We found this circuit in an English publication from 1969. It shows how we can implement a bridge null detector using common general purpose transistors.
This circuit found in French documentation, works with 15 V logic, but can be modified to TTL or 5...
This configuration with the 741 Operational Amplifier has an NAB equalization for magnetic...
This circuit was obtained from an American documentation from the 90's. The components can be...