Circuit arrangement for judging the lifetime of a battery in a no-break power supply system

• US 4,779,050 A
• Filed: 08/28/1986
• Issued: 10/18/1988
• Est. Priority Date: 01/14/1986
• Status: Expired due to Fees

• Current Assignee: Eikoh Giken Company Limited
• Original Assignee: Eikoh Giken Company Limited
• Inventors: Ohnari, Eiji
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Harvey, Jack B.
• Application Number:
  US06/901,186
• Time in Patent Office: 782 Days
• Field of Search: 324/425-428, 324/433, 340/636, 320/48, 307/66
• US Class Current: 324/426
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: H02J 7/007184 in response to battery voltage gradient
• CPC Class Codes: H02J 9/00 Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

A circuit arrangement for judging the lifetime of a battery used in a no-break power supply system includes a step-down transformer connected to an AC power source, a first switch connected between the transformer and a rectifier, a voltage detector connected to one electrode of a battery, an auto-timer connected to the voltage detector, and a second switch connected to the auto-timer and interlocked to the first switch.

Claims

1. A circuit arrangement for judging the lifetime of a battery in a no-break power supply system, comprising rectifier means having an input coupled to an AC power source;

an inverter, having an automatic voltage regulating function, connected to an output of said rectifier means;

a load connected to an output of said inverter;

a diode having a cathode connected to an input of said inverter;

a battery having one electrode connected to an anode of said diode and another electrode connected to ground; and

a charging unit connected between the input of said rectifier means and a junction point of said battery and said diode;

characterized in that said circuit arrangement further comprises;

a step-down transformer connected to said AC power source, said step-down transformer having at least two taps on a secondary side thereof;

first switching means for electively connecting one of said two taps to the input of said rectifier means thereby coupling said rectifier means to said AC power source, whereby one of said taps is connected to the input of said rectifier means in a normal operating mode, while another of said taps, supplying a lower voltage than said one of said taps, is connected to the input of said rectifier means in a battery judging mode;

a voltage detector, having a predetermined threshold level, connected to the junction point of said diode and said battery;

an auto-timer for indicating a time duration having a stop input connected to an output of said voltage detector;

second switching means connected to a start input of said auto-timer; and

means for interlocking said second switching means to said first switching means, whereby when judging said battery, said first switching means is switched to connect said another tap to said rectifier means while said second switching means starts said auto-timer, said auto-timer being stopped by said voltage detector when a voltage at said junction point drops below said threshold level, the time duration indicated by said auto-timer being a measure of the lifetime of the battery.

2. A circuit arrangement as claimed in claim 1, wherein, in said battery judging mode, an input voltage of the inverter is higher than a discharge final voltage of the battery, and the threshold level of the voltage detector is higher than the input voltage of the inverter.

3. A circuit arrangement as claimed in claim 1, wherein the rectifier means comprises a rectifier and a smoothing capacitor connected thereto.

4. A circuit arrangement as claimed in claim 1, wherein the load is a computer.

5. A circuit arrangement for judging the lifetime of a battery in a no-break power supply system, comprising rectifier means connected to an AC power source;

an inverter having an input connected to an output of said rectifier means and having an automatic voltage regulating function;

a load connected to an output of said inverter;

a battery having one electrode connected to the input of the inverter and another electrode connected to ground; and

a thyristor control unit connected to the output of and a control input of said rectifier means, said thyristor control unit having a change-over mechanism therein for changing over a controlled voltage level;

characterized in that said circuit arrangement further comprises;

a voltage detector having a predetermined threshold level and having an input connected to a junction point of said battery and said inverter and an output connected to a reset input of said thyristor control unit for the change over mechanism therein;

an auto-timer, for indicating a time duration, having a stop input also connected to the output of said voltage detector; and

switching means connected to both a start input of said auto-timer and a set input of said thyristor control unit for the changeover mechanism therein, whereby, when judging the lifetime of the battery, said switching means sets the change-over mechanism to a lower controlled voltage level and starts said auto-timer, said change-over mechanism being reset and said auto-timer being stopped by said voltage detector when a voltage at said junction point drops below said threshold level, the time duration indicated by said auto-timer being a measure of the lifetime of the battery.

6. A circuit arrangement as claimed in claim 5, wherein, in a battery judging mode, an input voltage of the inverter is higher than a discharge final voltage of the battery, and the threshold level of the voltage detector is higher than the input voltage of the inverter.

7. A circuit arrangement as claimed in claim 5, wherein the rectifier means comprises a rectifier and a smoothing capacitor connected thereto.

8. A circuit arrangement as claimed in claim 7, wherein the rectifier is a thyristor.

9. A circuit arrangement as claimed in claim 5, wherein the load is a computer.

10. A circuit arrangement for judging the lifetime of a battery in a no-break power supply system, comprising a first rectifier having an input connected to an AC power source;

an inverter having an input connected to an output of said first rectifier;

a load connected to an output of said inverter;

a second rectifier having an input connected to an engine-generator and an output also connected to the input of said inverter;

a diode having a cathode connected to the input of the inverter; and

a battery having one electrode connected to an anode of said diode and another electrode connected to ground;

characterized in that said circuit arrangement further comprises;

a voltage detector having a predetermined threshold level and an input connected to a junction point of said diode and said battery;

timer means, for measuring a time duration, having a stop input connected to an output of said voltage detector;

a dummy load;

change-over means for selectively short-circuiting said diode or connecting said dummy load to the junction point of said diode and said battery;

switching means connected to a start input of said timer means; and

means for interlocking said switching means to said change-over means, whereby, when judging the lifetime of said battery, said change-over means connects said dummy load to said junction point and said switching means starts said timer means, said voltage detector stopping said timer means when a voltage at said junction point drops below said threshold level, the time duration indicated by said timer means being a measure of the lifetime of the battery.