Lamp fault detection

• US 6,396,216 B1
• Filed: 11/15/2000
• Issued: 05/28/2002
• Est. Priority Date: 05/15/1998
• Status: Expired due to Fees

• Current Assignee: Noontek Limited
• Original Assignee: Noontek Limited
• Inventors: Mc Carthy, Paul, Quinlan, Michael, Noone, Sean, Durkan, Thomas
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US09/700,466
• Time in Patent Office: 559 Days
• Field of Search: 315/119,122,127,129-131,86,292,312,316,324,360,362
• US Class Current: 315/119
• CPC Class Codes: H02J 9/02 in which an auxiliary distribution system and its associated lamps are brought into service
• CPC Class Codes: H05B 47/22 with communication between the lamps and a central unit

Abstract

A fault detection apparatus for a public lighting system has a number of lamps. Each lamp incorporates an operating and control circuit which will emit signals on a fault occurring or conditions arising indicating a potential fault, for example, of a gas discharge tube forming part of the lamp. The apparatus, which can be incorporated in the lamp operating and control circuit or be provided as a separate plug in unit incorporates a host interface. A control unit and an externally visible signalling device such as a flag or flashing beacon will allow the detection of a fault or potential fault for example during normal daylight hours.

Claims

1. A fault detection apparatus for a public lighting system of the type having a plurality of lamps, each lamp including an operating and control circuit incorporating fault detection signalling to signal both existing and imminent fault conditions for various portions of the operating and control circuit characterised in that the fault detection apparatus (1) comprises:

a host interface (5) for connection to the lamp operating and control circuit (3) for the reception of fault detection signals;

a control unit (6) for reception of the fault detection signal; and

an externally visible signalling device (7) connected to the control unit (6) and operable by the control unit (6) to signal the fault condition.

2. A fault detection apparatus as claimed in claim 1 in which the signalling device (7) is a flag (42).

3. A fault detection apparatus as claimed in claim 1 in which signalling device (7) is a signalling beacon (34).

4. A fault detection apparatus as claimed in claim 1 in which there is provided additional signalling means for sending the fault detection signal to a host control station (37).

5. A fault detection apparatus as claimed in claim 4 in which the additional signalling means provides a short range radio signal for sending the fault detection signal to a remote but relatively near host station (37).

6. A fault detection apparatus as claimed in claim 5 in which the host station (37) is incorporated in a portable device.

7. A fault detection apparatus as claimed in claim 6 in which portable device is a hand held device.

8. A fault detection apparatus as claimed in claim 1 in which the fault detection apparatus (1) is housed in a separate plug in unit (30) for connection to the lamp (2).

9. A fault detection apparatus as claimed in claim 1 in which the control unit (16) includes means for additionally deactivating the lamp (2) on detection of a fault.

10. A fault detection apparatus as claimed in claim 1 in which the control unit (6) includes analysis means for fault detection signals to identify a particular fault and to cause the signalling device (7) to emit a signal indicating the fault.

11. A fault detection apparatus as claimed in claim 1 in which the control unit (6) includes means for deactivating the lamp (2) in response to the particular fault identified.

12. A fault detection apparatus as claimed in claim 1 in which the control unit incorporates an oscillating circuit.

13. A fault detection apparatus as claimed in claim 1 in which the control unit incorporates an opto-coupler (21).

14. A fault detection apparatus as claimed in claim 3 in which the signalling beacon (34) is a high intensity light source (34).

15. A fault detection apparatus as claimed in claim 3 in which the signalling beacon (34) emits a coloured light.

16. A fault detection apparatus as claimed in claim 5 in which the colour changes depending on the fault identified.

17. A fault detection apparatus as claimed in claim 5 in which the control unit (6) includes an additional indicator lamp (36) to signal correct operation of the control unit (6) and the signalling device (7).

18. A fault detection apparatus as claimed in claim 1 in which the control unit (6) includes additional control means to only operate the signalling device (7) during certain times.

19. A fault detection apparatus as claimed in claim 1 in which the control unit (6) includes light sensors (35) to control the level of light during which the signalling device operates.

20. A fault detection apparatus as claimed in claim 1, wherein the control unit is provided with means for measuring the voltage across lamp contacts and means for generating the fault signal when the voltage across the lamp contacts strays from a certain pre-set level.