JPH1197956A - On-vehicle sound device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the on-vehicle sound device which prevents a decrease in sound output when a power amplifier is in a high-power state. SOLUTION: The on-vehicle sound device consists of a battery 3 mounted on a vehicle 2 and a vehicle-side connector 12 connected to the battery 3. The vehicle-side connector 12 is connected to a battery power source system 3a and an ACC power source system 3b together with various connection cables. A power supply path 100 for supplying electric power to the power amplifier 8 extends from the battery power source system 3a of a car-stereo side connector 13 and a wiring pattern part 20 extends from the ACC power source system 3b; and a diode 101 which supplies deficient electric power at the time of the maximum output of the power amplifier 8 is connected between the terminals of the wiring pattern part 20 and power supply path 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle audio device such as a car stereo, for example, and more particularly, to a reduction in the audio output of a power amplifier due to a voltage drop in a power supply path connected to the power amplifier. The present invention relates to an in-vehicle acoustic device to be prevented.

[0002]

2. Description of the Related Art In recent years, with the development of electronic technology and the increasing needs of users, multi-functional and high-performance audio devices for vehicles have been developed. As an example of these on-vehicle audio devices, the use of car stereos is remarkable, and FM tuners and compact discs (CDs) are incorporated in car stereos.
The style of enjoying music and listening to traffic information has become established.

[0003] Power is supplied to the car stereo from a rechargeable battery (battery) provided in the vehicle. That is,
The power supply to the car stereo is supplied from the battery power supply system directly connected to the battery for the power supply path to which the audio amplifier (power amplifier) is connected, and the power supply to the control system such as the microcomputer is ignition. The operation is performed by an ACC (accessory) power supply system that is linked to the ON operation of the switch.

[0004] The DC voltage of the battery is about 14 V, but a current exceeding 10 A may flow through the power supply path at the maximum output of the power amplifier. Therefore, the effect of the voltage drop in the power supply path is large, and even if the resistance is very small, the sound output of the power amplifier is directly reduced. As a countermeasure, it is important to reduce the resistance value of the power supply path as much as possible. However, there is a limit to this, and as a result, the audio output of the power amplifier is inevitably reduced to some extent.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of such a viewpoint, and an object of the present invention is to provide a conventional on-vehicle acoustic device with the effect of a voltage drop in a power supply path connected to a rechargeable battery. An object of the present invention is to provide an on-vehicle acoustic device capable of resolving a problem that a sound output of a power amplifier is easily reduced and obtaining a stable and high power amplifier output.

[0006]

In order to solve the above-mentioned problems of the present invention, the following means have been taken. That is, as a basic configuration of the on-vehicle acoustic device of the present invention, a power supply path directly connected to a rechargeable battery disposed in a vehicle (a power supply line of a sound amplifying means system that uses a large amount of current is defined as a power supply path for convenience). Control) in conjunction with the on operation of the sound amplifying means (power amplifier) connected to the power supply path, the sound output means (speaker) connected to the sound amplifying means, and the starting means arranged in the vehicle. An accessory power supply path for supplying power to the system, comprising: a diode for supplying power from the accessory power supply path to the power supply path when the audio amplifying means outputs excessive power. It is characterized in that it is arranged so that the direction toward the power supply path is the forward direction.

In the vehicle-mounted acoustic device of the present invention, in order to avoid the effect of a voltage drop in the power supply path for supplying power to the audio amplification means (power amplifier), the power is supplied from the accessory power supply path to the power supply path via the diode. To supply. As a result, power can be supplied from the accessory power supply path to the power supply path via the diode in a situation where the audio output of the power amplifier has momentarily increased, and a decrease in the audio output of the power amplifier can be prevented.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, the configuration of a vehicle-mounted acoustic device according to the present invention will be described with reference to FIG. FIG. 1 is a block circuit diagram showing an example of an on-vehicle acoustic device of the present invention. In the embodiment of the present invention, a car stereo will be described as an example of an on-vehicle acoustic device, and the description will be given.

A car stereo 1 according to the present invention as shown in FIG. 1 is supplied with power from a battery 3 of a vehicle 2. That is, the power supply from the battery 3 to the car stereo 1 is basically supplied from the battery power supply system 3 a directly connected to the battery 3. On the other hand, power supply to a control system such as a microcomputer is provided from an ACC (accessory) power supply system 3b via an ignition switch 4. Then, the clock display and the like of the car stereo 1 are started in conjunction with the ON operation of the ignition switch 4, and the respective parts of the car stereo 1 are supplied with power controlled on / off by the microcomputer.

The detailed structure of the car stereo 1 includes a tuner (TUNER), a compact disc (CD), a mini disc (MD: trade name), and a tape recorder (TAPE).
And the like, a selector 6, an electronic volume 7, a power amplifier 8, a speaker 9, a microcomputer 10, an operation unit 11, and the like. Note that a compact disk (CD) or a mini disk (MD) may be input to the selector 6 from an external input (not shown).
In addition, the circuit configuration of the car stereo 1 is not limited to the above-described configuration, and other configurations having the same function may be used.

The operation of the on-vehicle acoustic device of the present invention having such a configuration will be described.

Audio signals output from various audio devices 5 such as a tuner (TUNER) and a compact disk (CD) are input to a selector 6. The selector 6 selects a desired audio device 5 selected by the user and outputs it to the electronic volume 7. The electronic volume 7 is a microcomputer 10
The desired volume level set by the user is set by the control of (1), and is output to the power amplifier 8 of the next stage. The power amplifier 8 amplifies music or the like set to a desired volume level and emits the sound from a speaker 9.

Selection of selector 6 and electronic volume 7
The volume adjustment is set by a volume adjustment button and a selection button (both not shown) provided on the operation unit 11.
That is, as a general usage of the car stereo 1, after starting the engine of the vehicle 2, a compact disc (CD) is inserted, or a desired program is selected by operating a selection button of the operation unit 11. The power of the selected music or the like is amplified by the power amplifier 8 and is emitted from the speaker 9.

The volume of music or the like emitted from the speaker 9 is adjusted by the electronic volume 7. That is, when the volume control button of the operation unit 11 is operated by the user, the microcomputer 10 determines the set level and drives the electronic volume 7 to control the volume of the car stereo 1. Note that the car stereo 1 of the present invention includes four speakers, a front speaker attached to the front of the vehicle 2 and a rear speaker attached to the rear.
Displayed in monaural for simplicity.

Next, the configuration of the power supply path in the vehicle-mounted acoustic device of the present invention will be described in detail with reference to FIG. FIG. 2 is a schematic diagram showing a configuration of a power supply path in the vehicle-mounted acoustic device of the present invention.

The on-vehicle acoustic device of the present invention comprises a battery 3 provided in a vehicle 2 and a vehicle-side connector 12 connected to the battery 3. A battery power supply system 3a and an ACC power supply system 3b are connected to the vehicle-side connector 12 together with various connection cables. The car stereo 1 is provided with a car stereo connector 13 connected to the vehicle connector 12, and receives power from the battery 3 via the car stereo connector 13.

A power supply path 100 extends from the battery power supply system 3a of the car stereo side connector 13. The power supply path 100 includes a wiring pattern section 14, a fuse 1
5, a wiring pattern section 16, a choke coil 17 and a capacitor 18 forming a low-pass filter for removing power supply noise, a wiring pattern section 19, a power amplifier 8, and a speaker 9 connected to the power amplifier 8. ing.

Further, a terminal A is provided in the wiring pattern portion 14 on the power supply path 100, and a terminal B is provided in the wiring pattern portion 16 between the fuse 15 and the choke coil 17.
Is provided, and the choke coil 17 of the wiring pattern portion 16 is provided.
A terminal C is provided between the capacitor 18 and the capacitor 18, and a terminal D is provided between the capacitor 18 and the power amplifier 8.

On the other hand, AC of the car stereo side connector 13
The anode (A) of the diode 101 is connected to the wiring pattern section 20 extending from the C power supply system 3b as a characteristic feature of the present invention. The connection position of the cathode (K) of the diode 101 can be freely selected from the terminals A, B, C, and D of the power supply path 100.

The portions of the power supply path 100 having a high resistance value as shown in FIG. 2 are the wiring pattern portions 14, 16, 19,
These include the fuse 15 and the choke coil 17.
As an example, it is assumed that the total resistance value of the power supply path 100 from the vehicle-side connector 12 to the power amplifier 8 is 100 mΩ. Assuming that the four speakers (not shown) provided in the car stereo 1 of the present invention output 40 W each, the output of the four speakers instantaneously becomes 160 W, A current of about 13 A flows. Therefore, the power supply path 100 has 1.3
A voltage drop of V will occur. The output drop per speaker due to this voltage drop reaches 10 W.

On the other hand, the battery 3 of the vehicle 2 has an ACC power supply system 3b interlocked with the ON operation of the ignition switch 4.
Are wired. The voltage of the ACC power supply system 3b is substantially equal to the battery voltage. The ACC power supply system 3b supplies power to a control system such as the microcomputer 10, and the current used in the car stereo 1 is extremely small and there is almost no voltage drop in the ACC power supply system 3b.

Therefore, in the car stereo 1 of the present invention, A
Power is supplied from the CC power supply system 3b to the power supply path 100 via the diode 101. That is, the diode 1
When 01 is a silicon diode, the potential difference is 0.6 V
With the potential difference of 0.6 V, the power supply path 100
To supply power. That is, when the audio output of the power amplifier 8 instantaneously increases and the voltage drop at the connection point of the diode 101 becomes 0.6 V or more, the diode 1
01 supplies power to the power supply path 100 by energizing. As a result, a voltage drop of 0.6 V or more in the power supply path 100 can be prevented, and a decrease in the audio output of the power amplifier 8 can be prevented.

The power supply path 100 from the ACC power supply system 3b
When the power is supplied to the power supply, the current including the influence of the power supply noise by the ACC power supply system 3b is supplied, but the diode 101 is energized only at the time of a large output in which a potential difference of 0.6 V or more occurs. Therefore, the influence of the power supply noise is not disturbing. That is, the diode 101 does not conduct at the time of a small signal in which the influence of the power supply noise is unpleasant. Therefore, the apparent configuration is the same as that of the conventional car stereo 1, and the diode 101 does not affect other circuits. .

Diode 101 on power supply path 100
Can be arbitrarily selected from the terminals A, B, C, and D described above. Diode 10
The connection point 1 can easily obtain a high sound output near the power amplifier 8 (terminal D).
Since it does not pass through a low-pass filter formed by the capacitor 7 and the capacitor 18 for removing power supply noise, power supply noise (noise) is likely to occur. If the diode 101 is connected to the terminal B, the signal passes through the low-pass filter, but the power amplifier 8 is hardly operated. The actual setting can be freely performed by manual switching or by automatic switching by the microcomputer 10 described above.

According to the car stereo of the present invention, the following specific effects can be obtained. 1. Only adding one diode to the power supply line of the car stereo can prevent the audio output of the power amplifier from lowering. 2. The current passing through the diode may include power supply noise without passing through the low-pass filter for removing power supply noise.However, the diode passes only at high output, and the effect of power supply noise is disturbing. Never. In the case of a small signal where the effect of power supply noise is unpleasant, there is no potential difference that the diode conducts.Therefore, a low-pass filter for removing sufficient power supply noise works, and a sound output similar to that of a conventional car stereo is obtained. Will be able to 3. The connection position of the diode to the power supply path can be arbitrarily adjusted, whereby the operating point of the low-pass filter for removing power supply noise can be freely changed.

Although the preferred embodiments of the present invention have been described in detail, various other embodiments of the present invention are possible in addition to these embodiments. For example, the fuse 15 and the choke coil 17 in the power supply path of the on-vehicle acoustic device of the present invention may be arranged at the center of the cord of the battery power supply system 3a, and are not limited to the illustrated configuration. In addition, it goes without saying that the present invention can be developed in various forms without being limited to the embodiment described above.

[0028]

As described above, according to the on-vehicle acoustic device of the present invention, in order to avoid the effect of the voltage drop in the power supply path for supplying power to the power amplifier of the on-vehicle acoustic device, the accessory power supply path is used. Since power is supplied to the power supply path via the diode, it is possible to prevent a voltage drop in the power supply path, such as when the audio output of the power amplifier increases instantaneously, and prevent a drop in the audio output of the power amplifier. It has the effect of doing.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing an example of an on-vehicle acoustic device of the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of a power supply path in the vehicle-mounted acoustic device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Car stereo, 2 ... Vehicle, 3 ... Battery, 4 ... Ignition switch, 5 ... Acoustic equipment, 6 ... Selector, 7
... Electronic volume, 8 ... Power amplifier, 9 ... Speaker,
DESCRIPTION OF SYMBOLS 10 ... microcomputer, 11 ... operation part, 12 ... vehicle side connector, 13 ... car stereo side connector, 14, 16, 1
9, 20: wiring pattern portion, 15: fuse, 17: choke coil, 18: capacitor, 100: power supply path, 101: diode

Claims (2)

[Claims] 1. An electric power supply path directly connected to a rechargeable battery arranged in a vehicle; an audio amplifier connected to the electric power supply path; an audio output means connected to the audio amplifier; And an accessory power supply path for supplying power to a control system in conjunction with the ON operation of the starting means. An on-vehicle acoustic device, comprising: a diode that supplies power to a power supply path such that a direction from the accessory power supply path toward the power supply path is a forward direction. 2. The power supply path includes a wiring pattern extending from the rechargeable battery, a power cutoff unit, a coil and a capacitor forming a low-pass filter, and the power supply path. The connection point on the power supply path is between the wiring pattern, the power cutoff means and the coil,
The on-vehicle acoustic device according to claim 1, wherein at least one of a portion between the coil and the capacitor and a portion behind the capacitor can be selected.