Patent ID: 6643112
Filing Date: 2003-11-04
Classification: H01H

Abstract:
An electromechanical relay designed to be inserted into an electrical circuit, the relay comprising:a mechanical displacement electrical contact; a transistor parallel-connected with the electrical contact; means for commanding a closing of the contact and a powering-on of the transistor in response to a first control signal and for commanding an opening of the contact and the powering-on of the transistor in response to a second control signal, wherein the means for commanding: generates, from the first control signal, a mechanical displacement contact closing signal that precedes the closing of the contact, the closing of the contact being done for a voltage V at terminals of the contact that correspond to a forward direction of the transistor, generates, from the first control signal, independently of the closing signal, a first signal for powering on the transistor that starts before the closing of the contact and ends after the closing of the contact, generates, from the second control signal, a mechanical displacement contact opening signal that precedes the opening of the contact, the opening of the contact being done for a current in the contact corresponding to the forward direction of the transistor, and generates, from the second control signal, independently of the opening signal, a second signal for powering on the transistor that starts before the opening of the contact and ends after the opening of the contact, wherein the means for commanding comprises a microcontroller having inputs that respectively receive control commands for the relay, a piece of information on current I in the electrical circuit and a piece of information on voltage V at the terminals of the contact and a control output giving the first and second control signals for opening and closing the contact and an output for powering on the transistor, and wherein the microcontroller has computation means for computing, after an appearance of the first control signal from the relay: a first waiting period for generating, at the powering-on output of the microcontroller, a first powering-on signal producing a saturation of the transistor in a half-wave corresponding to the forward direction of the transistor and at a point in time close to the change in alternation of the voltage at the terminals of the contact, and second waiting period for generating a signal for closing the contact which, by the amplifier, powers the control coil for the contact, the second waiting period being computed so that the contact will be closed shortly after the saturation of the transistor.