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 generates a 1296 MHz signal from 100 or 1,000 kHz crystals. We found it in an...
Unlike the previous circuit, this circuit from Electronics Now, October 1993, has the load...
Found in a 1966 American publication, this circuit invert the phase of a low frequency signal. The...