JP2007227173A - Light control device and luminaire using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control light of an incandescent lamp to an optional optical output, and reduce switching loss and noise when a switching element is turned on. <P>SOLUTION: A control means 2 changes average power supplied to the incandescent lamp L in a unit time and adjusts the optical output of the incandescent lamp L by adjusting a ratio of a time for turning on the switching element SW and a time for turning off the switching element SW on every unit time, wherein an integral multiple of a half period of an output voltage of an alternating current power source AC is the unit time. The control means 2 includes a zero cross detection part 4 for detecting a zero cross point of the output voltage of the alternating current power supply AC, and a pattern control part 5 for controlling on and off of the switching element SW in accordance with an output pattern at a timing synchronizing with the zero cross point detected by the zero cross detection part 4, wherein a time-series pattern of the on and off of the switching element SW in the unit time is prescribed as an output pattern. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dimmer for dimming an incandescent lamp by adjusting electric power supplied from an AC power supply to the incandescent lamp, and a lighting fixture using the same.

  In general, as a dimmer technology for dimming an incandescent lamp by adjusting the power supplied from the AC power supply to the incandescent lamp, the AC power supplied to the incandescent lamp is half-wave rectified by a rectifier, There is known a technique for dimming an incandescent lamp by reducing the supplied power to ½ of the total lighting (see, for example, Patent Document 1).

  However, only by half-wave rectification of the AC power supplied to the incandescent lamp, it is not possible to make settings other than halving the power supplied to the incandescent lamp, so dimming the incandescent lamp to any light output I can't do it.

On the other hand, as a dimmer capable of dimming the incandescent lamp to an arbitrary light output, a switching element composed of a three-terminal bidirectional thyristor is provided between the AC power supply and the incandescent lamp, and the phase angle for turning on the switching element is changed. Thus, as shown in FIG. 5, a phase control method is known in which the length of the on-time in which the switching element is turned on in the half cycle of the output voltage of the AC power supply is adjusted.
JP2003-297589A (page 4-5)

  However, in the conventional phase control method, since the switching element is turned on while voltage is applied between both ends of the switching element, switching loss occurs when the switching element is turned on, and the current waveform is not a sine wave. As a result, the noise terminal voltage level is relatively large. Therefore, there is a problem that wasteful power consumption due to switching loss occurs and parts such as a noise prevention coil are increased in size.

  The present invention has been made in view of the above-described reason, and is capable of dimming the incandescent lamp to an arbitrary light output, and switching loss when the switching element is turned on as compared with the conventional phase control method. It is another object of the present invention to provide a dimmer capable of reducing noise and a lighting fixture using the same.

  According to the first aspect of the present invention, a switching element inserted between the AC power source and the incandescent lamp to open and close the power supply path to the incandescent lamp, and an integral multiple of a half cycle of the output voltage of the AC power source as a unit time. The switching element is turned on and off so as to adjust the light output of the incandescent lamp by changing the average power supplied to the incandescent lamp per unit time by adjusting the ratio between the time when the switching element is turned on and the time when the switching element is turned off. A control means for controlling, and the control means outputs, as an output pattern, a zero-cross detector that detects a zero-cross point of the output voltage of the AC power supply, and an on-off time series pattern of the switching element for each zero-cross point in the unit time. The switching element is turned on at the timing synchronized with the zero-cross point detected by the zero-cross detector. Dimmer, characterized in that it comprises a pattern control unit that controls the off according to the output pattern.

  According to this configuration, on / off of the switching element is controlled at a timing synchronized with the zero-cross point of the output voltage of the AC power supply detected by the zero-cross detection unit. Therefore, when the switching element is turned on / off, the voltage between both ends of the switching element is It takes little. Therefore, there is an advantage that switching loss and noise hardly occur when the switching element is turned on. In addition, in the control means, a time-series pattern of switching element on / off at each zero cross point in unit time is defined as an output pattern, and on / off of the switching element is controlled according to the output pattern. By adjusting the on / off ratio, the ratio between the time when the switching element is turned on and the time when it is turned off per unit time can be adjusted. Therefore, by adjusting the ON / OFF ratio of the switching element in the output pattern, the incandescent lamp can be dimmed to an arbitrary light output by changing the average power supplied to the incandescent lamp per unit time.

  According to a second aspect of the present invention, in the first aspect of the invention, the pattern control unit defines a plurality of types of the output patterns, and the control means includes a selection unit that selects any one of the plurality of types of output patterns. And the pattern control unit controls on / off of the switching element according to the output pattern selected by the selection unit.

  According to this configuration, since the on / off of the switching element is controlled according to the output pattern selected by the selection unit among the plurality of types of output patterns, the light output of the incandescent lamp is switched by switching the output pattern selected by the selection unit. Can do.

  According to a third aspect of the present invention, the appliance body includes the dimmer and the incandescent lamp according to the first or second aspect.

  According to this configuration, in the luminaire using the dimmer, the incandescent lamp can be dimmed to an arbitrary light output as in the invention of claim 1 or 2, and the conventional phase control is performed. Compared to the method, the switching loss and noise when the switching element is turned on can be reduced.

  The present invention has a pattern control unit that controls the on / off of the switching element at a timing synchronized with the zero cross point detected by the zero cross detection unit, and the control means has both ends of the switching element when the switching element is turned on / off. Since almost no voltage is applied between them, the switching loss and noise generated when the switching element is turned on can be reduced as compared with the conventional phase control method. In addition, the time-series pattern of switching element on / off in unit time is defined as an output pattern, and the pattern control unit controls the switching element on / off according to the output pattern. If adjusted, the average power supplied to the incandescent lamp per unit time can be changed, and the incandescent lamp can be dimmed to an arbitrary light output.

  The dimmer of the present embodiment dimmes the incandescent lamp by adjusting the power supplied from the AC power source to the incandescent lamp. For example, the dimmer for dimming the space in a house, hall, banquet hall, etc. Used for light control.

  As shown in FIG. 1, the dimmer 1 includes a switching element SW that is inserted between the AC power supply AC and the incandescent lamp L and opens and closes a power supply path from the AC power supply AC to the incandescent lamp L, and the switching element SW is turned on and off. Control means 2 for controlling the light intensity, and input means 3 for setting the dimming level of the incandescent lamp L.

  The input means 3 includes a select switch (here, a rotary switch) operated to select an arbitrary dimming level from a plurality of dimming levels with different light outputs of the incandescent lamp L. As is well known, the switching element SW is a three-terminal bidirectional thyristor (here, triac), and is turned on when a voltage is applied to the gate, and once turned on, the on state is maintained until the applied voltage becomes zero. To do. The control means 2 adjusts the ratio of the on time during which the switching element SW is turned on and the off time during which the switching element SW is turned off during a specified unit time T, which will be described later, according to the dimming level set by the input means 3. The light output of the incandescent lamp L is adjusted by changing the average power supplied to the incandescent lamp L per unit time T.

  By the way, in this embodiment, the timing when the control means 2 turns on / off the switching element SW is limited to the zero cross point of the output voltage of the AC power supply AC. That is, the timing at which the switching element SW is turned on / off is limited to when the output voltage of the AC power supply AC is close to 0 V, so that when the switching element SW is turned on / off, the voltage between both ends of the switching element SW is Since it hardly takes, there is an advantage that switching loss hardly occurs and noise such as noise generated between the harmonic current and the power supply terminal hardly occurs. As described above, if the switching element SW is turned on / off only at the zero cross point of the output voltage of the AC power supply AC, the on time and the off time of the switching element SW are half cycles between the zero cross point and the zero cross point of the output voltage of the AC power supply AC. Therefore, the unit time T is defined as an integral multiple of a half cycle of the output voltage of the AC power supply AC so that the ratio between the on time and the off time in the unit time T can be adjusted. .

  As a configuration for turning on / off the switching element SW only at the zero-cross point, the control means 2 includes a zero-cross detector 4 that detects the zero-cross point of the output voltage of the AC power supply AC, and the zero-cross point detected by the zero-cross detector 4. There is provided a pattern control unit 5 that performs on / off control of the switching element SW in synchronization with the timing. Here, the pattern control unit 5 is configured using an MPU. Further, in the pattern control unit 5, an on / off time-series pattern in the switching element SW for each zero cross point in the unit time T is defined as an output pattern, and the switching element SW is controlled to be turned on / off according to this output pattern.

  That is, the switching element SW is turned on and off in time series in the unit time T in the order of arrangement of the output pattern on and off. Here, the ratio between the ON time and the OFF time of the switching element SW in the unit time T is determined by the ON / OFF ratio in the output pattern regardless of the ON / OFF arrangement order in the output pattern. Therefore, if the ratio between on and off in the output pattern is changed, the ratio between the on time and the off time of the switching element SW in the unit time T is changed, and the light output of the incandescent lamp L is adjusted. . However, since the incandescent lamp L may appear to flicker when the switching element SW OFF time continues for a long time, the ON / OFF in the output pattern is set so that the OFF time of the switching element SW does not continue as much as possible in the unit time T. It is desirable to set the array.

  In the present embodiment, a numerical value of a plurality of bits in which each bit is represented by a binary value (1, 0) is used as an output pattern (PTN), and the values “1” and “0” of each bit are turned on and the switching element SW is turned on. Each is associated with off. The pattern control unit 5 performs on / off control of the switching element SW by using the output pattern one bit at a time every time the zero cross point is detected by the zero cross detection unit 4. Here, since one bit of the output pattern is used for each half cycle of the output voltage of the AC power supply SW, the number of bits of the output pattern is determined in accordance with the number of half cycles included in the unit time T.

  Further, when dimming is possible at a plurality of dimming levels as in the present embodiment, a plurality of types of output patterns are prepared corresponding to each dimming level. The pattern control unit 5 includes a selection unit (not shown) that selects an output pattern corresponding to the dimming level set by the input unit 3 from the plurality of types of output patterns, and is selected by the selection unit. The switching element SW is on / off controlled according to the output pattern.

  Hereinafter, as an example of the present embodiment, an example in which two periods that are four times the half period in the output voltage of the AC power supply AC are defined as the unit time T will be described.

  In this example, since the unit period T includes four half cycles, the unit time T can be determined by a 4-bit output pattern (“1111”, “1110”, “1010”, “1000”, “0000”). The ratio of the ON time of the switching element SW in can be changed in five stages of 4/4, 3/4, 2/4 (= 1/2), 1/4, and 0/4. As a result, all lighting, 3/4 dimming for lighting the incandescent lamp L with an average power of 3/4 at the time of full lighting, and 1/2 for lighting the incandescent lamp L with an average power of 1/2 at the time of all lighting. It is possible to set five dimming levels: two dimming, ¼ dimming for turning on the incandescent lamp L with an average power of ¼ when fully lit, and full extinction. That is, the output patterns “0000”, “1000”, “1010”, “1110”, “1111” are all turned off (the light control level LV = 0), and the light control is 1/4 (the light control level LV = 1). ), 1/2 dimming (dimming level LV = 2), 3/4 dimming (dimming level LV = 3), full lighting (dimming level LV = 4), respectively. Correspond. For example, even if the output pattern corresponding to ½ dimming is set to “1100”, there is no problem because the ON / OFF ratio does not change, but as described above, the OFF time of the switching element SW is not continuous as much as possible in the unit time T. It is desirable to set an array of on and off in the output pattern.

  Next, the operation of the control means 2 will be described with reference to the flowchart of FIG.

  When the power is turned on, the control means 2 first reads the dimming level from the input means 3 (S1), and selects an output pattern corresponding to the read dimming level (S2). Next, the zero cross point of the AC power supply AC is detected by the zero cross detection unit 4 (S3), and each time the zero cross point is detected (S3: Yes), the value is read bit by bit for the output pattern selected in step S2. (S5).

  If the read value is “1” (S5: Yes), a pulse voltage is applied to the gate of the switching element SW to turn on the switching element SW (S6). As a result, the switching element SW is turned on for the half wave from the detection of the zero cross point of the AC power supply AC in step S3 to the next zero cross point. On the other hand, if the read value is “0” (S5: No), no pulse voltage is applied to the gate of the switching element SW (S7). In this case, the switching element SW is turned off for a half wave from the detection of the zero cross point of the AC power supply AC in step S3 to the next zero cross point.

  Thereafter, every time a zero-cross point is detected, a value is read out one bit at a time for the output pattern, the switching element SW is turned on and off, and when the fourth bit of the output pattern is read, the value of the first bit is read again. Repeat the process. However, when the input unit 3 is operated, the control unit 2 is configured to shift to step S1 in order to read the dimming level after the operation from the input unit 3 again. In order to repeatedly use a 4-bit output pattern, a counter (CNT) on a program that repeatedly counts 1 to 4 is used here (S4, S8, S9).

  Hereinafter, with reference to FIG. 3 showing voltage waveforms applied to the incandescent lamp L, the operation of the dimmer 1 will be described in detail. In FIG. 3, the output voltage waveform of the AC power supply AC is indicated by a dotted line, and the voltage waveform applied to the incandescent lamp L is indicated by a solid line.

  When full lighting is set as the dimming level by the input means 3, the output pattern becomes “1111”. Therefore, as shown in FIG. 3A, the incandescent lamp L is supplied from the AC power source AC over the entire period. All lights up when power is supplied.

  On the other hand, when 3/4 dimming is set by the input means 3, the output pattern is “1110”. Therefore, as shown in FIG. 3B, the incandescent lamp L is fully lit from the AC power supply AC. The average power of 75% (= 3/4) is supplied, and the incandescent lamp L is lit with 3/4 dimming. When ½ dimming is set by the input means 3, the output pattern is “1010”. Therefore, as shown in FIG. % (= 1/2) of average power is supplied, and the incandescent lamp L is lit with 1/2 light control. In addition, when 1/4 dimming is set by the input means 3, the output pattern is “1000”, so that the incandescent lamp L is fully lit from the AC power source AC as shown in FIG. 25% (1/4) of the average power is supplied, and the incandescent lamp L is lit with 1/4 light control.

  When the input unit 3 is set to be completely turned off, the output pattern is “0000”. Therefore, as shown in FIG. 3E, the incandescent lamp L is not supplied with power over the entire period. L goes out.

  Moreover, in FIG. 4, schematic structure of the lighting fixture using the dimmer 1 mentioned above is shown. The lighting fixture includes a fixture main body 7 including a power plug 6 connected to a commercial power outlet, an incandescent lamp L, and the dimmer 1 described above. The dimmer 1 is connected between the power plug 6 and the incandescent lamp L. Thus, in the lighting fixture using the dimmer 1 of the present invention, when the switching element SW is turned on / off, switching loss and noise are less likely to occur. Therefore, noise prevention components can be omitted, and the switching element SW In addition to reducing unnecessary power consumption due to noise and noise prevention components, it is possible to reduce the size and cost of lighting fixtures.

  In the above embodiment, in order to realize the dimmer 1 having five levels of dimming levels including the extinction, two periods that are four times the half period of the output voltage of the AC power supply AC are defined as the unit time T. In order to realize the dimmer 1 having the dimming level of N (N is an arbitrary integer) using the present invention, a half cycle in the output voltage of the AC power supply AC is shown. (N-1) times as long as the unit time T may be defined. As described above, by using the technical idea of the present invention, the dimmer 1 having a plurality of dimming levels can be easily realized.

It is a block diagram which shows the dimmer of embodiment of this invention. It is a flowchart which shows operation | movement same as the above. It is a wave form diagram which shows operation | movement same as the above. It is a block diagram which shows the lighting fixture using the dimmer same as the above. It is a wave form diagram which shows operation | movement of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dimmer 2 Control means 4 Zero cross detection part 5 Pattern control part 7 Instrument main body AC AC power supply L Incandescent lamp SW Switching element T Unit time

Claims (3)

  A switching element that is inserted between the AC power supply and the incandescent lamp and opens and closes the power supply path to the incandescent lamp, and a time for which the switching element is turned on per unit time with an integral multiple of a half cycle of the output voltage of the AC power supply as a unit time And control means for controlling on / off of the switching element so as to adjust the light output of the incandescent lamp by changing the average power supplied to the incandescent lamp per unit time by adjusting the ratio of the off time to the off time. The control means defines a zero-cross detection unit for detecting a zero-cross point of the output voltage of the AC power supply, and an on-off time series pattern of the switching element for each zero-cross point in the unit time as an output pattern. The switching element is turned on and off at the timing synchronized with the zero cross point detected by the Dimmer, characterized in that it comprises a pattern control unit that controls according to emissions.   The pattern control unit defines a plurality of types of output patterns, and the control means includes a selection unit that selects one of the plurality of types of output patterns, and the pattern control unit is selected by the selection unit. The dimmer according to claim 1, wherein on / off of the switching element is controlled according to the output pattern. An illumination fixture using a dimmer, comprising the dimmer according to claim 1 or 2 and an incandescent lamp in a fixture body.

Images