JPH07336789A - Speaker protection device - Google Patents

Abstract

PURPOSE:To obtain a speaker protection device advantageous in heat generation and in cost without using an external resistor while avoiding intermittent sound. CONSTITUTION:A double voice coil 1 for a speaker is made up of two voice coils 11, 12 connected in series. The voice coils are provided with a circuit protector 2 which is open only when current prescribed or larger flows to the voice coil 11 to connect the two voice coils in series electrically while supplying current only to the other voice coil 12 in the normal state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker protection device, and more particularly to a speaker protection device for preventing interruption of audio output from a speaker when a protection function is operating.

[0002]

2. Description of the Related Art When a speaker for generating and outputting sound is used in an audio system or the like, when an attempt is made to increase the volume, a large current flows in the voice coil of the speaker. At this time, if the volume is set too high, an excessive current of a specified value or more flows into the voice coil, and the coil is burned. In order to prevent the burning of the voice coil itself due to the excessive current supply to the voice coil, a circuit protector has been conventionally used which detects that a nonstandard overcurrent flows and cuts off the current supply to the voice coil. There is.

[0003]

As described above, in the conventional speaker protection device of this type, the circuit protector prevents a large nonstandard current from flowing into the voice coil. The operation of the circuit protector is automatically restored after a certain time has passed after the start, or manually. However, after starting the protect operation, until the recovery,
Since no current is supplied to the voice coil, there is a problem that the output sound is interrupted.

In order to eliminate the interruption of the output sound,
A configuration is adopted in which a voice coil and an external resistor are connected in series, and a circuit protector is connected in parallel to the resistor. FIG. 2 shows an example of such a circuit. In FIG. 2, an external resistor 4 is connected in series to the voice coil 3 between the voice input terminals T1 and T2, and a circuit protector 5 is connected in parallel to the external resistor 4. In the normal state, the switch of the circuit protector 5 is closed and the external resistor 4 is short-circuited. When an excessive current flows and the circuit protector 5 operates, the switch is opened, the external resistor 4 is connected in series to the voice coil 3, and therefore the current supplied from the input terminals T1 and T2 decreases. In such a conventional circuit, the heat generated by the current flowing through the external resistor 4 gives a problem to other peripheral semiconductor elements and the like and a space problem.

Therefore, an object of the present invention is to provide a speaker protection device which has no interruption of sound, uses no external resistance, and is advantageous in terms of heat generation and cost.

[0006]

In order to solve the above-mentioned problems, a speaker protection device according to the present invention comprises a double voice coil for a speaker in which two voice coils are connected in series, and two double voice coils. A circuit protector, which is connected in parallel to one of the voice coils, has a switch section normally closed, and the switch section is opened when a current of a predetermined value or more flows, It is configured with.

[0007]

According to the present invention, the voice coil is opened only when a current of a predetermined value or more flows in one voice coil of the two voice coils connected in series which form the double voice coil used for the speaker. Are electrically connected in series, and in a normal state, a circuit protector for supplying an audio current to only the other voice coil is provided.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a circuit diagram of a main part showing an embodiment of a speaker protection device according to the present invention.

The present embodiment uses a double voice coil speaker in which two independent windings (voice coils) are connected in series. The double voice coil speaker is usually used, for example, to supply an L channel signal and an R channel signal of a stereo audio signal from two input terminals to generate a monaural audio signal.

In FIG. 1, voice signals are supplied from input terminals T1 and T2 at both ends of each voice coil 11 and 12 constituting the double voice coil 1. The circuit protector 2 is connected in parallel to one voice coil 11 of the two voice coils. When the input signal level is low and the circuit protector 2 is inactive, the switch is closed and the voice coil 1
1 is short-circuited and has no circuit function. on the other hand,
When an excessive current exceeding the specified value is supplied from the input terminals T1 and T2, the circuit protector 2 operates, the switch is opened, the voice coils 11 and 12 are connected in series, and the current flowing through the double voice coil 1 is increased. Can be reduced to prevent the voice coil from burning.

In the present embodiment, the conventional double voice coil is used without using a separate and independent resistor, and the contribution of the resistance component of one voice coil to the circuit is controlled by the operation of the circuit protector. It is possible to solve the problem of heat generation due to the installation of separate resistors and the problem of cost and space factor.

In the above-described embodiments, the circuit protector is assumed to be a poly switch or a contact switch having a switch section that performs a switching operation according to a current value, but it is of course possible to use any other switching element.

[0013]

As described above, according to the present invention,
The output sound is not interrupted even when the speaker protection device is in operation, and it is not necessary to use a separate external resistor, so not only the heat generated by the external resistor does not affect the surrounding semiconductor elements, but also the cost and space are reduced. But it is advantageous. Further, as in the conventional case, when the external resistance is used, the current flowing through the external resistance is simply converted into heat.
According to the present invention, since the current flowing through the voice coil 11 is converted into sound, there is also an effect that a decrease in output during operation of the speaker protection device is significantly reduced as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a main part circuit diagram showing an embodiment of a speaker protection device according to the present invention.

FIG. 2 is a circuit diagram of a conventional speaker protection device.

[Explanation of symbols]

 1 Double voice coil 2, 5 Circuit protector 3, 11, 12 Voice coil 4 External resistance

Claims (1)

[Claims] 1. A double voice coil for a speaker, in which two voice coils are connected in series, and one voice coil of the two voice coils of the double voice coil are connected in parallel. A speaker protector comprising: a circuit protector which is in a closed state and in which a switch protector is opened when a current of a predetermined value or more flows.