Power supply device

• US 20010048295A1
• Filed: 04/05/2001
• Published: 12/06/2001
• Est. Priority Date: 04/08/2000
• Status: Abandoned Application

• Current Assignee: Mannesmann VDO AG (Continental AG)
• Original Assignee: Mannesmann VDO AG (Continental AG)
• Inventors: Joch, Christoph
• Application Number:
  US09/828,291
• Publication Number:
  US 20010048295A1
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

In a power supply device to which a DC voltage can be fed and which outputs a stabilized voltage for operating an electronic circuit in a motor vehicle, a step-up converter is arranged between an input for the operating voltage and an output of a voltage regulator, which step-up converter is activated when a battery voltage is below a predefined threshold voltage, and raises the battery voltage to at least the threshold value.

Claims

1. A power supply device to which a DC voltage can be fed and which outputs a stabilized voltage for operating an electronic circuit in a motor vehicle, wherein a step-up converter (6, 7, 8, 9) is arranged between an input (2) for the operating voltage and an input of a voltage regulator (5), which step-up converter (6, 7, 8, 9) is activated when a battery voltage is below a predefined threshold value, and raises the battery voltage to at least the threshold value.

2. The power supply device as claimed in

claim 1

, wherein the threshold value is approximately 5 V to 6 V.

3. The power supply device as claimed in one of claims 1 or 2, wherein the step-up converter is formed by a series circuit which is composed of an inductor (6) and a diode (7) and is connected between the input (2) and the input of the voltage regulator (5), the connecting point of the inductor (6) to the diode (7) being connected to ground potential via a semiconductor switch (8, 11), and the input of the voltage regulator (5) being connected to ground potential via a capacitor (9), and wherein the semiconductor switch (8, 11) is controlled in a pulsating fashion when the voltage drops below the threshold value.

4. The power supply device as claimed in

claim 3

, wherein the semiconductor switch is a field-effect transistor (11).

5. The power supply device as claimed in one of the preceding claims 3 or 4, characterized in that a differential amplifier (12) is provided for driving the semiconductor switch (11) in a pulsating fashion, the output of which differential amplifier (12) is connected to a control input of the semiconductor switch (11), to one input of which pulses can be fed from a clock transmitter and to the other input of which the input voltage of the voltage regulator (5) is applied via a voltage divider (14, 15).