JP4735404B2 - Remote control device - Google Patents

Description

  The present invention relates to a remote control device that is mounted on, for example, an automobile and performs predetermined audio processing in accordance with a user operation from a remote control terminal.

  In Patent Document 1, a light receiving unit is disposed in a dashboard portion diagonally to the left front of a driver's seat in a car cabin (FIG. 1 of Patent Document 1), and from a multi-controller (corresponding to a remote control terminal). The remote control signal in the optical signal format is received by the light receiving unit (paragraph 0012 of Patent Document 1), and it is disclosed that an accessory device such as an air conditioner or an acoustic device is controlled from a multi-controller.

  On the other hand, an audio system in which a user brings a portable digital audio player into a car, plays music stored in the built-in memory of the portable digital audio player, and plays the reproduced sound from the car speaker has become known. ing. The audio system uses, for example, a black box (for example, the black box 13 in FIG. 1). The black box is disposed under a driver's seat or in a trunk room, and a user can use a portable digital audio player or the like. An external audio device is connected to the auxiliary input terminal of the black box with a cable, the black box transmits the playback sound signal input from the terminal with weak radio waves, and the in-vehicle tuner receives the radio waves, It is designed to flow from the speaker.

  Since the black box itself does not have a display unit, the display unit of the tuner is used for information display in black box function settings and the like.

  In order for the user to give an instruction to the black box, a handy type remote control terminal (example: remote control terminal 17 in FIG. 1 described later) is prepared, and a light receiving unit (example: remote control reception unit 12 in FIG. 1 described later) is provided. An optical remote control signal provided on the dashboard and received from the remote control terminal is received by the light receiving unit. The remote control signal is sent from the light receiving unit to the black box via a predetermined signal line, and the black box performs processing corresponding to the input remote control signal.

Since the light receiving unit needs to be powered for operation, the remote control signal received at the light receiving unit is received between the black box and the light receiving unit in addition to the signal line for sending the light receiving unit to the black box. A feeder line and a ground line are wired to the unit.
Japanese Utility Model Publication No. 6-68958

  In order to save power, it is desirable to turn off the power of the black box, the remote control signal light receiving unit and the tuner when the black box is not used. In addition, in order to save power, when the power of the tuner is turned on only during use of the black box, the user can determine whether the black box is turned on or off without relying on the tuner display, that is, Even if the tuner is turned off, you need to know. In order to cope with this, it is only necessary to provide a black box power switch so that the user can observe the switching state of the power switch.

  When the power switch of the black box is deployed on a dashboard or other part where the driver reaches out from the driver's seat, information on switching the power switch on / off is sent to the black box below the driver's seat, etc. Need to be notified. Adding a single signal line and letting the signal to notify the black box detector, which is far away from the dashboard, the on / off position of the power switch via the signal line is the addition of a long wiring Due to the necessity and the increase in the number of wires, the cable bundled with all wires becomes thick and difficult to use.

  As a measure to notify the black box of the switching state of the manually operated power switch without adding a signal line, the code related to the switching state of the power switch is set and the remote control signal line is It is conceivable to notify the black box of the code signal. However, in this measure, it is necessary to deal with a new code and to change the code signal generator IC in the light receiving unit, the change in the decoding processor in the black box, and the like, and the handling becomes enormous.

  In Patent Document 1, when a power switch for switching power on / off of a controlled device is provided at a location away from the controlled device, the switching state of the power switch is indicated by wiring between the remote control signal receiving unit and the controlled device. No mention is made of a method for notifying the controlled device without adding the.

  An object of the present invention is to save power by providing a power supply switch that is shared between power-on and off of a remote control signal receiver and a controlled device, and to newly add a signal line to the switching state of the power supply switch. In addition, it is possible to notify the controlled device side without assigning a new code signal to the switching state and appropriately control the power source of the remote control signal receiving unit and the controlled device based on the switching state of the power supply switch. It is to provide a remote control device that can be used.

The remote control device of the present invention has the following.
A remote control signal receiving unit that is in an active state during power feeding and converts the remote control signal received wirelessly from the remote control terminal into an electrical signal format and outputs it to the remote control signal line,
Controlled device controlled based on a remote control signal input from a remote control signal line,
A power supply switch that is manually operated to switch between power supply and non-power supply to the remote control signal receiver,
Detection means for detecting a switching state of the power supply switch based on an electric signal level at an end of the remote control signal line on the controlled device side, and power supply control means for controlling power supply to the controlled device based on detection by the detection means.

  According to the present invention, a common power supply switch for power supply control of the remote control signal receiving unit and the controlled device is provided on the remote control signal receiving unit side to cope with power saving of the remote control signal receiving unit and the controlled device, and for the user Recognizes from the switching state of the power supply switch whether or not the controlled device is in an operating state, and takes appropriate measures (eg, channel selection operation for turning on / off the RDS tuner and receiving weak radio waves) ).

  According to the present invention, the electrical signal level in the remote control signal line between the remote control signal receiving unit and the controlled device is switched according to the switching state of the remote control signal receiving unit, and the remote control signal line of the controlled device side is switched. The switching state of the power supply switch is detected based on the electric signal level. Accordingly, it is possible to eliminate the inconvenience of assigning a code for the switching state in order to newly add a long signal line or to notify the controlled device of the switching state information of the power feeding switch via the remote control signal line.

  FIG. 1 is a schematic configuration diagram of an audio processing apparatus 10. The audio processing apparatus 10 includes a remote control receiving unit 12, a black box 13, and a remote control terminal 17, and is mounted on an automobile. The remote control receiving unit 12 is disposed on the dashboard in front of the driver's seat, and the black box 13 is disposed in a space between the driver's seat and the passenger compartment floor, a trunk room outside the passenger compartment, or the like. The cable 14 is wired between the remote control receiver 12 and the black box 13 and includes a total of three wires as will be described later.

  The black box 13 is connected to an auxiliary input (AUX) terminal with an external audio device such as a portable digital audio player such as iPod (registered trademark), a CD changer, or a digital tuner, as appropriate. An RDS (Radio Data System) standard FM signal is generated from an audio signal such as music input to the terminal, and the FM signal is blown by weak radio waves.

  For example, an RDS tuner is mounted on the automobile as a genuine product of the automobile. The RDS tuner receives radio waves from the black box 13 from an antenna, generates an audio signal, and generates an automobile speaker (see FIG. (Not shown) play music playback sound.

  The remote control terminal 17 is large enough to be placed on the palm of the user, and the user issues various instructions to the audio processing device 10 by key operations on the remote control terminal 17. A remote control signal from the remote control terminal 17 is transmitted to the remote control receiving unit 12 by light. The remote control receiver 12 generates a digital electrical signal related to the code corresponding to the received optical signal, and outputs it to the signal line 29 (FIG. 2).

  When the user sets the function of the black box 13 from the remote control terminal 17, the display section of the RDS tuner described above is used. That is, the black box 13 generates RDS data corresponding to the information to be displayed in order to perform display necessary for processing related to the remote control signal from the remote control terminal 17 on the display unit of the RDS tuner, and converts this into the modulator. And fly with FM radio waves. The RDS tuner receives the radio wave at the antenna, demodulates the radio wave, extracts RDS data, and displays information corresponding to the RDS data on the display unit of the own device.

  FIG. 2 is a configuration diagram of the main part of the audio processing apparatus 10. The remote controller light receiving IC 20 is built in the remote controller receiver 12 (FIG. 1). The black box 13 includes a remote control code detection circuit 24, a power on / off detection circuit 25, a power supply control circuit 26, and a power supply terminal 27. When the engine key of the vehicle on which the audio processing device 10 is mounted is in the accessory (ACC) position or the on (ON) position, power from the battery is supplied to the power supply terminal 27, and in the off position (OFF) of the engine key, power is supplied. The terminal 27 is in a non-powered state.

  The cable 14 extends between the black box 13 and the remote control light receiving IC 20, and includes a total of three wires: a signal line 29, a feeder line 30, and a ground line 31. The signal line 29 branches into two on the black box 13 side, and is connected to the input terminals of the remote control code detection circuit 24 and the power on / off detection circuit 25 at each branch end. The power supply control circuit 26 controls power supply to the black box 13 based on the detection of the power on / off detection circuit 25. Note that the power on / off detection circuit 25 is always supplied with power during the period in which power is supplied to the power supply terminal 27 and maintains the operating state.

  The power supply switch 34 is disposed in a dashboard portion in the vicinity of the remote control light receiving IC 20 and can be operated by a driver reaching out from the driver's seat. When the power supply switch 34 is turned on, the remote control light receiving IC 20 is supplied with electric power from the power supply terminal 27 via the power supply line 30 and enters an operating state. When the power supply switch 34 is turned off, the remote control light receiving IC 20 is disconnected from the power supply via the power supply line 30 and becomes inoperative.

  An LED (Light Emitting Diode) 35 is disposed on the surface of the remote control receiver 12 or the case of the power supply switch 34 or on a dashboard portion near the power supply switch 34, and is connected to the remote control light receiving IC 20 side terminal of the power supply switch 34. Yes. The LED 35 enters a power supply state via the power supply switch 34 and lights up when the power supply switch 34 is in the on position. As will be described later, the black box 13 enters a power supply state (operating state) and a non-power supply state (non-operating state) in conjunction with the ON position and the OFF position of the power supply switch 34, so that the user turns on and off the LED 35. Thus, the power-on state and off-state of the black box 13 can be grasped.

  For example, the user turns on the RDS tuner while the LED 35 is lit, and turns the RDS tuner off when the LED 35 is off and does not listen to the RDS program. To do. Thereby, power saving of the RDS tuner when the RDS tuner is not used can be achieved.

  When the power feed switch 34 is in the OFF position, the remote control light receiving IC 20 is in an inoperative state. As a result, it is difficult for the remote control light receiving IC 20 to receive a remote control signal from the remote control terminal 17 and the signal line 29 from the remote control light receiving IC 20 is. The output voltage to is maintained at the ground voltage (= 0). It is desirable that the power supply switch 34 automatically returns to the off position when the voltage from the power supply terminal 27 is no longer applied to the terminal on the black box 13 side. Thus, even if the user forgets to switch to the off position while keeping the power supply switch 34 in the on position, the power supply switch 34 can be in the off position as the initial position when the next vehicle operation starts.

  When the power supply switch 34 is in the ON position, the remote control light receiving IC 20 is in an operating state. As a result, the remote control light receiving IC 20 can receive a remote control signal from the remote control terminal 17 and can output an output voltage to the signal line 29. The ground voltage is raised to a predetermined value + V. During the operation, the remote control light receiving IC 20 maintains the output voltage to the signal line 29 at + V during the non-reception period of the remote control signal from the remote control terminal 17. Further, during the operation, the remote control light receiving IC 20 outputs a digital signal representing a code corresponding to the content of the received remote control signal to the signal line 29 in the reception period of the remote control signal from the remote control terminal 17. The digital signals are assigned to the logic “1” and “0”, for example, with no pulse widths of 1.69 msec and 0.56 msec.

  The remote control code detection circuit 24 and the power on / off detection circuit 25 detect the switching state of the remote control code and the power feed switch 34 from the terminal voltage on the black box 13 side of the signal line 29, respectively. Since the power on / off detection circuit 25 needs to monitor the voltage of the signal line 29 even when the black box 13 is powered off, the power supply terminal 27 is always supplied with power from the automobile battery. Power is supplied from the power supply terminal 27, and the operating state is maintained.

  FIG. 3 is a flowchart of the power on / off detection method 40 implemented in the power on / off detection circuit 25 of FIG. As described above, the power on / off detection circuit 25 in FIG. 2 has a dedicated input terminal for the signal line 29 separately from the input terminal of the remote control code detection circuit 24. Therefore, power on / off detection circuit 25 does not perform remote control code detection processing.

  The power on / off detection method 40 is executed at regular time intervals while the engine key is in the on position or the accessory position and the black box 13 is in the power off (power off) state. The power on / off detection circuit 25 detects the switching state of the power feeding switch 34 based on the voltage of the terminal on the black box 13 side of the signal line 29, and the remote control receiving unit 12 receives the remote control from the remote control terminal 17 on the signal line 29. Since a digital signal related to the remote control signal exists during the period in which the signal is received, the power on / off detection circuit 25 is desired to take a countermeasure for preventing erroneous detection caused by the digital signal. S43 and S44 in the power-on / off detection method 40 are related to the prevention measures.

  In S41, the timer is reset. The timer is incremented by 1 every time a fixed time has elapsed after resetting. In S42, the time for which the data continues is measured from the count value of the timer. Here, “continuation of data” means that the detection voltage in the power on / off detection circuit 25 is kept constant at either a high level or a low level. In order to determine whether the detection voltage of the power on / off detection circuit 25 is high level or low level, for example, + V / 2 is set as a threshold value, and the detection voltage of the power on / off detection circuit 25 is equal to or higher than the threshold value. In some cases, the voltage is determined to be at a high level, and when the detection voltage in the power on / off detection circuit 25 is less than the threshold value, the voltage is determined to be at a low level.

  In S43, it is determined whether or not the continuation of data is equal to or shorter than a first predetermined time. The first predetermined time is set to be longer than both the pulse width and the non-pulse width corresponding to 1-bit “1” and “0” of the digital signal related to the remote control signal on the signal line 29, for example, 10 msec. If the determination in S43 is positive, the process proceeds to S44, and if not, the process proceeds to S48.

  In S44, the current high-level or low-level voltage maintenance is determined to be chattering, and the voltage maintenance period is ignored. That is, assuming that the level before the current level change is maintained as it is, the process returns to S42 without going through the timer reset process of S41.

  In S48, it is determined whether or not the continuation of data is equal to or shorter than a second predetermined time. The second predetermined time is set to a value longer than the first predetermined time in S43. The second predetermined time is set to be longer than the maximum pulse width expected to appear in the digital signal related to the remote control signal on the signal line 29 for the continuation of the data “1”, and the data “0” is Continuation is set longer than the maximum no-pulse width expected to appear in the digital signal related to the remote control signal on the signal line 29. If this time is long, the response of the power on / off detection circuit 25 becomes slow, so it is desirable to set it to 30 to 1000 msec. If the determination in S48 is positive, the process returns to S41, and if not, the process proceeds to S49.

  In S49, it is determined whether or not the data, that is, the input voltage of the power on / off detection circuit 25 from the signal line 29 is at a high level. If the determination is positive, the process proceeds to S50. Proceed to The high level and low level of the input voltage of the power on / off detection circuit 25 from the signal line 29 correspond to the on position and the off position of the power supply switch 34, respectively.

  The power supply control circuit 26 controls the power supply from the power supply terminal 27 to the black box 13 based on the detection of the power on / off detection circuit 25 (corresponding to the determination in S49). In S50, the power supply control circuit 26 supplies the power of the power supply terminal 27 to the black box 13, puts the black box 13 into an operating state, and then returns to S41. In S51, the power supply control circuit 26 stops the power supply from the power supply terminal 27 to the black box 13, and puts the black box 13 into an inoperative state.

  FIG. 4 is a block diagram showing the main part of another audio processing apparatus 53. As shown in FIG. Regarding the elements of the audio processing apparatus 53, the same elements as those of the audio processing apparatus 10 are designated by the same reference numerals and description thereof is omitted. Differences between the audio processing device 53 and the audio processing device 10 will be described. The audio processing device 53 includes a black box 54 instead of the black box 13 of the audio processing device 10. Among the elements of the black box 54, the same elements as those of the black box 13 are designated by the same reference numerals, and description thereof is omitted. Differences between the audio processing device 53 and the black box 54 with respect to the audio processing device 10 will be described.

  The black box 54 includes a common detection circuit 55. The common detection circuit 55 serves as both functions of the remote control code detection circuit 24 and the power on / off detection circuit 25 in the black box 13 of the audio processing apparatus 10. Corresponding to this, the signal line 29 is branched into two on the black box 13 side in the audio processing device 10, but the audio processing device 53 is connected to the input terminal of the common detection circuit 55 without branching. Has been. The common detection circuit 55 detects the remote control code and the switching state of the power supply switch 34 at the same time.

  FIG. 5 is a flowchart of the remote control code and power on / off detection method 56 implemented in the common detection circuit 55 of the black box 54 of FIG. In each step of the black box 54, the same step as the step of the power on / off detection method 40 in FIG. Differences of the black box 54 with respect to the power on / off detection method 40 will be described.

  In the period in which the digital signal corresponding to the remote control code is transmitted through the signal line 29, such as the period indicated as reception of the remote control code in the balloon shown in FIG. 4, the pulse width is generally constant at 0.56 msec. The duration of 1 "data corresponds to a pulse width and a period of a pulse width of 2.25 msec, and the duration of data of" 0 "corresponds to a period of a pulse width and a pulse width of 1.125 msec. That is, the duration of “1” data has a non-pulse width of 1.69 msec, and the duration of “0” data has a no-pulse width of 0.56 msec.

  In S43, it is determined whether or not the continuation of data is equal to or shorter than a first predetermined time. The first predetermined time is set to be shorter than both the pulse width and the non-pulse width corresponding to 1-bit "1" and "0" of the digital signal related to the remote control signal on the signal line 29, for example, 0.5 msec. If the determination in S43 is positive, the process proceeds to S44, and if not, the process proceeds to S48.

  In the power on / off detection method 40, when the determination in S48 is positive, the process immediately returns to S41, whereas in the remote control code and power on / off detection method 56, the process proceeds to S57, and after the process of S57, The process returns to S41. If the determination in S48 is positive, the current remote control code input period to the common detection circuit 55 is considered, so in S57, the remote control code is fetched.

  FIG. 6 is a block diagram of the remote control device 70. The remote control device 70 includes a remote control signal receiving unit 71, a controlled device 72, a power supply switch 73, a detection unit 74, and a power supply control unit 75. The remote control device 70 can further include remote control signal extraction means 77. The aforementioned audio processing device 10 is an example of the remote control device 70. The remote control device 70 is typically mounted on an automobile, but is not limited to this. The remote control device 70 may be deployed at home, a store, a workplace, or the like.

  The remote control signal receiving unit 71 is in an operating state during power feeding, converts the remote control signal received wirelessly from the remote control terminal 80 into an electric signal format, and outputs the signal to the remote control signal line 81. The controlled device 72 is controlled based on a remote control signal input from the remote control signal line 81.

  The power feeding switch 73 is manually operated to switch between power feeding and non-power feeding to the remote control signal receiving unit 71. The detecting means 74 detects the switching state of the power feeding switch 73 based on the electric signal level at the end of the remote control signal line 81 on the controlled device 72 side. The power supply control means 75 controls power supply to the controlled device 72 based on the detection by the detection means 74.

  The controlled device 72 may be an audio signal processing device such as the black box 13 described above. The audio signal processing device is, for example, a transmitter that modulates an input audio signal from an external audio device and wirelessly transmits it to a tuner. In the black box 13, the input audio signal is applied to a modulator to generate a weak radio wave having a predetermined frequency in the FM broadcast frequency band, and the weak radio wave is sent to an antenna of a tuner such as an RDS tuner.

  The remote control signal receiving unit 71 typically receives a remote control signal from the remote control terminal 80 as an optical signal. The remote control signal receiving unit 71 may receive a remote control signal from the remote control terminal 80 by an infrared or other wireless medium other than the optical signal.

  The electric signal level of the remote control signal line 81 is, for example, a voltage level or a current level. The remote control signal transmitted from the remote control signal receiving unit 71 to the controlled device 72 via the remote control signal line 81 is, for example, a digital electric signal associated with a remote control code representing each instruction.

  Preferably, when the electric signal level continues for a predetermined time longer than the maximum pulse width of the remote control signal on the remote control signal line 81, the detection means 74 detects that the power supply switch 73 is in the ON position. Preferably, when the electric signal level continues for a predetermined time longer than the maximum no-pulse width of the remote control signal on the remote control signal line 81, the detection means 74 detects that the power supply switch 73 is in the off position.

  The electrical signal level of the remote control signal line 81 in the typical remote control device 70 is the level of the pulse of the remote control signal during the period when the remote control signal receiver 71 is in the power supply state, and the period during which the remote control signal receiver 71 is in the non-power supply state. Then, the remote control signal has no pulse level. On the other hand, since the remote control signal line 81 transmits a digital signal related to the remote control signal during the period in which the remote control terminal 80 is receiving the remote control signal, the electric signal level of the remote control signal line 81 varies during that period. The detection based on the maximum pulse width or the maximum no-pulse width of the remote control signal described above by the detection means 74 contributes to prevention of erroneous detection of the detection means 74 due to the presence of the remote control signal in the remote control signal line 81.

  Preferably, the remote control signal extracting means 77, when the electrical signal on the remote control signal line 81 continues for a predetermined level is not less than the first predetermined value and not more than the second predetermined value, the electrical signal is It is determined that a remote control signal is configured, and the remote control signal is extracted from the end of the remote control signal line 81 on the controlled device 72 side. 5 described above corresponds to the processing of the remote control signal extracting means 77. The first and second predetermined values correspond to the first and second predetermined times of S43 and S48 in FIG. 5, respectively.

  For example, the power supply switch 73 turns on / off power in a power supply line (for example, the power supply line 30 in FIGS. 2 and 5) from the controlled device 72 to the remote control signal receiving unit 71. Correspondingly, the controlled device 72 includes a power feeding terminal (for example, the power feeding terminal 27) and switching means (for example, the power feeding control circuit 26). The power supply terminal is supplied with electric power from an external power source (for example, an automobile battery) and is always connected to the end of the power supply line on the controlled device side. In addition, the switching unit switches between supply and non-supply of power at the power supply terminal to the controlled device 72.

  Preferably, the remote control device 70 includes a lighting unit (e.g., LED 35) that is powered and turned on when the power supply switch 73 is turned on.

  When the remote control device 70 is mounted on an automobile, in the typical remote control device 70, the remote control signal receiving unit 71 and the power supply switch 73 are disposed in the vehicle interior (eg, dashboard) in front of the driver's seat, The controlled device 72 is disposed in a passenger compartment (eg, under the driver seat) or outside the passenger compartment (eg, trunk room) other than in front of the driver seat.

  Although the present invention has been described with respect to various specific embodiments, the present invention is not limited to this, and each component in the various specific embodiments is modified (including deletion) without departing from the gist of the invention. And can be materialized. Various inventions can also be formed by replacing constituent elements between various specific forms or combining a plurality of constituent elements in various specific forms.

It is a schematic block diagram of an audio processing device. It is a principal part block diagram of an audio processing apparatus. 3 is a flowchart of a power on / off detection method implemented in the power on / off detection circuit of FIG. 2. It is a principal part block diagram of another audio processing apparatus. 5 is a flowchart of a remote control code and a power on / off detection method implemented in the shared detection circuit of FIG. 4. It is a block diagram of a remote control device.

Explanation of symbols

70: remote control device, 71: remote control signal receiving unit, 72: controlled device, 73: power supply switch, 74: detection means, 75: power supply control means, 77: remote control signal extraction means, 80: remote control terminal, 81: remote control signal line.

Claims (7)

A remote control signal receiving unit that is in an active state during power feeding and converts the remote control signal received wirelessly from the remote control terminal into an electrical signal format and outputs it to the remote control signal line,
A controlled device controlled based on a remote control signal input from the remote control signal line;
A power supply switch that is manually operated to switch between power supply and non-power supply to the remote control signal receiver;
Detection means for detecting a switching state of the power supply switch based on an electric signal level at an end of the remote control signal line on the controlled device side, and power supply control for controlling power supply to the controlled device based on detection by the detection means means,
A remote control device comprising:   When the electric signal level continues for a predetermined time longer than the maximum pulse width of the remote control signal in the remote control signal line, the detection means detects that the power supply switch is in the ON position and / or 2. The remote control according to claim 1, wherein when the signal level continues for a predetermined time longer than the maximum no-pulse width of the remote control signal in the remote control signal line, the power supply switch is detected to be in an off position. apparatus. If the time for which the electrical signal on the remote control signal line continues at the predetermined level is not less than the first predetermined value and not more than the second predetermined value, it is determined that the electrical signal constitutes the remote control signal. Remote control signal extracting means for extracting a remote control signal from an end of the remote control signal line on the controlled device side;
The remote control device according to claim 1, further comprising: The power supply switch is for turning on / off the power in the power supply line from the controlled device to the remote control signal receiver,
The power supply control means is supplied with power from an external power source and is always connected to an end of the power supply line on the controlled device side, supply of power from the power supply terminal to the controlled device, and 4. The remote control device according to claim 1, further comprising switching means for switching non-supply.   5. The remote control device according to claim 1, further comprising a lighting unit that is turned on when the power supply switch is in an on position.   The remote control device is mounted on an automobile, the remote control signal receiver and the power supply switch are disposed in a passenger compartment in front of the driver's seat, and the controlled device is provided in the passenger compartment or outside the passenger compartment. The remote control device according to claim 1, wherein the remote control device is provided.   7. The remote control device according to claim 1, wherein the controlled device is a transmitter that modulates an input audio signal from an external audio device and wirelessly transmits the modulated signal to a tuner.

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