This 4-tube counter was found in Radio Electronics magazine from December 1959. The circuit uses a coil as a sensor to detect the passage of metallic parts or magnets.
This circuit encodes the two channel signals from an amplifier for a multiplex-stereo...
The purpose of this circuit, which we found in the November 1986 Radio Electronics issue, is to...
This circuit is from an old American documentation. In it we have a simple way to fire an SCR from...