Circuit arrangement for momentarily maintaining an internal operating direct current voltage in the event of an interruption in the vehicle electrical system power supply voltage

• US 20050111152A1
• Filed: 11/13/2002
• Published: 05/26/2005
• Est. Priority Date: 01/18/2002
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schou, Frank
• Granted Patent: US 7,342,326 B2
• Time in Patent Office: Days
• US Class Current: 361/90
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices

Abstract

A circuit arrangement is described, to which the vehicle electric system supply voltage is applied and which for briefly maintaining at least one internal normal d.c. voltage in the event of failure of the vehicle electric system supply voltage includes an reserve energy accumulator to which a charging voltage higher than the at least one internal normal d.c. voltage is applied in regular operation and which in the event of failure of the vehicle electric system supply voltage delivers a reserve voltage with which operation of at least some electronic circuits may be maintained for a limited period of time, and it includes at least one step-down regulator which steps down the applied input direct voltage to the at least one internal normal d.c. voltage. In regular operation the supply direct voltage is applied directly as a charging voltage to the reserve energy accumulator and is also applied as the input direct voltage to the step-down regulator.

Claims

1-9. -9. (canceled)

10. A circuit arrangement to which a motor vehicle electric system supply voltage is applied and for briefly maintaining at least one internal normal d.c. voltage for electronic circuits in the event of failure of the motor vehicle electric system supply voltage, comprising:

a reserve energy accumulator to which a charging voltage higher than the at least one internal normal d.c. voltage is applied during regular operation and which, in the event of failure of the motor vehicle electric system supply voltage, delivers a reserve voltage with which operation of at least one of the electronic circuits can be maintained for a period of time; and

at least one step-down regulator that steps down an input direct voltage applied to thereto to the at least one internal normal d.c. voltage, wherein in regular operation the motor vehicle electric supply voltage is applied directly as a charging voltage to the reserve storage energy accumulator and is applied as an input direct voltage to the step-down regulator.

11. The circuit arrangement as recited in claim 10, wherein the reserve voltage is applied directly as input direct voltage to the at least one step-down regulator in an emergency.

12. The circuit arrangement as recited in claim 10, further comprising:

an upstream step-down regulator to which is applied the reserve voltage, the upstream step-down regulator deriving from the reserve voltage the input direct voltage for the at least one step-down regulator.

13. The circuit arrangement as recited in claim 12, wherein:

the upstream step-down regulator includes a switching regulator, and

the at least one step-down regulator includes a linear regulator.

14. The circuit arrangement as recited in claim 10, wherein:

in order to maintain a plurality of internal normal d.c. voltages, the at least one step-down regulator includes a plurality of step-down regulators to which the motor vehicle electric system supply voltage is applied as an input direct voltage during regular operation, each step-down regulator stepping down the motor vehicle electric system supply voltage to one of the plurality of internal normal d.c. voltages for a group of electronic circuits.

15. The circuit arrangement as recited in claim 14, wherein the reserve voltage is applied directly as an input direct voltage to the plurality of step-down regulators in an emergency.

16. The circuit arrangement as recited in claim 14, further comprising:

an upstream step-down regulator, wherein the reserve voltage is applied to the upstream step-down regulator, the upstream step-down regulator deriving therefrom the input direct voltage for the plurality of step-down regulators.

17. The circuit arrangement as recited in claim 16, wherein:

the upstream step-down regulator includes a switching regulator, and

the plurality of step-down regulators are linear regulators.

18. The circuit arrangement as recited in claim 10, wherein the reserve energy accumulator includes a capacitor.