JP2009037850A - Constant-current generator for electronic light-emitting light source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant-current generator for electronic light-emitting light source, in which high accuracy of luminance adjustment is realized using a simple circuit configuration and a maintenance burden of the lamp can be alleviated to a lamp, using the so-called "electronic light-emitting light source", such as LED and HID lamps. <P>SOLUTION: The constant current generator has a commercial AC power supply 110, a capacitor 120, and a primary side coil 130P of an output transformer 130 connected in series, and a plurality of lamps 140 for mounting electronic light-emitting light sources 140B are connected, in series with the secondary side coil 130S of the output transformer 130, and a plurality of input side switching taps which change linearly the amplitude of the AC constant current generated in the secondary side coil 130S of the output transformer 130 are provided at the primary side coil 130P of the output transformer 130. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a constant current generator used as a power source for an electroluminescent light source such as an LED (Light Emitting Diode) or an HID lamp (High Intensity Discharged Lamp). As described above, the present invention relates to a constant current generator for lighting a lighting facility comprising a large number of lamps having a long wiring distance and a wide range.

  In general, in an airfield, various airfield lights are arranged to operate an aircraft safely even when visibility is poor due to bad weather. These airfield lights include landing lights that indicate the final approach path, runway lights that indicate the outline of the runway, taxiway lights that indicate the edges of the taxiway and apron (the area where the airplane is parked), etc. Can be mentioned.

  In such airfields and public facilities such as highways, tunnels, and parks, a large number of lamps equipped with thermoluminescent light sources such as tungsten lamps and halogen lamps are installed over a wide area. In order to supply electric power, wiring over a very long distance is required. Therefore, in consideration of power loss due to this wiring, it is necessary to keep the luminous intensity of each lamp uniform, and even if a non-lighting occurs in any one of the lights, a lighting system that stably lights other lights is required. is there.

  Further, in the above-described lighting system, the visibility of the lamp changes depending on whether it is daytime or nighttime, and the weather condition, so it is necessary to adjust the luminance of the lamp according to the change of these conditions. For example, in the daytime when the ambient illuminance is high, that is, when the surroundings are bright, the visibility of the lamp is reduced, so that it is necessary to increase the brightness of the lamp. On the other hand, since the visibility of the lamp is good at night when the ambient illuminance is low, that is, the surrounding is dark, power consumption can be reduced by reducing the brightness of the lamp.

  As a power supply device suitable for such applications, the present inventor has developed a constant current light intensity adjustment device 200 as shown in FIG. This constant current luminous intensity adjusting device 200 is connected in series to a constant voltage AC power source 210 and the constant voltage AC power source 210, has an output of the constant voltage AC power source 210 and a time constant that satisfies a predetermined resonance condition, And an output transformer 230 in which a primary winding 230P is connected in series with the output of the resonance circuit 220.

  Further, a plurality of lamps 240 connected in series to the secondary winding 230S of the output transformer 230 via a relatively long distance wiring 280, and a sine wave alternating current flowing in the primary winding 230P only for an arbitrary period. On the basis of one cycle of the sine wave alternating current I output from the resonance circuit 220 based on the secondary current of the shunt circuit 250 that is short-circuited and the secondary current of the output transformer 230 detected by the current detector 270, that is, the load current IL. It has a cycle control circuit 260 that adjusts the magnitude of the load current IL by performing short circuit control (cycle control) on the shunt circuit 250.

  In such a constant current light intensity adjustment device 200, a resonance circuit 220 is connected in series to a constant voltage AC power supply 210, and a time constant determined from a capacitor 220A and a reactor 220B so as to satisfy a predetermined resonance condition. By selecting the frequency, voltage, and current of the AC power supply output, a constant current I that is unrelated to load fluctuations can be obtained. This current I is supplied to the primary winding 230P of the output transformer 230, boosted, and equally supplied as a constant load current IL to each lamp 240 connected in series to the secondary winding 230S of the output transformer 230. Is done.

  As a result, even if the wiring 280 from the output transformer 230 to each lamp 240 is very long, an equal current is supplied to the thermoluminescent light source 240B of each lamp 240 via the insulating transformer 240A. Each thermoluminescent light source 240B can be lit at a uniform luminous intensity. Even if any of the thermoluminescent light sources 240B is not lit, the series circuit on the load side is not disconnected by the insulating transformer 240A, so that the other thermoluminescent light sources 240B are not affected. The shunt circuit 250 includes thyristors 250A and 250B connected in parallel so that the polarities are opposite to each other. During a short circuit operation, the thyristor 250A is turned on during a period in which the sine wave alternating current is positive, The thyristor 250B is turned on during the minus period.

FIG. 3 is a signal waveform diagram showing signals at various parts of the conventional constant current light intensity adjustment apparatus 200 shown in FIG. 2, and here, the current I output from the resonance circuit 220 is equivalent to eight periods (period T1). The case where one cycle (cycle T2) is short-circuited is shown as an example. The cycle control circuit 260 calculates a wave number ratio R = T2 / T1 for obtaining a desired load current IL based on the load current IL detected via the current detector 270. For example, when the wave number ratio R = 1/8, as shown in FIG. 3, the current I is shunted so as to short-circuit one cycle (cycle T2) of eight cycles of the sine wave (cycle T1). The circuit 250 is controlled. As a result, the current supplied to the lamp 240 is reduced to 7/8. And the electric current supplied to the lamp | ramp 240 can be changed by changing the wave number ratio R (for example, refer patent document 1).
Japanese Patent No. 3364407

However, in the conventional constant current light intensity adjustment device 200 described above, the load current IL is adjusted by short-circuiting the current Ia flowing on the primary side of the output transformer 230 at a predetermined wave number ratio R. When the frequency of the constant voltage AC power supply 210 is 50 Hz, the step size of the load current IL is 2%, and there is a problem that current adjustment below that is impossible.
Further, in order to reduce the load current IL, the load current IL is short-circuited at a predetermined wave number ratio R. Therefore, there is a problem that the lamp 240 flickers as the load current IL is reduced.
In addition, the conventional constant current light intensity adjustment apparatus 200 requires the resonance circuit 220, the shunt circuit 250, the cycle control circuit 260, and the like as shown in FIG.

  In addition, since the brightness gradually decreases as dust adheres to the lamp glove (the member that covers the light source), you must polish the glove or replace the light source even though the lamp life has not yet expired. There was a problem with maintenance that it was not possible.

  On the other hand, in recent years, in a lighting system in which a large number of lamps are arranged over a wide range, in consideration of power consumption and maintainability, a lamp using a filament such as a tungsten lamp or a halogen lamp as described above as a light source, so-called thermoluminescence The introduction of a so-called electroluminescent light source that does not have a filament such as an LED or an HID lamp that is not a light source but can efficiently obtain a desired luminescent color and that does not have a fear of a broken bulb (broken filament) and has a long life. It is being considered.

  However, in a conventionally used thermoluminescent light source such as a tungsten lamp or a halogen lamp, the luminance of the light source with respect to the load current has a current-luminance characteristic along a cubic curve as shown in FIGS. Therefore, for example, when the luminance is 100% when the load current is 6.6 A, the load current of 2.8 A is necessary even when the luminance is adjusted to 0.2%. As a result, it is not necessary to supply and adjust a minute load current amount, and the constant current light intensity adjusting device 200 as described above can sufficiently cope with it.

  On the other hand, when an electroluminescent light source such as an LED or an HID lamp is used as the light source, the luminance of the light source with respect to the load current is a current-luminance characteristic along a linear curve. As described above, when the luminance is 100% when the load current is 6.6 A, the necessary current becomes a small load current of about 0.01 A when the luminance is adjusted to 0.2%. Therefore, supply and adjustment of a minute load current amount are required. Therefore, the constant current light intensity adjusting device 200 as described above has a problem in that it cannot cope with a lighting system using an electroluminescent light source because it cannot accurately adjust a minute load current amount.

  Moreover, in a lighting system using an electroluminescent light source, when the luminance is lowered to 0.2%, the required current may be 0.2% when the luminance is 100%, whereas conventional thermoluminescence is used. In the lighting system using the light source, even when the luminance is lowered to 0.2%, a current of 40% or more when the luminance is 100% is required, and there is a problem that the energy efficiency is extremely low. .

In recent years when global warming has become a serious social problem, there is a great interest in developing a lighting system using an electroluminescent light source that contributes to CO ₂ emission reduction by energy saving.

  Accordingly, an object of the present invention is to increase the accuracy of brightness adjustment with a simple circuit configuration for a lamp using a so-called electroluminescent light source such as an LED or an HID lamp, and to reduce the maintenance burden of the lamp. An object of the present invention is to provide a constant current generator for an electroluminescent light source.

  First, according to the first aspect of the present invention, a constant voltage AC power source, a capacitor, and a primary side winding of an output transformer are connected in series, and an electroluminescent light source is provided on the secondary side winding of the output transformer. A constant current generator for an electroluminescent light source in which a plurality of internal lights are connected in series, and a plurality of inputs for linearly changing the amplitude of an AC constant current generated in the secondary winding of the output transformer The side switching tap is provided in the primary side winding of the output transformer, thereby solving the problem.

  In the present invention, an electroluminescent light source is a generic term for a light source that does not have a filament such as an LED or an HID lamp, and whose luminance with respect to a load current has a current-luminance characteristic along a linear curve. However, it is particularly preferable to use an LED as an electroluminescent light source in terms of durability, impact resistance, life and the like.

  In addition to the configuration of the invention according to claim 1, the invention according to claim 2 includes a plurality of output side switchings for finely adjusting the amplitude of the AC constant current generated in the secondary winding of the output transformer. The tap is provided in the secondary winding of the output transformer, thereby further solving the above-mentioned problem.

  In addition to the configuration of the invention according to claim 1 or 2, the invention according to claim 3 further solves the above-described problem by the fact that the electroluminescent light source is an LED.

In the constant current generator for an electroluminescent light source according to the present invention, a constant voltage AC power source having an output voltage of V (volt), a capacitor of stored charge Q (Coulomb), and a primary winding of an output transformer are connected in series. In addition, since Q is fixed by a very simple configuration in which a plurality of lamps having an electroluminescent light source are connected in series to the secondary winding of the output transformer, the primary side of the output transformer Since a constant current I ₁ = QV flows in the winding, a load (determined by the number of electroluminescent light sources to be turned on and the length of wiring, etc.) connected in series to the secondary winding of the output transformer. Even if it increases or decreases, the power supply voltage is not affected, and a stable constant current supply can always be realized to the secondary side of the output transformer. In addition, special effects corresponding to the following unique configurations are achieved. Can be played.

That is, the constant current generator for an electroluminescent light source according to claim 1 includes a plurality of input side switching taps that linearly change the amplitude of the AC constant current generated in the secondary winding of the output transformer. By being provided in the primary side winding of the transformer, the product I ₁ · T ₁ (ampere turn) of the constant current I ₁ flowing through the primary side winding and the number of turns T ₁ to the selected input side switching tap However, the product I ₂ · T ₂ (ampere turn) of the AC constant current I ₂ generated in the secondary side winding and the number T ₂ of turns of the secondary side winding is constant, that is, I ₁ · T ₁ = I ₂ · When the relationship of T ₂ is established, I ₁ is constant as described above, and T ₂ is fixed, an AC constant current I ₂ proportional to the number of turns T ₁ up to each input-side switching tap is generated by the output transformer. Since it occurs in the secondary winding, is the load current applied to the electroluminescent light source 100% applied? Therefore, for example, it can be adjusted with high accuracy by switching the input side switching tap to a very small energization of 0.2%.

Moreover, if the adjustment is to be achieved by varying the magnitude of the amplitude of the alternating constant current I ₂ is a sine wave generated in the secondary winding of the output transformer, which went to reduce the load current However, good visibility can be exhibited without flickering the lamp. Furthermore, unlike the voltage-type tap switching, the current-type tap switching does not generate a potential difference between the taps, so that a failure such as a dielectric breakdown is suppressed.

  Further, the constant current generator for an electroluminescent light source according to claim 2 is generated in the secondary winding of the output transformer in addition to the effect exhibited by the constant current generator for electroluminescent light source according to claim 1. A plurality of output side switching taps for finely adjusting the amplitude of the AC constant current are provided in the secondary winding of the output transformer, so that dust is attached to the lamp glove and the brightness is lowered. However, since the load current flowing to the lamp can be increased by switching the output side switching tap to compensate for the decrease in brightness, special maintenance is performed during the operation of the electroluminescent light source that has a longer life than the thermoluminescent light source. Without repeating the above, 100% safety required luminance can be maintained until the lifetime of the electroluminescent light source is exhausted.

The constant current generator for an electroluminescent light source according to claim 3 is an LED in addition to the effect produced by the constant current generator for an electroluminescent light source according to claim 1 or claim 2. Therefore, the LED is made of a solid structure called a pn junction using a semiconductor, and light is emitted by directly converting the energy of electrons into light energy in this structure. Since no intervention is required, excellent durability, impact resistance, long life and high efficiency can be realized.
Moreover, in a thermoluminescent light source such as a halogen lamp, it was necessary to install an overcurrent relay in order to prevent the filament from fusing due to overcurrent. Since there is no need to install an overcurrent relay without fusing, the device configuration can be simplified.

  In the constant current generator for an electroluminescent light source according to the present invention, a constant voltage AC power source, a capacitor, and a primary side winding of an output transformer are connected in series, and the secondary side winding of the output transformer is electroluminescent. A constant current generator for an electroluminescent light source in which a plurality of lamps having a light source are connected in series, wherein a plurality of alternating current constant amplitudes generated in a secondary winding of the output transformer are linearly changed If the input side switching tap is provided in the primary winding of the output transformer and achieves high accuracy in adjusting the brightness of the lamp and reduces the maintenance burden, the specific Any embodiment may be used.

An embodiment of the present invention will be described with reference to FIGS.
Here, FIG. 1 is a circuit diagram of a constant current generator for an electroluminescent light source that is an embodiment of the present invention, and FIG. FIG. 5 is a table showing a kind of halogen lamp, and FIG. 5 is a graph of the table of FIG.

  As shown in FIG. 1, a constant current generator 100 for an electroluminescent light source according to an embodiment of the present invention includes a constant voltage AC power source 110, a capacitor 120 having a constant accumulated charge Q (capacitance C), and an output transformer. The primary side winding 130P of 130 is connected in series, and a plurality of lamps 140 including the electroluminescent light source 140B are connected in series to the secondary side winding 130S of the output transformer 130. In this embodiment, an LED is used as the electroluminescent light source 140B.

  In addition, in order to prevent the other electroluminescent light sources 140B from being affected even if any one of the electroluminescent light sources 140B included in the plurality of lamps 140 connected in series is not lit, Includes an insulating transformer 140A, and a diode 140C for blocking reverse current applied to the electroluminescent light source 140B is connected in series with the electroluminescent light source 140B. In addition, instead of blocking the reverse current applied to the electroluminescent light source 140B using the diode 140C, two electroluminescent light sources 140B connected in parallel so that the polarities are opposite to each other are connected to the secondary of the insulating transformer 140A. You may connect to the side. In this case, the two electroluminescent light sources 140B are alternately turned on when the sine AC current is applied in the forward direction and the reverse direction, thereby improving the energy efficiency and further reducing the flickering of the lamp 140.

Further, a plurality of input-side switching taps 130A for varying the amplitude of the alternating constant current I ₂ generated in the secondary winding 130S output transformer 130 to linearly, the primary winding 130P of the output transformer 130 Is provided. The input-side switching tap 130A has a required luminance (%) change stage, for example, as shown in FIG. 4, 100%, 30%, 25%, 10%, 5%, 1%, 0.2%. And the number of turns of the primary winding 130A are in a proportional relationship. In FIG. 1, the input side switching tap 130A corresponding to 5%, 1%, and 0.2% is omitted.

Since the voltage drop in the output transformer 130 is sufficiently smaller than the voltage between the terminals of the capacitor 120, the output voltage of the constant voltage AC power supply 110 is constant at V (volts), and the accumulated charge of the capacitor 120 is Q The constant current I ₁ = QV flows through the primary winding 130A of the output transformer 130 by being fixed at (Coulomb). Further, the product I ₁ · T ₁ (ampere turn) of the constant current I ₁ and the number of turns T ₁ up to the selected input side switching tap 130A is equal to the AC constant current I ₂ generated in the secondary side winding 130S and the two The product I ₂ · T ₂ (ampere turn) of the number of turns T ₂ of the secondary winding 130S is constant, that is, the relationship of I ₁ · T ₁ = I ₂ · T ₂ is established, so that I ₁ is constant as described above. in, the number of turns _{T 2} of the secondary winding 130S If fixed, the secondary winding 130S of alternating constant current _{I 2} output transformer 130 which is proportional to the number of turns _{T 1} of the to each input side switch taps 130A appear.

As a result, the input side changeover switch 130B, desired by selecting the input side switching taps 130A, alternating constant current proportional to the number of turns T ₁ of the secondary winding 130S to the primary winding 130P of the output transformer 130 I ₂ can be generated. For example, if T ₁ is 1000 turns and T ₂ is 3000 turns, which is three times T ₁ , I _{1 is set} to a constant current of 20 A, so that I ₂ is 6.6 A which is one third of I ₁ Constant current is obtained. Then, by switching the _{T 1} to 300 turns of 30% of the number of whole volume, as _{I 2,} a constant current of 1.98A is 30% of 6.6A is obtained.

In addition, as shown in FIG. 1, the constant current generator 100 for an electroluminescent light source according to the present embodiment has, for example, 1%, 3%, A plurality of output-side switching taps 130C that reduce the number of turns at fine intervals of 5% are provided. Then, by selecting a desired output-side change-over tap 130C by the output-side changeover switch 130D, the number T ₂ of turns of the secondary-side winding 130S is set in the relationship of I ₁ · T ₁ = I ₂ · T ₂ described above. since it is possible to slightly decrease, can be slightly amplitude of the AC constant current I ₂ supplied to the load (a few percent of the increase). Thereby, when dust adheres to the glove | globe of the lamp | ramp 140 and brightness | luminance falls, it can finely adjust so that an initial stage brightness | luminance may be maintained. Here, the reason why the switching tap for fine adjustment of the luminance of the lamp 140 is provided on the secondary side of the output transformer 130 is that the load side without changing the linear relationship of the number of turns of the input side switching tap 130A provided on the primary side. This is because the current can be slightly increased.

  In the present invention, when a constant voltage V is applied to a capacitor having a fixed capacity (accumulated charge Q), a constant current that satisfies the relationship of I = QV is generated, and a constant current generator can be configured with a very simple configuration. By connecting the primary side winding of the output transformer in series to this constant current generator, a new idea that a constant current proportional to the number of turns of the primary side winding can be generated in the secondary side winding. Based on the lighting system of the airfield, the brightness adjustment of the lighting system of public facilities such as highways, tunnels, stadiums, parks, etc., high efficiency of energy efficiency, maintenance The maintenance burden can be reduced and its industrial applicability is extremely high.

The circuit diagram of the constant current generator for electroluminescent light sources of this invention. The circuit diagram of the conventional constant current luminous intensity adjustment apparatus for thermoluminescent light sources. The signal waveform diagram in each part of the conventional constant current light intensity adjustment apparatus shown in FIG. The table | surface which showed the electric current-luminance characteristic of the electroluminescent light source and the thermoluminescent light source. The graph based on the table | surface shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Constant current generator 200 for electroluminescent light sources ... Constant current light intensity adjustment apparatus 110, 210 ... Constant voltage alternating current power supply 120 ... Capacitor 220 ... Resonance circuit 220A ... ) Capacitor 220B (Resonant circuit) Reactor 130, 230 ... Output transformer 130A ... (Output transformer) Input side changeover tap 130B ... (Output transformer) Input side changeover switch 130C ... Output-side changeover tap 130D (of the output transformer) Output-side changeover switches 130P, 230P (of the output transformer) Primary windings 130S, 230S ... (of the output transformer) Secondary windings 140, 240 ... light 140A, 240A ... (light) insulation transformer 140B ... (light) electroluminescent light source 240B ... (light) Thermal emission source 140C ... (the lamp) diode 250 ... shunt circuit 250A, (shunt circuit) 250B ... Thyristor 260 ... cycle control circuit 270 ... current detector 280 ... wire

Claims (3)

A constant voltage AC power source, a capacitor, and a primary side winding of the output transformer are connected in series, and a plurality of lamps with an electroluminescent light source are connected in series to the secondary side winding of the output transformer. A constant current generator for an electroluminescent light source,
A plurality of input side switching taps for linearly changing the amplitude of the AC constant current generated in the secondary winding of the output transformer is provided in the primary winding of the output transformer. Constant current generator for electroluminescent light source.   A plurality of output side switching taps for finely adjusting the amplitude of the AC constant current generated in the secondary winding of the output transformer is provided in the secondary winding of the output transformer. The constant current generator for an electroluminescent light source according to claim 1. The constant current generator for an electroluminescent light source according to claim 1 or 2, wherein the electroluminescent light source is an LED.

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