JP2010231900A - Lamp-lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lamp-lighting device with improved luminescence efficiency for a fluorescent lamp. <P>SOLUTION: The lamp-lighting device includes power MOSFET 12 and 13, which apply an AC voltage between one ends 171A and 172B of a pair of filaments 171 and 172 of a lamp 17; a preheating current energizing capacitor 22 connected between other ends 171B and 172B of the filaments 171 and 172; a triac 21 connected in series to the preheating current energizing capacitor 22; a resonance parallel capacitor 16 connected in parallel to a serial circuit of the preheating current energizing capacitor 22 and the triac 21; and a control part 11 which causes a preheating current to flow the filaments 171 an 172 for heating by closing the triac 21 at the time of preheating, and after a predetermined period, opens the triac 21 to start discharging between the filaments 171 and 172. The capacitance of a capacitor is switched between preheating and lighting, to reduce the power loss due to the internal resistance. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lamp lighting device.

In order to turn on the fluorescent lamp, a preheating current is applied to the filament coated with the emitter to heat the filament to make it easy to emit electrons, and then a high voltage is applied between the filaments.
At that time, if the power supply voltage is unstable or the ambient temperature is uneven and uneven, a high voltage is applied to both filaments of the fluorescent lamp while the heating of the filament by the preheating current is insufficient, There is a problem in that the emitter applied to each filament is scattered and the life of the fluorescent lamp is shortened.

  In order to solve this problem, a method is known in which a high voltage is prevented from being applied to both filaments when a preheating current is passed by connecting the cathode of a fluorescent lamp and a starting capacitor in parallel. (For example, refer to Patent Document 1).

JP 09-045485 A

  In the technology described in the patent document, since the current continues to flow to the starting capacitor and power is consumed by the internal resistance not only when the filament of the fluorescent lamp is preheated but also during normal lighting, the light emission of the fluorescent lamp The efficiency cannot be improved.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a lamp lighting device that improves the luminous efficiency of a fluorescent lamp.

A lamp lighting device according to an aspect of the present invention is:
A power supply for applying an alternating voltage between each one end of a pair of filaments of the lamp;
A first capacitor connected between the other ends of the pair of filaments of the lamp, and for passing a preheating current of the filament;
A switch connected in series to the first capacitor and opening and closing the electrical path of the preheating current;
A second capacitor connected in parallel with a series circuit of the first capacitor and the switch between the other ends of the pair of filaments of the lamp;
By closing the switch during preheating of the filament, the AC voltage generated by the power supply unit is applied to each filament of the lamp via the first capacitor and the second capacitor, The filament is heated by supplying a preheating current, and after a predetermined period of time, the switch is opened, the AC voltage generated by the power supply unit is applied to each filament of the lamp, and a discharge is caused between both filaments of the lamp. And a control means.

  According to the lamp lighting device of the present invention, the efficiency of the fluorescent lamp can be improved.

It is a figure which shows an example of the structure of the discharge lamp lighting device which concerns on embodiment of this invention, and the state through which an electric current flows at the time of lighting. It is a figure which shows an example of the structure of the discharge lamp lighting device of this invention, and the state through which an electric current flows at the time of preheating. It is a figure which shows the structure of a general discharge lamp lighting device, and the state through which an electric current flows.

  Hereinafter, a discharge lamp lighting device according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment)
As shown in FIG. 1, the discharge lamp lighting device 10 according to the present embodiment includes a control unit 11, power MOSFETs 12 and 13, a resonance inductor 14, and a resonance capacitor 15 in order to turn on the discharge lamp 17. , A resonance parallel capacitor 16, a triac 21, and a preheating current conduction capacitor 22. The discharge lamp lighting device 10 is supplied with electric power via a commercial power supply 31, a switch 32, and an AC / DC converter 33.
The discharge lamp 17 includes a filament 171 having one terminal 171A and the other terminal 171B, and a 172 having one terminal 172A and the other terminal 172B.

  Power MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) 12 and 13 are power supply units of the present invention. The source terminal of the power MOSFET 12 and the drain terminal of the power MOSFET 13 are connected. The drain terminal of the power MOSFET 12 and the source terminal of the power MOSFET 13 are connected to the AC / DC conversion unit 33, and the gates of the power MOSFETs 12 and 13 are connected to the control unit 11. The power MOSFETs 12 and 13 are alternately opened and closed by the control signal of the control unit 11 to convert the DC voltage into a high frequency voltage.

A resonance inductor 14 and a resonance capacitor 15 are connected in series between a connection node n1 between the source terminal of the power MOSFET 12 and the drain terminal of the power MOSFET 13 and one terminal 171A of the filament 171 of the discharge lamp 17. The One terminal 172A of the filament 172 of the discharge lamp 17 is connected to a connection node n2 between the source terminal of the power MOSFET 13 and the AC / DC converter 33.
The resonance parallel capacitor 16 is connected between the other terminal 171B of the filament 171 and the other terminal 172B of the filament 172.
Further, a preheating current conducting capacitor 22 and a triac 21 connected in series are connected in parallel with the resonance parallel capacitor 16 between the other terminal 171B of the filament 171 and the other terminal 172B of the filament 172. .
By connecting these elements to the power MOSFETs 12 and 13, the capacitance of the capacitor connected between the other terminal 171B of the filament 171 of the discharge lamp 17 and the other terminal 172B of the filament 172 can be switched. An LC resonance circuit is configured.
The high-frequency AC voltage generated by the power MOSFETs 12 and 13 is series-resonated by the resonance inductor 14 and the resonance capacitor 15 and applied to the filaments 171 and 172 of the discharge lamp 17.

The discharge lamp 17 includes two filaments 171 and 172 coated with an emitter (electron emitting material made of an oxide such as barium, strontium, and calcium), and a discharge medium (mercury vapor and an inert gas such as argon, krypton, or neon). ) And a bulb coated with a fluorescent material in the tube. As described above, the filament 171 includes one terminal 171A and the other terminal 171B. The filament 172 includes one terminal 172A and the other terminal 172B.
When lighting the discharge lamp 17, the controller 11 first supplies a preheating current to the filaments 171 and 172 of the discharge lamp 17 to raise the temperature of the filaments 171 and 172. After the temperature of the filaments 171 and 172 rises, the control unit 11 increases the voltage difference between the filaments 171 and 172 by setting one of the filaments 171 and 172 of the discharge lamp 17 to a high potential and the other to a low potential. Cause a discharge.

  In the triac (bidirectional thyristor) 21, the control unit 11 is connected to the gate. One terminal MT (Main Terminal) 1 of the triac 21 is connected to the other terminal 171 B of the filament 171. The other terminal MT2 is connected to the electrode on the side not connected to the other terminal 172B of the filament 172 of the preheating energization capacitor 22. The triac 21 is an example of the switch of the present invention.

  The preheating current energization capacitor 22 energizes / de-energizes an alternating current when the triac 21 opens and closes the electric circuit. The preheating current conducting capacitor 22 has a capacity 0.5 to 5 times that of the resonant parallel capacitor 16.

The commercial power supply 31 is an AC power supply of 60 Hz and 50 Hz, for example.
The switch 32 controls turning on / off of the discharge lamp 17 by opening and closing.
The AC / DC (Alternating Current / Direct Current) conversion unit 33 is configured by a rectifier circuit, a smoothing capacitor, or the like, and converts an AC voltage supplied from the commercial power supply 31 into a DC voltage.

The control unit 11 is connected to the gates of the power MOSFETs 12 and 13.
When the controller 11 is turned on, the power MOSFETs 12 and 13 are alternately opened and closed, so that the DC voltage supplied from the AC / DC converter to the power MOSFETs 12 and 13 is 20 kHz to 70 kHz (remote control frequency band 33 kHz to 40 kHz). Converted to AC voltage.

The control unit 11 is connected to the gate of the triac 21.
When preheating the filament, the control unit 11 causes the power MOSFETs 12 and 13 to generate an alternating voltage having a frequency lower than that at the time of lighting. Further, the control unit 11 outputs a pulse signal whose polarity is inverted in accordance with the direction in which the AC voltage converted by the power MOSFETs 12 and 13 is applied to the discharge lamp 17 to the gate of the triac 21. This pulse signal is output from the control unit 11 to the triac 21 at a timing that takes into account the phase delay of the LC resonance circuit. This preheating current is 1.1 to 1.8 times the current that flows during normal lighting.
The controller 11 supplies a preheating current to both electrodes of the discharge lamp 17 and outputs a pulse signal to the gate of the triac 21 until both electrodes are heated. Specifically, the control unit 11 includes a timer, the switch 32 is closed, a DC voltage is applied to the power MOSFETs 12 and 13 from the AC / DC conversion unit 33, and the timer is started for 0.25 seconds to A pulse signal is output to the triac 21 until 3 seconds elapse.

Next, the operation of the discharge lamp lighting device 10 of the present invention will be described.
When the switch 32 is closed, the discharge lamp lighting device 10 closes the triac 21 and applies a preheating current to heat the filaments 171 and 172. After heating the filaments 171 and 172, the discharge lamp lighting device 10 opens the triac 21 to cause a discharge between the filament 171 and the filament 172.

First, the operation when the discharge lamp lighting device 10 passes the preheating current will be described with reference to FIG.
When the switch 32 is closed, an AC voltage is applied from the commercial power supply 31 to the AC / DC converter 33.
The AC / DC converter 33 converts the applied AC voltage into a DC voltage. The control unit 11 generates high-frequency voltage by alternately opening and closing the power MOSFETs 12 and 13 to which a DC voltage is applied, and causes series resonance in the resonance inductor 14 and the resonance capacitor 15 to thereby generate a discharge lamp. An AC voltage is applied to the 17 filaments 171 and 172.

The control unit 11 supplies an alternating preheating current to the filament 171, the filament 172, and the resonance parallel capacitor 16.
Further, the control unit 11 outputs a pulse signal with the polarity reversed to the gate of the triac 21, causes the triac 21 to close the electric circuit, and causes the preheating current to flow also to the preheating current energizing capacitor 22.
When flowing the preheating current, there is no large potential difference between the electrodes of the resonance parallel capacitor 16 and between the electrodes of the preheating current energizing capacitor 22, so that the filaments 171 and 172 are not sufficiently heated. It is possible to prevent a high voltage from being applied between the filament 171 and the filament 172 of the discharge lamp 17.

  The power consumed by the discharge lamp lighting device 10 when the preheating current flows is the power consumed by the alternating current i1 flowing through the resonance inductor 14 and the resonance capacitor 15 and the resonance parallel capacitor 16 is AC. This is the sum of the power consumed when the current i3A flows and the power consumed when the alternating current i3B flows through the preheating current conduction capacitor 22.

Next, the operation when the discharge lamp lighting device 10 supplies an alternating current for stable lighting will be described with reference to FIG.
The control unit 11 causes the triac 21 to open the electric circuit by not outputting a pulse signal. Since the electric circuit is opened, the alternating current i3B does not flow through the preheating current conducting capacitor 22.
The control unit 11 stops the flow of the preheating current through the filaments 171 and 172 and applies a momentary high potential difference between the filaments 171 and 172, thereby causing a discharge between the filaments 171 and 172. Let

At the time of stable lighting, the discharge lamp lighting device 10 causes an alternating current to flow through the resonance inductor 14 other than the preheating current conduction capacitor 22, the resonance capacitor 15, and the resonance parallel capacitor 16.
The power consumed by the discharge lamp lighting device 10 during stable lighting is the power consumed by the alternating current i1 flowing through the resonant inductor 14 and the resonant capacitor 15, and the alternating current i3A flows through the resonant parallel capacitor 16. It is the sum with the electric power consumed by.

For comparison, an operation when a general discharge lamp lighting device passes current will be described.
As shown in FIG. 3, a general discharge lamp lighting device includes a starting capacitor 18 having a capacity corresponding to the capacity of both capacitors instead of the resonant parallel capacitor 16 and the preheating current conducting capacitor 22 of the present invention. The other components are the same as those of the present invention.
When a general discharge lamp lighting device passes a preheating current, an alternating current i3 flows through the starting capacitor 18, and thus the same power as in this embodiment is consumed. The alternating current i3 flowing through the starting capacitor 18 is the sum of the alternating current i3A flowing through the resonance parallel capacitor 16 and the alternating current i3B flowing through the preheating current conducting capacitor 22 (i3 = i3A + i3B).
Therefore, when the power consumed by the internal resistance of the capacitor increases in proportion to the capacity of the capacitor, the power consumption of the general discharge lamp lighting device and the discharge lamp lighting device 10 of the present invention is the same during lighting. It is.

However, when a general discharge lamp lighting device passes an alternating current for stable lighting, not only the alternating current i3A but also an alternating current i3 including the alternating current i3B flows through the starting capacitor 18.
The power consumed by a general discharge lamp lighting device during stable lighting is the power consumed by the alternating current i1 flowing through the resonant inductor 14 and the resonant capacitor 15, and the alternating current i3 flows through the starting capacitor 18. And the power consumed by The power consumed by the starting capacitor 18 is equal to the sum of the power consumed by the resonance parallel capacitor 16 and the power consumed by the preheating current conducting capacitor 22.
That is, during stable lighting, a general discharge lamp lighting device is consumed by the internal resistance of the preheating current energizing capacitor 22 because the AC current i3B flows by an amount corresponding to the capacity corresponding to the preheating current energizing capacitor 22. It consumes more power than the discharge lamp lighting device 10 of the present invention by the amount of power.

  As described above, according to the discharge lamp lighting device 10 according to the present embodiment, the capacitor connected between the filament 171B and the filament 172B of the discharge lamp 17 is the resonance parallel capacitor 16, the preheating current conduction capacitor 22, and the like. By separately controlling the energization of the preheating current energizing capacitor 22, the capacity of the capacitor during preheating and stable lighting can be switched.

Specifically, the total capacity of the resonance parallel capacitor 16 and the preheating current energizing capacitor 22 is set to the same capacity as the starting capacitor 18.
As a result, during preheating, the discharge lamp lighting device 10 can cause an alternating current to flow through both capacitors in the same manner as a general discharge lamp lighting device, so that the temperature of the filaments 171 and 172 is being heated. It is possible to prevent a high potential difference from occurring between the filament 171 and the filament 172.
Further, at the time of normal lighting, the discharge lamp lighting device 10 does not pass an alternating current through the preheating current energizing capacitor 22, so that the power consumed by the internal resistance of the preheating current energizing capacitor 22 is reduced and the discharge lamp 17 emits light. Efficiency can be improved.
Accordingly, the discharge lamp lighting device 10 can increase the luminous efficiency of the discharge lamp 17 during normal lighting without reducing the preheating current during preheating.

For example, the capacitance of the resonant parallel capacitor 16 is made the same as that of the starting capacitor 18.
As a result, during preheating, the discharge lamp lighting device 10 allows an alternating current to flow through the preheating current energizing capacitor 22, so that a sufficient current can flow to increase the temperature of both filaments. For example, when the discharge lamp lighting device 10 is used to light a fluorescent lamp installed in a place where the room temperature is low, the filament can be sufficiently preheated until it reaches an optimum state.

The following examples can be considered for this embodiment.
(A) For example, as a lighting device for lighting a fluorescent lamp, there are a starter type lighting device, a rapid start type lighting device, an inverter type lighting device, and the like.
(B) For example, the discharge lamp 17 may be a discharge lamp such as an HID (High Intensity Discharge lamp) lamp or a fluorescent lamp. In the case of a fluorescent lamp, the discharge lamp 17 is a straight tube, a round tube, a bent tube, or a plurality of shapes. For example, a U-shaped lamp connected by a bridge may be used.
(C) For example, the discharge lamp lighting device of the present invention may be used as a lighting device for a light bulb type fluorescent lamp.
(D) The method of turning on and off the preheating current conducting capacitor 22 using a triac has been described. However, in addition to the triac, for example, two thyristors are used, or a thyristor and a diode are connected in reverse parallel. Or a reverse conducting element may be used.
(E) For example, the discharge lamp lighting device 10 may be provided with a plurality of discharge lamps 17.

  Although the embodiments of the present invention have been described above, various modifications and combinations necessary for design reasons and other factors are described in the inventions and embodiments of the invention described in the claims. It should be understood that the invention falls within the scope of the invention corresponding to the specific example.

DESCRIPTION OF SYMBOLS 10 Discharge lamp lighting device 11 Control part 12, 13 Power MOSFET
14 Resonant Inductor 15 Resonant Capacitor 16 Resonant Parallel Capacitor 17 Discharge Lamp 21 Triac 22 Preheating Current Carrying Capacitor

Claims (4)

A power supply for applying an alternating voltage between each one end of a pair of filaments of the lamp;
A first capacitor connected between the other ends of the pair of filaments of the lamp, and for passing a preheating current of the filament;
A switch connected in series to the first capacitor and opening and closing the electrical path of the preheating current;
A second capacitor connected in parallel with a series circuit of the first capacitor and the switch between the other ends of the pair of filaments of the lamp;
By closing the switch during preheating of the filament, the AC voltage generated by the power supply unit is applied to each filament of the lamp via the first capacitor and the second capacitor, The filament is heated by supplying a preheating current, and after a predetermined period of time, the switch is opened, the AC voltage generated by the power supply unit is applied to each filament of the lamp, and a discharge is caused between both filaments of the lamp. Control means,
A lamp lighting device characterized by that. The capacity of the first capacitor is 0.5 to 5 times the capacity of the second capacitor;
The lamp lighting device according to claim 1. The control means sets the amount of preheating current to 1.1 to 1.8 times the amount of current that flows after causing discharge.
The lamp lighting device according to claim 1 or 2, characterized in that. The control means has a predetermined period from closing the switch to opening it is 0.25 seconds to 3 seconds,
The lamp lighting device according to any one of claims 1 to 3, wherein:

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