摘要:
A circuit arrangement is described for automatically monitoring several analog electric signals and for maintaining predetermined ranges of tolerances by successive comparison with reference values. Error alarm signals are produced and stored, dependent upon the comparison and timed (synchronized) simultaneously with the connection of the respective signals to be monitored to a comparator (20). Access is provided to a reference value storage (30) from which reference signals assigned to each single signal and ranges of tolerances defining reference values are timed and led to the comparator (20). The respective outlet (output) signal of the comparator (20) for producing similar error alarm signals to be stored is logically linked with an evaluating signals (ZB 0) indicating which of the two reference values lies at any time on the comparator (20).
摘要:
A voltage source with preset values of the source voltage and the internal resistance is simulated by a computing circuit (25, 26; 35, 36; 47) which calculates a reference parameter (S.sub.UO ; S.sub.IO) for a current or voltage regulator (20; 30; 40) that forms the output of the voltage source. The reference parameter (S.sub.UO ; S.sub.IO) corresponds to the output current (I.sub.O) or the output voltage (U.sub.O) and is obtained from a measured parameter (M.sub.UO ; M.sub.IO) and the input parameters (S.sub.U ; S.sub.R) which correspond to the values to be set. The measured parameter (M.sub.UO ; M.sub.IO) is derived from the output voltage (U.sub.O) or the output current (I.sub.O). When using this simulation circuit, separate high load resistors and mechanical switching contacts are unnecessary and the input parameters (S.sub.U ; S.sub.R) can be set with analog switches.
摘要:
A protective circuit-breaker comprising includes an operating mechanism for closing and opening main contacts. An evaluation unit is provided for processing a measured value of the phase current, comparing the processed measured value to an adjustable fault criterion, and tripping the operating mechanism via a trip solenoid by outputting a trip signal when the fault criterion is exceeded. A measuring terminal is connected to the evaluation unit at an input side thereof and configured to supply a monitored electrical quantity supplied by a temperature-dependent resistor connected to a motor-driven system supplied via the protective circuit-breaker. The evaluation unit includes a measuring device for measuring a change in the monitored electrical quantity and for outputting a trip signal when the monitored electrical quantity exceeds a predefined limit.