JP5660924B2 - Amplifier with speaker connection detection function - Google Patents

Description

  The present invention relates to an amplifier with a speaker connection detection function capable of easily and safely detecting whether or not a speaker is properly connected to an amplifier of a vehicle audio device, for example, in a vehicle production line.

  Audio devices for vehicles are indispensable for car users to spend comfortably in the vehicle, and most vehicles are equipped with audio devices. In many cases, this audio device is installed in a vehicle production line. Sometimes, a user's favorite audio device is purchased separately and installed at a car dealer or a vehicle-related equipment dealer. Yes.

  Such a car audio device is connected to a head unit attached to a front panel or the like with a speaker that is firmly and firmly fixed in a place where the sound effect is good in the car and not in the way for users in the car. use.

  In many cases, this head unit has a radio reception function, and in addition, there are many that appropriately select and incorporate various devices such as a CD player, a television receiver, and a DVD player. In some cases, a DVD disk changer or the like is connected.

  The head unit amplifies and outputs the volume of the audio or sound (hereinafter abbreviated as “voice”) of these devices from a speaker at an appropriate volume. At that time, the sound is output from a speaker whose position, sound quality, etc. are adjusted so that the acoustic effect such as 4.1 surround can be exhibited so that the acoustic effect is as good as possible in the vehicle.

  For this reason, the head unit or the like is provided with an amplifier for finally outputting the sound at a volume desired by the user, and the speakers that can output the specific sound quality provided in various places in the vehicle are the respective speakers. Is connected to a connection portion provided for each speaker in the amplifier. As a result, the sound from the amplifier that amplifies at an appropriate balance for each speaker is output as a whole in the vehicle at a sound volume preferred by the user and at an appropriate sound volume balance for each individual speaker.

  In such an in-car audio apparatus, it is important to properly connect the amplifier and the speaker in the car. In this case, the first must be properly connected, and the second is a connection coat or the like. Do not short-circuit directly in contact with conductive objects in the car. Moreover, the speaker which should be connected must be connected to the amplifier for each speaker.

  Therefore, in the production line of a vehicle in which an audio device is mounted on the vehicle as described above, an inspection process for checking whether or not the device is properly connected is often provided after the device is incorporated into the vehicle. In the inspection, in many cases, it is inspected whether or not an appropriate current is flowing from the amplifier to the speaker. For this purpose, for example, a resistance of about 0.5Ω is inserted in the circuit from the amplifier to the speaker connection portion. , Sine wave current is passed through this circuit, the current flowing through the specified resistor is detected, and this is input to the A / D input part of a personal computer etc., and it is detected whether proper connection is made by software By doing the inspection.

  The predetermined current that flows at the time of the inspection can be accurately measured with a large current with less error. For example, in the case of a tweeter of a small speaker, if a large current is applied, the speaker is damaged. A large current cannot flow. When the speaker connection is inspected, it is checked whether the circuit to be inspected is for a tweeter, and selecting and supplying a current suitable for the speaker deteriorates the working efficiency.

  In addition, since the current flowing through the speaker adopts a structure that vibrates in response to the vibration of the audio signal from the speaker, it is not possible to flow a large direct current that is easy to conduct a current test. For this reason, a large current of sine waves is passed as described above during the inspection of the speaker.

  A technique for detecting the presence / absence of a speaker connection and bass reproduction capability and automatically selecting the optimum mode is disclosed in Patent Document 1, and the energization detection in which a connection state of a plurality of speakers is provided for each speaker. Japanese Patent Application Laid-Open No. 2004-228688 discloses a technique for detecting an image by means and performing an optimum audio output setting. A technique for detecting a current flowing in an electric motor or the like by a Hall element is disclosed in Patent Document 3, and a technique for detecting a current flowing in various electric wires by an MR element is disclosed in Patent Document 4.

JP 2000-023300 A JP 2003-134591 A JP 05-223848 A JP 2004-020371 A

  As described above, when detecting whether or not a speaker is properly connected, conventionally, a current detection unit is generally provided for each channel corresponding to each speaker. As a result, there is a problem that the entire circuit becomes complicated and expensive. In addition, if a resistor for current detection is inserted in the connection circuit in advance, the sound is output through this resistor even during normal operation of the speaker, which affects the sound quality of the speaker. There is also a problem that the deterioration is noticeable.

  In addition, when performing speaker connection detection for each speaker, it is necessary to repeat the same operation for each speaker. Therefore, the larger the number of speakers to be connected, the longer the time and the lower the work efficiency. It was.

  Furthermore, in addition to the influence on the damping factor due to the introduction of a resistor of 0.5Ω or the like in advance for detecting the speaker connection as described above, in order to detect the connection state as reliably as possible, a high current sine group is sent. There is also a problem that a small speaker such as a tweeter has an adverse effect, and the reliability of the speaker is deteriorated. For this reason, there is a dilemma that the inspection performance decreases when the current is reduced.

  In addition, even when the current is detected using the magnetic detection element as disclosed in Patent Documents 3 and 4, it is necessary to dispose the magnetic detection element for each electric wire in the techniques disclosed therein, When a large number of speakers are connected, the device must be an expensive device.

  Therefore, according to the present invention, even when a large number of various speakers are connected to an amplifier, only one small current is allowed to flow almost simultaneously by a single detection element, and there is no need to provide a resistor in the circuit. A main object is to provide an amplifier with a speaker connection detection function which can detect connection of a speaker.

In order to solve the above-described problem, an amplifier with a speaker connection detection function according to the present invention includes a plurality of output blocks that respectively amplify signals of audio signal input lines for a plurality of speakers,
The speaker connection part that connects the output wiring from the plurality of output blocks and the wiring of a plurality of external speakers, and the positive wiring or the negative wiring in the output wiring from the output block, respectively. A magnetic sensor for detecting magnetism due to electric current, a test signal output means for outputting a test signal to each of the input lines to the plurality of output blocks, and a test signal from the test signal output means by the magnetic sensor is output wiring The current that flows when the speaker is properly connected to the speaker connecting portion, and the current detected by the passing current detecting means that inputs a magnetic signal due to the current flowing through the current and converts it into a current. A threshold value setting means for setting a threshold value indicating the range of the current and a test signal detected by the passing current detection means. A connection state determination unit that determines whether or not a current value is within a threshold range set by the threshold setting unit, and a plus-side wiring or a minus-side wiring in each output wiring from the plurality of output blocks is The magnetic sensor is arranged so as not to cause magnetic interference with each other, and the magnetic sensor is arranged at a position for detecting the magnetism of the current flowing through the wiring from all the output blocks of the plurality of plus side wirings or minus side wirings. Features.

  In another amplifier with a speaker connection detection function according to the present invention, in the amplifier with a speaker connection detection function, the threshold setting unit includes an upper limit threshold and a lower limit threshold, and the connection state determination unit includes the passing current detection When the current value detected by the means is in the range between the upper limit threshold and the lower limit threshold, it is determined that a speaker is properly connected to the speaker connection unit.

  In another amplifier with speaker connection detection function according to the present invention, in the amplifier with speaker connection detection function, in the connection state determination unit, when the current value detected by the passing current detection unit is equal to or greater than the upper limit threshold value. 3. The amplifier with a speaker connection detection function according to claim 2, wherein it is determined that the connection wiring to the speaker is short-circuited, and it is determined that the connection is defective when the connection wiring is below the lower limit threshold value.

  Further, another amplifier with a speaker connection detection function according to the present invention is the amplifier with a speaker connection detection function, wherein the test signal output means outputs a test signal shifted in timing for each output block, and the connection In the state determination unit, the current value obtained by converting the magnetism detected by the magnetic sensor into a current is divided according to the timing at which the test signal is output by the test signal output unit, and the divided current value and a threshold value corresponding to each speaker The threshold value set by the setting means is compared, and the connection state for each speaker is determined.

  In another amplifier with speaker connection detection function according to the present invention, in the amplifier with speaker connection detection function, the test signal output means simultaneously outputs a common test signal to each output block, and the connection state determination means Then, the current value obtained by converting the magnetism detected by the magnetic sensor into a current is compared with the threshold value set by the threshold setting means corresponding to the total current of the plurality of speakers, and the connection state of the plurality of speakers as a whole is determined. It is characterized by performing.

  Further, another amplifier with speaker connection detection function according to the present invention is the above-mentioned amplifier with speaker connection detection function, wherein the magnetic sensor is a part in which the plus side wiring of each output block is gathered, and a part in which the minus side wiring is gathered. The connection state determination means performs the determination based on the outputs of both magnetic sensors.

  Further, another amplifier with speaker connection detection function according to the present invention is arranged such that the output plus side wiring and the output minus side wiring from the two output blocks are opposite to each other in the amplifier with speaker connection detection function. The magnetic sensor is arranged in a portion where the wirings inside each other are collected.

  Further, another amplifier with speaker connection detection function according to the present invention collects all four wirings of the plus side wiring and the minus side wiring coming out of the four output blocks in the amplifier with speaker connection detection function. When arranging the magnetic sensor in the part, two wires are arranged on the first substrate, and the other two wires are arranged on the second substrate provided with the first substrate and the insulating material sandwiched between them. One magnetic sensor is arranged at a position where the magnetism due to the current of the wiring is detected.

  Since the present invention is configured as described above, even when a large number of various speakers are connected to the amplifier, only one small current flows almost simultaneously by one detection element, and there is no need to provide a resistor in the circuit. Speaker connection detection can be performed easily and accurately.

It is a block diagram which shows the basic principle of this invention. It is a figure which shows the example of a connection determination process based on the basic principle. It is a figure which shows the embodiment which applied this invention to the connection of two speakers based on the basic principle of this invention. It is a figure which shows the other embodiment applied to the connection of the two said speakers. It is a figure which shows other embodiment applied to the connection of the two said speakers. It is a figure which shows the embodiment which applied this invention to the connection of four speakers based on the basic principle of this invention. It is a detailed functional block diagram of the connection determination control part in the Example of this invention. It is an operation | movement flowchart which performs the process which determines whether the connection of a speaker is appropriate using a magnetic sensor in this invention. It is an operation | movement flowchart which performs connection determination of a speaker in the operation | movement flow of the determination process. It is sectional drawing of the magnetic sensor arrangement | positioning part vicinity in the Example of this invention.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a basic principle of an embodiment of the present invention, showing a basic speaker connection circuit configuration and a basic functional block diagram for performing a predetermined function using the speaker connection circuit configuration. Yes. In addition, in the same figure and each other figure, the function part which performs each function can be said to be a means which performs each function.

  FIG. 1 shows the basic principle of the present invention as described above, and the present invention can be implemented in various modes based on the basic principle. In the diagram of the basic principle shown in FIG. 1, for convenience of explanation, only one speaker is connected to the amplifier. However, the present invention is based on this basic principle and connects a plurality of speakers as will be described later. In this case, a more specific effect can be exhibited.

  In the diagram showing the basic principle shown in FIG. 1, when one speaker 5 is connected to the amplifier 1 and connected to the connection portion 4 provided at the output portion of the amplifier, the speaker 5 is surely connected to the connection portion 4. The connection wiring of the speaker connected to the connection portion 4 is not in contact with the vehicle body or the like at the bare wire portion in the middle, and is not short-circuited, that is, The figure which enabled it to detect also whether the speaker connection wiring is not short-circuited is shown.

  In the example of the amplifier 1 in FIG. 1, for example, in the audio function section of the head unit, various waveform shaping and the like are performed on audio signals from various sound sources, and finally output to the speaker 5 at a predetermined volume. An output block 2 is provided. In the output block 2, the signal as described above is taken from the signal input line 6, and the amplified signal is output from the speaker connection unit 4 to the speaker 5, but the (+) output line reaching the speaker connection unit 4. In the illustrated example, the output plus line 7 and the output minus line 8 as the (−) output line are bent so that both the output plus line 7 and the output minus line are separated from each other, and then the speaker connecting portion 4. Connected to.

  In the example of FIG. 1, the magnetic sensor 3 is disposed via an insulating material with respect to the plus-side bent portion 9 of the output plus line 7 among the output lines. The magnetic sensor 3 can function in the same manner even if it is disposed on the bent portion 10 side of the output minus line 8.

  In the present invention, the magnetic sensor detects whether or not a predetermined current flows through the speaker. Therefore, if the output plus line and the output minus line are close to each other in the output line, the magnetic sensor Since the magnetic fields cancel each other, in the present invention, as shown in the figure, the output plus line bent portion 9 and the output minus line bent portion 10 are placed in opposite directions so as not to cancel each other as much as possible. An example of bending is shown. Therefore, if the current detection by the magnetic sensor is not affected, the bent portion 10 can be omitted from the output minus line 8. Such an output line can be formed by arranging each wiring on the wiring board.

  Various magnetic sensors can be used here, but in recent years, the magnetic sensor has been downsized and made into a semiconductor element, and can be easily incorporated into a circuit board. Therefore, the present invention can be implemented by arranging such a magnetic sensor in an insulated state in proximity to the bent portion 9 of the output line formed on the substrate.

  Many magnetic sensors use magnetoresistive effect MR (magnetoresistance) .For example, positive MR in semiconductors and semimetals uses Lorentz force, and spin MR scattering is observed in negative MR found in magnetic semiconductors. Used: AMR, which is an anisotropic magnetoresistance of a ferromagnetic material, GMR, which is a giant magnetoresistance of a magnetic / non-magnetic / magnetic structure, and a tunnel magnetoresistance of a magnetic / insulating layer / magnetic structure. TMR, CMR, which is a giant magnetoresistance of a strongly correlated oxide, are known, and an arbitrary one can be selected.

  In the example shown in FIG. 1, an example is shown in which the signal of the magnetic sensor 3 is input to the A / D conversion unit 12 in the connection determination control unit 11 as a microcomputer provided on the substrate of the amplifier 1. The connection determination control unit 11 includes a magnetic detection unit 13 and detects the signal of the magnetic sensor 3 input to the A / D conversion unit 12 as a digital signal. Based on the magnetic detection signal of the magnetic detection unit 13, the passing current detection unit 16 converts the current into the output plus line.

  The connection determination control unit 11 includes a test signal output unit 14, and a predetermined sine wave signal that has been conventionally output to the output block of the amplifier at the time of speaker connection inspection is input to the input line 6 of the output block 7. And output from the test signal output line 19. Thus, as will be described in detail later, the connection state determination unit 17 compares the output signal from the signal output unit 14 with the signal of the passing current detection unit 15 based on the signal detected by the magnetic sensor 3, and the passing current detection unit 17 Whether or not the speaker is connected is determined by determining whether or not the current value detected in 15 is within the range of the upper and lower thresholds set by the threshold setting unit 16.

  The determination result is output from the connection determination result output unit 18 to an external inspection result display device or the like. In this way, by incorporating the magnetic sensor, the connection determination control unit 11 and the like in advance in the amplifier, an accurate connection determination result can be obtained by simply connecting a simple device during speaker connection inspection.

  As described above, the magnetic sensor is previously installed on the amplifier substrate and the connection determination control unit is prepared in advance. It is also possible to install a predetermined magnetic sensor at a magnetic sensor installation position and perform connection determination by software of a separate PC. In this case, the magnetic sensor may be arranged on the substrate in advance, and a connection signal may be determined by inputting a detection signal from a signal output unit to a separate personal computer or the like.

  FIG. 2 shows an example in which the speaker connection is actually detected based on the configuration of the basic principle of the present invention shown in FIG. In the example shown in FIG. 2, a sine wave as shown in FIG. 2B is output to the input line 6 of the output block 2 from the test signal output unit 14 of the connection determination control unit 11 as in the example of FIG. To do. From the output block 2, it is amplified as necessary and outputted. In the magnetic sensor 3, the current on the plus side of the sine wave is detected by the magnetic sensor 3 provided in the bent portion 9 of the output plus line 7 in the signal.

  The magnetism detected at this time varies greatly depending on the characteristics of the magnetic sensor used here. However, in the example shown in the figure, the magnetism sensor accurately detects the magnetism generated by the current. The example at the time of detecting the electric current which flows into the curved part 9 as shown to the same figure (b)-(e) is shown. Therefore, there can be various modes such as detecting the magnetism generated by the positive currents of multiple sine waves within a predetermined time depending on the characteristics of the magnetic sensor, but in any case, detecting the current flowing on the positive side is the same. It is. In the example shown in FIG. 2, in order to make the explanation of the relationship between the input and output currents easier to understand, an example in which a current change of a sine wave of a test signal is accurately detected is shown.

  FIG. 2B shows an example in which the magnetic sensor does not detect magnetism at all in response to the test signal as described above, and thus does not detect current. At this time, the connection determination result output unit 18 of the connection determination control unit 11 outputs a display indicating that the speaker is poorly connected to the inspection device or the like connected thereto, and further outputs a sound as necessary.

  FIG. 2C shows a state where the maximum current value among the detected current values is lower than the lower limit threshold L1 set by the threshold setting unit 15. The threshold value at this time is a value set in advance in consideration of the characteristics detected by the magnetic sensor used in the predetermined amplified signal from the output block 2 when the predetermined test signal as described above is passed. The lower limit threshold L1 and the upper limit threshold L2 are set in anticipation of upper and lower limits of the value that should be detected.

  Therefore, in the example of FIG. 2C, since the maximum value of the detected current is lower than the lower limit threshold L1, an output indicating that the connection is not properly performed is performed. At this time, a warning output similar to that shown in FIG. Further, in FIG. 2D, since the maximum current value of the detected current exists between the lower limit threshold value L1 and the upper limit threshold value L2, it is determined that they are properly connected. This is often the case in an audio device assembly process in a normal vehicle production line.

  FIG. 2E shows a state where the maximum current value of the detected current is larger than the upper limit threshold L2. This state indicates that there is a high possibility that the wiring system from the speaker connection portion 4 of the amplifier 1 to the speaker 5 is short-circuited to the vehicle body or the like for some reason or that there is another abnormality. At this time, the same warning output as described above is performed. At that time, for example, a warning such as “the connection cord to the speaker may be short-circuited” may be issued.

  FIG. 3 shows an example in which two speakers 5a and 5b are connected to the amplifier 1 based on the basic principle of the present invention shown in FIG. In the illustrated example, each speaker has an output block, and a signal is input from the first input line 6a to the first output block 2a and from the second input line 6b to the second output block 2b.

  In the illustrated example, the bent portion 9a of the output 1 plus line 7a that is a positive output from the first output block 2a and the bent portion 10a of the output 2 plus line 8a that is a positive output from the output block 2b are close to each other. The magnetic sensor 3 is arranged with an insulating material sandwiched between the portions so that the current flowing through the bent portions can be detected. Thereafter, the output 1 plus line 9a is led to the plus side of the first speaker connecting portion 4a, and the output 2 plus line 10a is led to the plus side of the second speaker connecting portion 4b.

  On the other hand, the output 1 minus line 8a of the first output block 2a is bent in the opposite direction to the bent portions 9a and 9b so as to be away from the magnetic sensor 3, as in the example of FIG. Is forming. In the illustrated example, it is assumed that the output 2 minus line 8b of the second output block 2b is sufficiently separated from the bent portions 9a and 9b, and the minus of the second speaker connecting portion 4b is not particularly provided. Leading to the side. However, when the output 2 minus line is approaching the bent portions 9a and 9b, it is bent in the same manner as the bent portion of the output 1 minus line 8a.

  On the other hand, from the test signal output unit 14 of the connection determination control unit 11, in the illustrated example, a sine wave signal is output from the first test signal output line 19a to the first input line 6a for the first output block 2a, A sine wave signal following the sine wave output from the first test signal output line 19a is output from the second test signal output line 19b to the second input line 6b for the 2-output block 2b.

  At this time, the output sine wave can be output for a plurality of periods in addition to outputting only for one period. In the illustrated example, the signals of the first test signal output line 19a and the second test signal output line 19b are not overlapped even at this time. Thereby, in the magnetic sensor 3, it becomes possible to detect separately the electric current from the 1st output block 2a, and the electric current from the 2nd output block 2b.

  That is, in the above example, the magnetism detection unit 13 detects the magnetic signal from the magnetic sensor 3 via the A / D conversion unit 12 of the connection determination control unit 11 and the passing current detection unit 15 detects the magnetism. When the connection state determination unit 17 performs the determination process by converting to current, the detection signal of the passing current is divided based on the output timing data in the test signal output unit 14, and the threshold value of each threshold setting unit 16 The connection state is determined by comparison.

  In the example of FIG. 3, the test signal output unit 14 outputs the test signals with different timings to the first output block 2a and the second output block 2b as described above. The same sine wave current is output from the test signal output unit 14 to both output blocks, and the magnetic sensor 3 detects magnetism due to both currents, as if it had one speaker as shown in the example of FIG. Similar processing is performed, and at this time, a threshold value for the current of two speakers is read from the threshold value setting unit 16.

  Thereby, in the connection state determination part 17, when the electric current of the passage current detection part 15 is in the range of the upper and lower threshold values, it is determined that all the systems of the two speakers are properly connected. On the other hand, when it is detected that it is out of the range of the upper and lower thresholds, it is determined that one or both of the speaker connection systems is inappropriate, and thereafter the connection state is individually detected in the individual detection mode. Anyway. In principle, this method can be efficiently inspected when a speaker is appropriately connected as in a vehicle production line.

  FIG. 4 shows an example in which output speakers 2a and 2b are individually provided for two speakers as in the example of FIG. 3, and the example of FIG. 3 uses two magnetic sensors. Is different. That is, in the example of FIG. 4, in addition to providing the first magnetic sensor 3a as a magnetic sensor corresponding to the magnetic sensor 3 of FIG. 3, the output 1 minus line bent portion 9b of the first output block 2a and the second output The output 2 minus line of the block 2b is brought close to the second magnetic sensor 3b in the same manner as the first magnetic sensor 3a.

  As a result, the first magnetic sensor 3a detects magnetism due to the current only on the plus side of the sine wave from the test signal output unit 14, whereas the second magnetic sensor 3b detects the minus side of the test signal. Only detect magnetism due to current. Even at this time, the test signal output from the test signal output unit 14 may output a sine wave that does not overlap with each speaker system, and outputs the same test signal to determine whether the two systems are appropriate at the same time. You may make it determine. By using two magnetic sensors in this way, it is possible to more accurately determine the speaker connection state.

  In FIG. 5, the two output blocks 2a and 2b are arranged horizontally on the board on which the amplifier is arranged, whereas the connection parts 4a and 4b of the two speakers corresponding thereto are arranged on the board. The example when arrange | positioning along with the vertical direction horizontally is shown. In the example of FIG. 5 (a), the first output block 2a and the second output block 2b both output the left and right output plus lines and the output minus line in the same manner. On the other hand, in the example of FIG. 5B, an example is shown in which the output plus line and the output minus line of each output block are arranged in reverse.

  In the example of the wiring state as shown in FIG. 5A, as shown in the drawing, the output minus line of the first output block 2a and the output minus line of the second output block 2b are connected to the respective bent portions 10a. The magnetic sensor 3 is disposed at that portion in proximity to each other at 10b. On the other hand, the output plus line 7a of the first output block 2a is bent away from the magnetic sensor 3 by the bent portion 9a, and the output plus line 7b of the second output block 2b is bent by the bent portion 9b. It is bent away from 3.

  The example of FIG. 5A is only one example of various aspects, and the same function can be performed by various wirings. However, as shown in FIG. In order to collect the wirings, there is a portion where the output plus line and the output minus line must be crossed, and it is necessary to make the wiring on the substrate three-dimensional. On the other hand, in the example of FIG. 5B, since the plus side and the minus side of the output of each output block are arranged in reverse, the wiring can be easily wired without crossing. Become.

  FIG. 6 shows an example in which four speakers are provided and the first output block 2a to the fourth output block 2d corresponding to each of the speakers 5a to 5d. Even when such a large number of speakers are provided, the output plus lines 9a to 9d of the respective output blocks are concentrated, and the magnetic sensor 3 is arranged in the portion, so that the same test signal output and magnetic sensor as described above can be obtained. By processing the signal 3, it is possible to determine whether or not each speaker is connected properly. Also at this time, the output minus lines 8a to 8d are also arranged so as to be appropriately bent away from the installation portion of the magnetic sensor 3.

  FIG. 7 is a functional block diagram showing the connection determination control unit 11 in the present invention in more detail. In the figure, the functional blocks shown in the respective drawings are denoted by the same reference numerals. The connection determination control unit 11 in FIG. 7 outputs the test signal as described above from the test signal output unit 14, and the output timing adjustment unit 20 therein generates a sine wave as shown in FIG. In accordance with each output block, it is possible to output with a time shift. However, as described above, the test signal can be simultaneously output to each output block.

  As described above, the signal of the magnetic sensor 3 is processed by the A / D conversion unit 12, the magnetic detection unit 13, and the passing current detection unit 15. However, in the example of FIG. When the output timing adjustment unit 20 of the test signal output unit 14 outputs a plurality of output signals at a predetermined timing, the signals are taken in and the current signal of the passing current detection unit 15 by the magnetic sensor 3 is divided.

  Accordingly, the connection state determination unit 17 reads the upper and lower threshold values from the threshold setting unit 16 as appropriate threshold values for each speaker, and compares the two as described above to determine the connection state of the speakers. The upper limit threshold and the lower limit threshold at this time are set in advance corresponding to various speakers such as whether the speaker to be connected is a woofer or a tweeter.

  The connection state determination unit 17 of FIG. 7 shows an example in which a single speaker determination unit 27 and a plurality of speaker batch determination units 28 are provided. Among them, the single speaker determination unit 27 determines the connection state of each individual speaker. At that time, the upper limit threshold 22 and the lower limit threshold 23 in the single speaker 21 of the threshold setting unit 16 are read and magnetically read. The speaker connection state is determined by comparison with the current detected by the sensor.

  Similarly, when the same test signal is collectively output to a plurality of speakers, the plurality of speaker simultaneous determination unit 28 reads the upper limit threshold 25 and the lower limit threshold 26 in the plurality of speakers 24 of the threshold setting unit 16 to read the magnetic sensor. The speaker connection state is determined by comparison with the detected current by.

  In the example shown in FIG. 7, the result determined by the connection state determination unit 17 is output from the connection determination result output unit 18 to the monitor 29 of the inspection device connected to this amplifier. In the illustrated example, the determination result of the connection state indicates a state in which it is determined that the connection is inappropriate, and the speaker connection determination result indicates an example in which a warning display indicating “connection failure” is performed.

  In the present invention comprising the functional blocks as described above, for example, the predetermined functions of the present invention can be performed by sequentially operating according to the operation flow shown in FIG. In the example of the speaker connection suitability determination process using the magnetic sensor shown in FIG. 8, the test signal is started by outputting a test signal for each speaker at a predetermined timing (step S1).

  Thereafter, the current is detected by the magnetic sensor (step S2), and then the detected current is divided at every predetermined timing (step S3). This state is shown in FIGS. 8B to 8D. When there are two current detection signals from the magnetic sensor as shown in FIG. 8B, this is matched with the predetermined timing performed in step S1. And split. The divided signals are shown in FIGS.

  Next, the connection state is determined based on the detected current value for each speaker as shown in FIG. In the example of the process for determining the connection state based on the detected current value for each speaker shown in FIG. 9, the threshold corresponding to the type of the detected speaker and the number of speakers to be tested at one time is used as the process after step S3 in FIG. Select (step S11).

  Next, in the illustrated example, it is determined whether or not the detected current is equal to or lower than the lower limit threshold (step S12). If it is determined that the value is not equal to or lower than the lower threshold, the process proceeds to step S13 to determine whether the detected current is equal to or higher than the upper threshold. If it is determined that the value is not equal to or greater than the upper threshold value, the process proceeds to step S14 to determine that the connection state is normal. This state is shown in FIG.

  On the other hand, when it is determined in step S12 that the detected current is equal to or lower than the lower limit threshold value and when it is determined in step S13 that the detected current is equal to or higher than the upper limit threshold value, the connection state is determined to be defective (step S15). In particular, when it is determined in step S12 that the detected current is equal to or lower than the lower limit threshold value, the state shown in FIGS. 2B and 2C is determined, and it is determined that the connection is poor (step S17). This state also shows two in FIG.

  When it is determined in step S13 that the detected current is equal to or greater than the upper limit threshold value, it is determined that the state is as shown in FIG. 2E and that a short circuit or other abnormality has occurred (step S16). After the determination as described above is performed in step S4 of FIG. 8, the determination result is output for each speaker (step S5), and the series of processes is terminated (step S6).

  FIG. 10 is a cross-sectional view showing the relationship between the magnetic sensor 3 and wiring for detecting current in the present invention. FIG. 2A shows a state in which the number of wires detected by the magnetic sensor is one as the most basic mode, and a lead wire 32 is wired on the back side of the substrate 31 made of an insulating material in the figure. At this time, an example in which the magnetic sensor 3 is arranged at a position corresponding to the lead line 32 on the front side of the substrate 31 in the drawing is shown.

  FIG. 10B shows an example in which two leader lines exist for two speakers. Lead lines 32a and 32b are arranged on the back side of the substrate 31 in the figure, and each of the leader lines is shown in the example shown in the figure. The example which has arrange | positioned the magnetic sensor 3 to the front side in the figure of the board | substrate 31 in between is shown.

  FIG. 4C shows an example in which four speakers are connected. First lead wires 32 a and 32 b are arranged on the front side of the first substrate 33 in the drawing, and the first lead wires 32 a and 32 b are interposed between the first substrate and the insulating material 34. Two substrates 35 are arranged. A third lead line 32 and a fourth lead line 32d are arranged on the back side of the second substrate 35 in the drawing so as to be inside the first lead line 32a and the second lead line 32b of the first substrate 32, respectively. Yes. In this wiring state, the magnetic sensor 3 is disposed between the first lead line 32a and the second lead line 32b on the front side of the first substrate in the drawing. With this arrangement, the current flowing through the four lead lines can be detected by one magnetic sensor.

  Although the present invention can be implemented in a very wide variety of embodiments as described above, it can be implemented in various modes depending on the characteristics of each magnetic sensor according to the selection of the type of magnetic sensor. it can.

DESCRIPTION OF SYMBOLS 1 Amplifier 2 Output block 3 Magnetic sensor 4 Speaker connection part 5 Speaker 6 Input line 7 Output plus line 8 Output minus line 9 Output plus side bending part 10 Output minus side bending part 11 Connection determination control part 12 A / D conversion part DESCRIPTION OF SYMBOLS 13 Magnetic detection part 14 Test signal output part 15 Passing current detection part 16 Threshold setting part 17 Connection state determination part 18 Connection determination result output part 19 Multiple input signal division | segmentation part 20 Output timing adjustment part 21 Single speaker 22 Upper limit threshold value 23 Lower limit threshold value 24 For multiple speakers 25 Upper threshold 26 Lower threshold 27 Single speaker determination unit 28 Multiple speaker determination unit 29 Monitor 31 Substrate 32 Leader 33 First substrate 34 Insulating material 35 Second substrate

Claims (7)

A plurality of output blocks that respectively amplify signals of audio signal input lines for a plurality of speakers;
A speaker connection section for connecting output wiring from the plurality of output blocks and wiring of a plurality of external speakers;
A magnetic sensor for detecting magnetism due to a current flowing through either the positive side wiring or the negative side wiring in the output wiring from the output block;
Test signal output means for outputting a test signal to each of the input lines to the plurality of output blocks;
Passing current detection means for inputting a magnetic signal due to current when the test signal from the test signal output means flows through the output wiring by the magnetic sensor, and converting it into current;
A threshold value setting means for setting a threshold value indicating a range of current that is detected when the current detected by the passing current detection means is properly connected to the speaker connection portion;
A connection state determination unit that determines whether or not a current value by the test signal detected by the passing current detection unit is within a threshold range set by the threshold setting unit;
The plus side wiring or the minus side wiring in each output wiring from the plurality of output blocks are arranged separately so as not to cause magnetic interference with each other,
The magnetic sensor is arranged in both the portion where the positive side wiring of each output block is gathered and the portion where the negative side wiring is gathered, and the connection state judgment means performs the judgment based on the outputs of both magnetic sensors. An amplifier with a speaker connection detection function. The threshold setting means comprises an upper threshold and a lower threshold,
The connection state determination means determines that a speaker is properly connected to the speaker connection section when the current value detected by the passing current detection means is in the range between the upper threshold and the lower threshold. The amplifier with a speaker connection detection function according to claim 1. The connection state determination unit determines that the connection wiring to the speaker is short-circuited when the current value detected by the passing current detection unit is equal to or greater than the upper limit threshold value, and indicates a poor connection when the current value is equal to or less than the lower limit threshold value. The amplifier with a speaker connection detection function according to claim 2, wherein: The test signal output means outputs a test signal whose timing is shifted for each output block,
The connection state determination unit divides the current value obtained by converting the magnetism detected by the magnetic sensor into a current according to the timing at which the test signal output unit outputs the test signal, and corresponds to the divided current value and each speaker. 2. The amplifier with a speaker connection detection function according to claim 1, wherein the threshold value set by the threshold value setting means is compared to determine the connection state for each speaker. The test signal output means simultaneously outputs a common test signal to each output block,
The connection state determination means compares the current value obtained by converting the magnetism detected by the magnetic sensor into a current and the threshold value set by the threshold setting means corresponding to the total current of the plurality of speakers, thereby The amplifier with a speaker connection detection function according to claim 1, wherein the connection state is determined. 2. The output plus side wiring and the output minus side wiring from the two output blocks are arranged so as to be opposite to each other, and a magnetic sensor is arranged in a portion where the wirings inside each other are collected. Amplifier with speaker connection detection function. When the magnetic sensor is arranged in a portion where all the four wirings of the plus side wiring and the minus side wiring coming out from the four output blocks are collected, the two wirings are arranged on the first substrate. The other two wirings are arranged on the second substrate provided with the substrate and the insulating material interposed therebetween, and one magnetic sensor is arranged at a position where the magnetism due to the current of all the wirings is detected. The amplifier with a speaker connection detection function according to 1.

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