JPH01176952A - Trouble diagnostic device for audio equipment - Google Patents

Abstract

PURPOSE:To diagnose whether or not a specific circuit is in trouble and to facilitate repairing operation by connecting the trouble diagnostic device to the prescribed circuit of the audio equipment, applying a prescribed voltage, and forming a voltage dividing circuit and comparing its voltage with a reference value. CONSTITUTION:If the audio equipment becomes faulty and no sound output is generated, whether the trouble is caused by the equipment main body or a speaker 51 is diagnosed. Further, when the speaker 51 is disconnected from the equipment main body by turning off a switch 52 and the diagnostic device is actuated by turning on a switch 10, a stabilized power source 1 is put in operation and at the same time, a base voltage is applied to a transistor (TR) 11, which turns on to form a circuit of the power source 1, a resistance 2, the speaker 51, a resistance 3, and the TR 11. Here, the upper-limit value and lower-limit value of a comparator 4 are set properly and then only when the speaker 51 is normal, the output of the comparator 4 becomes Hi, but when a display device 5 lights, it is judged that the speaker 51 is faulty.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a failure diagnosis device for audio equipment.

<Prior Art> When a malfunction occurs in an audio device, such as no sound being output, it is often impossible to determine whether it is a malfunction in the audio device itself or in the speaker system just by looking at the phenomenon.

Therefore, conventionally, each time a failure occurs, the wiring of the speaker system must be disconnected and checked using a tester or the like, which has the drawback of requiring a great deal of effort to diagnose the failure location. Particularly in the case of in-vehicle audio devices, it takes a lot of man-hours to install and remove them, so diagnosis is time-consuming.

<Summary of the Invention> The present invention aims to improve the above-mentioned conventional drawbacks and provide a failure diagnosis device for audio equipment that can easily diagnose failure locations. a voltage source connected to the circuit and supplying a predetermined voltage to the circuit; a means connected between a predetermined circuit of the audio equipment and the voltage source and forming a voltage dividing circuit with the circuit during failure diagnosis; The basic feature is that it has means for detecting the voltage of the means forming the circuit and comparing it with a reference value, and means for making a notification corresponding to the comparison result of the comparing means.

Effect> When a failure occurs in the audio equipment, a voltage source and means for forming a voltage dividing circuit are connected to a predetermined circuit (for example, a speaker system). Then, the voltage of the means forming this voltage dividing circuit is detected. Since the voltage of the means is determined by the voltage division ratio between the means and the audio equipment, the state of the predetermined circuit can be known by comparing this voltage with a reference value using the means for comparing. The notification means executes the notification according to the comparison result.

<Example> An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a speaker circuit of an amplifier 50 and a speaker 51 is connected to the main body of the audio equipment (not shown), and in this embodiment, a fault diagnosis device is connected to this speaker circuit to determine the location of the fault. There is. This failure diagnosis device may be built into the audio equipment body or may be a separate body, and the speaker 51 may also be built into the audio equipment body or may be a separate body like a component. Good too.

A switch 52 is provided on the device main body side of the amplifier 50,
It is configured so that it can be separated from the main body of the device during failure diagnosis.

A stabilized power source 1 is provided to the power source of the main body of the device and can be connected to and disconnected from the power source by a switch 10. One output side of this stabilized power supply 1 is connected to the + side of a speaker 51 via a resistor 2, and the other output side is connected to one side of the speaker 51 via a transistor 11 and a resistor 3. The resistor 2 and the resistor 3 form a voltage dividing circuit with the speaker 51, and in this embodiment, the resistance value is R1=R2=R (DC impedance of the speaker 51).
It is set to .

A comparator 4 is connected to the point A to compare the partial voltage value of the resistor 2 with a reference value. In this embodiment, a window comparator is used as the comparator 4, and is configured to set an upper limit value and a lower limit value, and to judge whether or not there is a voltage at point A between these values.

The reference value of the comparator 4 is set by the reference voltage 6,
The reference voltage 6 is obtained by dividing the voltage of the stabilized power supply 1 using a resistor of a predetermined value, and has an upper limit value and a lower limit value set at the B point and the 0 point.

The reference values of the upper and lower limits of the comparator 4 are set as follows.

(However, EO is the voltage of the stabilized power supply 1.) The output side of the comparator 4 is connected to the power supply element B via a diode 40, and an indicator 5 such as an LED is connected to this power supply element B via an inverter 41. The configuration is such that the comparison result of the comparator 4 is announced.

In this embodiment, a display device such as an LED is used as the display device 5, but it may also be a voice output device such as a voice synthesis device.

Next, the operation will be explained.

When a failure occurs in the audio equipment and audio output is lost, it is diagnosed whether the failure is related to the audio equipment itself or the speaker 51. First, the switch 52 is turned off, the speaker 51 is disconnected from the main body of the audio equipment, and the switch 10 is turned on to start the diagnostic device.

When the switch 10 is turned on, the stabilized power supply 1 is activated, and at the same time, a base voltage is applied to the transistor 11 to turn it on, forming a circuit of the stabilized power supply 1, the resistor 2, the speaker 51, the resistor 3, and the transistor 11.

When this circuit is formed, the voltage at point A is the speaker 51
Depending on the state of the failure, the following will occur:

A. When the speaker 51 is normal, R1+82+R3 B. When the speaker 51 is defective due to a short circuit, and the + side of the speaker 51 falls to the ground: R1+0 O. When one side of the speaker 51 falls to the ground: Therefore,
If the upper and lower limits of the comparator 4 are set as described above, the output of the comparator 4 becomes Hi only when the speaker 51 is normal. In this embodiment, the state of the output side of the comparator 4 is inverted by an inverter 41 in order to light up the display 5 during the above-mentioned conditions A to E.

From the above, when the indicator 5 lights up, it is clear that the speaker 51 is malfunctioning. Further, when there is a failure in the audio equipment main body and the display 5 does not light up, the speaker 51 is normal, so it can be diagnosed that there is a failure in the audio equipment main body.

In the above embodiment, the comparator 4 only determines whether or not the speaker 51 has a failure, but since the voltage at point A indicates the failure state of the speaker 51, the configuration of the comparator 4 By changing the value, it becomes possible to determine the failure state of the speaker 51.

An example of this is shown in FIG. This embodiment is the same as the embodiment shown in FIG. 1 except for the configuration of the comparator 4.

The comparators that take the voltage at point A as one input are comparators 4a,
There are three reference voltages 6a and 6b, respectively.
, 6bl, 6b2.6c are set as follows.

Reference voltage 6a: 0.9EOV 1.3 Reference voltage 6 b 1 knee EO 0,9 Reference voltage 6b2 knee EO Reference voltage 6c: 00IEO By setting the reference voltage 6 as above, the display 5
The lighting states of a, b, and c are as follows.

Speaker 51197 line: Display 5a lights up Speaker 5
1 short or the speaker 51 is grounded on one side: The display 5b is lit.The speaker 51 is grounded on the + side: The display 5c is lit.The failure state of the speaker 51 can be diagnosed.

Next, FIG. 3 shows an embodiment using a microcomputer (hereinafter referred to as CPU 7).

In this embodiment, a CPU 7 is used in place of the comparator 4, and a display device 8 that can display various conditions is used instead of a lamp. The CPU 7 inputs the voltage at point A, as well as the voltages at points D and E, as in the above embodiment, and can determine whether the switches 52 and 10 are on or off. In addition, by controlling the base voltage of the transistor 11, the transistor 11 is turned on and off.
It is configured so that it can be turned off.

The CPU 7 detects that the switch 52 is turned off and the point D is Ov, and that the switch 10 is turned on and the point E is more than Ov, and turns on the transistor 11 to turn on the stabilized power supply 1. A circuit including the resistor 2, the speaker 51, the resistor 3, and the transistor 11 is formed, and a failure diagnosis is performed. CPU
7 inputs the voltage at point A, and makes the above-mentioned judgments based on the voltage value.

This operation will be explained with reference to FIG.

The CPU 7 first checks whether the D point is Ov (step 60), and then checks whether the E point is Ov (step 61).
When it is not V, it is determined that the switch 52 is off and the switch 10 is on, and the transistor 11 is turned on to start the fault diagnosis operation. CPU7 inputs the voltage at point A.

Check the voltage at point A using as the check point (
Steps 62, 63, 64) Then, in response to this check, the state of the speaker 51 is diagnosed, and the result is output to the display 8 for display and notification (steps 65, 66, 67, 68). ).

Note that when checking the voltage at point A mentioned above, there is actually a range in the voltage at point A, so set a certain upper and lower limit value and judge whether or not the voltage at point A is between them. become. Further, the on/off of the transistor 11 may be controlled by the on/off of the switch 1o without depending on the CPU 7.

Furthermore, the on/off of the stabilized power supply 1 may be directly controlled from the CPU 7 without providing the switch 10.

The failure diagnosis device for audio equipment having the configuration described above can determine whether or not there is a failure in a predetermined circuit of the audio equipment, and in the embodiments shown in FIGS. 2 and 3, the state of the failure. , it becomes possible to perform repairs and replacements easily and quickly.

Particularly in the case of in-vehicle audio equipment, failures can be diagnosed without the need to remove or install the audio equipment, thereby greatly reducing the effort required for repair or replacement.

- <Effects of the Invention> As explained above, the failure diagnosis device for audio equipment of the present invention has a voltage source that is connected to a predetermined circuit of the audio equipment and supplies a predetermined voltage to the circuit during failure diagnosis, and a means connected between a predetermined circuit of the device and the voltage source to form a voltage divider circuit with the circuit; means for detecting the voltage of the means forming the voltage divider circuit and comparing it with a reference value; It is possible to immediately diagnose whether the malfunction of the audio equipment is in a predetermined circuit or elsewhere, and for the purpose of diagnosis. There is no need to disconnect wiring or remove the main body of the device, which has the effect of simplifying work such as troubleshooting.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of the present invention, Fig. 2 is a block diagram showing another embodiment, Fig. 3 is a block diagram showing still another embodiment, and Fig. 4 explains its operation. FIG. 1: Stabilized power supply, 2: Resistor, 3: Resistor, 4: Comparator, 5
: Display, 6: Reference voltage, 7: CPU, 8: Display, 10: Switch, 11: Transistor, 4o: Diode, 41: Inverter, 5o: Amplifier, 51: Speaker, 52: Switch. Patent Applicant Clarion Co., Ltd. Agent Patent Attorney Kiyoshi Takahashi and 1 other person Figure 1 Figure 2

Claims (1)

[Scope of Claims] A voltage source that is connected to a predetermined circuit of the audio equipment and supplies a predetermined voltage to the circuit when diagnosing a fault; and a voltage source that is connected between the predetermined circuit of the audio equipment and the voltage source during the fault diagnosis. means for forming a voltage dividing circuit with the circuit; means for detecting the voltage of the means for forming the voltage dividing circuit and comparing it with a reference value; and means for making a notification corresponding to the comparison result of the comparing means. A failure diagnosis device for audio equipment characterized by the following.