# US 2018/0025871 A1 · Electromagnetic contactor provided with means for detecting the open or closed position of controlled switches

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- Number: US 2018/0025871 A1
- Document ID: US20180025871A1
- Status: Published application
- Kind: A1
- Application number: 15/645,807
- Filed: 2017-07-10
- Published: 2018-01-25
- Earliest claimed: 2016-07-20
- Assignees: Zodiac Aero Electric
- Applicants: Zodiac Aero Electric
- Inventors: Jean-Pierre Balbinot
- Web page: https://patentgrep.com/patent/US20180025871A1

## CPC

- H01H 47/32: Energising current supplied by semiconductor device
- H01H 1/0015: {Means for testing or for inspecting contacts, e.g. wear indicator (measuring circuits G01R31/3274)}
- H01H 9/167: {Circuits for remote indication}
- H01H 47/002: {Monitoring or fail-safe circuits}
- H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00)

## Abstract

This electromagnetic contactor comprises a set of controlled switches (C1, C2, C3), at least one electromagnetic field generator (L; L1, L2), for example a coil, associated with an adjustable core (P) controlling the state of the controlled switches and a unit (UC) controlling the power supply of the electromagnetic field generator. It comprises means for detecting the position of the adjustable core to detect the state of the controlled switches.

## Claims

### Claim 1

An electromagnetic contactor, comprising a set of controlled switches, at least one electromagnetic field generator, for example a coil, associated with an adjustable core (P) controlling the state of the controlled switches, a unit controlling the power supply of the electromagnetic field generator and means for detecting the position of the adjustable core to detect the state of the controlled switches wherein it comprises storage means in which are stored impedance values, notably values of the resistance of the generator, as a function of the temperature of the generator, said impedance value of the generator being extracted from the storage means.

### Claim 2 (depends on 1)

The electromagnetic contactor as claimed in claim 1, wherein the means for detecting the position of the adjustable core comprise means for computing the value of the impedance of said generator, notably the inductance.

### Claim 3 (depends on 2)

The electromagnetic contactor as claimed in claim 2, wherein the value of said impedance is computed from the value of a power supply voltage of the generator for a predetermined duration and from a measured value of the current circulating in the generator.

### Claim 4 (depends on 1)

The electromagnetic contactor as claimed in claim 1 in which the computation means comprise means for comparing the value of the inductance of the generator with inductance values corresponding respectively to an open and closed state of the contactor.

### Claim 5 (depends on 1)

The electromagnetic contactor as claimed in claim 1, in which the contactor comprises a single electromagnetic field generator.

### Claim 6 (depends on 1)

The electromagnetic contactor as claimed in claim 1, comprising two electromagnetic field generators acting on a common adjustable core and each driven by a switch, a first generator ensuring the closure of the contactor, and a second generator ensuring the maintained closure of the contactor.

### Claim 7 (depends on 1)

A method for determining the open or closed state of an electromagnetic contactor as claimed in claim 1, in which:
the contactor is powered for a predetermined duration with a power supply voltage;
the current circulating in the generator is measured;
the value of the impedance of the generator is computed; and
the computed impedance value is compared with a set of at least one threshold value for detecting the open or closed state of the contactor.

### Claim 8 (depends on 7)

The method as claimed in claim 7, wherein the impedance value is computed from a measurement of a current circulating in the generator.

### Claim 9 (depends on 7)

The method as claimed in claim 7, wherein said contactor having a single electromagnetic field generator, a detection current is superimposed on a maintaining current, the current circulating in the generator is measured, the value of the maintaining current is subtracted from the measured current value and the value of the impedance is computed.