JP2008054050A - Digital amplifier system with dimmer, and speaker system with illumination - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital amplifier system with a dimmer, which has a high tone quality, and a speaker system with illumination. <P>SOLUTION: A clock signal 902 of a frequency fa is supplied to a digital amplifier 200, and a clock signal 903 of a frequency fb is supplied to a LED dimmer 300, and a clock signal 904 of a frequency fc is supplied to a switching power source 400. When frequencies fa, fb, and fc of respective clock signals are set so as to be integer multiples or integer fractions of each other, an influence upon the digital amplifier 200 of high frequency noise generated from the LED dimmer 300 and the switching power source is reduced to be able to suppress the occurrence of beats, so that quality of an audio signal output from a speaker connection terminal 206 can be kept high. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital amplifier system with a dimmer having a digital amplifier and a dimmer and a speaker system with illumination.

Amplifiers used in audio equipment often use digital amplifiers for miniaturization and power saving. However, when the switching power supply unit is integrated with a digital amplifier, beats are generated when the carrier frequencies used by them and their harmonics approach each other, and the quality of the output signal of the digital amplifier deteriorates. As a countermeasure, Patent Document 1 uses the frequency output from the reference oscillator as the carrier frequency of the digital amplifier, and uses an integer multiple or a fraction thereof as the carrier frequency of the switching power supply.
JP 2005-136717 A

By the way, an audio amplifier is often used as a high-definition audio output device for projecting a video such as a movie on a large screen television or screen. In such a use, when viewing a video, if there is a light control device that gradually darkens or brightens the room, the taste becomes even deeper. A product in which a dimming device is combined with a lighting fixture has been developed, but it has been complicated for a user because an audio amplifier or a dimming device has to be prepared. In addition, many users listen to music in a room where lighting is turned off. Even in such a case, visual enjoyment increases when the illumination changes in accordance with the music. However, even in this case, the same trouble as described above occurs.
Furthermore, since switching noise of pulse width modulation (hereinafter referred to as PWM) control used in the light control device is mixed in the signal system of the audio amplifier, there is a problem that the sound quality is deteriorated.

  The present invention has been made in view of the above-described circumstances, and is capable of reproducing audio signals with a digital amplifier and performing dimming control, and is not affected by switching noise of the dimming circuit. It is an object to provide a digital amplifier system with an instrument and a speaker system with illumination.

  In order to solve the above-described problems, the present invention performs a digital amplifier for performing power amplification by performing pulse width modulation based on a first clock signal on an audio signal, and performing pulse width modulation based on a second clock signal. And a dimmer for controlling the power supplied to the light emitting means, and the frequency of the first clock signal and the second clock signal is obtained by multiplying or dividing the frequency of the clock signal generated from the common oscillation circuit. Provided is a digital amplifier system with a dimmer characterized in that it is used as a circumference or as it is and has a relation of an integral multiple or a fraction of an integer.

  The present invention also provides a digital amplifier for performing power amplification by performing pulse width modulation on an audio signal based on a first clock signal, and supplying power to a light emitting means by performing pulse width modulation on a second clock signal. A dimmer for controlling electric power; and a switching power source for performing power supply to the power line of the digital amplifier and the dimmer by performing pulse width modulation based on a third clock signal. The frequencies of the clock signal, the second clock signal, and the third clock signal are obtained by multiplying, dividing, or directly using the frequency of the clock signal generated from the common oscillation circuit, and having an integer multiple or a fraction of an integer. A digital amplifier system with a dimmer is provided.

  The present invention also provides a digital amplifier that performs power amplification by performing pulse width modulation on an audio signal based on a first clock signal, and power supply to the light emitting means based on the result of pulse width modulation of the digital amplifier. A dimmer with a dimmer is provided.

  In another preferred embodiment, the first clock signal includes a switching power source that performs pulse width modulation based on a third clock signal to control power supply to the power line of the digital amplifier and the dimmer. The frequency of the third clock signal is obtained by multiplying, dividing, or using the frequency of the clock signal generated from the common oscillation circuit as it is, and having a relationship of an integral multiple or a fraction of an integer. Also good.

  In another preferred embodiment, the dimmer-equipped digital amplifier system includes a speaker to which an audio signal amplified by the digital amplifier is supplied, and a light source that receives power from the dimmer. An illuminated speaker system may be provided.

  According to the present invention, a digital amplifier system with a dimmer and a speaker system with illumination that can reproduce an audio signal with a digital amplifier and perform dimming control and are not affected by switching noise of the dimming circuit. Can be provided.

  Hereinafter, an embodiment of the present invention will be described.

  FIG. 1 is a block diagram showing a configuration of a digital amplifier system 100 with a dimmer according to an embodiment of the present invention. FIG. 2 is an external view of the digital amplifier system with dimmer 100 as viewed from the back.

  In FIG. 1, an oscillation circuit 500 includes an oscillator such as a crystal and a circuit for exciting the oscillator, and outputs a clock signal 900 having a frequency fo. The clock signal 900 is multiplied by predetermined multipliers 602, 603, and 604, and is output as a clock signal 902 having a frequency fa, a clock signal 903 having a frequency fb, and a clock signal 904 having a frequency fc. Note that when the frequency fo is divided instead of multiplied, a frequency divider may be used instead of the multiplier, and when the frequency fo is used as the frequency fo, the multiplier may not be used.

  Here, the frequencies fa, fb, and fc of the respective clock signals are set so as to have an integer multiple or a fraction of an integer. That is, fa / fb, fa / fc, and fb / fc are each an integer or a fraction of an integer.

  Next, the digital amplifier 200 will be described. The triangular wave generation circuit 201 generates a triangular wave having the same frequency as the frequency fa of the clock signal 902. The PWM circuit 202 receives the triangular wave and the audio signal Sin, performs PWM modulation on the audio signal Sin, generates a PWM signal 920, and outputs the PWM signal 920 to the amplifier circuit 204. Here, as shown in FIG. 3, the PWM modulation is such that the triangular wave and the audio signal Sin are compared, and when the output of the audio signal Sin is larger than that of the triangular wave, it becomes “HIGH”, and when it is smaller, it becomes “LOW”. The modulation is performed.

  The volume controller 203 generates a volume control signal Sa for controlling the volume according to the volume set by the volume 208. The amplification circuit 204 amplifies the amplitude of the PWM signal 920 in accordance with the volume control signal Sa from the volume variator 203. The low pass filter 205 demodulates the amplified PWM signal 920 and outputs an amplified audio signal from the speaker connection terminal 206.

  Next, the LED dimmer 300 will be described. The triangular wave generation circuit 301 generates the same triangular wave as the frequency fb of the clock signal 903. The dimming variable device 302 generates a light amount control signal Sb for controlling the light amount in accordance with the dimming amount set by the volume 307.

  The PWM circuit 303 performs PWM modulation of the light amount control signal Sb based on the triangular wave and the light amount control signal Sb to generate a PWM signal. Here, as shown in FIG. 4, the PWM modulation is performed by comparing the triangular wave with the light amount control signal Sb, and when the output of the light amount control signal Sb is larger than the output of the triangular wave, it is “HIGH”, and when it is smaller, “LOW”. Modulation is performed in such a way.

  The constant current source 304 controls the current based on the PWM signal generated by the PWM circuit 303. For example, when the PWM signal is “HIGH”, the current is supplied to the LED connection terminal 305, and the “LOW” When it does, control to cut off the supply of current.

  Next, the switching power supply 400 will be described. The triangular wave generation circuit 401 generates the same triangular wave as the frequency fc of the clock signal 904. The error amplifier circuit 406 compares the voltage Vout output from the rectifier circuit 405 with the reference voltage Vref, generates an amplified error signal Sc, and outputs the error signal Sc to the PWM circuit 402.

  The PWM circuit 402 performs PWM modulation of the error signal Sc based on the triangular wave and the error signal Sc, generates a PWM signal, and outputs the PWM signal to the switching circuit 403. The switching circuit 403 is a transistor that is turned on / off by a PWM signal, and converts the DC voltage Vdc input to the primary coil of the high-frequency transformer 404 to AC by turning on / off the transistor. The high-frequency transformer 404 transmits the AC voltage of the primary side coil to the secondary side coil. Here, the voltage output to the secondary coil changes corresponding to the on / off ratio (duty) of the transistor.

  The rectifier circuit 405 outputs the AC voltage transmitted to the secondary coil as a DC voltage. Here, when there is a deviation between the output voltage Vout and the reference voltage Vref as described above, an error signal Sc corresponding to the deviation amount is generated by the error amplification circuit 406, and the result is reflected in the duty of the PWM signal. Therefore, feedback is applied to the output voltage, so that it can be used as a power source having a stabilized voltage output. Then, electric power having the reference voltage Vref is supplied to the power lines of the digital amplifier 200 and the LED dimmer 300.

  In this way, it is possible to provide a dimmer-equipped digital amplifier system 100 in which the digital amplifier 200, the LED dimmer 300, and the switching power supply 400 are integrally arranged in one case as shown in FIG. A signal for dimming the LED illumination can be supplied to the LED connection terminal 305 while outputting the amplified audio signal to the connection terminal 206.

  Further, the clock signals used in the digital amplifier 200, the LED dimmer 300, and the switching power supply 400 are such that the frequencies fa, fb, and fc are in an integer multiple or a fraction of an integer. Since it is set, the influence of the high frequency noise generated from the LED dimmer 300 or the switching power supply on the digital amplifier 200 is reduced, and the occurrence of beats can be suppressed. Audio signals can be maintained at high quality.

  As mentioned above, although embodiment of this invention was described, this invention can be implemented in various aspects as follows.

<Modification 1>
In the embodiment, the oscillation circuit uses the externally-excited externally-excited digital amplifier 200. However, as shown in FIG. 5, a self-excited type having an oscillation circuit 207 that generates a clock signal may be used. In this case, the clock signal 922 generated from the self-excited digital amplifier 210 is passed through the multipliers 603 and 604 to multiply the frequency, and the triangular wave generation circuit 301 of the LED dimmer 300 and the triangular wave generation circuit 401 of the switching power supply 400. To supply. As in the embodiment, the frequency may be divided by a frequency divider instead of the multiplier, or the clock signal 922 may be used as it is. Thereby, the oscillation circuit 500 used in the embodiment can be reduced. Although the digital amplifier 210 is described as an example, the clock signal can be similarly supplied and the oscillation circuit 500 can be reduced even if the LED dimmer 300 or the switching power supply 400 is self-excited instead of the digital amplifier 210. can do.

<Modification 2>
In the embodiment, as the digital amplifier system 100 with a dimmer, the digital amplifier 200 has the speaker connection terminal 206 and the LED dimmer 300 has the LED connection terminal 305, but as shown in FIG. The speaker connection terminal 206 may be connected to the speaker 220, and the LED connection terminal 305 may be connected to the LED illumination 320 to provide a speaker system 110 with illumination. Further, these components may be housed in a speaker enclosure and configured as a powered speaker with LED illumination. In the case of stereo correspondence, the speaker boxes may be divided into L and R speaker boxes or may be combined into one speaker box.

<Modification 3>
In the embodiment, the clock signal 903 is supplied to the triangular wave generation circuit 301 of the LED dimmer 300. However, as shown in FIG. 7, the PWM signal 920 generated by the PWM circuit 202 of the digital amplifier 200 is used as the LED dimmer. It may be supplied to the control circuit 306 of 310. The control circuit 306 performs signal processing based on the supplied PWM signal 920, controls the current of the constant current source 304 based on the result, and outputs a current to the LED connection terminal 305. As a result, the signal output to the LED connection terminal 8 can be correlated with the signal output to the speaker connection terminal 206, and the dimming control according to the audio signal such as a musical tone can be performed. . Instead of supplying the PWM signal 920 to the control circuit 306, the volume control signal Sa output from the volume variator 203 may be supplied to perform dimming control according to the volume of a musical tone or the like, or the audio signal Sin may be supplied to perform dimming control according to the musical tone. Alternatively, an envelope of the audio signal Sin may be supplied to perform dimming control according to a change in volume such as a musical sound.

<Modification 4>
In the embodiment, the LED dimmer 300 can be used to adjust the LED illumination, but the fluorescent lamp or the incandescent lamp may be dimmed. For example, when dimming a fluorescent lamp, a fluorescent lamp adjuster 350 configured as shown in FIG. 8 may be used. The dimming control circuit 354 outputs, to the fluorescent lamp connection terminal 355, power whose light emission period is controlled by modulating the inverter signal based on the PWM signal from the PWM circuit 353. In this way, the fluorescent lamp 356 connected to the fluorescent lamp connection terminal 355 can be dimmed. In this case, the clock signal 903 may be supplied to the triangular wave generation circuit 351. Also, when dimming an incandescent lamp, a dimmer capable of dimming the incandescent lamp and emitting light based on the PWM signal in the same manner as a fluorescent lamp may be used.

<Modification 5>
In the embodiment, the control of the sound amplification amount and the dimming amount of the LED illumination is performed using the volumes 208 and 307 in the volume variable unit 203 and the dimming variable unit 302, respectively. Remote control. In this case, as shown by a broken line in FIG. 1, a light receiving unit 800 may be provided and the received signal may be configured to be sent to the volume variable unit 203 and the dimming variable unit 302. For example, as shown in FIG. 9, the remote controller 810 may be provided with an infrared transmitter 811, a single volume 812, and a switch 813, and controlled by switching between volume control and dimming control by switching the switch. However, a volume may be provided for controlling volume and dimming. Also, digital amplifiers often come with remote controls that perform various operations such as volume adjustment, input switching, and sound field setting. However, as shown in FIG. A remote controller 820 that can be operated may be used.

<Modification 6>
In the embodiment, the dimmer-equipped digital amplifier system 100 supplies power having the voltage generated by the switching power source 400 to the digital amplifier 200 and the LED dimmer 300, but instead of the switching power source. Power may be supplied to the power lines of the digital amplifier 200 and the LED dimmer 300 using a power source that does not easily generate high-frequency noise. In this case, since the clock signal 904 is not necessary, the frequencies fa and fb of the remaining clock signals 902 and 903 may be set so as to have an integer multiple or a fraction of an integer.

It is a block diagram which shows the structure of the digital amplifier system with a light modulator which concerns on embodiment of this invention. It is an external view which shows the back surface of the digital amplifier system with a light modulator which concerns on embodiment of this invention. It is explanatory drawing which shows the production | generation method of the PWM signal produced | generated with the PWM circuit of a digital amplifier. It is explanatory drawing which shows the production | generation method of the PWM signal produced | generated by the PWM circuit of LED dimmer. It is a block diagram which shows the structure of the digital amplifier system with a light modulator which concerns on the modification 1. FIG. It is a block diagram which shows the structure of the speaker system with illumination which concerns on the modification 2. It is a block diagram which shows the structure of the digital amplifier system with a light modulator which concerns on the modification 3. It is a block diagram which shows the structure of the fluorescent lamp dimmer which concerns on the modification 4. It is an external view of the remote control which concerns on the modification 5. FIG. It is an external view of the remote control which concerns on the modification 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Digital amplifier system with a light controller, 110 ... Illuminated speaker system, 200, 210 ... Digital amplifier, 201, 301, 351, 401 ... Triangular wave generation circuit, 202, 303, 353, 402 ... PWM circuit, 203 ... Volume Variable circuit, 204 ... Amplifier circuit, 205 ... Low pass filter, 206 ... Speaker connection terminal, 207,500 ... Oscillator circuit, 208,307,357,812 ... Volume, 220 ... Speaker, 300,310 ... LED dimmer, 302 , 352 ... Dimming variable, 304 ... Constant current source, 305 ... LED connection terminal, 306 ... Control circuit, 320 ... LED illumination, 350 ... Fluorescent lamp dimmer, 354 ... Dimming control circuit, 355 ... Fluorescent lamp connection Terminals, 356 ... Fluorescent lamps, 400 ... Switching power supply, 403 ... Switching circuit, 404 ... High frequency tiger 405 ... rectifier circuit, 406 ... error amplifier circuit, 602, 603, 604 ... multiplier, 800 ... light receiver, 810,820 ... remote control, 811 ... infrared transmitter, 813 ... switch, 900,902,903,904 , 922 ... Clock signal, 920 ... PWM signal

Claims (5)

A digital amplifier for performing power amplification by performing pulse width modulation on the audio signal based on the first clock signal;
A dimmer for performing pulse width modulation based on the second clock signal to control the power supplied to the light emitting means,
The frequencies of the first clock signal and the second clock signal are obtained by multiplying, dividing, or using the frequency of the clock signal generated from the common oscillation circuit as an integer multiple or a fraction of an integer. A digital amplifier system with a dimmer. A digital amplifier for performing power amplification by performing pulse width modulation on the audio signal based on the first clock signal;
A dimmer for performing pulse width modulation based on the second clock signal to control the power supplied to the light emitting means;
A switching power supply that performs pulse width modulation based on a third clock signal to control power supply to the power line of the digital amplifier and the dimmer,
The frequencies of the first clock signal, the second clock signal, and the third clock signal are obtained by multiplying, dividing, or using the frequency of the clock signal generated from the common oscillation circuit as an integer multiple or an integer. A digital amplifier system with a dimmer characterized by the following relationship: A digital amplifier for performing power amplification by performing pulse width modulation on the audio signal based on the first clock signal;
A dimmer with a dimmer, comprising: a dimmer that controls power supplied to the light emitting means based on a result of pulse width modulation of the digital amplifier. A switching power supply that performs pulse width modulation based on a third clock signal to control power supply to the power line of the digital amplifier and the dimmer;
The frequencies of the first clock signal and the third clock signal are obtained by multiplying, dividing, or using the frequency of the clock signal generated from the common oscillation circuit as an integer multiple or a fraction of an integer. The digital amplifier system with a dimmer according to claim 3, wherein: A digital amplifier system with a dimmer according to any one of claims 1 to 4,
A speaker to which an audio signal amplified in the digital amplifier is supplied;
And a light source that receives power from the dimmer.

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