DETECTING DEVICE AND CURRENT SENSOR

• US 20140159756A1
• Filed: 05/29/2012
• Published: 06/12/2014
• Est. Priority Date: 05/30/2011
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho, Melexis NV (Sensinnovat BVBA)
• Original Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho, Melexis NV (Sensinnovat BVBA)
• Inventors: Ueno, Hiroshi, Kanemaru, Kenji, Mori, Daisuke, Piette, Francois, Leten, Wouter
• Granted Patent: US 9,291,666 B2
• Time in Patent Office: Days
• US Class Current: 324/750.01
• CPC Class Codes: G01R 15/202 using Hall-effect devices Hall elements in arrangements for measuring electrical power G01R21/08
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844
• CPC Class Codes: G01R 33/072 Constructional adaptation of the sensor to specific applications
• CPC Class Codes: G01R 33/091 Constructional adaptation of the sensor to specific applications

Abstract

A detecting device includes a detecting part configured to detect a change in an object to be detected so as to output a detection signal, an amplifying part configured to amplify the detection signal output from the detecting part to output a first amplification signal, a reference voltage supply part configured to supply a reference voltage to the amplifying part, the reference voltage being input to the amplifying part to be output as a second amplification signal, a switching part configured to switch a connection between the detecting part and the amplifying part or a connection between the amplifying part and the reference voltage supply part based on a control signal input thereto, and a comparing part configured to compare a predetermined amplification factor in the amplifying part, with an amplification factor obtained from the second amplification signal so as to output the comparison result as a comparison signal.

Claims

1. A detecting device, comprising:

a detecting part configured to detect a change in an object to be detected so as to output a detection signal;

an amplifying part configured to amplify the detection signal output from the detecting part so as to output a first amplification signal;

a reference voltage supply part configured to supply a reference voltage to the amplifying part, the reference voltage being input to the amplifying part so as to be output as a second amplification signal;

a switching part configured to switch a connection between the detecting part and the amplifying part or a connection between the amplifying part and the reference voltage supply part based on a control signal input thereto; and

a comparing part configured to compare a predetermined amplification factor in the amplifying part, with an amplification factor obtained from the second amplification signal so as to output the comparison result as a comparison signal.

2. The detecting device according to claim 1, wherein the detecting part comprises a magnetic sensor.

3. The detecting device according to claim 2, wherein the magnetic sensor comprises a bridge circuit comprising a first magnetic sensor element to a fourth magnetic sensor element, and the reference voltage supply part generates a first reference voltage corresponding to a first divided voltage of the first magnetic sensor element and the second magnetic sensor element, and a second reference voltage corresponding to a second divided voltage of the third magnetic sensor element and the fourth magnetic sensor element in an initial state.

4. The detecting device according to claim 3, wherein the comparing part is configured to compare a third amplification signal obtained by differentially amplifying the first divided voltage and the second divided voltage by the amplifying part, with a fourth amplification signal obtained by differentially amplifying the first divided voltage and the second reference voltage by the amplifying part so as to output the comparison signal.

5. The detecting device according to claim 3, wherein the comparing part is configured to compare a third amplification signal obtained by differentially amplifying the first divided voltage and the second divided voltage by the amplifying part, with a fifth amplification signal obtained by differentially amplifying the first reference voltage and the second divided voltage by the amplifying part so as to output the comparison signal.

6. A current sensor comprising:

the detecting device according to claim 1.

7. The current sensor according to claim 6, wherein the current sensor is connected to at least two phases of a three phase motor.

8. The detecting device according to claim 1, wherein the predetermined amplification factor is variable.

9. The detecting device according to claim 1, further comprising:

a judging part configured to judge an abnormality of the detecting part and the amplifying part based on the comparison signal output from the comparing part.

10. The detecting device according to claim 1, wherein the detecting part comprises an acceleration sensor configured to detect a change in an electrical capacity.