JP2009104917A - Dimness controlling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce jamming of electric wave noise to other electronic apparatuses in a dimness controlling system controlling lighting of a light source by power obtained by superposing an AC operating voltage on a rectangular wave control voltage. <P>SOLUTION: The dimness control system includes the light source 10, a power circuit 20 supplying lighting power to the light source 10 and a system control unit 30 controlling dimness of the power circuit 20 via a communication passage 40. The lighting power is formed by a superposed output voltage V3 obtained by superposing the sinusoidal operating voltage V1 on the rectangular wave control voltage V2(f) to change the frequency of the rectangular wave of the control voltage V2(f) depending on whether the sinusoidal wave of the operating voltage V1 has a positive or negative value. Thus, concentration of the electric wave noise generated in the power circuit 20 within a specific frequency range is eliminated to reduce the noise level, thereby reducing jamming of the electric wave noise to the other electronic apparatuses and radio apparatuses near the power circuit 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dimming control system that controls lighting of a light source with electric power obtained by superimposing an AC operating voltage and a rectangular wave control voltage.

  Conventionally, in a dimmer for dimming a light source, the AC power supply is turned on / off with a rectangular wave having a frequency higher than that frequency, and the pulse duty of the rectangular wave is controlled to turn on the AC power supply applied to the light source. A device that controls light control by controlling the light intensity is known. For example, Patent Document 1 discloses a dimmer that performs dimming control by applying a trigger signal to a switching element provided between an AC power source and a light source, and switching in a preset time division period. Yes.

However, in a dimmer that performs dimming control by turning on and off such an AC power source with a high-frequency rectangular wave, the switching element has a superimposed output voltage on which the AC voltage and the rectangular wave control voltage are superimposed. A superimposed output current flows through the output power circuit including the switching element. This superimposed output current also flows through the electrical components connected to the switching elements and the wiring of the circuit board on which they are mounted. For this reason, these electric members serve as antennas, and noise is radiated to the surrounding space mainly based on a current component of a rectangular wave having a high frequency included in the superimposed output current. Here, if the frequency of the rectangular wave is a fixed value, noise is concentrated in the frequency range, and the level cannot be ignored. This noise becomes a jamming radio wave, and for example, it is difficult to arrange electronic devices and wireless devices that are sensitive to noise in the vicinity. In addition, various digital control circuits for dimming control in the dimmer may malfunction.
JP 2007-128669 A

  The present invention has been made to solve the above-described problem, and prevents radio waves from being transmitted to other electronic devices or the like that exist near the power supply circuit so that noise is not concentrated in the frequency region of the rectangular wave control voltage. An object of the present invention is to provide a dimming control system capable of reducing noise interference.

  In order to achieve the above object, an invention according to claim 1 includes a light source, and a power supply circuit that supplies the light source with lighting power obtained by superimposing a sine wave operating voltage and a rectangular wave control voltage. In the light control system, the frequency of the control voltage in the power supply circuit can be switched to an arbitrary value at a predetermined time interval.

  According to a second aspect of the present invention, the dimming control system according to the first aspect further includes a filter for smoothing the lighting power, and the lighting power is smoothed by the filter and then supplied to the light source. is there.

  According to a third aspect of the present invention, in the dimming control system according to the first or second aspect, the operating voltage of the sine wave forms a waveform pattern that alternately shows positive and negative values, and the frequency of the control voltage is The value is switched depending on whether the operating voltage is a positive value or a negative value.

  According to the first aspect of the present invention, the frequency of the rectangular wave control voltage can be switched to an arbitrary value, so that radio noise generated in the power supply circuit is not concentrated in a specific frequency range, and the noise level is reduced. Is done. Therefore, it is possible to reduce interference of radio wave noise to other electronic devices and wireless devices existing near the power supply circuit.

  According to the second aspect of the present invention, since the lighting power is smoothed, the frequency component of the rectangular wave superimposed on the lighting power is filtered and reduced, so that the level of radio noise is reduced, and other electronic devices It is possible to further reduce the interference of radio noise to the etc.

  According to the invention of claim 3, since the frequency of the control voltage is switched depending on whether the operating voltage is positive or negative, the system configuration for frequency switching can be simplified.

  Hereinafter, a dimming control system (hereinafter referred to as the present system) according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, this system includes a light source 10, a power supply circuit 20 that supplies lighting power to the light source 10, a system control unit 30 that controls the entire system, a system control unit 30, and a power supply circuit. 20 and a communication path 40 that connects 20 wirelessly. The communication path 40 may be a wired transmission path.

  The light source 10 is an illuminating lamp that is turned on by the power supply circuit 20 and is dimmed and controlled by the system control unit 30. The light source 10 can be an incandescent bulb, a fluorescent lamp, an LED, or the like.

  The power supply circuit 20 includes an AC power supply unit 21, a setting unit 22, a voltage control unit 23, a voltage superimposing unit 24, and a filter unit 25. The AC power supply unit 21 is an AC power supply that supplies the voltage superimposing unit 24 with a sine wave operating voltage V1 having a waveform pattern that alternately shows positive and negative values. The setting unit 22 sets the dimming rate of the light source 10 based on the dimming control signal from the system control unit 30, and sets the frequency of the control voltage V2 (f) of the voltage control unit 23 to be switchable. The voltage control unit 23 generates a rectangular wave control voltage V2 (f) based on the dimming rate and frequency set by the setting unit 22, and the light source 10 is turned on by the control voltage V2 (f). Control. The lighting control by the voltage control unit 23 is performed by controlling the pulse width of the rectangular wave of the control voltage V2 (f) based on the dimming rate set by the setting unit 22, and the frequency f of the rectangular wave. The value is switched at a predetermined time interval set by the setting unit 22. The voltage superimposing unit 24 superimposes the operating voltage V1 and the control voltage V2 (f) and outputs a superimposed output voltage V3. The filter unit 25 smoothes the superimposed output voltage V3 from the voltage superimposing unit 24, and outputs a lighting voltage V4 for lighting the light source 10. The AC power supply unit 21 is supplied with operating power from a main AC power line in a house or the like.

  The system control unit 30 includes an operation unit 31 and a wireless communication unit 32. The operation unit 31 is for the user to operate and specify the dimming rate of the light source 10. The wireless communication unit 32 generates a dimming control signal for dimming control of the light source 10 based on the dimming rate designated by the operation unit 31 and transmits the dimming control signal to the power supply circuit 20. . Various control processes performed by the system control unit 30 are embodied by a CPU or the like. Further, DMX (Digital Multiplex), which is a protocol for performing data communication between lighting equipments, is used for transmission of the dimming control signal from the system control unit 30. For this reason, the system control unit 30 converts the dimming control signal including the dimming rate specified by the operation unit 31 into DMX data, and transmits the DMX data from the wireless communication unit 32.

  As shown in FIG. 2, the setting unit 22 includes a wireless communication unit 26, a frequency setting unit 27, a time interval setting unit 28, and a control voltage determination unit 29. The wireless communication unit 26 receives the DMX data transmitted from the system control unit 30 via the wireless communication path 40, demodulates the dimming control signal based on the received DMX data, and operates the operation unit 31. Detects the specified dimming rate.

  The frequency setting unit 27 can set the frequency f of the rectangular wave of the control voltage V2 (f) to a plurality of values so that the frequency can be arbitrarily switched. A plurality of values of the frequency to be switched are set in advance by the user.

  The time interval setting unit 28 sets a predetermined time interval in order to switch the frequency value set by the frequency setting unit 27 at a constant time interval. Here, the predetermined time interval is set by providing the time interval setting unit 28 with a positive / negative voltage detection function for detecting whether the sine wave of the operating voltage V1 is a positive value or a negative value. The positive / negative of the sine wave of the voltage V1 is detected, and the half wavelength time interval at which the sine wave of the operating voltage V1 becomes a positive value or a negative value is automatically set as a predetermined time interval. It should be noted that the setting of the time interval in the time interval setting unit 28 can be arbitrarily performed manually in advance by a user by providing a volume or the like in the time interval setting unit 28.

  The control voltage determining unit 29 is a value arbitrarily selected from the predetermined time interval set by the time interval setting unit 28 and the values of a plurality of frequencies set by the frequency setting unit 27 (here, frequencies f1, f2 and The switching time interval of the frequency of the control voltage V2 (f) and the frequency value to be switched are determined based on the voltage of the control voltage V2 (f), and the voltage is set so that the switching of the rectangular wave frequencies f1 and f2 is periodically repeated at each switching time interval. The control unit 23 is controlled. Further, the control voltage determination unit 29 determines the dimming rate based on the dimming control signal detected by the wireless communication unit 26, and sets each determined switching frequency value, switching time interval, and dimming rate set value as a voltage. Input to the controller 23.

  Based on the switching frequency value and time interval determined by the control voltage determination unit 29 and the dimming rate setting values, the voltage control unit 23 performs negative and positive operations when the sine wave of the operating voltage V1 is a positive value. When the value is a value, rectangular waves having frequencies f1 and f2 are generated, and a control voltage V2 (f) formed by switching these rectangular waves at every half wavelength interval of the sine wave is generated. Moreover, the voltage control part 23 sets the pulse duty of the rectangular wave of frequency f1, f2, respectively based on the set light control rate. Here, for example, as shown in FIGS. 3A and 3B, the pulse duty of the rectangular waves having the frequencies f1 and f2 is set to the period T1 (frequency f1 = 1 / T1) and the period of each rectangular wave. This is done by adjusting the on-duty widths w1 and w2 of the rectangular wave of T2 (frequency f2 = 1 / T2). These on-duty widths w1 and w2 are set with the same on-duty ratios of the rectangular waves of the frequencies f1 and f2 for the same dimming rate specified by the operation unit 31. As a result, the voltage control unit 23 generates the control voltages V2 (f1) and V2 (f2) having the on-duty widths w1 and w2 by switching each half-wavelength interval of the sine wave of the operating voltage V1. The light source 10 is dimmed by controlling the control voltage V2 (f) by changing the on-duty widths w1 and w2 of the respective rectangular waves in accordance with the set dimming rate.

  The voltage superimposing unit 24 includes transistors Q1 and Q2 as semiconductor switching elements. As the switching element, a MOSFET, a bipolar transistor, a diode, or the like can be used. The sine wave operating voltage V1 shown in FIG. 4A is applied to the collectors of the transistors Q1 and Q2 of the voltage superimposing unit 24, and the bases of the transistors Q1 and Q2 shown in FIG. The rectangular wave control voltage V2 (f) shown in b) is input. The frequency f of the control voltage V2 (f) is alternately switched between the frequency f1 and the frequency f2 every positive and negative half wavelength period in the sine wave operating voltage V1, and as a result, as shown in FIG. Furthermore, the output voltage of each emitter of the transistors Q1 and Q2 has a waveform in which the sine wave operating voltage V1 is turned on and off by the rectangular waves of the control voltage V2 (f1) and the control voltage V2 (f2). A superimposed output voltage V3 in which the operating voltage V1 and the rectangular-wave control voltages V2 (f1) and V2 (f2) are superimposed is output. Here, the superposition of the operating voltage V1 and the control voltage V2 (f) means that the operating voltage V1 is switched on and off by the rectangular wave of the control voltage V2 (f). The output becomes the superimposed output voltage V3. The superimposed output voltage V3 is input to the filter unit 25.

  The filter unit 25 is a smoothing filter composed of a low-pass filter having the same choke coils L1 and L2 and an electrolytic capacitor C1, and smoothes the superimposed output voltage V3 of the voltage superimposing unit 24 to output a lighting voltage V4. The choke coils L1 and L2 are connected to the emitters of the transistors Q1 and Q2, respectively. The terminals on the output side of the choke coils L1 and L2 are terminated with a capacitor C1. As a result, as shown in FIG. 4D, the output of the filter unit 25 is applied to the light source 10 as a lighting voltage V4 whose voltage level is lower than the operating voltage V1, and the smoothed lighting power is supplied to the light source 10. To be supplied. When the superimposed output voltage V3 is smoothed by the filter unit 25, the frequency component of the rectangular wave superimposed on the lighting voltage V4 is filtered and reduced by the characteristics of the low-pass filter of the filter unit 25.

  In the present system configured as described above, when the user instructs the setting value of the dimming rate of the power supply circuit 20 by the operation unit 31 of the system control unit 30, the instructed dimming control signal is transmitted through the communication path 40. Via the wireless communication unit 32 to the wireless communication unit 26 of the setting unit 22 of the power supply circuit 20. The setting unit 22 sets the dimming rate based on the dimming control signal received by the wireless communication unit 26, and based on the dimming rate, the preset switching frequency value, and the switching time interval setting value. The voltage control unit 23 controls the voltage control unit 23 to form a control voltage V2 (f) generated by periodically switching the rectangular waves having the frequencies f1 and f2 for each half wavelength of the sine wave of the operating voltage V1. Thus, the voltage superimposing unit 24 superimposes the rectangular wave control voltage V2 (f) and the operating voltage V1 to form the lighting voltage V4, and the lighting control of the light source 10 is performed. Therefore, the system control unit 30 performs dimming control of the light source 10 by controlling the control voltage V <b> 2 (f) formed by rectangular waves of two frequencies according to the dimming rate specified by the operation unit 31.

  Here, the setting of the on-duty of the rectangular wave in the voltage control unit 23 will be described. The on-duty ratio corresponding to the dimming rate set by the operation unit 31 is tabulated in advance as shown in Table 1 below and stored in the voltage control unit 23. Therefore, the voltage control unit 23 automatically selects the on-duty ratio (%) from the table of Table 1 based on the dimming rate determined by the control voltage determining unit 29, and sets the dimming The on-duty width is controlled to match the rate. If the power supply circuit 20 is not connected to the system control unit 30 via the communication path 40, a dimming rate adjusting volume or the like is provided in the setting unit 22 to adjust the dimming rate individually. Good.

  Further, for example, when the user instructs the dimming rate to 5% using the operation unit 31, the on-duty ratio at the dimming rate of 5% is 14% from Table 1, so that the control voltage V <b> 2 ( As shown in FIG. 5, the waveform of the rectangular wave of f) (with a frequency of 32 kHz) has a width (period T1) of one rectangular wave of 1/32000 (s) and an on-duty width w1 of 1 /32000×0.14 (s). Thus, the on-duty width is easily calculated from Table 1 based on the dimming rate specified by the user, and the light source 10 is dimmed and controlled by controlling the on-duty width. Further, for the frequency of the rectangular wave of 36 kHz, the on-duty width can be obtained by calculation using the same table as in Table 1.

  Next, a description will be given of each radio noise when the frequency of the rectangular wave of the control voltage V2 (f) is switched to f1, f2 (assuming f1 <f2) and when the frequency is fixed to f1 without switching. To do.

  When the frequency of the rectangular wave is switched to f1 and f2, as shown in FIG. 6A, the frequency of the rectangular wave is the control voltage V2 of f1 and f2 for each half-wavelength interval of the sine wave of the operating voltage V1. (F1) and the control voltage V2 (f2) are alternately switched, and these two frequencies f1 and f2 are repeatedly generated. At this time, the operating voltage V1 and the control voltages V2 (f1) and V2 (f2) are superimposed on the power supply circuit 20 to cause a superimposed output current to flow, and a rectangular wave frequency f1 is included in the superimposed output current. , F2 is included. This high-frequency current also flows through the transistors Q1 and Q2, the electrical components connected to these transistors Q1 and Q2, and the wiring of the circuit board on which they are mounted. For this reason, these electric members serve as antennas, and a part of the current of the rectangular wave is radiated into the air as radio noise from the power supply circuit 20. As shown in FIG. 6B, the noise spectrum of the radio wave noise in this case is dispersed into noise spectra 61 and 62 having two frequencies f1 and f2. The respective noise levels are shown as substantially the same level (Nv1).

  On the other hand, when the frequency of the rectangular wave is fixed to the same frequency (f1 = f2), as shown in FIG. 6C, the control voltage V2 (f1) is applied over the entire one wavelength of the sine wave of the operating voltage V1. The frequency f1 of the rectangular wave does not change. Therefore, as shown by the dotted waveform in FIG. 6B, the noise spectrum is always concentrated on the same frequency f1 and is not temporally dispersed, and the radio noise at the frequency f1 is as in the noise spectrum 63. The noise level (Nv2) is greater than the noise level (Nv1) of the noise spectrum 61, 62. Thus, in this system, since the frequency of the rectangular wave is switched, the noise spectra have different frequencies and are dispersed in time. As a result, these noise levels (Nv1) are reduced to approximately half compared to the noise level (Nv2) when the frequency of the rectangular wave is fixed to one.

  Here, for example, when the frequencies f1 and f2 of the rectangular wave of the control voltage V2 (f) are switched to 32 kHz and 36 kHz for each half wavelength of the operating voltage V1, the noise spectrum due to the frequency of the rectangular wave is shown in FIG. ), The noise level is distributed in two on the frequency axis, and each noise level becomes a noise level Nv1. On the other hand, when the frequency of the rectangular wave is not switched and is fixed to 32 kHz (f1) of the same frequency, as shown in FIG. 7B, the noise level Nv2 concentrates on the frequency of 32 kHz and the noise level Nv1 About twice as much. Therefore, by switching the frequency of the rectangular wave and dispersing it in time, the noise level generated from the power supply circuit 20 can be reduced, and the influence of radio noise can be reduced.

  Further, as shown in FIG. 8 (a), the superimposed output voltage V3 is smoothed by the filter unit 25, which is a low frequency filter, so that the sine wave frequency (for example, the operating voltage V1 superimposed on the lighting voltage V4) The frequency f1 (32 kHz) and f2 (36 kHz) components higher than 60 Hz) can be filtered. As a result, as shown in FIG. 8B, the noise levels of the frequencies f1 and f2 can be further reduced as compared to the noise level Nv1 when the filter unit 25 is not provided.

  As described above, according to the present embodiment, the frequency of the rectangular-wave control voltage V2 (f) can be switched to an arbitrary value. Therefore, by periodically switching the frequency of the control voltage V2 (f), the power supply The radio noise generated in the circuit is not concentrated in a specific frequency range, and the noise level is reduced. Accordingly, it is possible to reduce interference of radio wave noise to other electronic devices and wireless devices existing near the power supply circuit 20. Further, in the dimming control system, it is possible to reduce malfunctions of various digital control circuits, obstructions to a wireless wired communication path, and the like, so that dimming control of the light source can be performed stably.

  In addition, since the lighting voltage V4 is smoothed by the filter unit 25, the frequency component of the rectangular wave superimposed on the lighting power is filtered and reduced, so that the level of radio noise is reduced and other electronic devices and the like are reduced. The interference of radio noise can be further reduced.

  Further, since the frequency of the control voltage V2 (f) is switched depending on whether the operating voltage V1 is positive or negative, the frequency switching system configuration can be simplified.

  In addition, this invention is not limited to the structure of said each embodiment, A various deformation | transformation is possible in the range which does not change the meaning of invention. In the above embodiment, the frequency of the rectangular wave of the control voltage is switched for each half wavelength of the sine wave of the operating voltage. However, the switching time interval is set to a longer time interval such as one to a plurality of wavelengths or a quarter wavelength. You may carry out by a shorter time interval like every time interval. Further, by setting two or more frequencies to be switched and switching, it is possible to widen noise temporal and frequency dispersion and further reduce the noise level. The predetermined time interval and the frequency to be switched can be set by an instruction from the operation unit together with the dimming rate. In the above-described embodiment, the case where the frequency of the rectangular wave is 32 kHz, 36 kHz, or the like has been described. However, the frequency of the rectangular wave is freely selected without being limited thereto. Moreover, although wireless communication was used for the communication path between each power supply circuit and the system control unit, power line carrier communication using a wired transmission line or AC power wiring that supplies power to each power supply circuit in common ( PLC) can also be used.

The block diagram of the illumination control system which concerns on the 1st Embodiment of this invention. The block diagram of the setting part of the power supply circuit in the said system. (A) is a figure which shows the rectangular wave before switching the frequency of the control voltage of the said power supply circuit, (b) is a figure which shows the rectangular wave after switching the frequency of the control voltage of the power supply circuit. (A) is a figure which shows the voltage waveform of the alternating current power supply of the power supply circuit in the said system, (b) is a figure which shows the waveform of the control voltage of the circuit, (c) is a figure which shows the waveform of the superimposed output voltage of the circuit, (D) is a figure which shows the output waveform of the filter part of the circuit. The figure which shows the on-duty waveform of the control voltage in case the frequency of the rectangular wave of the said power supply circuit is 32 kHz and the light control rate is 5%. (A) is a diagram for explaining the superimposed output voltage when the frequency of the control voltage of the power supply circuit is switched between positive and negative of the operating voltage, (b) is a diagram for explaining the noise level due to the frequency of the control voltage of the power supply circuit, FIG. 6C is a diagram for explaining the superimposed output voltage when the frequency of the control voltage of the power supply circuit is not switched. (A) is a figure explaining the noise level at the time of switching the frequency of a rectangular wave to 32 kHz and 36 kHz, (b) is a figure explaining the noise level at the time of fixing the frequency of a rectangular wave to 32 kHz. (A) is a figure explaining the noise level when there is a filter, (b) is a figure explaining the noise level when there is no filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light source 20 Power supply circuit 25 Filter part 30 System control part

Claims (3)

A dimming control system comprising: a light source; and a power supply circuit that supplies lighting power to the light source by superimposing a sine wave operating voltage and a rectangular wave control voltage,
A dimming control system characterized in that the frequency of the control voltage in the power supply circuit can be switched to an arbitrary value at predetermined time intervals. A filter for smoothing the lighting power;
The dimming control system according to claim 1, wherein the lighting power is supplied to the light source after being smoothed by the filter. The operating voltage of the sine wave forms a waveform pattern that alternately shows positive and negative values,
3. The dimming control system according to claim 1, wherein the frequency of the control voltage is switched depending on whether the operating voltage is a positive value or a negative value. 4.

Images