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 can convert an AC voltage signal into a current up to 1 A for powering a load. The...
This circuit was found in a Popular Electronics from the 90's. The operating curve is given next...
April 2017 - The new Maxim Integrated MAX20733 and 20745 switched regulators are available from...