Magnetic tripping device for electrical switchgear of circuit breaker or contactor type, comprising a coil, a yoke forming a core of the coil, a first spring element and a second spring element, the yoke comprising a fixed first portion, a mobile second portion and a mobile third portion, the mobile second portion being able to move with respect to the fixed first portion between a separated position (P E), in which the mobile second portion is located at a distance from the fixed first portion, and a coupled position (P C), in which the mobile second portion is in contact with the fixed first portion, the mobile third portion being able to move with respect to the fixed first portion between a rest position and an actuation position, the first spring element acting on the mobile second portion so as to keep the mobile second portion in the separated position, the second spring element acting on the mobile third portion so as to keep the mobile third portion in the rest position, the coil, the yoke, the first spring element and the second spring element being configured and arranged to cause the mobile second portion to move from the separated position to the coupled position when the coil has a current of a first magnitude flowing through it and configured and arranged to cause the mobile third portion to move from the rest position to the actuation position when the coil has a current of a second magnitude greater than the first magnitude flowing through it, which magnetic tripping device is characterized in that the magnetic tripping device comprises a transmitter mechanically connected to the first spring and to the mobile second portion of the yoke, and in that the magnetic tripping device comprises a striker arranged to move in conjunction with the mobile third portion. the yoke comprising a fixed first portion, a mobile second portion and a mobile third portion, the mobile second portion being able to move with respect to the fixed first portion between a separated position (P E), in which the mobile second portion is located at a distance from the fixed first portion, and a coupled position (P C), in which the mobile second portion is in contact with the fixed first portion, the mobile third portion being able to move with respect to the fixed first portion between a rest position and an actuation position, the first spring element acting on the mobile second portion so as to keep the mobile second portion in the separated position, the second spring element acting on the mobile third portion so as to keep the mobile third portion in the rest position, the coil, the yoke, the first spring element and the second spring element being configured and arranged to cause the mobile second portion to move from the separated position to the coupled position when the coil has a current of a first magnitude flowing through it and configured and arranged to cause the mobile third portion to move from the rest position to the actuation position when the coil has a current of a second magnitude greater than the first magnitude flowing through it, which magnetic tripping device is characterized in that the magnetic tripping device comprises a transmitter mechanically connected to the first spring and to the mobile second portion of the yoke, and in that the magnetic tripping device comprises a striker arranged to move in conjunction with the mobile third portion.