Dc electrical circuit breaker

A DC electrical circuit breaker, comprising:

• first and second input and output terminals for a DC electric current,
• first and second electrical contacts, connected respectively to the first and second terminals and being selectively displaceable with respect to one another, along a longitudinal plane of the circuit breaker, between:
• a closed position, in which respective contact zones of the first and second electrical contacts are in contact with one another so as to permit the flow of the DC electric current between the first and second electrical contacts, and
• an open position, in which these contact zones are remote from one another,
• an electric arc formation chamber, in which the contact zones are placed;
• an electric arc quenching chamber;
• wherein the circuit breaker comprises a magnetic circuit comprising a magnet and generating a magnetic field which is able to guide, in the direction of the quenching chamber, an electric arc forming between the contact zones in the open position, the magnetic field generated by the magnetic circuit exhibiting for this purpose curved field lines which extend essentially perpendicularly to opposite lateral walls of the electric arc formation chamber, these lateral walls being disposed on either side of the contact zones essentially parallel to the longitudinal plane, these field lines converging, at the level of a central region of the arc formation chamber containing the contact zones, towards the quenching chamber while extending parallel to the longitudinal plane.