This circuit with a maximum current of 50 mA was found in the August 1998 issue of Electronics Now magazine. The integrated circuit used is not very common today.
This circuit with only one transistor was found in Japanese documentation from the 1960s. The...
This circuit uses a common multimeter on the voltage scale. The calibration of the scale should be...
This interface shield circuit is from the 1983 Intersil Databook. The components used are uncommon...