JP4345012B2 - Audio system and power control method - Google Patents

Description

  The present invention relates to an audio system and a power supply control method, and is suitably applied to an audio system in which an audio amplifier and a subwoofer are connected by a wired connection with a PIN cable, for example.

  Conventionally, in an audio system, for example, a system is generally constructed by connecting an audio amplifier and a subwoofer by a wired connection using a PIN cable.

On the other hand, in order to simplify the installation work by eliminating the wiring work associated with the wired connection between the transmission unit and the reception unit, the transmission unit and the reception unit are wirelessly connected, and the control signal is used as the transmission signal. There is a wireless transmission / reception system that superimposes and controls the output level of an audio signal (see, for example, Patent Document 1).
JP 2000-165961 A

  By the way, in the audio system having such a configuration, the power of the subwoofer cannot be turned on / off from the audio amplifier, and must be turned on / off by the power switch of the subwoofer.

  In order to turn on / off the power of the subwoofer from the audio amplifier in the audio system, a DC voltage is superimposed on the PIN cable and transmitted to the subwoofer, and the power relay is turned on / off based on the DC voltage on the subwoofer side. Conceivable.

  However, in a PIN cable, it is generally limited to superimpose a DC voltage, and it is physically impossible to turn on / off the power relay of the subwoofer via the PIN cable. There was a problem that the power of the subwoofer could not be managed and the usability of the user was poor.

  The present invention has been made in consideration of the above points, and an object of the present invention is to propose an audio system and a power supply control method capable of controlling the power supply between an audio signal transmission target and a reception target.

In order to solve such a problem, the present invention is an audio system in which a transmission target and a reception target are connected by a predetermined transmission cable, and an audio signal is transmitted through the transmission cable. A high-frequency signal generating means for generating a high-frequency signal in a non-audible range in a higher frequency band than the signal; a dedicated high-frequency signal amplifying means for current-amplifying the high-frequency signal for controlling the power of the reception target; and a predetermined level of the audio signal A synthesized signal obtained by synthesizing the audio signal amplifying means for amplifying the voltage, the high-frequency signal current-amplified by the high-frequency signal amplifying means, and the audio signal voltage-amplified by the audio signal amplifying means with a transmission cable; comprising a transmitting means for feeding heat from the transmitted to the receiving subject via the receiving object, it transmits pairs And the low frequency component extracting means for outputting from the speaker only extracted by a filter audio signal corresponding to the low-frequency component of the transmitted combined signal through the cable from a high frequency signal corresponding to high wave component of the combined signal By providing a rectifying and smoothing means for extracting a DC voltage of a predetermined potential by extracting, rectifying and smoothing, and a power supply relay for turning on or off the power to be received by the DC voltage, a dedicated high-frequency signal amplifying means is provided. By using this to amplify the high-frequency signal, it is possible to reliably generate a direct-current voltage necessary for turning on or off the power to be received and control the power, and at that time, a high-frequency signal in a non-audible range is used. Therefore, adverse effects on the audio signal can be prevented in advance .

According to the present invention, there is also provided a power control method for an audio system in which a transmission target and a reception target are connected by a predetermined transmission cable and an audio signal is transmitted via the transmission cable. A high-frequency signal generating step for generating a high-frequency signal in an inaudible range in a higher frequency band by a high- frequency signal generating unit, and a high-frequency signal amplifying step for current-amplifying the high-frequency signal by a dedicated high-frequency signal amplifying unit to perform power supply control of a reception target And an audio signal amplifying step for amplifying the audio signal to a predetermined level by the audio signal amplifying means, a high-frequency signal that has been current-amplified by the high-frequency signal amplifying means, and an audio signal that has been voltage-amplified by the audio signal amplifying means. the synthesis signal obtained by the transmission Comprising a transmission step of sending heat to be received from the transmission subject via Buru extraction, receiving the subject, the only filter audio signal corresponding to the low-frequency component of the transmitted combined signal from transmitted via a cable and a low-frequency component extraction step of outputting from the speaker, a radio frequency signal corresponding to high wave component of the combined signal by rectifying and smoothing means, the extracted I by the rectifying and smoothing retrieve a DC voltage of a predetermined potential rectifier on smooth the steps, by having a power supply relay control step for turning on or off the power of the received object by the DC voltage, the power to be received by the current amplifying a high frequency signal by using a dedicated high-frequency signal amplification means In addition, it is possible to reliably generate a DC voltage necessary for turning off and to control the power supply, and at that time, a high frequency signal in a non-audible range is generated. Since Iteiru can previously prevent an adverse effect to the audio signal.

According to the present invention, it is possible to reliably generate a direct-current voltage necessary for turning on or off a power to be received by current-amplifying a high-frequency signal using dedicated high-frequency signal amplifying means, and to control the power supply. At that time, since a high-frequency signal in a non-audible range is used, it is possible to prevent adverse effects on the audio signal in advance, so that the power management of the reception target is executed without adversely affecting the audio signal. The obtained audio system and power control method can be realized.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(1) First Embodiment (1-1) Overall Configuration of Audio System in First Embodiment In FIG. 1, reference numeral 1 denotes an audio system as a whole, and an audio amplifier 2 and a subwoofer 3 are connected to a PIN cable. 4, the audio amplifier 2 transmits the audio signal to the subwoofer 3 via the PIN cable 4, and the subwoofer 3 outputs the low frequency component of the audio signal.

  Further, the audio amplifier 2 is provided with a subwoofer power button 5 for controlling the power supply of the subwoofer 3 from the audio amplifier 2 side, and the subwoofer power button 5 is pressed in response to the pressing operation of the subwoofer power button 5. The power supply can be turned on or off.

(1-2) Circuit Configuration of Audio System in First Embodiment As shown in FIG. 2, the audio amplifier 2 of the audio system 1 includes, for example, 20 [KHz] PWM (Pulse) generated by the square wave oscillator 11. A non-audible high-frequency signal S1 composed of a wide modulation signal is sent to the mixer circuit 12 via the switch circuit SW1, and an analog audio signal S2 is sent to the mixer circuit 12.

  Here, the audio amplifier 2 closes the switch circuit SW1 when the subwoofer power button 5 (FIG. 1) for controlling the power supply of the subwoofer 3 from the audio amplifier 2 side is pressed by the user, so that the high-frequency signal is closed. While S1 is output to the mixer circuit 12, in other cases, the switch circuit SW1 is opened and the high-frequency signal S1 is not output to the mixer circuit 12.

  The mixer circuit 12 mixes the high-frequency signal S1 shown in FIG. 3A and the audio signal S2 shown in FIG. 3B to generate a composite signal S3, and amplifies it to a predetermined level via the amplifier 13 As a result, a composite signal S4 as shown in FIG. 3C is generated and transmitted to the subwoofer 3 by the PIN cable 4.

  Here, in the audio amplifier 2, the input impedance of the amplifier 13 is very high, and the high frequency signal S1 and the audio signal S2 are voltage-transmitted, thereby preventing fluctuations in the high frequency signal S1 and the audio signal S2. Has been made.

  In the subwoofer 3, the synthesized signal S4 supplied from the audio amplifier 2 via the PIN cable 4 is sent to the low-pass filter LPF composed of the resistor R1 and the capacitor C1, and also sent to the voltage doubler rectifier circuit 14.

  In the low-pass filter LPF, only the low-frequency component of the synthesized signal S4 is passed, amplified through the amplifier 15, and then output to a speaker (not shown) as a speaker output signal S5 as shown in FIG. It is made to do.

  The voltage doubler rectifier circuit 14 is mainly composed of capacitors C2 and C3 as smoothing elements connected in series, and diodes D1 and D2 as rectifying elements connected in series, and includes a capacitor C2 and diodes D1 and D2. A resistor R1 of the low-pass filter LPF and a resistor R2 for protecting the diodes D1 and D2 are connected between them.

  In this voltage doubler rectifier circuit 14, as shown in FIG. 3E, the diodes D1 and D2 as rectifier elements can obtain a rectified voltage V1 that is twice that of the combined signal S4. The power supply relay 16 is controlled to be turned on / off.

  By the way, with respect to the capacitor C2 of the voltage doubler rectifier circuit 14, a signal of 20 [KHz] or less (in this case, an audio signal in the audible range) is blocked without passing, and a high-frequency signal is included in the synthesized signal S4. Only the signal component corresponding to S1 is input, and the low frequency component corresponding to the audio signal S2 in the synthesized signal S4 is input only to the low-pass filter LPF.

(1-3) Operation and Effect in First Embodiment In the above configuration, in the audio system 1, the amplifier 13 generates the synthesized signal S3 obtained by mixing the high frequency signal S1 and the audio signal S2 in the mixer circuit 12. A synthesized signal S4 is generated by amplifying the signal with the PIN cable 4 and transmitted to the subwoofer 3 via the PIN cable 4.

  In the subwoofer 3, only the low-frequency component of the composite signal S4 is passed through the low-pass filter LPF, and is output as a speaker output signal S5 to a subsequent speaker (not shown).

  Further, in the subwoofer 3, the double voltage rectifier circuit 14 obtains the rectified voltage V1 that is twice the combined signal S4, and the power relay 16 can be controlled on and off using this voltage.

  Therefore, since the audio amplifier 2 of the audio system 1 can transmit the high-frequency signal S1 as power for controlling the power supply of the subwoofer 3 through the PIN cable 4, the power management of the subwoofer 3 from the audio amplifier 2 can be performed. It can be carried out.

At this time, the audio amplifier 2 of the audio system 1 uses, for example, a high frequency signal S1 having a frequency band higher than that of the audio signal S2 in the audible band, for example, 20 [KHz], and the low frequency of the synthesized signal S4 through the low pass filter LPF. Since only the component is output as the speaker output signal S5, the power relay 16 of the subwoofer 3 can be controlled on and off without adversely affecting the audio signal S2 due to the high-frequency signal S1.

  According to the above configuration, it is possible to realize an audio system 1 with excellent usability that can execute power management of the subwoofer 3 from the audio amplifier 2 using the PIN cable 4.

(2) Second Embodiment (2-1) Overall Configuration of Audio System in Second Embodiment By the way, in audio system 1 in the first embodiment, audio amplifier 2 amplifies audio signal S2. The high-frequency signal S1 is also amplified together using the amplifier 13, but there are cases where it is insufficient to obtain the power required when the power relay 16 of the subwoofer 3 is on / off controlled.

Therefore, as shown in FIG. 4 , in the audio system 31 in the second embodiment, the high frequency signal S1 is amplified in advance to a level sufficient to turn on and off the power supply relay 16 and then transmitted to the subwoofer 3. Is.

  Incidentally, the audio system 31 in the second embodiment also has a configuration in which the audio amplifier 32 and the subwoofer 3 are wiredly connected by the PIN cable 4 as in the audio system 1 in the first embodiment. .

(2-2) Circuit Configuration of Audio System in Second Embodiment In FIG. 4 in which the same reference numerals are assigned to the parts corresponding to those in FIG. 2, the audio amplifier 32 of the audio system 31 is generated by the square wave oscillator 11. The non-audible high-frequency signal (for example, 20 [KHz]) S1 is supplied to the switch circuit SW1.

  The switch circuit SW1 is closed when the subwoofer power button 5 for controlling the power supply of the subwoofer 3 from the audio amplifier 32 side is pressed by the user, and sends the high frequency signal S1 to the amplifier circuit 33. On the other hand, in other cases, the switch circuit SW1 is opened and the high frequency signal S1 is not sent to the amplifier circuit 33.

  In the amplifying circuit 33, the high-frequency signal S1 is sent to the NPN transistor Tr1 (hereinafter referred to as the transistor Tr1) via the bias resistor R11, and the PNP transistor Tr2 (hereinafter referred to as the transistor) via the bias resistor R12. (Referred to as Tr2). The bias resistors R11 and R12 are grounded via a resistor R13.

  Here, the transistors Tr1 and Tr2 are used as switching elements. When a positive drive voltage signal in the high frequency signal S1 is given, the transistor Tr1 is turned on, and a negative drive voltage signal in the high frequency signal S1 is given. When this occurs, the transistor Tr2 is turned on.

  The collector of the transistor Tr1 is connected to the collector and base of the transistor Q1 via the collector resistor R14 and to the base of the transistor Q2, and the emitters of the transistors Q1 and Q2 are connected to the positive power source via the emitter resistors R15 and R16. Connected to Vcc.

Here, the transistors Q1 and Q2 constitute a current mirror circuit, and when the transistor Tr1 is turned on by a positive drive voltage signal in the high frequency signal S1, the same voltage as that generated in the emitter resistor R15 of the transistor Q1 is applied to the transistor Q2. A current flows between the emitter and collector of the transistor Q2 so as to be generated in the emitter resistor R16.

  The collector of the transistor Tr2 is connected to the collector and base of the transistor Q3 via the collector resistor R17 and to the base of the transistor Q4. The emitters of the transistors Q3 and Q4 are negative power supplies via the emitter resistors R18 and R19. Connected to Vss.

  Also in this case, the transistors Q3 and Q4 also constitute a current mirror circuit, and when the transistor Tr2 is turned on by a negative drive voltage signal in the high frequency signal S1, the same amount of current as that flowing between the emitter and collector of the transistor Q3 is obtained. It flows between the emitter and collector of transistor Q4.

  Therefore, when the transistor Tr1 of the amplifier circuit 33 is turned on by the positive drive voltage signal in the high frequency signal S1, the audio amplifier 32 has the same amount of current as that flowing between the emitter and collector of the transistor Q1 between the emitter and collector of the transistor Q2. Therefore, the collector current of the transistor Q2 is output from the output terminal T1 as the high frequency output S10.

  Similarly, in the audio amplifier 32, when the transistor Tr2 of the amplifier circuit 33 is turned on by a negative drive voltage signal in the high frequency signal S1, the same current as the current flowing between the emitter and collector of the transistor Q3 is the emitter and collector of the transistor Q4. Therefore, the collector current of the transistor Q4 is output from the output terminal T1 as the high frequency output S10.

  Here, since the output impedance of the current mirror circuit in the amplifier circuit 33 is very high when viewed from the output side of the amplifier 13, the audio amplifier 32 does not leak the audio signal S2 into the amplifier circuit 33, resulting in a high-frequency signal. The variation of S1 is prevented.

  On the other hand, the audio amplifier 32 amplifies the analog audio signal S2 to a predetermined level via the amplifier 13 and then outputs it as an audio signal S11 via the coil L1. As a result of the amplification circuit 33 amplifying the high-frequency signal S1. The synthesized high frequency output S10 and the audio signal S11 are synthesized at the synthesis point T2 to generate a synthesized signal S12 as shown in FIG. 3C, and this is transmitted to the subwoofer 3 via the PIN cable 4. To do.

  Incidentally, in the audio amplifier 32 in this case as well, the input impedance of the amplifier 13 is very high, and the audio signal S2 is transmitted by voltage, thereby preventing the fluctuation of the audio signal S2.

  The coil L1 prevents the audio signal S11 output from the amplifier 13 from flowing back to the amplifier 13.

  In this audio amplifier 32, since the input impedance of the amplifier circuit 33 is low and the output impedance is high, the high-frequency signal S1 is current-transmitted, while the audio signal S2 is voltage-transmitted. The high-frequency signal S1 is brought to a predetermined level by the amplifier circuit 33. By amplifying, the voltage level necessary for on / off control of the power relay 16 of the subwoofer 3 can be secured.

  In the subwoofer 3, as in the first embodiment, the composite signal S12 supplied from the audio amplifier 32 via the PIN cable 4 is sent to the low-pass filter LPF including the resistor R1 and the capacitor C1, and the voltage doubler rectifier circuit 14 to send.

  In the low-pass filter LPF, only the low-frequency component of the composite signal S12 is passed, amplified through the amplifier 15, and then sent to a speaker (not shown) as a speaker output signal S13 as shown in FIG. It is designed to output.

  The voltage doubler rectifier circuit 14 is mainly composed of capacitors C2 and C3 as smoothing elements connected in series, and diodes D1 and D2 as rectifying elements connected in series, and includes a capacitor C2 and diodes D1 and D2. A resistor R1 of the low-pass filter LPF and a resistor R2 for protecting the diodes D1 and D2 are connected between them.

  In the voltage doubler rectifier circuit 14, as shown in FIG. 3E, a rectified voltage V2 that is twice the combined signal S12 can be obtained by the diodes D1 and D2 as rectifier elements. The power supply relay 16 is turned on and off.

  By the way, with respect to the capacitor C1 of the voltage doubler rectifier circuit 14, a signal of 20 [KHz] or less (in this case, an audio signal in the audible range) is blocked without passing through, and the high frequency signal of the synthesized signal S12 is blocked. Only the signal component corresponding to S1 is input, and the low frequency component corresponding to the audio signal S2 in the synthesized signal S12 is input only to the low-pass filter LPF.

(2-3) Operation and Effect In the above configuration, in the audio amplifier 32 of the audio system 31, the power relay 16 of the subwoofer 3 is controlled to be turned on / off by amplifying the high frequency signal S1 to a predetermined level by the amplifier circuit 33. The synthesized signal S12 can be generated by synthesizing the high frequency output S10 having a sufficient voltage level and synthesizing the high frequency output S10 and the audio signal S11 amplified through the amplifier 13 at the synthesis point T2.

  At this time, in the audio amplifier 32, the back flow of the audio signal S11 is prevented by the coil L1, and the impedance at the output terminal T1 of the amplifier circuit 33 is very high to prevent the back flow of the audio signal S11. The synthesized signal S12 can be generated without using the mixer circuit 12 in the embodiment.

  The audio amplifier 32 does not amplify the high frequency signal S1 using the amplifier 13 for amplifying the audio signal S2 as in the first embodiment, but uses the amplifier circuit 33 to power the relay of the subwoofer 3. 16 can be amplified to a voltage level capable of on / off control, so that the power relay 16 can be reliably on / off controlled by the rectified voltage V2 extracted by the voltage doubler rectifier circuit 14 of the subwoofer 3.

  Therefore, in the audio amplifier 32 of the audio system 31, the high frequency signal S 1 that is power for controlling the power supply of the subwoofer 3 is amplified by the amplifier circuit 33 to a voltage level that can control the power relay 16 on and off, and transmitted by the PIN cable 4. Therefore, power management of the subwoofer 3 can be reliably executed from the audio amplifier 32.

  At this time, the audio amplifier 32 of the audio system 31 uses a high-frequency signal S2 having a frequency band higher than that of the audio signal S2 in the audible band, for example, 20 [KHz], and the low frequency of the synthesized signal S12 through the low-pass filter LPF. Since only the component is output as the speaker output signal S13, the power relay 16 of the subwoofer 3 can be controlled on and off without adversely affecting the audio signal S2 due to the high-frequency signal S1.

  According to the above configuration, it is possible to realize an audio system 31 with excellent usability that can execute power management of the subwoofer 3 from the audio amplifier 32 using the PIN cable 4.

(3) Other Embodiments In the first and second embodiments described above, a case is described in which a high-frequency signal S1 of 20 [KHz] higher than the frequency band necessary for the subwoofer 3 is used. However, the present invention is not limited to this, and for example, a high frequency signal S1 of 50 [KHz] or 100 [KHz] may be used.

  In the second embodiment described above, the case where the high-frequency signal S1 is current-transmitted and the audio signal S2 is voltage-transmitted has been described. However, the present invention is not limited to this, and the high-frequency signal S1 is amplified by the amplifier 13. The audio signal S2 may be current-transmitted via the amplifier circuit 33.

  Further, in the second embodiment, the case where the power amplifier 16 of the subwoofer 3 is controlled to be turned on / off from the audio amplifier 32 has been described. However, the present invention is not limited to this, and the subwoofer 3 is connected to the audio amplifier. You may make it carry out on-off control of the power supply of 32. In this case, the low-pass filter LPF and the voltage doubler rectifier circuit 14 may be provided in the audio amplifier 32, and the square wave oscillator 2, the amplifier circuit 33, the amplifier 13, and the coil L1 may be provided in the subwoofer 3.

  Further, in the first and second embodiments described above, the case where the high-frequency signal S1 is transmitted using the PIN cable 4 has been described. However, the present invention is not limited to this, and a USB (Universal Serial Bus) is used. You may make it transmit using a cable.

  Further, in the first and second embodiments described above, the case where the audio systems 1 and 31 of the present invention are configured by the audio amplifiers 2 and 32 and the subwoofer 3 has been described. The audio system is configured with an audio amplifier and an equalizer, or the audio system is configured with an audio amplifier and a CD (Compact Disc) player, and the power of the equalizer and the CD player is managed from the audio amplifier. Also good.

  Further, in the above-described embodiment, the audio system of the present invention includes the audio amplifiers 2 and 31 as transmission targets, the square wave oscillator 11 as high-frequency signal generation means, the PIN cable 4 as transmission cable, and the mixer as transmission means. Although the circuit 12, the amplifier 13 or the amplifier circuit 33, and the amplifier 13 are configured, the subwoofer 3 as a reception target is configured by the voltage doubler rectifier circuit 14 and the power supply relay 16 as rectifying and smoothing means. The present invention is not limited to this, and the audio system may be configured with other various circuit configurations.

  The audio system and the power supply control method according to the present invention are applied to, for example, an application in which the other power supply is controlled between an audio amplifier that is a transmission target of an audio signal and a subwoofer that is a reception target connected to the audio amplifier by a cable. can do.

It is a rough-line perspective view which shows the whole structure of the audio system in 1st and 2nd embodiment. 1 is a schematic diagram illustrating a circuit configuration of an audio system according to a first embodiment. It is a basic diagram which shows a signal waveform. It is a basic diagram which shows the circuit structure of the audio system in 2nd Embodiment.

Explanation of symbols

1, 31 ... Audio system, 2 ... Audio amplifier, 3 ... Subwoofer, 4 ... PIN cable, 11 ... Square wave oscillator, 12 ... Mixer circuit, 13, 15 ... Amplifier, 14 ... Double Voltage rectifier circuit 33... Amplifier circuit.

Claims (3)

An audio system that connects a transmission target and a reception target with a predetermined transmission cable and transmits an audio signal through the transmission cable,
The above transmission target is
High-frequency signal generating means for generating a non-audible high-frequency signal in a higher frequency band than the audio signal;
A dedicated high frequency signal amplifying means for amplifying the current of the high frequency signal to perform power control of the reception target;
Audio signal amplification means for amplifying the voltage of the audio signal to a predetermined level;
A synthesized signal obtained by synthesizing the high-frequency signal current-amplified by the high-frequency signal amplifying means and the audio signal voltage-amplified by the audio signal amplifying means is sent via the transmission cable to the transmission target. comprising a transmitting means for feeding heat to said received target from,
The above reception target is
Low-frequency component extraction means for extracting only the audio signal corresponding to the low-frequency component of the synthesized signal transmitted from the transmission target via the cable and outputting it from a speaker;
Rectifying and smoothing means for extracting a DC voltage of a predetermined potential by extracting the rectified and smoothed high-frequency signal corresponding to a high-frequency component from the synthesized signal ;
Luo over audio system comprising a power relay for turning on or off the power of the received object by the DC voltage. A coil for preventing backflow of the audio signal is provided at the output end of the audio signal amplifying means.
Audio system as claimed in 請 Motomeko 1. An audio system power control method for connecting a transmission target and a reception target with a predetermined transmission cable and transmitting an audio signal through the transmission cable,
The above transmission target is
A high-frequency signal generating step for generating a high-frequency signal in a non-audible range at a higher frequency band than the audio signal by a high- frequency signal generating means ;
A high-frequency signal amplification step for current-amplifying the high-frequency signal by dedicated high-frequency signal amplification means for performing power control of the reception target;
An audio signal amplification step of amplifying the audio signal to a predetermined level by an audio signal amplification means;
A synthesized signal obtained by synthesizing the high-frequency signal current-amplified by the high-frequency signal amplifying means and the audio signal voltage-amplified by the audio signal amplifying means is sent via the transmission cable to the transmission target. comprising a transmission step of feeding heat to said received target from,
The above reception target is
A low-frequency component extracting step of extracting only the audio signal corresponding to a low-frequency component of the synthesized signal transmitted from the transmission target via the cable and outputting it from a speaker;
The high-frequency signal corresponding to high wave component of the combined signal, and rectifying and smoothing steps of the rectifying and smoothing means, extracting taken out DC voltage of the rectifier and a predetermined potential I by to smooth,
Power control method and a power supply relay control step for turning on or off the power of the received object by the DC voltage.

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