Intrinsically safe battery-powered device

• US 7,550,943 B2
• Filed: 09/19/2006
• Issued: 06/23/2009
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: Energizer Brands, LLC (Energizer Holdings, Inc.)
• Original Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Inventors: Hoffman, Peter F., Spartano, David
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US11/523,157
• Publication Number:
  US 20080079393A1
• Time in Patent Office: 1,008 Days
• Field of Search: 320/107, 320/112, 320/114, 320/106, 320/110
• US Class Current: 320/107
• CPC Class Codes: H02J 1/00 Circuit arrangements for dc mains or dc distribution networks

Abstract

An intrinsically safe battery powered device (100) includes a housing (102), a battery receiving region (104), an intrinsically safe power supply (108, 110), and device electrical circuitry (112). The power supply (108, 110) uses energy from batteries (106) received in the batter receiving region (104) of the device (100) to power the circuitry (112). In one implementation, the power supply includes an intrinsically safe charge pump circuit.

Claims

1. An intrinsically safe device comprising:

a battery receiving region which accepts at least a first generally cylindrical battery;

first device electrical circuitry;

a first boost converter which converts electrical energy from the at least a first battery to a level suitable for powering the first device electrical circuitry, wherein the device is intrinsically safe for use in a hazardous location; and

an energy limiter that limits an energy available from the at least a first battery to the first device electrical circuitry so as to render the device incapable of causing ignition of a flammable or combustible material.

2. The device of claim 1 wherein at a least a first battery is a AAA, AA, C, or D-size battery.

3. The device of claim 1 wherein the device is intrinsically safe for use in a location where ignitable concentrations of flammable gases, vapors, or liquids are present for long periods of time or continuously.

4. The device of claim 3 including second device electrical circuitry which operates using a voltage produced by the at least a first battery.

5. The device of claim 3 including second device electrical circuitry and a second converter which converts electrical energy from the at least a first battery to a level suitable for powering the second electrical circuitry.

6. The device of claim 1 wherein the converter includes a closed loop voltage controller.

7. The device of claim 1 wherein the converter includes a charge pump.

8. The device of claim 7 wherein the charge pump includes a plurality of flying capacitors.

9. The device of claim 1 wherein the converter operates in a first mode in which the converter functions as a voltage boost converter and a second mode in which a maximum output voltage of the converter is less than or equal to an input voltage of the converter.

10. The device of claim 1 wherein the device includes a battery charger for charging the at least a first battery.

11. The device of claim 1 wherein the energy limiter includes:

a resistive component that limits an electrical current available to both the first device circuitry and the converter; and

a fuse that limits thermal effects of operation, wherein the energy limiter causes the device, under normal and fault conditions, to be incapable of causing ignition of the flammable or combustible material.

12. The device of claim 1 wherein the device is a hand-held device.

13. The device of claim 1 wherein the device includes a wireless communication device.

14. The device of claim 1 wherein the device includes a transducer which, in operation, is mounted at a fixed location in the external environment.

15. The device of claim 1 wherein the device includes at least one of a voltmeter, an ohmmeter, and an ammeter.

16. An intrinsically safe, battery powered device including a first electrical circuitry which performs a function of the device, a battery receiving region, and an intrinsically safe, active power supply circuit which uses energy from a battery received in the battery receiving region to power the first electrical circuitry.

17. The device of claim 16 wherein the battery receiving region receives exactly two generally cylindrical batteries and the power supply circuit uses energy from the exactly two batteries to power the first electrical circuitry.

18. The device of claim 16 wherein the power supply circuit includes a passive electrical component which limits the energy from the battery so that, in the event of a device fault condition, the device is incapable of causing ignition of a mixture of a flammable or combustible material associated with the battery receiving region making the device safe for use in a hazardous location.

19. The device of claim 18 wherein the energy is limited so that the device is intrinsically safe for use in a hazardous location where ignitable concentrations of flammable gases, vapors or liquids exist under normal operating conditions.

20. The device of claim 16 wherein the power supply circuit includes a capacitive charge pump.

21. The device of claim 20 wherein the charge pump includes first and second charge pump capacitors, and wherein the first and second capacitors are connected electrically in parallel when connected to an input side of the charge pump and electrically in series when connected to an output side of the charge pump.

22. The device of claim 20 wherein the charge pump includes a charge pump capacitor, and wherein the charge pump capacitor is stacked on top of an input of the charge pump for supplying energy to an output of the charge pump.

23. The device of claim 20 wherein the charge pump includes a multiphase clock.

24. The device of claim 16 wherein the device includes an electrical connector for connecting the device to fixed, external wiring.

25. The device of claim 24 wherein the fixed, external wiring provides operating power to the device.

26. The device of claim 16 wherein the device includes a user operable signaling device.

27. The device of claim 16 wherein the device includes a warning device.

28. The device of claim 16 wherein the device is readily transportable by a human user.

29. The device of claim 16 wherein the active power supply circuit includes a closed loop output controller.

30. A method of operating an electrical device comprising:

receiving electrical energy from at least a first battery disposed in a battery receiving region of the device;

using a first intrinsically safe active power supply circuit to supply electrical energy received from the at least a first battery to first electrical circuitry of the device, wherein the first intrinsically safe active power supply circuit limits available energy so that a thermal effect cannot cause ignition of a flammable or combustible material thereby rendering the device incapable of causing ignition of a flammable or combustible material.

31. The method of claim 30 wherein the device is intrinsically safe for use in a Group I, Division I hazardous location.

32. The method of claim 30 wherein the device is intrinsically safe for use in a Zone 0 hazardous location.

33. The method of claim 30 wherein the power supply circuit includes at least one of a capacitive voltage doubler or a capacitive voltage divider.

34. The method of claim 30 wherein the power supply circuit includes an input side for receiving energy from the at least a first battery and an output side for providing energy to the first electrical circuitry and using an active power supply circuit includes using a flying capacitor to transfer energy from the input side to the output side.

35. The method of claim 30 including using a second active power supply circuit to supply electrical energy to second electrical circuitry of the device when the device is operated in the hazardous location.

36. The method of claim 30 wherein receiving includes receiving electrical energy from a plurality of secondary batteries.

37. The method of claim 30 including using the device to perform a measurement function.

38. The method of claim 30 including using the device to perform a communication function.

39. The method of claim 30 including using the device to perform an automatic warning function.

40. The method of claim 30 including using the device to perform a user-controlled visual or audible signaling function.

41. The method of claim 30 including fixedly mounting the device in the hazardous location.

42. The method of claim 30 including

measuring, during an operation of the device, a voltage supplied to the first electrical circuitry;

and

using the measured value to adjust the voltage supplied to the first electrical circuitry.

43. An intrinsically safe battery powered device comprising:

a battery receiving region adapted to receive at least a first battery;

first device electrical circuitry; and

a first intrinsically safe charge pump which uses energy from the at least a first battery to power the device electrical circuitry, wherein the device is intrinsically safe in that it limits available energy so that a thermal effect cannot cause ignition of flammable or combustible material.

44. The device of claim 43 including second device electrical circuitry and a second intrinsically safe charge pump which uses energy from the at least a first battery to power the second device electrical circuitry.

45. The device of claim 43 wherein the device electrical circuitry includes an actuator.

46. The device of claim 43 wherein the device electrical circuitry includes a MEMS.

47. The device of claim 43 wherein the device performs a function specific to one of a petrochemical facility, a mine, an agricultural facility, or an industrial facility.

48. A battery powered, intrinsically safe charge pump power supply which transfers electrical energy from at least a first battery to an electrical load, wherein the power supply is intrinsically safe in that it limits available energy so that a thermal effect cannot cause ignition of a flammable or combustible material.