JPH01300799A - Over-input protection device for electroacoustic transducer - Google Patents

Abstract

PURPOSE:To cut off an excessive input when its input has been applied by providing a protecting device for cutting off a circuit in accordance with the excessive input on at least one part in a part of an input terminal of a transducer. CONSTITUTION:On an input terminal 5, a terminal plate 5a of roughly a plate which has been formed by an insulating material, and at least three pieces of terminals 6 being electric conductors provided on this terminal plate 5a are provided, and between the respective terminals, an insulating state is held mutually. To the first terminal among these three pieces of terminals, one lead part 2a of a voice coil 2 is connected. To the third terminal 6c, the other lead part 2b of the voice coil 2 is connected. Also, between the second terminal 6b and the third terminal 6c, an electric conductor 7 of a copper wire, etc., is provided, and this electric conductor 7 constitutes an excessive input protecting device 8 which is heated by a current and fused when it exceeds some current value.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an excessive input protection device for an electroacoustic transducer.

(Prior Art) In a conventional electroacoustic transducer (speaker), as shown in FIG. They were directly connected via an eyelet 15 provided on the diaphragm 14 of the diaphragm 14. Therefore, there is no protection device to protect the speaker from excessive input, and it cannot cope with the increase in amplifier output in modern times and large input due to digital signals. Burnout had occurred.

For this reason, it has been proposed to provide a fuse between at least one lead wire and a relay terminal (eyelet) provided on the diaphragm (Japanese Utility Model Publication No. 141496/1983).

(Intelligence to be Solved by the Invention) In the above-described conventional excessive input protection device for an electroacoustic transducer, at least one of the lead portions of the voice coil disposed on the diaphragm is has two intermediate terminals and a fuse between these two intermediate terminals, so
There is a drawback that the fuse mounting part may be damaged by the vibration of the diaphragm or the like, causing the fuse to break, making it unclear whether the break was due to excessive input. Furthermore, with this method, there is a risk of damaging the diaphragm when replacing a new fuse.

The present invention has been made in view of the above-mentioned circumstances.The purpose of the present invention is to provide an electrical system with a simple structure that can cut off the input when excessive input is applied, and that can easily perform maintenance and management after the cut-off. It is an object of the present invention to provide an excessive input protection device for an acoustic transducer.

(Means for Solving the Problems) In order to achieve the above object, the over-input protection device for an electro-acoustic transducer of the present invention provides protection against excessive input at at least one part of the input terminals of the electro-acoustic transducer. A protection device is provided to cut off the electroacoustic conversion circuit accordingly.

(Function) With the above configuration, when an excessive input is applied to the electro-acoustic transducer, the excessive input is cut off at the input terminal position before reaching the electro-acoustic transducer. Since no voltage is applied, the electroacoustic transducer can be completely protected.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 and 2. The first part is a top view of the excessive input protection device, and the second part is an explanatory diagram of the circuit.

In FIG. 1, 1 is an electroacoustic transducer.

This electroacoustic transducer 1 is a speaker that converts a signal current into a sound wave, and applies the signal current to a voice coil 2 wound around a voice coil bobbin provided in a magnetic circuit formed by a yoke, a magnet, and a plate. The vibration of the voice coil bobbin caused by the applied signal current is converted into a sound wave by a diaphragm 3 provided on the voice coil bobbin. The diaphragm 3 is supported by a frame 4 serving as an outer frame of the electroacoustic transducer l. This frame 4
An input terminal 5 for inputting a signal current from an externally provided amplifier is provided on the top, and a connection is made to the voice coil via this input terminal 5.

The input terminal 5 includes a substantially flat terminal plate 5a made of an insulating material, and at least three conductive terminals 6 provided on the terminal plate 5a, and the terminals are insulated from each other. Keep it. As shown in FIG. 2, one lead portion 2a of the voice coil 2 is connected to the first terminal 6a of these three terminals. The other lead portion 2b of the voice coil 2 is connected to the third terminal 6c. Further, a conductor 7 such as a copper wire is provided between the second terminal 6b and the third terminal 6C, and this conductor 7 generates heat due to the current and melts when the current exceeds a certain value to protect against excessive input. It constitutes a device 8.

Due to the action of this excessive input protection device 8, the voice coil 2
This prevents thermal damage to the diaphragm and avoids mechanical damage due to excessive input. Further, since the allowable current can be accurately set depending on the thickness (cross-sectional area) of the conductor 7, the limit value can be easily and accurately determined for the input value of the electroacoustic transducer. Moreover,
Since the excessive input protection device 8 has a simple structure, it can be easily replaced even if the conductor 7 is blown out, and normal operation can be immediately restored after replacement.

Note that a fuse or the like may be used instead of the conductor 7. Further, the second terminal 6b and the third terminal 6c
If a holder is provided for attaching the conductor 7 to the holder, handling of the conductor 7 will be facilitated.

(Effects of the Invention) As explained above, the present invention provides an electroacoustic transducer that emits sound waves by applying a signal current, in which a circuit is installed in at least one part of the input terminals in response to an excessive input. A protection device is provided to cut off the input when excessive input is applied, preventing damage to the voice coil due to heat, avoiding scorching of the diaphragm and mechanical damage, and a simple structure. This has the advantage that it is easy to take measures against melting of the conductor.

[Brief explanation of the drawing]

Figures 1 and 2 show embodiments of the present invention; Figure 1 is a top view of the excessive input protection device, Figure 2 is a circuit diagram of the excessive input protection device, and Figures 3 (a) and (b). is an explanatory diagram of a conventional example. l...Electric sound 9 converter 8...Excessive input protection device

Claims (1)

[Claims] In an electroacoustic transducer that emits sound waves by applying a signal current, at least one
1. An excessive input protection device for an electroacoustic transducer, characterized in that a protection device is provided at a location to interrupt a circuit in response to excessive input.