A digital impedance bridge with auto-balancing source ratio

A digital impedance bridge with auto-balancing source ratio is described in this summary paper. Unlike impedances can be compared in audio frequency range with arbitrary magnitude and phase ratio produced by two digital generators. An automatic source balance method is introduced to the bridge with no need for fine adjustment of the complex source ratio and faster balancing of the bridge. The synchronous sampling method is adopted to measure the complex ratio at different frequency in normal conditions. Preliminary tests on L-R comparison were carried out.