JP2008269943A - Electrodeless discharge lamp lighting device, and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress noise generated immediately after a state where the lighting of an electrodeless discharge lamp can not be kept is changed over to a state where the lighting can be kept while the electrodeless discharge lamp is being lit with light modulation. <P>SOLUTION: By setting a drive frequency of a high-frequency power circuit 5, a light dimming control circuit 6 of this electrodeless discharge lamp lighting device 1 controls the frequency of the high-frequency voltage applied to an induction coil 4 wound around a magnetic core 3 and inducing an induction electric field in the electrodeless discharge lamp 2 in a lighting period in which the electrodeless discharge lamp 2 keeps lighting while the electrodeless discharge lamp 2 is being lit with light dimming, a non-lighting period in which the electrodeless discharge lamp 2 can not keep the lighting, and a re-ignition period immediately after the non-lighting period is changed over to the lighting period, and thereby varies the value of the high-frequency voltage. The light dimming control circuit 6 sets the frequency of the high-frequency voltage in the non-lighting period at a value making the high-frequency voltage in the re-ignition period constant, in a frequency characteristic of the high-frequency voltage of the re-ignition period previously measured by applying a high-frequency voltage having a different frequency in the non-lighting period. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrodeless discharge lamp lighting device and a lighting fixture for controlling lighting of an electrodeless discharge lamp.

  As a conventional electrodeless discharge lamp lighting device that controls lighting of an electrodeless discharge lamp, Patent Document 1 discloses that a ballast generates a radio frequency electric field that feeds an electrodeless discharge lamp with a capacitance-inductance resonance circuit. What includes a load circuit having a radio frequency inductor is disclosed. In the electrodeless discharge lamp lighting device of Patent Document 1, a DC-AC converter circuit is coupled to a load circuit and induces an AC current used therein by a radio frequency inductor. Frequency shift keying (FSK) shunts the voltage of the coupled secondary inductor when a pulse is applied to the gate of the dimming switch. When a pulse is applied to the gate of the dimming switch, the ballast frequency shifts to a higher level, reducing the radio frequency inductor current and extinguishing the arc of the electrodeless discharge lamp. The dimming operation is performed by repeating this at a certain duty cycle.

As another example of a conventional electrodeless discharge lamp lighting device, Patent Document 2 discloses an induction coil that is wound around a magnetic core and induces an induction electric field in an electrodeless discharge lamp, and high-frequency power is supplied to the induction coil. Dimming that controls the high-frequency power supply circuit and the high-frequency power supply circuit to apply a high-frequency voltage to the electrodeless discharge lamp during the lighting period when the electrodeless discharge lamp is lit and during the non-lighting period when the electrodeless discharge lamp is turned off And a control circuit, wherein the non-lighting period is a predetermined period (for example, 0.02 milliseconds to 0.25 milliseconds) in which ions in the electrodeless discharge lamp remain.
JP 2000-353600 A (paragraphs 0006 to 0019 and FIGS. 1 to 4) JP 2006-155961 A (paragraph 0019 and FIG. 1)

  However, in the electrodeless discharge lamp lighting device of Patent Document 1, when the arc is extinguished and turned on again, a high high-frequency voltage may have to be applied to the induction coil. There is a problem that current flows, and the large current causes the induction coil and the magnetic core around which the induction coil is wound to vibrate and generate noise.

  Further, the electrodeless discharge lamp lighting device of Patent Document 2 also has a limited period during which ions of the electrodeless discharge lamp remain and may require application of a re-ignition voltage. Similar to the electrode discharge lamp lighting device, the induction coil and the magnetic core vibrate to generate noise.

  The present invention has been made in view of the above points, and its purpose is immediately after switching from a state in which the electrodeless discharge lamp cannot be lit to maintain lighting during dimming lighting of the electrodeless discharge lamp. An object of the present invention is to provide an electrodeless discharge lamp lighting device and a lighting fixture capable of suppressing generated noise.

  The electrodeless discharge lamp lighting device according to claim 1 is an electrodeless discharge lamp lighting device for dimming and lighting an electrodeless discharge lamp in which a discharge gas is sealed, and is supplied with a high-frequency current wound around a magnetic core. An induction coil that induces an induction electric field in the electrodeless discharge lamp, a high-frequency power circuit that applies a high-frequency voltage to the induction coil to supply the high-frequency current, and dimming lighting of the electrodeless discharge lamp The frequency of the high-frequency voltage when the electrodeless discharge lamp is kept lit, the frequency of the high-frequency voltage when the electrodeless discharge lamp cannot be kept lit, and the state where the electrodeless discharge lamp is kept lit from the state where the electrodeless discharge lamp cannot be kept lit A dimming control circuit that controls the frequency of each of the high-frequency voltages immediately after switching to the dimming control circuit to vary the magnitude of each high-frequency voltage, and the dimming control circuit includes the electrodeless discharge lamp. In the relationship between the frequency of the high-frequency voltage when the lighting cannot be maintained and the magnitude of the high-frequency voltage immediately after switching from the state in which the electrodeless discharge lamp cannot be maintained to the state in which lighting is maintained, the electrodeless discharge lamp is maintained in lighting. The frequency of the high-frequency voltage when the electrodeless discharge lamp cannot be kept lighting is set from a range in which the magnitude of the high-frequency voltage immediately after switching from the impossible state to the lighting-maintaining state is constant.

  The invention related to the electrodeless discharge lamp lighting device according to claim 2 is the invention according to claim 1, wherein the frequency of the high-frequency voltage when the electrodeless discharge lamp cannot be kept on is when the electrodeless discharge lamp is kept on lighting. The frequency of the high-frequency voltage is 1.5 times or more.

  The invention related to the electrodeless discharge lamp lighting device according to claim 3 is the invention according to claim 1 or 2, wherein the frequency of the high-frequency voltage when the electrodeless discharge lamp cannot be maintained is 200 kHz or more and 300 kHz or less. And

  The invention according to claim 4 is characterized by including the electrodeless discharge lamp lighting device according to any one of claims 1 to 3.

  According to the invention of claim 1, since the high-frequency voltage immediately after switching from the state in which the electrodeless discharge lamp cannot be lit to the state in which lighting is maintained can be suppressed low, the vibration of the magnetic core can be reduced, As a result, noise can be suppressed.

  According to the invention of claim 2, since the high-frequency voltage immediately after switching from the state in which the electrodeless discharge lamp cannot be lit to the state in which the lamp is maintained can be further reduced, the vibration of the magnetic core can be further reduced. This can increase the noise suppression effect.

  According to the invention of claim 3, for example, when the frequency of the high-frequency voltage when the electrodeless discharge lamp is kept on is 135 kHz, the frequency of the high-frequency voltage when the electrodeless discharge lamp cannot be kept on is set to 200 kHz or more. Thus, the high-frequency voltage immediately after switching from the state in which the electrodeless discharge lamp cannot be lit to the state in which lighting is maintained can be suppressed low, and noise can be suppressed. Further, by switching the state of the electrodeless discharge lamp from the state where it cannot be lit to the state where the lighting is maintained and setting the frequency of the high frequency voltage immediately after it to 300 kHz or less, a general high voltage integrated circuit (as a driver constituting the dimming control circuit) HVIC) can be used, so that the circuit can be simplified.

  According to the invention of claim 4, since the high frequency voltage immediately after switching from the state in which the electrodeless discharge lamp cannot be kept on to the state in which lighting is maintained can be kept low, the vibration of the magnetic core can be reduced, As a result, noise can be suppressed.

(Embodiment 1)
The structure of the electrodeless discharge lamp lighting device 1 of Embodiment 1 will be described with reference to FIGS. As shown in FIG. 1, this electrodeless discharge lamp lighting device 1 performs dimming lighting of an electrodeless discharge lamp 2 in which a discharge gas is sealed, and is wound around a magnetic core 3 and a magnetic core 3 so as to have a high frequency. The induction coil 4 that induces an induction electric field in the electrodeless discharge lamp 2 when a current is supplied, the high-frequency power circuit 5 that applies a high-frequency voltage to the induction coil 4 to supply a high-frequency current, and the electrodeless discharge lamp 2 are adjusted. The frequency of the high-frequency voltage is controlled by controlling the frequency of the high-frequency voltage in each of a lighting period in which the electrodeless discharge lamp 2 is kept on and a non-lighting period in which the electrodeless discharge lamp 2 cannot be kept on during the lighting. And a dimming control circuit 6.

  In the electrodeless discharge lamp 2, a discharge gas is enclosed in a bulb-shaped glass bulb 20, and a phosphor is applied to the inner surface of the glass bulb 20. The discharge gas is a discharge gas such as an inert gas or metal vapor (for example, mercury or a rare gas). The glass bulb 20 is formed with a bottomed cylindrical cavity 21 in the vertical direction toward the center. The electrodeless discharge lamp 2 having such a structure is lit when an induction electric field is induced inside the glass bulb 20.

  The induction coil 4 is formed by winding a conductive wire such as copper or a copper alloy around the magnetic core 3 and is disposed in the cavity 21 of the electrodeless discharge lamp 2. The magnetic core 3 is made of a material having good high frequency magnetic characteristics such as a soft magnetic material.

  The high-frequency power supply circuit 5 is an inverter composed of a DC power supply E configured with a step-up chopper circuit (not shown) with a commercial power supply as an input, and two switching elements Q1 and Q2 connected in series to the output terminal of the DC power supply E, for example. And a resonance circuit 51 including a series circuit of an inductor Ls and a capacitor Cp connected to both ends of the switching element Q2 and a capacitor Cs connected to both ends of the capacitor Cp.

  The DC power source E converts an AC voltage from an AC power source (not shown) into a DC voltage, and boosts the converted DC voltage. Further, the DC power supply E smoothes the boosted DC voltage and outputs the smoothed DC voltage to the inverter circuit 50. The inverter circuit 50 converts the DC voltage from the DC power source E into a high frequency voltage, and outputs the converted high frequency voltage to the resonance circuit 51. The resonance circuit 51 is connected to the induction coil 4 on the output end side, and supplies the induction coil 4 with a high-frequency current whose magnitude varies based on the frequency of the high-frequency voltage from the inverter circuit 50.

  The dimming control circuit 6 includes a driver 60 that controls on / off of the switching elements Q1 and Q2 of the inverter circuit 50, a capacitor C1 and a resistor R1 connected between the driver 60 and the ground, and the driver 60 and the ground. And a series circuit of a resistor R2 and a switching element Q3 connected in parallel to the resistor R1.

  The driver 60 incorporates an oscillator (not shown), and the oscillation frequency fluctuates when the switching element Q3 is switched on and off by a dimming signal from the outside. The switching signal Q1, a rectangular wave switching signal is changed at this oscillation frequency. By alternately outputting to Q2, the switching elements Q1 and Q2 are switched to switch the driving frequency of the high frequency power supply circuit 5. The driver 60 sets the high-frequency voltage (hereinafter referred to as “re-ignition voltage”) applied immediately after switching from the non-lighting period to the lighting period (re-ignition period) so that the magnitude of the non-lighting period is constant. The drive frequency of the high frequency power supply circuit 5, that is, the frequency of the high frequency voltage applied to the induction coil 4 during the non-lighting period is set.

  The dimming signal for switching the switching element Q3 is, for example, a voltage as shown in FIG. 2, and the ratio between the lighting period and the non-lighting period of the electrodeless discharge lamp 2 is changed by changing the on-duty. In addition, the repetition frequency of ON / OFF of the dimming signal is set to 100 Hz or more so that the human eye does not feel flicker.

  The oscillation frequency of the driver 60 at this time is determined by the capacitor C1, the resistors R1 and R2, and the switching element Q3. When the switching element Q3 is turned off by the dimming signal, the oscillation frequency becomes a frequency based on 1 / (R1 × C1). When the element Q3 is on, the frequency is based on 1 / {(1 / R1 + 1 / R2) × C1}. From the above, the oscillation frequency is higher when the switching element Q3 is on than when it is off.

  FIG. 3 shows a time-dependent change waveform of the driving frequency of the high-frequency power supply circuit 5 (FIG. 3A) and a time-change waveform of the voltage across the induction coil 4 (FIG. 3B). The driving frequency fo in the lighting period Ton is set to a frequency in the vicinity of the resonance frequency of the resonance circuit 51 so as to be a high frequency voltage at which the electrodeless discharge lamp 2 is maintained to be lit. On the other hand, the drive frequency foff in the non-lighting period Toff is set to a frequency that provides a high-frequency voltage that the electrodeless discharge lamp 2 cannot keep lit. Then, the dimming control circuit 6 switches the driving frequency fon of the lighting period Ton and the driving frequency foff of the non-lighting period Toff at a relatively short cycle (for example, a frequency of 500 Hz or more and 1 kHz or less), thereby the electrodeless discharge lamp 2. The light is turned on and off repeatedly so that the light is lit. The dimming control circuit 6 performs time-division output control, and dimming the electrodeless discharge lamp 2 by changing this time ratio (= Ton / (Ton + Toff)) (hereinafter referred to as “on-duty”). To do. Here, in order to relight the electrodeless discharge lamp 2 at the time of re-ignition immediately after switching from the non-lighting period to the lighting period, it is necessary to apply a high high-frequency voltage to both ends of the induction coil 4. The high-frequency voltage at this time is called a re-ignition voltage. When a high re-ignition voltage is applied at the time of re-ignition, a large high-frequency current is supplied to the induction coil 4, and the induction coil 4 and the magnetic core 3 around which the induction coil 4 is wound by this large high-frequency current. Vibrates and generates noise. Therefore, in order to suppress noise, it is necessary to keep the re-ignition voltage low.

  Here, the setting of the drive frequency of the high frequency power supply circuit 5 during the non-lighting period will be described. FIG. 4 shows the relationship between the drive frequency foff of the high-frequency power supply circuit 5 during the non-lighting period and the height of the re-ignition voltage Von1. Thus, the height of the re-ignition voltage Von1 is affected by the drive frequency foff of the high-frequency power supply circuit 5 during the non-lighting period, and the re-ignition voltage Von1 decreases as the drive frequency foff during the non-lighting period increases. When the drive frequency f1 is exceeded, the re-ignition voltage Von1 becomes a substantially constant height.

  Generally, when the ions of the discharge gas sealed in the electrodeless discharge lamp 2 do not remain, the re-ignition voltage increases. Therefore, when the driving frequency of the high-frequency power supply circuit 5 in the non-lighting period is low, the re-ignition voltage becomes high because when the driving frequency is low, the high-frequency voltage applied to the induction coil 4 increases and a large high-frequency current This is because a large induction electric field is induced in the electrodeless discharge lamp 2 and the induction electric field promotes the diffusion of ions, although the lighting cannot be maintained. On the other hand, when the driving frequency of the high-frequency power supply circuit 5 in the non-lighting period is increased, the high-frequency voltage applied to the induction coil 4 is decreased, and the high-frequency current is also decreased, ion diffusion can be suppressed. Therefore, when the driving frequency of the high-frequency power supply circuit 5 in the non-lighting period is increased and becomes higher than a certain driving frequency, it is saturated at a predetermined re-ignition voltage and becomes substantially constant. Note that the fluctuation of the re-ignition voltage at a substantially constant time is about ± 5% or less even if the drive frequency of the high-frequency power supply circuit 5 during the non-lighting period varies somewhat.

  In the present embodiment, the resistors R1, R2 and R2 are set so that the driving frequency of the non-lighting period (f1 or higher in FIG. 4) is such that the re-ignition voltage becomes substantially constant even when the driving frequency of the non-lighting period varies. Set the constant of capacitor C1.

  As described above, according to the present embodiment, the re-ignition period (non-electrode discharge) is obtained by setting the drive frequency of the non-lighting period so that the re-ignition voltage becomes substantially constant even if the driving frequency of the non-lighting period changes. Since the high-frequency voltage (re-ignition voltage) of the lamp 2 can be kept low after switching from the state in which the lamp 2 cannot be lit to the state in which the lamp is maintained to be lit, the vibration of the magnetic core 3 can be reduced. Noise can be suppressed.

(Embodiment 2)
The electrodeless discharge lamp lighting device 1a according to the second embodiment includes the intermittent oscillation control unit 7 as shown in FIG. 5, and the frequency of the high-frequency voltage in the non-lighting period is 1.5 times the frequency of the high-frequency voltage in the lighting period. This is the difference from the first embodiment. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The intermittent oscillation control unit 7 shown in FIG. 5 includes a signal generator 70. The input terminal of the signal generator 70 includes a reference power source E2, a resistor R3 connected in series to the reference power source E2, and a series circuit of a switching element Q4 and a resistor R4 that switch according to an external dimming signal. The capacitor C3 is connected to the negative electrode of the reference power source E2 and the resistor R3. A capacitor C2 is connected to the input terminal. The output terminal of the signal generator 70 is connected to the switching element Q4. In addition, a voltage corresponding to a dimming signal from the outside is input to the input terminal. When the on-duty ratio of the dimming signal is large, the time during which the switching element Q4 is turned on becomes longer and the amount of current that is shunted to the resistor R4 increases, so that the voltage value across the capacitor C3 decreases. On the other hand, when the on-duty ratio is small, the time during which the switching element Q4 is turned on is shortened, and the amount of current that is shunted to the resistor R4 is decreased, so that the voltage value across the capacitor C3 increases.

  Therefore, the duty ratio between the lighting period and the non-lighting period of the electrodeless discharge lamp 2 changes according to the on-duty ratio of the dimming signal, but unlike the first embodiment, regardless of the frequency of the dimming signal, Each frequency of the lighting period and non-lighting period of the electrodeless discharge lamp 2 can be determined. Therefore, it is possible to set an appropriate frequency in order to reduce re-ignition voltage and noise.

  Next, the relationship between the drive frequency of the high-frequency power supply circuit 5 during the non-lighting period and the re-ignition voltage in the present embodiment will be described with reference to FIG. FIG. 6 shows an electrodeless discharge lamp 2 having a diameter of about 110 mm, a height of about 200 mm, and a recess having an inner diameter of about 28 mm. The repetition frequency of the lighting period and the non-lighting period is about 1 kHz, and the on-duty is about 50%. When the dimming lighting is performed under the conditions (circle in FIG. 6), the electrodeless discharge lamp 2 having a diameter of about 180 mm, a height of about 300 mm, and a hollow portion having an inner diameter of about 42 mm is used for a lighting period and a non-lighting period. When dimming is performed with the repetition frequency being about 1 kHz and the on-duty being about 50% (■ in FIG. 6), the diameter is about 180 mm, the height is about 300 mm, and the inner diameter of the recess is about 42 mm. This shows a case where the electrode discharge lamp 2 is dimmed and lit under the condition that the repetition frequency of the lighting period and the non-lighting period is about 500 Hz and the on-duty is about 50% (▲ in FIG. 6). In any case, the driving frequency during the lighting period is about 135 kHz. When the driving frequency during the non-lighting period exceeds a certain frequency, the re-ignition voltage becomes substantially constant, and the re-ignition voltage becomes substantially constant. The driving frequency during the lighting period is 1.5 times or more the driving frequency during the lighting period. Further, when the same electrodeless discharge lamp 2 is used, the minimum driving frequency of the non-lighting period in which the re-ignition voltage becomes substantially constant when the repetition frequency of the lighting period and the non-lighting period is about 1 kHz rather than about 500 Hz. The value becomes smaller (compare ■ and ▲ in FIG. 6).

  In the second embodiment, the switching element Q4 is turned on / off according to the dimming signal so as to continuously dim the light. However, the dimming ratio is fixed, and only the reference power source E2 corresponding to the dimming ratio is used. You may make it connect to the input terminal of the signal generator 70. FIG.

  In the second embodiment, the signal generator 70 is provided to determine the frequency of the lighting period and the non-lighting period. However, a timer (not shown) composed of a capacitor and a resistor detects the voltage across the induction coil 4. The lighting period may be determined by providing or a non-lighting period may be determined by providing a counter (not shown).

(Embodiment 3)
The electrodeless discharge lamp lighting device 1 according to the third embodiment is different from the first embodiment in that the frequency of the high-frequency voltage during the non-lighting period is 200 kHz or more and 300 kHz or less. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  According to the present embodiment, for example, when the frequency of the high-frequency voltage in the lighting period is 135 kHz, the high-frequency voltage in the re-ignition period can be kept low by setting the frequency of the high-frequency voltage in the non-lighting period to 200 kHz or more. Noise can be suppressed. In addition, by setting the frequency of the high-frequency voltage during the non-lighting period to 300 kHz or less, a general high-voltage integrated circuit can be used as the driver 60, so that the circuit can be simplified.

  As a modification of the third embodiment, as shown in FIG. 7, a function of suppressing noise by suppressing a steep voltage change at the time of re-ignition by performing a frequency sweep every time at re-ignition, and a lighting period and A function of suppressing the high-frequency voltage at the time of re-ignition by reducing the non-lighting period of one cycle and suppressing the disappearance of ions may be combined by setting the repetition frequency of the non-lighting period high.

(Embodiment 4)
FIG. 8 shows a street lamp 8 that includes the electrodeless discharge lamp lighting device 1 (1a) according to any one of Embodiments 1 to 3 together with a lamp for attaching the electrodeless discharge lamp 2 as a lighting fixture. . In addition, about the component similar to Embodiment 1 thru | or 3, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  Even in this embodiment, since the high-frequency voltage during the re-ignition period can be kept low, vibration of the magnetic core 3 can be reduced, and as a result, noise can be suppressed.

  As a modification of the fourth embodiment, FIG. 9 shows a lamp for attaching the electrodeless discharge lamp lighting device 1 (1a) of any of the first to third embodiments as a lighting fixture. The crime prevention light 8a provided with is shown. Also in this modification, noise can be suppressed as in the fourth embodiment.

1 is a circuit diagram of Embodiment 1. FIG. It is a figure which shows the light control signal same as the above. It is a figure which shows the same as above, (a) is a figure which shows a drive frequency, (b) is a figure which shows the both-ends voltage of an induction coil. It is a figure which shows the re-ignition voltage same as the above. FIG. 6 is a circuit diagram of a second embodiment. It is a figure which shows the re-ignition voltage same as the above. It is a figure which shows the drive frequency of the modification of Embodiment 3. FIG. 6 is an external view of a fourth embodiment. It is an external view of the modified example same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Electrodeless discharge lamp lighting device 2 Electrodeless discharge lamp 3 Magnetic core 4 Inductive coil 5 High frequency power supply circuit 6 Dimming control circuit 8 Street lamp 8a Security light

Claims (4)

An electrodeless discharge lamp lighting device for dimming and lighting an electrodeless discharge lamp filled with a discharge gas,
An induction coil that induces an induction electric field in the electrodeless discharge lamp when a high frequency current is supplied by being wound around a magnetic core;
A high frequency power supply circuit for applying a high frequency voltage to the induction coil to supply the high frequency current;
During the dimming lighting of the electrodeless discharge lamp, the frequency of the high frequency voltage when the electrodeless discharge lamp is kept lighting, the frequency of the high frequency voltage when the electrodeless discharge lamp cannot be kept lighting, and the electrodeless discharge A dimming control circuit that controls the frequency of each of the high-frequency voltages immediately after switching from a state in which the lamp cannot be lit to a state in which lighting is maintained, and varies the magnitude of each high-frequency voltage,
The dimming control circuit is configured such that the frequency of the high-frequency voltage when the electrodeless discharge lamp cannot be kept on and the magnitude of the high-frequency voltage immediately after switching from a state where the electrodeless discharge lamp cannot be kept on to a state where the lighting is maintained. In relation to the above, when the electrodeless discharge lamp cannot be kept lit from the range in which the magnitude of the high frequency voltage immediately after switching from the state in which the electrodeless discharge lamp cannot be kept lit to the state to keep lit is constant An electrodeless discharge lamp lighting device characterized by setting a frequency of a high-frequency voltage.   2. The frequency of the high-frequency voltage when the electrodeless discharge lamp cannot be kept on is 1.5 times or more the frequency of the high-frequency voltage when the electrodeless discharge lamp is kept on. The electrodeless discharge lamp lighting device described.   The electrodeless discharge lamp lighting device according to claim 1 or 2, wherein the frequency of the high-frequency voltage when the electrodeless discharge lamp cannot be kept on is 200 kHz or more and 300 kHz or less.   A lighting fixture comprising the electrodeless discharge lamp lighting device according to any one of claims 1 to 3.

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