Redundant and dissimilar monitoring system for monitoring the status of control contactors , said monitoring system comprising: - at least one electrical power source generating an electric current with an electrical power supply voltage VA, - at least one calculator , - a plurality of control contactors , each control contactor comprising several switches controlled simultaneously, and - at least two monitoring circuits for monitoring the status of said switches of said control contactors , one switch of each control contactor being respectively integrated in one monitoring circuit , each monitoring circuit being connected to at least one electrical power source and to at least one calculator , each monitoring circuit comprising: • an electronic unit comprising a bottom receiver and at least two control receivers arranged in series with each other, each control receiver being equipped respectively with two primary terminals , and • at least two switches equipped respectively with two secondary terminals , a first secondary terminal of a switch being electrically connected to a first primary terminal of a control receiver and each switch being arranged in parallel with at least one control receiver so as to short-circuit said at least one control receiver when said switch is in the closed status, the number of said switches being equal to the number of said control receivers , characterised in that each calculator is configured so as to measure at least one electrical characteristic of said electronic unit and to determine the status of said switches and said control contactors . - at least one electrical power source generating an electric current with an electrical power supply voltage VA, - at least one calculator , - a plurality of control contactors , each control contactor comprising several switches controlled simultaneously, and - at least two monitoring circuits for monitoring the status of said switches of said control contactors , one switch of each control contactor being respectively integrated in one monitoring circuit , each monitoring circuit being connected to at least one electrical power source and to at least one calculator , each monitoring circuit comprising: • an electronic unit comprising a bottom receiver and at least two control receivers arranged in series with each other, each control receiver being equipped respectively with two primary terminals , and • at least two switches equipped respectively with two secondary terminals , a first secondary terminal of a switch being electrically connected to a first primary terminal of a control receiver and each switch being arranged in parallel with at least one control receiver so as to short-circuit said at least one control receiver when said switch is in the closed status, the number of said switches being equal to the number of said control receivers , • an electronic unit comprising a bottom receiver and at least two control receivers arranged in series with each other, each control receiver being equipped respectively with two primary terminals , and • at least two switches equipped respectively with two secondary terminals , a first secondary terminal of a switch being electrically connected to a first primary terminal of a control receiver and each switch being arranged in parallel with at least one control receiver so as to short-circuit said at least one control receiver when said switch is in the closed status, the number of said switches being equal to the number of said control receivers , <EOS>