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 old circuit uses na operational amplifier not easy to find in these days. But the circuit can be...
Found in a Popular Electronics from 1992, this circuit uses a PLL567 in an audio meter bridge that...
Using a 4046 PLL, which is not very common nowadays, this circuit was found in the October 1994...