Battery Pack Control Circuit for Handheld Battery Operated Device

• US 20120136493A1
• Filed: 11/30/2010
• Published: 05/31/2012
• Est. Priority Date: 11/30/2010
• Status: Active Grant

• Current Assignee: Bayco Products Incorporated
• Original Assignee: Bayco Products Ltd
• Inventors: Adams, Paul, Ellis, Robert, Newton, James
• Granted Patent: US 8,548,633 B2
• Time in Patent Office: Days
• US Class Current: 700/286
• CPC Class Codes: F21L 4/005 the device being a pocket lamp F21L4/022, F21L4/045, F21L4/085 take precedence
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• 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 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A heat sink for a handheld device is formed as a one piece chassis for supporting heat-producing circuits inside the device while having heat radiating surfaces outside the device. In another embodiment a battery pack control circuit under microprocessor control allows battery packs having different battery chemistries and characteristics to be interchanged in the same device without switches or adapters. Control of operating modes of the device despite changes in the battery pack including battery chemistry, state of charge, available voltage, or desired operating mode are automatic. The microprocessor measures the battery pack characteristics, using look up tables in a suitable program to adjust the circuit operating modes. The microprocessor also responds to sequential switch contact closures in setting operating modes.

Claims

1. A battery pack control circuit for a handheld device, comprising:

first and second terminals for connecting said circuit to said battery pack;

a processor in said circuit connected to a memory and having a plurality of A/D inputs coupled to predetermined nodes in said circuit for detecting at least one battery parameter of said battery pack in said circuit to select a corresponding battery identity; and

a program stored in said memory and executable on said processor responsive to said corresponding battery identity to select one of a plurality of battery operating modes of said circuit responsive to said battery parameters;

wherein said battery operating modes of said circuit are selected based on detection of said battery parameters corresponding to the type of battery pack connected to said circuit.

2. The circuit of claim 1, wherein said circuit is operable with either of at least two different types of battery pack to automatically control said selected battery operating mode of said circuit.

3. The circuit of claim 2, wherein said different types of battery pack provide different voltage outputs at said first and second terminals of said circuit.

4. The circuit of claim 2, wherein said different types of battery pack includes a NiMH battery pack and a Li/MnO₂ battery pack.

5. The circuit of claim 1, wherein said program comprises:

at least one table of values associated with each type of battery pack for determining said battery operating mode to be selected;

wherein

said table of values associates a drive current output level with the detected battery parameter.

6. The circuit of claim 5, wherein said drive current level corresponds to a selected light output of a handheld light device.

7. The circuit of claim 5, wherein said drive current output level is adjustable depending upon the type of battery pack.

8. The circuit of claim 7, wherein said drive current level is selected based on the state of charge of said battery pack.

9. The circuit of claim 1, further comprising:

a program stored in said memory and executable on said processor responsive to a sequence of switch contact states for determining a plurality of operating states of said circuit.

10. The circuit of claim 9, wherein said plurality of operating states exceeds three distinct operating states.

11. The circuit of claim 10, wherein each one of said operating states is selected from the group consisting of momentary ON flash, momentary ON full current, latched ON full current;

latched ON half current;

latched ON strobe; and

OFF.

12. The circuit of claim 11, wherein said program comprises:

a first table of values associated with a first type of battery pack for determining said operating mode to be selected;

a second table of values associated with a second type of battery pack for determining said operating mode to be selected; and

a third table of values associated with respective switch contact states of a single switch for determining said operating state to be selected.

13. A battery pack control circuit, comprising:

first and second terminals for connecting said circuit and said operating load to said battery pack;

a processor in said circuit connected to a memory and having a plurality of A/D inputs coupled to predetermined nodes in said circuit for sensing parameters of said battery pack in said circuit to produce a corresponding output for each sensed parameter; and

a program stored in said memory and executable on said processor responsive to said corresponding outputs to select one of a plurality of operating modes of said circuit responsive to the type of battery pack connected to said circuit, responsive to the state of charge of said battery pack, and responsive to said operating load upon said battery pack.

14. The circuit of claim 13, wherein said operating modes of said circuit are selected regardless of the type of battery chemistry utilized in said battery pack.

15. The circuit of claim 13, wherein said operating modes of said circuit are selected in response to data read from information associated with said battery pack.

16. The circuit of claim 15, wherein said processor determines said operating modes by setting parameter references based on said data read from information associated with said battery pack, and adjusting said corresponding outputs responsive to said parameters of said battery pack in said circuit relative to said parameter references.

17. The circuit of claim 15, wherein said data is read from an identification device associated with said battery pack.

18. The circuit of claim 17, wherein said identification device is attached to said battery pack.

19. The circuit of claim 17, wherein said identification device is an electronic chip attached to said battery pack and connected to be read by said processor.

20. The circuit of claim 16, wherein said parameter references are read during execution of said program from look up tables associated in said memory with said data read from said identification device.