Stand-by power system

• US 3,928,791 A
• Filed: 05/20/1974
• Issued: 12/23/1975
• Est. Priority Date: 05/20/1974
• Status: Expired due to Term

• Current Assignee: Gates Energy Products, Inc. (Schneider Electric SE)
• Original Assignee: Ferdinand H. Mullersman
• Inventors: Mullersman, Ferdinand H.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/471,594
• Time in Patent Office: 582 Days
• Field of Search: 320/2,5-7,14-18 307/66
• US Class Current: 320/119
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence

Abstract

A charging system for a stand-by power supply comprising a battery having plurality of series-connected cells and a switching means for periodically and sequentially charging sections of the battery, thereby to minimize voltage variation between the normal DC power source voltage and the stand-by power supply discharge voltage applied to a load during the nonfunctioning of the DC power source.

Claims

1. A battery charging apparatus for a high voltage stand-by power system, said system comprising a power source connected in circuit with a load and a battery of rechargeable cells coupled across said load to provide stand-by power upon the nonfunctioning of said source, said battery being divisible into a plurality of sections of at least one cell each for charging, and a supplemental battery section, said apparatus comprising:

a. charging means for supplying a source of charging current;

b. switching means, coupled between said charging means and each of said plurality of sections, for sequentially switching said plurality of sections, one section at a time, to said charging means for charging, said switching means comprising;

1. a plurality of circuit paths for electrically connecting said charging means in circuit with each of said sections;

2. current control means in said circuit paths for controlling the transmission of current from said charger to each of said sections; and

3. first control section means for activating said current control means to sequentially transmit said current to said sections, one at a time; and

c. a supplemental switching means, coupled between said supplemental battery section and said battery, for automatically, electrically connecting said supplemental battery section in circuit with said battery when one of said sections is being charged, said supplemental switching means comprising;

1. a plurality of supplemental circuit paths for connecting said supplemental section to each of said battery sections;

2. supplemental current control means in said supplemental circuit paths for controlling the conductivity of said circuit paths;

3. second control section means for activating said supplemental current control means to sequentially connect said supplemental section in parallel with each of said battery sections, one section at a time; and

4. third control section means for activating said supplemental current control means to disconnect each of said sections from said battery and from said supplemental section.

2. current control means in said circuit paths for controlling the transmission of current from said charger to each of said sections;

and

3. first control section means for activating said current control means to sequentially transmit said current to said sections, one at a time;

and c. a supplemental switching means, coupled between said supplemental battery section and said battery, for automatically, electrically connecting said supplemental battery section in circuit with said battery when one of said sections is being charged, said supplemental switching means comprising;

4. third control section means for activating said supplemental current control means to disconnect each of said sections from said battery and from said supplemental section.

5. The apparatus of claim 1 further comprising:

activation means, coupled between said battery and said source, for electrically connecting said battery to said load responsive to the non-functioning of said source, said activation means further comprising first means in the circuit path between said source and said battery for controlling the conductivity thereof, and second means in the circuit path between said battery and said load for controlling the conductivity thereof; and

detector means connected to said source and said activation means for sensing the decrease of the voltage from said source below a predetermined level, for activating said first means to prevent transmission of battery current from the battery to the source, and for activating said second means to permit the transmission of battery current from said battery to said load.

6. The apparatus of claim 1 wherein said charging means comprises means for supplying pulsed charge current.

7. A stand-by power system for a load normally powered by a power source connected in circuit with said load comprising:

a. a battery comprising a plurality of cells coupled across said load to provide stand-by power upon the non-functioning of said source, said battery being divisible into a plurality of sections of at least one cell each for charging;

b. charging means for supplying charge current;

c. switching means, coupled between said charging means and each of said plurality of sections for sequentially connecting said plurality of sections, one section at a time, to said charging means for charging, said switching means comprising;

8. The system of claim 7 further comprising load resistance means for causing each of said plurality of sections to slowly decay in voltage after chargiNg.

9. The system of claim 7 wherein said switching means comprises a timing means for sequencing the operation of said second section means and third section means with said control means for the charging of each battery section such that, in order, (1) the second section means activates said supplmental current control means to connect said supplemental section in parallel with one of said battery sections, (2) the third section means activates said supplemental current control means to disconnect said one battery section from said battery and from said supplemental section, (3) the first section means activates said current control means to transmit said current to said one battery section, (4) the first section means deactivates said current control means to terminate said current transmission, (5) the second section means deactivates said supplemental current control means to reconnect said one section in said battery in parallel with said supplemental section, and (6) the third section means deactivates the supplemental contact means to disconnect said supplemental section from said one section.

10. The system of claim 7 wherein said charging means comprises means for supplying pulsed charge current.

11. The system of claim 7 further comprising:

activation means, coupled between said battery and said source, for electrically connecting said battery to said load responsive to the non-functioning of said source, said activation means further comprising first means in the circuit path between said source and said battery for controlling the conductivity thereof, and second means in the circuit path between said battery and said load for controlling the conductivity thereof; and

detector means connected to said source and said activation means for sensing the decrease of the voltage from said source below a predetermined level, for activating said first means to prevent transmission of battery current from the battery to the source and for activating said second means to permit the transmission of battery current from said battery to said load.