FR2517461A2

FR2517461A2 - ELECTROMAGNET SUPPLY CIRCUIT WITH CALL AND HOLD COILS

Info

Publication number: FR2517461A2
Application number: FR8122956A
Authority: FR
Inventors: Jean-Pierre Guery; Jacques Olifant
Original assignee: La Telemecanique Electrique SA
Current assignee: Telemecanique SA
Priority date: 1981-11-30
Filing date: 1981-11-30
Publication date: 1983-06-03
Also published as: FR2517461B2; JPS6238844B2; JPS58105529A; DE3243704A1

Abstract

In a circuit for supplying an electromagnet from an AC network, having a main winding (M1) for attraction of the armature of the electromagnet, as well as an auxiliary winding (M2) for holding the armature, having an insulating and isolating contact (C2) which is opened when the armature is attracted, and having a bridge which comprises four rectified elements (D1 to D4) and supplies the main winding (M1) by means of the isolating contact (C2), in which bridge the auxiliary winding (M2) is supplied during the holding phase by means of a path which is independent of the isolating contact, it is provided for the auxiliary winding (M2) to be connected to connections of a DC arm of the bridge between the connection (D1-D2) and the connection (A1 or A2). This circuit can be used, for example, for driving contacts or switches.

Description

CIRCUIT D'ALIMENTATION D'ELECTRO-AIMANT AVEC BOBINES
D'APPEL ET DE MAINTIEN
L'invention a pour objet un perfectionnement au circuit d'alimentation d'électro-aimant du brevet principal, lequel comporte un enroulement principal pour l'appel de l'armature de l'électro-aimant et un enroulement auxiliaire pour son maintien, un contact d'isolement dont l'ouverture se produit lorsque l'armature est attirée, un pont de quatre éléments redresseurs alimentant l'enroulement principal à l'aide du contact d'isolement, l'enroulement auxiliaire étant alimenté pendant la phase de maintien, par une voie indépendante du contact d'isolement.ELECTROMAGNET SUPPLY CIRCUIT WITH COILS
CALL AND HOLD
The subject of the invention is an improvement to the electromagnet supply circuit of the main patent, which comprises a main winding for calling up the armature of the electromagnet and an auxiliary winding for maintaining it, a isolation contact, the opening of which occurs when the armature is attracted, a bridge of four rectifying elements supplying the main winding using the insulation contact, the auxiliary winding being supplied during the holding phase, by a channel independent of the isolation contact.

Selon le brevet principal, le contact d'isolement est placé en série entre le pont et une borne du circuit d'alimentation reliée au réseau alternatif, tandis que l'enroulement auxiliaire est branché aux bornes de l'ensemble série formé par ledit contact d'isolement et ledit pont.According to the main patent, the isolation contact is placed in series between the bridge and a terminal of the supply circuit connected to the alternating network, while the auxiliary winding is connected to the terminals of the series assembly formed by said contact d isolation and said bridge.

Dans un tel montage, l'effort électromagnétique nécesssaire à l'attraction de l'armature pendant la phase d'appel est entièrement fourni par le courant redressé qui circule dans l'enroulement principal.In such an arrangement, the electromagnetic force necessary for the attraction of the armature during the call phase is entirely supplied by the rectified current which circulates in the main winding.

Lorsque l'électro-aimant est par exemple celui qui commande un contacteur et que des manoeuvres doivent être effectuées à une cadence horaire élevée (1200 manoeuvres à l'heure par exemple), l'enroulement principal risque de s'échauffer.When the electromagnet is for example that which controls a contactor and that maneuvers have to be carried out at a high hourly rate (1200 maneuvers per hour for example), the main winding may heat up.

L'addition propose de réduire ce risque en faisant travailler l'enroulement auxiliaire en courant alternatif redressé à mono-alternance pendant la phase d'appel de l'électroaimant.The addition proposes to reduce this risk by making the auxiliary winding work in rectified alternating current at mono-alternation during the call phase of the electromagnet.

Suivant l'addition, ce résultat est obtenu en branchant l'enroulement auxiliaire sur une branche à courant continu du pont d'éléments redresseurs.According to the addition, this result is obtained by connecting the auxiliary winding to a DC branch of the bridge of rectifier elements.

Les avantages de l'addition apparaitront clairement à l'aide de la description ci-apres.The advantages of the addition will become apparent with the aid of the description below.

La figure unique du dessin annexé représente un circuit d'alimentation d'électro-aimant conforme à l'addition.The single figure of the accompanying drawing shows an electromagnet supply circuit according to the addition.

Le dispositif représenté à la figure comprend, branché entre les bornes A1 et A2 soumises à la tension alternative du réseau, un pont de Graetz composé de diodes D1 à D4 et, d'autre part entre A2 et le point commun à D1 et D2, une bobine de maintien M2 et,entre A2 et le point commun à D2
D3, un contact d'isolement C2.The device represented in the figure comprises, connected between the terminals A1 and A2 subjected to the alternating voltage of the network, a Graetz bridge composed of diodes D1 to D4 and, on the other hand between A2 and the common point at D1 and D2, a retaining coil M2 and, between A2 and the point common to D2
D3, an isolation contact C2.

C1 est le contact de commande général de l'électro-aimant.C1 is the general control contact of the electromagnet.

La bobine d'appel M1 est branchée dans la diagonale interne du pont comprise entre les pints communs à D1 D2 et à D3 D4
Pendant la phase d'appel de l'électro-aimant, le contact C2 est fermé. La bobine principale M1 est parcourue par un courant redressé bi-alternance important Toutefois, comme la bobine auxiliaire M2 est, dans le montage décrit, parcourue par un courant redressé mono-alternance, qui circule à travers la diode D1, D2 servant de diode de roue-libre ; ce courant contribue à augmenter pour un sens d'enroulement convenable des bobines, d'environ 10 % par exemple, les ampères-tours nécessaires pour obtenir l'attraction du circuit magnétique mobile de l'électro-aimant (ce qui n'était pas le cas avec le montage du brevet principal, dans lequel la bobine auxiliaire était branchée entre les bornes dites "courant alternatif" du pont).The call coil M1 is connected in the internal diagonal of the bridge between the pints common to D1 D2 and D3 D4
During the call phase of the electromagnet, contact C2 is closed. The main coil M1 is traversed by a large full-wave rectified current However, as the auxiliary coil M2 is, in the assembly described, traversed by a full-wave rectified current, which flows through the diode D1, D2 serving as a diode of freewheeling; this current contributes to increasing, for a suitable winding direction of the coils, by about 10% for example, the ampere-turns necessary to obtain the attraction of the mobile magnetic circuit of the electromagnet (which was not the case with the assembly of the main patent, in which the auxiliary coil was connected between the so-called "alternating current" terminals of the bridge).

Par ailleurs, l'interaction entre les deux bobines se trouve notablement réduite par rapport au montage du brevet principal, et il en résulte un lissage de l'ondulation dans la bobine d'apppel M1 pendant la phase d'appel, donc une amélioration du rendement et une réduction de l'échauffement de la bobine d'appel.Furthermore, the interaction between the two coils is significantly reduced compared to the assembly of the main patent, and this results in a smoothing of the ripple in the call coil M1 during the call phase, therefore an improvement in the efficiency and a reduction in the heating of the take-up coil.

Lorsque, la course d'attraction du circuit magnétique mobile étant terminée, le contact C2 est ouvert (phase de maintien), le montage fonctionne sensiblement comme celui du brevet principal, c'est-à-dire que l'excitation magnétique nécessaire au maintien est principalement produite par le courant alternatif qui circule dans la bobine de maintien M2.When the attraction stroke of the movable magnetic circuit is finished, the contact C2 is open (holding phase), the assembly functions substantially like that of the main patent, that is to say that the magnetic excitation necessary for the maintenance is mainly produced by the alternating current which circulates in the holding coil M2.

On notera que la bobine auxiliaire M2 pourrait tout aussi bien restée branchée entre le point commun à D1 et D2 et la borne A2. It will be noted that the auxiliary coil M2 could just as easily remain connected between the point common to D1 and D2 and the terminal A2.

Claims

Patent claim

Circuit for supplying an electromagnet from the AC network, comprising a main winding (M1) for calling up the armature of the electromagnet and an auxiliary winding (M2) for maintaining it, a contact isolation (C2), the opening of which occurs when the reinforcement is attracted, a bridge of four rectifying elements (D1 D4) supplying the main winding (M1) using the isolation contact (C2), the auxiliary winding (M1) being supplied during the holding phase, by a channel independent of the isolation contact, characterized in that the auxiliary winding (M2) is connected to the terminals of a DC branch of the bridge between the junction (D1 D2) and the bridge (A1 or A2).