals whose frequencies are determined by C...