Dual-source bridge circuits as signal converters for sensors of interrelated quantities - review of state of the art and directions of new research

The article discusses the fundamental dependencies and provides an example of a new type of signal converter for physical quantities that are related in the tested object. The review consolidates a relatively niche but critical area: dual-source bridge circuits, which are often scattered across instrumentation and sensor literature. Three key objectives are as follows: to systematically review dual-source bridge circuits used as signal converters, particularly in the context of sensors that measure interrelated physical quantities (e.g., strain and temperature); to analyze existing circuit topologies and conversion principles used in such systems; and to assess the applicability, limitations, and performance of various bridge configurations across different sensor applications. Performance metrics like sensitivity, linearity, and temperature compensation are often superior in dual-source setups when compared to single-source designs. Signal processing and calibration complexity can be reduced at the hardware level using these bridge configurations. Several circuit implementations offer trade-offs between complexity, power consumption, and accuracy. The literature review and bibliographic data on dual-source circuits, experimental studies, and prototype designs of dual-current DC bridges as prototype transducers of signals of associated quantities and their application are included. Further functions of these circuits in future systems are outlined.