Device for measuring a chopped current

Patent metadata

Field	Value
Publication number	US-9645176-B2
Application number	US-201414571595-A
Country	US
Kind code	B2
Filing date	Dec 16, 2014
Priority date	Dec 16, 2013
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A device for measuring a chopped current capable of flowing in a circuit having an H-bridge structure including a first branch and a second branch is disclosed. The device includes two transformers respectively connected to a branch and each comprising a primary circuit configured for the flow of a chopped current and a secondary circuit, two demagnetizing circuits, and two measuring circuits respectively connected to the terminals of the secondary circuit of an associated transformer, and respectively including at least one unit which comprises two switch connected in reverse, the two switches being respectively implemented by a transistor and being capable of being controlled. The measuring circuits include a common measuring resistor connected via a terminal to the ground, and via another terminal to the source of the first transistor of the first measuring circuit and to the source of the first transistor of the second measuring circuit.

First claim

The invention claimed is:

1. A device for measuring a chopped current capable of flowing in a circuit having an H-bridge structure including a first branch and a second branch, the device comprising:
two transformers respectively connected to a branch of the H-bridge, the transformers respectively comprising a primary circuit configured for the flow of a chopped current, and a secondary circuit;
two circuits for demagnetizing the two transformers; and
two measuring circuits respectively connected to the terminals of the secondary circuit of an associated transformer, the measuring circuits respectively including at least one unit which comprises a first switch and a second switch connected in reverse, the two switches being respectively implemented by a transistor and being capable of being controlled so as to:
allow the flow of the current induced by the chopped current, in the measuring circuit when the primary circuit of an associated transformer is closed, and
prevent the flow of the demagnetizing current in the measuring circuit when the primary circuit of an associated transformer is open;

the measuring circuits including a common measuring resistor connected via a first terminal to the ground, and via a second terminal to the source of the first transistor of the first measuring circuit and to the source of the first transistor of the second measuring circuit.

2. The device according to claim 1 , in which the first switch and the second switch are respectively implemented by a field effect transistor.

3. The device according to claim 1 , wherein:
the first switch of a measuring circuit comprises a terminal connected to a second terminal of the measuring resistor, the first terminal of the measuring resistor being connected to the ground; and
the second switch of a measuring circuit comprises a terminal connected to the ground.

4. The device according to claim 1 , wherein:
the branches of the circuit respectively include a first switch and a second switch,
the first transformer is connected to the first switch of the first branch and the second transformer is connected to the first switch of the second branch, and
the unit of the first measuring circuit configured for allowing or preventing the flow of a current induced by the chopped current in the first measuring circuit, is configured for being controlled by the inverse of the control signal of the second switch of the first branch and
the unit of the second measuring circuit configured for allowing or preventing the flow of a current induced by the chopped current in the second measuring circuit is configured for being controlled by the inverse of the control signal of the second switch of the second branch.

5. The device according to claim 1 , wherein:
the first measuring circuit comprises a first resistor and a second resistor, the terminal common to the two resistors being connected to the gate of the first transistor and of the second transistor of the first measuring circuit, and
the second measuring circuit comprises a first resistor and a second resistor, the terminal common to the two resistors being connected to the gate of the first transistor and of the second transistor of the second measuring circuit.

6. The device according to claim 1 , wherein a demagnetizing circuit is connected between the two output terminals of the secondary circuit of the associated transformer.

7. The device according to claim 6 , in which a demagnetizing circuit comprises two Zener diodes mounted in series and in opposite directions.

Assignees

• Valeo Systemes De Controle Moteur

Inventors

• Sardat Pierre
• Moreau Maxime

Classifications

• G01R19/20

  using transductors {, i.e. a magnetic core transducer the saturation of which is cyclically reversed by an AC source on the secondary side} · CPC title

• G01R19/0092

  Measuring current only · CPC title

• H02M2001/0009

  Electricity · mapped topic

• H02M3/337

  in push-pull configuration {(H02M3/33576 takes precedence; with self-oscillating arrangements H02M3/3382, H02M3/3385)} · CPC title

• G01R19/0046 Primary

  characterised by a specific application or detail not covered by any other subgroup of G01R19/00 · CPC title