This analog ammeter circuit was found in documentation from the 1980s. The components admit equivalents and the scales are determined by the values of the components in the range selection.
This application is from a circuit manual from the 90s and only works with incandescent lamps. The triac...
This circuit was found in an American magazine in 1978. It activates a relay when the speed of a...
This circuit is from 1976 documentation, but it can be assembled with more modern transistors like...