We found this bridge circuit in Electronics Now magazine from September 1995. The instrument can be from 50 uA to 1 mA. The trimpot value depends on this instrument.
This circuit activates one of the selected circuits with a touch of a switch, keeping it...
This circuit was published in the July 1993 issue of Electronics Now magazine. It uses a sensor from...
This circuit was found in a 1969 Mullard publication. The transistor may be the modern equivalent...