This circuit was found in the July 1994 issue of Electronics Now magazine. The relay can be rated at up to 12 V and 100 mA. The transistor is a general purpose transistor.
We found this circuit in an ancient American documentation. It can be adapted to operate in other...
This circuit was found in a 1965 Electronics Design. The configuration can be applied to current...
Found in an old publication, this circuit uses an analog milliammeter to indicate the position of a...