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 is from a 1974 publication by Motorola. The unijunction may be 2N2646 and bipolar BC558...
The figure shows how to obtain a higher output current for an operational amplifier. With the...
This voice scrambling scrambler was published in the August 1982 issue of Radio Electronics...