Measuring a Balanced Circuit with an Unbalanced Measurement Instrument
Publication Number: 5091-4480E
Publication Date: 2019.11.01
Language: English
Application Notes

Measuring a Balanced Circuit with an Unbalanced Measurement Instrument

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How a balanced circuit differs from an unbalanced circuit

 

A balanced circuit has its electrical midpoint grounded. An unbalanced circuit, however, has one side grounded. A balanced circuit is typically used in communications equipment because a balanced circuit has the advantage of better spurious noise suppression.

Figure 1 shows a balanced cable which is an example of a balanced circuit. The voltages of the cable’s two conductors are at every point equal in amplitude and opposite in phase. Figure 2 shows an unbalanced cable which is an example of an unbalanced circuit. Most measurement circuits in the Keysight Technologies, Inc. impedance analyzers and LCR meters are unbalanced.