JP2005190895A - Lighting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting apparatus wherein a situation where an overcurrent flows into a feeder circuit to heat a mouthpiece part for melting a resin ornament part etc. when equipped with the lighting load exceeding a rated power can be prevented beforehand, and which automatically recovers and a normal feed operation is performed without requiring an operation like exchange of a fuse when exchanging to a lighting load not exceeding the rated value. <P>SOLUTION: In the lighting system 10 including the feeder circuit C1 supplying power to the lighting load L from a commercial AC power source, a polymer PTC thermistor is used as a load current limit means 11 provided at a proper position of the feeder circuit C1. When the lighting load L with the rated power or less is attached, the element resistance is limited at a low level, and the lighting load L is lit with rated consumption power. When the lighting load L exceeding rated power is attached, the element resistance becomes remarkably high as the element temperature increases, the current flowing in the feeder circuit C1 is suppressed, and the lighting load L is turned off. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lighting device including a circuit for supplying power to a lighting load such as a light bulb or a fluorescent lamp.

  Conventionally, in a lighting device including a circuit for supplying power to an illumination load such as a light bulb or a fluorescent lamp, a rated power for limiting the connected illumination load has been determined. The base part of the lighting device does not become abnormally high temperature, and the lighting device can be operated stably for a long time.

  In the case of an illumination load where the filament part is approaching, such as a U-shaped fluorescent lamp, the base part may become hot at the end of its life. Safety measures were taken to turn off the temperature fuse when the part became hot. In addition, in order to suppress the increase in size and cost of the lighting device by providing a plurality of temperature fuses, a temperature fuse is provided in the preheating circuit, and the temperature fuse blows off due to the temperature rise of the base part, so that the preheating circuit There has also been proposed a control circuit that includes a control circuit that stops the operation of a switching element that generates high-frequency alternating current when the current stops flowing, and turns off the lamp (for example, see Patent Document 1).

JP-A-11-3379

  However, the illumination device described in Patent Document 1 generates high-frequency alternating current from commercial alternating current and supplies it to the filament of the fluorescent tube. An illumination load exceeding the rated power of the illumination device is attached, and the base portion is attached. It cannot be applied to safety measures when the temperature becomes high. Moreover, since the temperature fuse is used, if the temperature fuse blows, it cannot be reused unless it is replaced, which is very inconvenient.

  The subject of the present invention is that when an illumination load exceeding the rated power is mounted, the load current is suppressed before an overcurrent flows through the power supply circuit and the base temperature rises and the resin decorative parts are melted. Therefore, if the lighting load is replaced with a lighting load that does not exceed the rated value, it can be automatically restored without requiring an operation such as replacing the fuse. It is providing the illuminating device with which electric power feeding operation is performed.

  In order to solve the above-mentioned problem, the invention according to claim 1 is to supply power when a lighting load that does not exceed a predetermined rated power is mounted in a lighting device including a circuit that supplies power to the mounted lighting load. Load that does not function at the current value that flows through the circuit, functions when the lighting load that exceeds the rated power is installed, and the current that flows through the power supply circuit reaches the threshold current, and limits the circuit current to a current value lower than the threshold current A current limiting means is provided.

  According to a second aspect of the present invention, in the illumination device according to the first aspect, the load current limiting means is a PTC thermistor inserted in a power feeding circuit.

  According to a third aspect of the present invention, in the lighting apparatus according to the first aspect, the load current limiting unit includes a circuit switching unit that opens and closes the power feeding circuit, and a current that flows through the power feeding circuit to which the lighting load is connected. When the current detection means for detecting the current detection value and the detected current value detected by the current detection means are determined to exceed the threshold stored in advance, the circuit switching means is operated to open the power supply circuit, And a power supply cutoff control means for cutting off the power supply to the illumination load.

  According to a fourth aspect of the present invention, in the illumination device according to any one of the first to third aspects, an air purifying function is provided by generation of negative ions and ozone.

  According to the lighting device device according to claim 1, when a lighting load that does not exceed a predetermined rated power is attached, the current value that flows through the feeder circuit does not function, and when a lighting load that exceeds the rated power is attached. Since the load current limiting means that functions when the current flowing through the power supply circuit reaches the threshold current and limits the circuit current to a current value lower than the threshold current is provided, if a lighting load exceeding the rated power is installed, the power supply circuit Before the overcurrent flows to the base part and the temperature of the base part rises and the decorative parts made of resin melt, the load current can be suppressed to prevent the temperature from rising. In addition, when the lighting load is replaced with a value that does not exceed the rated value, the usual power feeding operation is performed without requiring an operation such as replacement of the fuses, so that convenience for the user can be improved.

  Further, according to the lighting device according to claim 2, since the PTC thermistor inserted in the power feeding circuit is used as the load current limiting means, the load current limiting means can be added to the lighting device with a small and light and simple structure. In addition to reducing the size and weight of the lighting device body, it is also possible to reduce the cost. Moreover, by appropriately selecting the element characteristics of the PTC thermistor, it is possible to arbitrarily set the amount of resistance change at the time of temperature rise due to overcurrent, so that it can be lit at an illuminance sufficiently lower than the original illuminance of the illumination load, Alternatively, by using a polymer-based PTC thermistor whose resistance value changes as high as 10 4 to the 6th power as the load current limiting means, the current value flowing through the power feeding circuit after the load current limiting means functions is extremely low. The lighting load can be substantially turned off.

  According to the illumination device of claim 3, the circuit switching means for opening and closing the power supply circuit, the current detection means for detecting the current flowing through the power supply circuit connected to the illumination load, and the detection detected by the current detection means When it is determined that the current value exceeds the threshold value stored in advance, the circuit switching means is activated to open the power supply circuit, and the power supply cut-off control means for cutting off the power supply to the lighting load and the load current limit If a lighting load exceeding the rated power is installed and an overcurrent flows through the power supply circuit, the power supply circuit is opened and the circuit current is shut off, and the base temperature rises. Can be prevented. In addition, when the power supply circuit is opened by attaching an illumination load exceeding the rated power, the current value detected by the current detection circuit becomes zero, and the power supply cutoff control means again turns the power supply circuit on with the circuit switching means. Since it will be closed, power supply and interruption will be repeated until the lighting load exceeding the rated power is removed, the lighting load will blink, and the user can recognize that an inappropriate lighting load is installed . In addition, when the power supply circuit is opened by mounting an illumination load that exceeds the rated power, a load circuit that holds the state of the circuit switching unit is provided in the load current limiting means, and the load current is limited by a reset switch, etc. The power supply circuit may be kept open until the function of the means is reset.

  Moreover, according to the illuminating device which concerns on Claim 4, the added value as an illuminating device can be raised by providing the air-cleaning function by generation | occurrence | production of a negative ion or ozone.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram illustrating a schematic configuration of a lighting apparatus 10 according to the first embodiment.

  The illuminating device 10 includes a power supply circuit C1 that supplies power from a commercial AC power source to an illumination load L (incandescent lamp such as an incandescent bulb or halogen lamp, glow starter type or inverter type fluorescent lamp). The load current limiting means 11 is inserted at an appropriate place. As this load current limiting means 11, a PTC (Positive Temperature Coefficient) thermistor having a positive temperature coefficient was used.

  The PTC thermistor is a device whose resistance value increases as the element temperature rises, and by appropriately selecting element characteristics, the amount of change in resistance at the time of temperature rise due to overcurrent can be arbitrarily set. For example, a polymer-based PTC thermistor is a device whose resistance value changes abruptly when the element temperature rises above a certain temperature, and the change in resistance value reaches as high as 10 4 to the 6th power. An example of the element temperature-element resistance characteristic of the polymer PTC thermistor is shown in FIG. In this characteristic diagram, the element temperature exhibits a steep increase in resistance value in the temperature range of approximately 130 ° C. to 150 ° C., and the element temperature due to the circuit current when the illumination load L of the rated power or less is attached is the above temperature. By setting the element temperature rise due to the circuit current when the illumination load L exceeding the rated power is set to be lower than the above temperature range, the “predetermined rated power is When the lighting load that does not exceed is installed, the current value that flows through the power supply circuit does not function.When the lighting load that exceeds the rated power is installed, the current that flows through the power supply circuit reaches the threshold current, and the circuit current is set to the threshold value. It can be made to function as a load current limiting means for limiting to a current value lower than the current.

  In addition, as the commercially available lighting load L, the rated power is standardized with discrete values, such as 9W, 30W, 50W, and 100W. By using a PTC thermistor that has element characteristics that reach a temperature range where the element resistance changes sharply in the middle of the range, there is no risk of malfunction due to slight movement of the commercial AC voltage, thus increasing the reliability of the current limiting function be able to. In addition, the PTC thermistor has a reversible resistance value, and when the temperature of the element is lowered by turning off the power supply etc., it returns to the original resistance value, so it is not necessary to replace it like a fuse. User convenience can be enhanced.

  In the lighting device 10 using the polymer PTC thermistor described above as the load current limiting means 11, when an illumination load L having a rated power or less is attached, the element temperature rises to a temperature range exhibiting a steep resistance change. Therefore, the element resistance is suppressed to a very low value, and the illumination load L can be turned on with the power consumption as rated.

  On the other hand, in the illuminating device 10 using the polymer PTC thermistor as the load current limiting means 11, when the illumination load L exceeding the rated power is attached, the element temperature rises, the element resistance increases remarkably, and the circuit current is extremely high. Since the circuit is balanced while being suppressed to a very small value, almost no circuit current flows through the power supply circuit C1, the illumination load L is extinguished, and the temperature rise of the base part is also suppressed.

  When a polymer PTC thermistor is used as the load current limiting unit 11, when an illumination load L exceeding the rated power is attached to the lighting device 10, the lighting load L is once lit and then the current limiting function by the load current limiting unit 11. Because it disappears after about a few seconds, there is a possibility that the user who sees it will have the illusion that the light has gone out due to the ball being cut. Therefore, when the load current limiting unit 11 functions, power supply control to the lighting load L is performed so that the lighting load L is different from that when the light is turned off, and the user is informed that the incompatible lighting load L has been connected. It is good also as a structure which makes it recognize. Therefore, as the element characteristics of the PTC thermistor used for the load current limiting means 11, the lighting load L is in a state where the temperature rise due to the circuit current when the lighting load L exceeding the rated power is mounted and the resistance value are balanced. It is only necessary to select an electric current that can be turned on with an illuminance lower than the original illuminance.

  Next, based on FIG. 3, the structure of the illuminating device 20 which concerns on 2nd Embodiment is demonstrated.

  The lighting device 20 includes a power supply circuit C2 that supplies electric power from a commercial AC power source to an illumination load L (incandescent lamp such as an incandescent lamp or halogen lamp, glow starter type or inverter type fluorescent lamp). A load current limiting means 21 for opening and closing an appropriate place and a current detection resistor 22 are provided at an appropriate place in the power feeding circuit C2.

  The load current limiting means 21 is configured by mounting electronic parts, IC chips, etc. on a substrate, for example, and generates an operation power supply (for example, DC 3V) necessary for operating each section by the power supply circuit section 21a.・ Supply. The power supply circuit unit 21a may generate an operating power supply from commercial alternating current used for power supply to the lighting load L, or may generate an operating power supply from a commercially available storage battery.

  The switching unit 21b serving as a circuit switching unit that opens and closes the power feeding circuit C2 includes a relay having a mechanical contact, a semiconductor relay having no mechanical contact, and the like. Is to do. The contact of the switching unit 21b may be a normally open contact (a contact) or a normally closed contact (b contact). However, when the normally open contact is used, the load current limiting means 21 functions normally. If the normally open contact of the switching unit 21b is not closed, power is not supplied from the power feeding circuit C2 to the lighting load L, so that the lighting load L is lit in a state where the load current limiting means 21 is not functioning. There is an advantage that can be prevented. On the other hand, if a normally open contact is used for the switching part 21b, if the load current limiting means 21 fails, power supply to the lighting load L cannot be performed at all. Therefore, in this embodiment, the lighting load In order to give priority to power supply to L, a normally closed contact is used for the switching unit 21b.

  The current detection circuit unit 21c as current detection means for detecting the current flowing through the power supply circuit C2 connected to the lighting load L detects the voltage across the current detection resistor 22 and outputs a signal corresponding to the voltage. Receiving this, the amplifier circuit unit 21d amplifies the voltage as appropriate and outputs it to the comparator circuit 21e. The comparison circuit 21e that has received the detection voltage from the amplification circuit unit 21d detects the threshold voltage that is assumed as a set voltage that is a comparison target (a load current that flows when the illumination load L exceeding the rated power is mounted). Then, this is a voltage equal to the output value amplified by the amplifier circuit unit 21d) and the detected voltage actually received from the amplifier circuit unit 21d. When the detected voltage exceeds the set voltage, the drive circuit unit 21f is reached. An ON signal (for example, H level) is output. Then, a relay drive signal is output from the driver circuit 21f to the switching unit 21b, and the switching control of the power feeding circuit C2 by the switching unit 21b is realized. As described above, in the present embodiment, the amplifying circuit unit 21d, the comparison circuit unit 21e, and the drive circuit unit 21f cooperate with each other so that "the detected current value detected by the current detecting unit is stored in advance. If it is determined that the power supply is exceeded, the circuit switching means is activated to open the power supply circuit and function as the power supply cutoff control means for cutting off the power supply to the lighting load. Other circuit configurations may be adopted as long as they can be realized.

  Further, as the commercially available lighting load L, the rated power is standardized with discrete values such as 9 W, 30 W, 50 W, and 100 W. If a threshold value is set with reference to the current flowing through the current detection resistor 22 when a lighting load around the middle of the load is connected, even if the voltage across the current detection resistor 22 slightly moves due to the slight movement of the commercial AC voltage, the load Since there is no risk that the current limiting means 21 malfunctions, the reliability of the current limiting function can be improved.

  In the lighting device 20 using the load current limiting means 21 having the circuit configuration described above, when a lighting load L having a rated power or lower is attached, the current detection circuit unit 21c and the current detection circuit unit 21c based on the voltage across the current detection resistor 22 Since the detection voltage output through the amplifier circuit unit 21d is determined to be equal to or lower than the set voltage in the comparison circuit unit 21e, no ON signal is output to the drive circuit unit 21f, and the switching unit 21b remains closed. Thus, the illumination load L can be lit with the power consumption as rated.

  On the other hand, in the lighting device 20 using the load current limiting means 21, when the lighting load L exceeding the rated power is attached, the current detection circuit unit 21c and the amplification circuit unit 21d are connected based on the voltage across the current detection resistor 22. Since the detected voltage output after that is determined to exceed the set voltage in the comparison circuit unit 21e, an ON signal is output to the drive circuit unit 21f, and the switching unit 21b is opened. No longer flows, the illumination load L is extinguished, and the temperature rise of the base part is also suppressed.

  In addition, after the power feeding circuit C2 by the load current limiting means 21 is opened as described above, the circuit current does not flow, so that the current detection circuit unit 21c and the amplifier circuit are based on the voltage across the current detection resistor 22. Since the detection voltage output through 21d is determined to be equal to or lower than the set voltage in the comparison circuit unit 21e, the ON signal to the drive circuit unit 21f is stopped, and the opening control of the switching unit 21b by the drive circuit unit 21f is stopped. The power supply circuit C2 is closed again and the lighting load L is lit. If the lighting load L still exceeds the rated power, the detection voltage acquired again based on the voltage across the current detection resistor 22 is obtained. Therefore, the switching unit 21b is activated to open the power feeding circuit C2, and the illumination load L is extinguished.

  As described above, in the lighting device 20 including the load current limiting unit 21 of the present embodiment, when the lighting load L exceeding the rated power is connected, the rated power is reduced by continuously opening and closing the power feeding circuit C2. Power supply and interruption are repeated until the excess illumination load L is removed, the illumination load L is blinked, and the user can recognize that an inappropriate illumination load L is attached to the illumination device 20. The blinking interval of the illumination load L can be arbitrarily set by providing an appropriate delay circuit unit in the load current limiting means 21. Further, if the illumination load L is changed to the rated power or lower, the detected voltage is held below the set voltage, so the switching unit 21b of the load current limiting means 21 does not operate and the power feeding circuit C2 is closed. Since the state is maintained, it is possible to automatically return to the normal state without taking the trouble of replacing the fuse, and the convenience for the user can be improved.

  In the second embodiment described above, when the load current limiting unit 21 functions, the power supply circuit C2 is repeatedly opened and closed to control the power supply to the lighting load L so that the lighting load L is different from that when the light is turned off. Although it was set as the structure which makes a user recognize that the lighting load L was connected, it is not limited to this. For example, when the power supply circuit C2 is opened by mounting an illumination load L that exceeds the rated power, a hold circuit unit that maintains the open state of the switching unit 21b is provided, and the load current is limited by a separately provided reset switch or the like. Until the function of the means 21 is reset, the power feeding circuit C2 may be kept open.

  FIG. 4 shows an appearance of the lighting device 30 according to the third embodiment. The lighting device 30 includes a load-current limiting means 31 in a socket-shaped casing, receives commercial AC power via a base portion 32, and is illuminated. Power is supplied through the base 41 of the lamp 40 that is a load.

  The lighting device 30 is provided with an AC / DC converter 33. The AC / DC converter 33 generates a high-voltage direct current from commercial alternating current, and supplies the direct-current high voltage to the air cleaning function unit 34. The air cleaning function unit 34 generates a discharge due to a strong electric field and generates negative ions and ozone. Note that a high-intensity light-emitting diode 35 is disposed at an appropriate position as a pilot lamp indicating the operating state of the air purification function unit 34.

  As in the present embodiment, in the lighting device 30 that is integrally provided with the air cleaning function unit 34, the appearance of the lighting device 30 is highly decorative, or a complicated internal structure suitable for the air cleaning function unit 34 is formed. In addition, it is desirable to increase the mass production effect of the exterior and internal parts by resin molding. On the other hand, even when a heat-resistant resin material is used, the heat-resistant temperature is lower than that of glass or metal, and when a lamp 40 with a wattage exceeding the rated power of the lighting device 30 is attached, the temperature rises due to overcurrent. There is a possibility that the heat of the cap part 41 propagates to the surroundings and the exterior of the lighting device 30 melts.

  Thus, the lighting device 30 according to the present embodiment does not function with the current value flowing through the power feeding circuit when the lamp 40 that does not exceed the predetermined rated power is attached, and the lamp 40 that exceeds the rated power is attached. Since the load current limiting means 31 that sometimes functions when the current flowing through the power supply circuit reaches the threshold current and can limit the circuit current to a current value lower than the threshold current is provided, the user accidentally sets the rated power. Even when the lamp 40 exceeding is attached to the illuminating device 30, the situation where the resin part melts can be effectively avoided.

  As the load current limiting means 31, a configuration based on the above-described current limiting function by the PTC thermistor may be applied, or the power feeding circuit is controlled to open and close by comparing and determining the detected current value and the set value. Alternatively, a current limiting configuration may be employed. Of course, when the current limiting operation is performed, the lighting load may be turned off, or power feeding control may be performed in a manner different from the turned off state.

It is a schematic block diagram of the illuminating device which concerns on 1st Embodiment. It is an element temperature-element resistance characteristic view of a polymer PTC thermistor. It is a functional block diagram of the illuminating device which concerns on 2nd Embodiment. It is an external view of the state which attached the lamp | ramp to the illuminating device which concerns on 3rd Embodiment.

Explanation of symbols

10. Illumination device (first embodiment)
11 Load current limiting means C1 Power supply circuit L Lighting load 20 Lighting device (second embodiment)
21 load current limiting means 21a power supply circuit unit 21b switching unit 21c current detection circuit unit 21d amplifier circuit unit 21e comparison circuit unit 21f drive circuit unit C2 power supply circuit 30 lighting device (third embodiment)
31 Load Current Limiting Means 32 Base Part 33 AC / DC Converter 34 Air Cleaner Function Part 35 Light Emitting Diode 40 Lamp 41 Base Part

Claims (4)

In a lighting device comprising a circuit for supplying power to an installed lighting load,
When the lighting load that does not exceed the predetermined rated power is installed, the current value that flows through the power supply circuit does not function.When the lighting load that exceeds the rated power is installed, the current that flows through the power supply circuit reaches the threshold current. A lighting device comprising a load current limiting unit that functions and limits a circuit current to a current value lower than a threshold current.   The lighting device according to claim 1, wherein the load current limiting means is a PTC thermistor inserted in a power feeding circuit. The load current limiting means is
Circuit switching means for opening and closing the power feeding circuit;
Current detection means for detecting a current flowing through a power supply circuit connected to a lighting load;
When it is determined that the detected current value detected by the current detection means exceeds a threshold value stored in advance, the power supply circuit is opened by operating the circuit switching means, and the power supply to the lighting load is cut off. Shut-off control means;
The lighting device according to claim 1, comprising:   The lighting device according to any one of claims 1 to 3, further comprising an air cleaning function by generation of negative ions and ozone.

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