Voltage ratio monitoring network - changes state when defined ratio occurs and has summing network connected to multiplier circuit

摘要

A network is used for monitoring the ratio of two input signal voltages which change state when a certain predefined ratio occurs. The system is accurate, stable and has accurately defined hysteresis. The circuit is more accurate than a combination of Schmitt triggers which can be used for this purpose. The incoming signals (U1, U2), are fed to a summing network (3) the output of which is fed to a multiplier circuit (6) to which a sign signal derived from a comparator (4) is also fed. The output of this is fed with one input to a further analogue comparator (7) and this feeds the sign comparator (4) in a feedback loop which latches and unlatches at accurately defined levels in the manner required.