Differential protection device for detecting leakage or fault currents in an electrical installation, which is able and intended to be powered, either by at least two conductors (2, 2', 2", N) of a network, or by at least one phase conductor (2, 2', 2") of the network and by a neutral conductor of the network, the device comprising: - a module for measuring a fault current configured to supply a fault signal proportional to the fault current in the case of a fault in the electrical installation comprising at least one toroid passed through by at least two of the conductors (2, 2', 2", N) forming a primary winding and comprising at least one secondary winding (5, 5") capable of supplying the fault signal, - a detection and control module configured to process an alternating component of the fault signal, the frequencies of which lie between a few tens of Hertz and a few tens of kiloHertz, and to control an actuator that the device comprises if the fault signal crosses a predetermined trigger threshold, the detection and control module being autonomous in terms of electrical power supply and being independent of the voltage of the network and being linked at least to said at least one secondary winding (5, 5") to be powered by the fault current, which device is characterized in that: the detection and control module comprises a processing unit for processing said fault signal, configured to supply, as output of the processing unit, a processed signal, the voltage at 50 Hertz of which is greater than the voltage at 1 kiloHertz for one and the same fault current intensity value and in that the processing unit comprises an electronic circuit comprising a first branch comprising a capacitor (Cz) of which at least the impedance at 50 Hertz is greater than the impedance at 1000 Hertz, in series with at least one component the resistance of which varies as a function of the voltage, preferentially a diode. - a module for measuring a fault current configured to supply a fault signal proportional to the fault current in the case of a fault in the electrical installation comprising at least one toroid passed through by at least two of the conductors (2, 2', 2", N) forming a primary winding and comprising at least one secondary winding (5, 5") capable of supplying the fault signal, - a detection and control module configured to process an alternating component of the fault signal, the frequencies of which lie between a few tens of Hertz and a few tens of kiloHertz, and to control an actuator that the device comprises if the fault signal crosses a predetermined trigger threshold, the detection and control module being autonomous in terms of electrical power supply and being independent of the voltage of the network and being linked at least to said at least one secondary winding (5, 5") to be powered by the fault current, which device is characterized in that: the detection and control module comprises a processing unit for processing said fault signal, configured to supply, as output of the processing unit, a processed signal, the voltage at 50 Hertz of which is greater than the voltage at 1 kiloHertz for one and the same fault current intensity value and in that the processing unit comprises an electronic circuit comprising a first branch comprising a capacitor (Cz) of which at least the impedance at 50 Hertz is greater than the impedance at 1000 Hertz, in series with at least one component the resistance of which varies as a function of the voltage, preferentially a diode. the detection and control module being autonomous in terms of electrical power supply and being independent of the voltage of the network and being linked at least to said at least one secondary winding (5, 5") to be powered by the fault current, which device is characterized in that: the detection and control module comprises a processing unit for processing said fault signal, configured to supply, as output of the processing unit, a processed signal, the voltage at 50 Hertz of which is greater than the voltage at 1 kiloHertz for one and the same fault current intensity value and in that the processing unit comprises an electronic circuit comprising a first branch comprising a capacitor (Cz) of which at least the impedance at 50 Hertz is greater than the impedance at 1000 Hertz, in series with at least one component the resistance of which varies as a function of the voltage, preferentially a diode. the detection and control module comprises a processing unit for processing said fault signal, configured to supply, as output of the processing unit, a processed signal, the voltage at 50 Hertz of which is greater than the voltage at 1 kiloHertz for one and the same fault current intensity value and in that the processing unit comprises an electronic circuit comprising a first branch comprising a capacitor (Cz) of which at least the impedance at 50 Hertz is greater than the impedance at 1000 Hertz, in series with at least one component the resistance of which varies as a function of the voltage, preferentially a diode.