The invention relates to an ignitor and ignitor indicator for facilitating the troubleshooting of a high intensity, gas discharge lamp.
High intensity, gas discharge luminaires, which are hereinafter referred to as HID luminaires, are commonly installed at high locations at commercial or industrial facilities such as on the ceiling of a warehouse or plant, or on light poles in a parking lot or stadium. HID luminaires can include, but are not limited to, metal halide or MH lamps, and high pressure sodium or HPS lamps. HID luminaires often use pulses from a high voltage source such as a starting circuit to ignite the lamp.
In many applications, the HID luminaires can be elevated on the order of thirty feet or more above the floor or ground at a commercial or industrial facility. The elevation of the luminaires makes repair of malfunctioning luminaires inconvenient and time consuming since service personnel must ascend to considerable heights in order to gain access to the luminaires, assess the problem and then repair or replace components of the luminaire. The malfunctioning of an HID luminaire can be attributed to any of a number of problems such as a defective ballast or ballast capacitor, a defective lamp, loss of supply voltage or defective lamp starting circuit, which is hereinafter referred to as an ignitor.
A number of devices exist to facilitate the assessment of a malfunctioning luminaire. For example, U.S. Pat. No. 4,318,031, to Lonseth et al, discloses a visual monitoring device having two indicator lights for indicating the operational conditions of a lamp, a ballast and a starter circuit, as shown in FIG. 1. The first indicator light is provided across the lamp and indicates whether the lamp or the ballast have failed. The second indicator light is driven by a voltage divider circuit comprising resistors connected to the output of the ballast. The starter circuit is connected to a power source, to the ballast, and to the junction between the lamp and a lead-type ballast capacitor, and is configured to provide the lamp with pulses. The pulses are divided by the voltage divider circuit and the resulting pulses are provided to a diode. The resulting pulses are of sufficient voltage to allow the conduction of the diode and storage by a capacitor. Under normal operating conditions of the starter circuit, pulses are stored during each cycle of a 60 Hertz supply. The indicator light operates when thirty pulses are stored or twice a second.
If the indicator light does not blink and the lamp is off, then the starting circuit is malfunctioning. A service person must then interrupt the supply of power to the luminaire and ascend a ladder or use other means to reach the elevated luminaire in order to remove the luminaire from the ceiling or other surface to which it is mounted. Secondly, the luminaire housing must be opened and circuit connections disconnected to remove the malfunctioning starter circuit and replace it with a new starter circuit. As stated previously, these types of repairs are costly in terms of man-hours required to perform the above operations. Further, such repair operations can potentially expose a service person to electric shock if the luminaire housing is opened before line power to the luminaire is terminated for repair purposes. Thus, a need exists for a luminaire which has an ignitor or starting circuit that is connected to the outside of the luminaire housing, as well as an ignitor indicator. The starting circuit can therefore be removed and replaced with relative ease and without having to interrupt power to the luminaire or risk exposure to electric shock.
The present invention overcomes the deficiencies of existing lamp trouble-shooting and indicator devices and realizes a number of advantages over these existing devices. An HID luminaire is provided which comprises an externally mounted ignitor and ignitor monitoring device. The ignitor monitoring device provides a visual indication of whether or not the ignitor of the lamp in the HID luminaire is functioning. If the lamp is not on and the ignitor and ignitor monitoring device is activated, sufficient open circuit voltage is present to operate the ignitor. The ballast therefore is most likely functioning properly, and power is present to operate the luminaire. A service person can assume that the lamp is defective and can replace the lamp as a first attempt to correct the problem with the luminaire. If the lamp is off and the ignitor and ignitor monitoring device is also not operating, the luminaire is not operating for any of a number of reasons such as a defective ignitor, a defective ballast or ballast capacitor, a defective lamp or loss of supply voltage. A service person can replace the ignitor in a first attempt to repair the luminaire. Replacing the ignitor is the simplest initial repair option since the ignitor is enclosed with the ignitor monitoring device in a housing that is externally mounted on the luminaire. If the ignitor is indeed the problem, the service person has repaired the luminaire without having to disassemble the luminaire which comprises the lamp, the ballast, and other components in a luminaire housing. In addition, the risk of exposing the service person to electrocution via the power supply wires to the luminaire is reduced since the service person did not have to open the luminaire to replace the ignitor. Further, supply voltage to the luminaire did not have to be interrupted by the service person to replace the externally mounted ignitor and ignitor monitoring device.
In accordance with an embodiment of the present invention, the ignitor provides for isolation of an LED charge/discharge loop from the ignitor loop for improved fail mode operation.