Block Diagram of Wheatstones Bridge with Digital Readout:
The tremendous increase in the use of digital circuitry has had a marked effect on electronic test instruments.
The early use of digital circuits in bridges was to provide a Digital Readout.
The actual measuring circuitry of the bridge remained the same, but operator error in observing the reading was eliminated.
The Block Diagram of Wheatstones Bridge with Digital Readout is shown in Fig. 11.16.
Note that a logic circuit is used to provide a signal to R3, sense the null, and provide a Digital Readout Bridge representing the value of Rx.