Circuit for detecting a current passing through a consumer

• US 6,703,822 B2
• Filed: 03/28/2002
• Issued: 03/09/2004
• Est. Priority Date: 08/12/2000
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Wenger, Christoph
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): Nguyen, Trung Q.
• Application Number:
  US10/089,466
• Publication Number:
  US 20020149356A1
• Time in Patent Office: 712 Days
• Field of Search: 324/142, 324/130, 324/117.R, 324/127, 324/144, 324/146, 324/151.A, 324/529, 324/263, 324/258, 307/261, 307/270, 307/228, 363/71, 363/67, 731/19.A, 731/19, 327/172, 327/205
• US Class Current: 324/117.00R
• CPC Class Codes: G01R 15/185 with compensation or feedback windings or interacting coils, e.g. 0-flux sensors using galvano-magnetic field sensors G01R15/20; conversion of DC into AC using transductors G01R19/20
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence

Abstract

A circuit arrangement for detecting a current through a consumer 16, which is disposed between the outputs 14c, 15c of two amplifiers 14, 15, which in order to be supplied with a unipolar operating voltage VCC, each have a supply voltage connection 14a, 15a and a ground connection 14b, 15b, is characterized in that between the connection 18a of the operating voltage source and the supply voltage connection 14a, 15a and/or between the ground connection 14b, 15b and ground 18b, an ohmic resistor 17 is provided, at which a voltage U_A falls, which is proportional to the current to be detected.

Claims

1. A circuit arrangement for detecting a current through a consumer (16;

26;

36), which is disposed between the outputs (14c, 15c;

24c, 25c;

34c, 35c) of two amplifier (14, 15;

24, 25;

34, 35), which in order to be supplied with a unipolar operating voltage (Vcc), each have a supply voltage connection (14a, 15a;

24a, 25a;

34a, 35a) and a ground connection (14b, 15b;

24b, 25b;

34b, 35b), characterized in that between the connection (18a;

28a;

38a) of the operating voltage source and the supply voltage connection (14a, 15a;

24a, 25a;

34a, 35a) and/or between the ground connection (14b, 15b;

24b, 25b;

34b, 35b) and ground (18b;

28b;

38b), an ohmic resistor (17;

27, 27′

;

37, 37′

) is provided, at which a voltage falls, which is proportional to the current to be detected, and the power output stages of the amplifiers (34, 35) are comprised of MOSFETs, which operate in push-pull B operation.

2. The circuit arrangement according to claim 1, characterized in that the ground connections (14b, 15b) are connected to each other and the ohmic resistor (17) is disposed between the connected ground connections (14b, 15b) and ground (18b).

3. The circuit arrangement according to claim 2, characterized in that the falling voltage at the consumer (16) is sent to an amplifier (19) and the output voltage of the amplifier (19) is used to determine the current direction.

4. The circuit arrangement according to claim 3, characterized in that the amplifier (19) is a comparator.

5. The circuit arrangement according to claim 1, characterized in that a separate ohmic resistor (27, 27′

;

37, 37′

) is disposed between each ground connection (24b, 25b;

34b, 35b) and ground (28b).

6. The circuit arrangement according to claim 1, characterized in that the power output stages of the amplifiers (34, 35) are each triggered by means of an operational amplifier (40, 41), which the output of the relevant power output stage is coupled back to.

7. The circuit arrangement according to claim 6, characterized in that the supply voltage (U_H) of the operational amplifiers (40, 41) is higher than the operating voltage (V_CC).

8. The circuit arrangement according to claim 7, characterized in that the supply voltage (U_H) of the operational amplifiers is generated by means of charging pump (42).