Switching system for high voltage battery pack

• US 4,563,627 A
• Filed: 06/13/1984
• Issued: 01/07/1986
• Est. Priority Date: 06/13/1984
• Status: Expired due to Fees

• Current Assignee: Vivitar Corporation (Syntax-Brillian Corporation)
• Original Assignee: Vivitar Corporation (Syntax-Brillian Corporation)
• Inventors: Orban, John M.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/620,027
• Time in Patent Office: 573 Days
• Field of Search: 320/2, 320/15, 320/19, 320/39, 320/40, 354/145.1
• US Class Current: 320/112
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 50/574 Devices or arrangements for the interruption of current
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10S 320/21 State of charge of battery

Abstract

There is disclosed herein a rechargeable battery pack for use with electronic devices, such as electronic flash units used in photography, and wherein the battery pack has a pair of exposed electrical terminals. At least one of the terminals is constructed in the form of a switch such that when the battery pack is removed from its case, the terminal will assume a switched state so as to eliminate any electrical shock hazard. The battery pack comprises rechargeable batteries, a DC/DC converter for converting the relatively low voltage of the rechargeable batteries to the relatively high output voltage of the battery pack, and includes a voltage monitor and limiting circuit which provides voltage regulation and provides a low battery voltage limit during discharge of the rechargeable batteries. In a preferred embodiment, a rechargeable battery pack for providing an output of approximately 330-360 volts DC is illustrated and wherein the positive output terminal of the battery pack is connected to the negative terminal thereof through a relatively large discharge resistance to both shunt the high voltage output terminals and to turn off the voltage converter to thereby eliminate any electrical shock hazard and to provide a very slow discharge of the rechargeable batteries of the battery pack.

Claims

1. A high voltage battery pack for providing a relatively high voltage output for electronic devices such as electronic flash units and wherein the battery pack is engaged with the power unit when in use comprising

battery converter circuit means for stepping up a low battery voltage and providing a high voltage across first and second electrical conductors,

first terminal means connected to one of said conductors for providing an electrical output terminal for said pack, and

second terminal means connected to the second of said conductors for providing a second output terminal of said pack, said first and second terminal means serving to provide a high voltage to electrical terminals of a power unit when the battery pack is engaged with the power unit, said second terminal means comprising switch means for connecting said second terminal means to said first terminal means through shunt circuit means when said second terminal means is disengaged from said power unit to turn off said battery converter circuit means and to shunt said first and second terminal means through said shunt circuit means.

2. A battery pack as in claim 1 wherein

said second electrical terminal means comprises the positive terminal of said pack, and

said shunt circuit means comprises a resistance connected between said switch means and said first terminal means.

3. A battery pack as in claim 1 wherein

said battery converter circuit means comprises a plurality of rechargable batteries, a DC to DC converter connected to said batteries for stepping up the battery voltage of said batteries to said high voltage, and monitor circuit means responsive to the voltage across said first and second terminal means for turning on and off said converter to cause said converter to maintain said high voltage within predetermined limits.

4. A battery pack as in claim 3 wherein

said shunt circuit means comprises a resistance connected between said switch means and said first terminal means, and

said monitor circuit means being responsive to closure of said switch means to cause said converter to turn off.

5. A high voltage rechargeable battery pack for providing a relatively high voltage output for electronic devices such as electronic flash units and wherein the battery pack is engaged with the power unit when in use comprising

battery converter circuit means for stepping up a relatively low battery voltage and providing a high voltage across first and second electrical conductors,

first terminal means connected to one of said conductors for providing an electrical output terminal for said pack,

second terminal means connected to the second of said conductors for providing a second output terminal of said pack, said first and second terminal means serving to provide a high voltage to electrical terminals of a power unit when the battery pack is engaged with the power unit, said second terminal means comprising switch means for connecting said second terminal means to said first terminal means through circuit means when said second terminal means is disengaged from said power unit to turn off said battery converter circuit means and to connect said first and second terminal means through resistance circuit means, and

said battery converter circuit means comprises a plurality of rechargeable batteries, a DC to DC converter connected to said batteries for stepping up the battery voltage of said batteries to said high voltage, and monitor circuit means responsive to the voltage across said first and second terminal means for turning on and off said converter to cause said converter to maintain said high voltage within predetermined limits, and said monitor circuit means being responsive to closure of said switch means to cause said converter to turn off.