Arrangement for protecting an electrical device

• US 20060232901A1
• Filed: 07/21/2004
• Published: 10/19/2006
• Est. Priority Date: 07/26/2003
• Status: Abandoned Application

• Current Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Huber, Jörg, Schulz, Thomas, Bierbaum, Gerd, Mäckel, Rainer
• Application Number:
  US10/565,881
• Publication Number:
  US 20060232901A1
• Time in Patent Office: Days
• US Class Current: 361/93.100
• CPC Class Codes: H02H 11/002 in case of inverted polarity or connection; with switching for obtaining correct connection
• CPC Class Codes: H02H 7/18 for batteries; for accumulators
• CPC Class Codes: H02J 7/0034 using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045

Abstract

The present invention relates to an arrangement (7) for protection of an electrical device. In this case, the device is connected via one pole terminal (4) to one pole (3) of a battery (1) . A protective contact unit (9) has a connecting section (10) which is connected directly to the pole terminal (4), and has a starting assistance contact section (11) which is connected to the connecting section (10) via a switch (12). An evaluation circuit (15) operates the switch (12) in order to disconnect the electrical connection between the starting assistance contact section (11) and the connecting section (10) as soon as the evaluation circuit (15) detects a fault current.

Claims

1. An arrangement for protection of an electrical device

having a pole terminal (4) which is connected to one pole (3) of a battery (1) and to which the electrical device is connected,

having a protective contact unit (9) which has a connecting section (10) (which is electrically connected directly to the pole terminal (4)) and a starting assistance contact section (11), with the connecting section (10) and the starting assistance contact section (11) being electrically connected in series by means of an intermediate closed switch (12), and

having an evaluation circuit (15) which opens the switch (12) as soon as it detects a fault current, with

a main line (5) being provided, which is electrically connected to the starting assistance contact section (11) as a function of the switch position of the switch (12) and leads to at least one second electrical device, and

the first device being electrically connected to the pole terminal (4), bypassing the main line (5) and independently of the switch position of the switch (12).

2. The protective arrangement as claimed in claim 1, characterized

in that a current sensor (17) is provided, which senses the current level and/or the current flow direction in the main line (5) and is connected to the evaluation circuit (15) in order to transmit a corresponding sensor signal,

in that the current sensor (17) is arranged on the main line (5) in such a way that the starting assistance contact section (11) is located between the current sensor (17) and the switch (12).

3. The protective arrangement as claimed in claim 1, characterized in that a secondary line (6) is provided, which leads to the first device and is connected to the pole terminal (4) independently of the main line (5).

4. The protective arrangement as claimed in claim 1, characterized by at least one of the following features:

in that the switch (12) disconnects the electrical connection between the starting assistance contact section (11) and the connecting section (10) as soon as a predetermined current is flowing through a control line (13),

in that the control line (13) electrically connects one control output (14) of an evaluation circuit (15) to the connecting section (10),

in that the control output (14) in the evaluation circuit (15) is electrically connected via a diode arrangement (16) to an opposing pole (2), which is the inverse of the pole (3) of the pole terminal (4),

in that the diode arrangement (16) is reverse-biased when connected in the correct direction, and is forward-biased when connected incorrectly,

in that a start signal transmitter (18) is provided, which produces a start signal during starting and is connected to the evaluation circuit (15) for transmission of the start signal,

in that the evaluation circuit (15) uses the sensor signal and the start signal to detect whether a fault current is present,

in that the evaluation circuit (15) drives a switching element (20) as soon as it detects a fault current in the main line (5),

in that the switching element (20) electrically connects the drive output (14) to the opposing pole (2) in the driven state, bypassing the diode arrangement (16),

in that the switching element is an MOS driver (20) which has an inverse diode (21),

in that the diode arrangement (16) in the control line (13) comprises the inverse diode (21) or is formed by the inverse diode (21), and

in that the diode arrangement (16) comprises the inverse diode (21) as well as at least one further diode connected in parallel with it, in particular a Schoftky diode.

5. The protective arrangement as claimed in claim 1, characterized in that an electrically insulating cover (22) is provided and completely covers the pole terminal (4) except for the starting assistance contact section (11).

6. The protective arrangement as claimed in claim 5, characterized in that the starting assistance contact section (11) has an extension section which projects beyond the pole terminal (4) and/or beyond the pole (3) from the battery (1).

7. The protective arrangement as claimed in claim 5, characterized in that the evaluation circuit (15) and/or the current sensor (17) are/is arranged within an area which is bounded by the cover (22).

8. The protective arrangement as claimed in claim 1, characterized

in that the switch (12) is in the form of a relay which switches when current is flowing through the control line (13), or

in that the switch (12) is in the form of a pyrotechnic explosive switch which fires when current is flowing through the control line (13).

9. The protective arrangement as claimed in claim 8, characterized in that the control line (13) contains a heating section which is heated when current is flowing through it and fires the explosive switch (12).

10. The protective arrangement as claimed in claim 1, characterized

in that the first device is a vehicle power supply system in a motor vehicle, and/or

in that the second device comprises a starter and a generator in a motor vehicle, or is a starter generator in a motor vehicle.

11. The protective arrangement as claimed in one of claim 1, characterized in that the protective arrangement is used in a motor vehicle for protection of a vehicle power supply system against fault currents while providing and receiving starting assistance.