JPS58181397A - Speaker protecting circuit - Google Patents

Abstract

PURPOSE:To protect a speaker system surely, by avoiding a current from being interrupted by suppressing an input signal when an excessive input signal is given. CONSTITUTION:An inductance to operate signal suppression, e.g., a primary winding 21 and a transformer 23 having a secondary winding 22 to control the impedance of the winding are provided between an input signal source 1 and a capacitor 10. A prescribed part of a yoke 24 is provided with a gap 27 of wide space so as to rock variable yokes 25 and 26, and the variable yokes 25 and 26 are entered in the gap 27 alternately in response to the level of the input signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speaker protection circuit, and particularly to a speaker protection circuit suitable for use in a speaker system that includes at least a tweeter speaker. Conventionally, wooha. Skoka. An example of a speaker system using multiple speakers such as theta is shown in Figure 1. In the figure, (1) is the input signal source, (2) and (3) are the coils and capacitors that constitute the woofer filter, and (4) is the woofer speaker % (5). (6) constitutes the filter for the squawker with coil percentage (7). (8) is a similar capacitor, (9) is a squawker for the squawker, and α is a filter for the tweeter. The configuration consists of a capacitor and a coil, and this is a speaker for Twee I. tangshi, 1st
The nine parts surrounded by broken lines in the figure constitute the so-called filter network of the speaker system and are fake. Figure 2 shows the characteristics of each fill I network in the iris diagram. Ia is the filter characteristic of the woofer,
Song IIlb is Skoka's fill J% characteristic, curve C is tweeter's? This is an Ilter characteristic. In such a circuit, if an incoming signal source (1), b) is supplied with an excessive input signal,
There is a risk that the high-current coil of the nine-way speaker will burn out, especially the seater section.
It is necessary to use a small number of lines, and therefore the ability to withstand extremely large incoming signals is reduced. Normally, it is relatively easy to incorporate a protection circuit against excessive input signals K into amplifiers, but in speaker system ▲ which does not have a power supply circuit, the protection circuit needs to be devised to protect against excessive input signals κ that impair speaker characteristics. It is quite difficult to take safety measures against this. An example of a conventional protective circuit is a method that uses a 9-current cutoff switch between the subica system and the subica system, and shuts off the switch when a large current flows. However, in the case of such conventional methods,
When an excessive input signal is input, the κ switch momentarily turns off and does not return automatically after that, which is an inconvenience. In view of this point, the present invention has been developed to reduce the
The current is completely reduced by suppressing the input signal! This provides a sveaker protection route that can reliably protect the sveeker system without interruption. Hereinafter, taking as an example the case in which various SM examples of the present invention are applied to the tweeter section of a speaker system, detailed explanation will be given from FIG. 3 to 9WA. O, in the same figure! Part 4c that corresponds to Figure 111 is given the symbol Tsumagoka, and the space between sov*am is omitted ●ai3FjAKThMte, input signal source (1) and: xy
-rytr) 4o, which acts as a signal suppressor between the primary winding (self) and the ζ0 primary winding (self). ＊Providing a wire with a wire ●l-order IIkIIm (self) is wrapped around a seal ■, one end of which is connected to one side of the input signal source (1), and the other end is connected to the; Connected to ytQIO Ichigo. t
As shown in the drawing, the secondary winding (self) is wound around a variable coil wire (self) that can be moved within a predetermined range, and both ends of the winding are connected to each other to form an intermediate circuit. , ζ This shows nine views from the front. In a predetermined part of the l-ji, a space O wide vh ear/@ is provided so that the variable carbon dioxide (self) and - (Fig. 1114) are slowed by swinging.The inside of the bibζO ear f@ will be described later. According to the magnitude of the input 1M, the second variable such as For (d), a single winding wire is used, regardless of its length. The variable yokes (c) and (d) are attached to each end of the wing extending from the top of the lever to the left and right in the drawing, as shown in Figure 4 when viewed from the side. The parts are pivotally mounted on bearings (to) via rotating shaft 4. Then, this rotating shaft (self) κ biasing member, for example, a spring 0 is attached, and by this spring 011,
In normal operation when the input signal is small, the lever (C) is pressed so that the variable eye (4) goes into the gas side (4) of the yoke (■). Note that (31') is a stock fixed to the fixed side, although it is not shown. Further, the lower end κ of the lever is connected to a drive device such as a JIS coil motor 0, which moves the lever intermittently using the rotary shaft 4 as a fulcrum depending on the magnitude of the input signal.
ζ0 & Iscoil motor (self) is at the lower end κ of lever (d)
It consists of a fixed coil (to) and a yoke (not shown) fixed to the fixed side. When the input signal is small, the lever (C) is biased toward the spring 0, and even though the variable length is inserted into the gap κ between 1 and 1, the input signal is When an excessive input signal exceeds a predetermined level, the rotational torque of the JIS coil motor causes it to rotate in a predetermined direction, for example clockwise in this case, and no winding is applied in place of the variable yoke (d). It works by inserting the variable yoke (d) into the gap (d) part of the yoke. Also, the secondary winding is 1 for the filter coil α polishing!
(to) is provided, and both ends of this winding (to) are connected to a rectifier circuit (to).
b) Input K is connected. This rectifier circuit (b) consists of a diode (37m) = (37b) and a Jenner diode (37e). (37d) and a diode (
37m) cathode side and diener diode (37d)
The anode side of the winding (to) is connected in common to one end of the winding (Kil).
On the other hand, the cathode side of the diode P' (37b) and the anode PII of the Zener diode P (37e) are commonly connected and connected to the other end of the winding lIl (to). In addition, the output side of the rectifier path 1 is connected to both ends of the coil 10 of the coil motor. That is, the anode sides of the diodes (37m) and (37k) are commonly connected and connected to the coil 101 side of the JIS motor (own), while the Jenner diodes (37e). (37d) Each cathode is connected to the other side of the coil. Note that the i-line (to) and Zener diode (37c), (37
In d), current does not flow to winding IIIo4 while the voltage across the primary winding, that is, coil α is small, but current only flows when the input signal becomes excessive. A preset siener voltage is used. Therefore, when the excessive input signal turns Im (to), it becomes 2.
When the next current flows, the gear coil motor is driven and the gears are controlled.

In addition, (to) is a smoothing capacitor, and a capacitor shown by a broken line between both ends of the primary winding η compensates for the drop in height due to the remaining component of the coil αp when it does not become completely zero. This capacitor @ can be installed as necessary. Next, the operation of the circuit shown in FIG. 3 will be explained. Now, during normal operation when the input signal is small, Schilleper ■ inserts the variable yoke member wrapped with the secondary winding (own) into the gap f@ of the yoke by Ssolling OXl, so the transformer (
The secondary winding of the (1) is essentially short-circuited, and the impedance seen from the primary side of the signal source (1) is approximately zero, and the tweeter subwoofer (1) seen from the input signal source (1) side is (self)'s impedance does not change. Therefore, the signal from the input signal source (1) is supplied to the speaker (self) without being affected by the primary winding man. On the other hand, when the input signal becomes excessive, the voltage induced between coil H and winding LW exceeds a predetermined voltage that is substantially determined by the Siener voltage of Siener diodes (37a) and (37d) in the rectifier circuit (B). I'm at the point where it's voluminous! A secondary current flows through the secondary current, and the signal obtained from this secondary current through a rectifying/smoothing circuit drives the JIS coil motor (self), which rotates the lever (d) clockwise. In place of Sieg (self), variable yoke 4 without any winding is inserted into Sieg ■'s chassis f (b). When this flexible f yoke (to) enters the gap (from), it becomes substantially l-order I
I! IIIi! (own) inductance increases,
The impedance seen from the primary side of Tosinsu (C) increases. Therefore, the speaker (
6) Confucian impedance will increase substantially. If the impedance on the speaker (6) side increases, the input signal (current) will be suppressed, so the speaker QIK
The speaker (6) can be protected from excessive input signals (current) by preventing excessive current from flowing. In addition, until the secondary current flows through the winding (self) of the filter coil (<11), its Lo value shows the initial setting value, but the voltage across this coil (b) becomes excessive. Winding (b) [When the secondary current starts to flow, this coil a
Since the impedance of the polishing is small, part of the current flowing through the speaker (6) will flow into the coil cA side, so this also prevents the speaker (b) from being caused by an excessive input signal. ．． Furthermore, Fig. 5 shows the case in which the variable yoke (C) part in Fig. 3 is not present, and is viewed from the side. In other words, a yoke (4) without any winding is attached to the lever (d), and the impedance of the winding (self) can be changed by inserting and removing this yoke (d). There is. In other words, when the input signal is small, no variable valve (B) is inserted in the gap part of the yoke (2), and in this case, the variable valve (B) is inserted into the gap part of the yoke (2).
Although the impedance on the primary side of the winding does not become substantially zero, the gap becomes extremely large, so L of the winding (self) becomes small, and the impedance becomes very small. On the other hand, when the input signal becomes large, the variable yoke 4, which has no winding wire, is inserted into the gap between the yoke and the inductance becomes large, and the impedance seen from the primary side becomes large. Therefore, the impedance on the speaker side as seen from the input signal source side will actually increase.
Therefore, in this case as well, it is possible to prevent excessive input signals from occurring. In this case, Volume 1 III
is set so that κ is small enough that the impedance is not a problem. FIG. 6 shows a second embodiment of the present invention. In the same figure, portions κ corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed explanation thereof will be omitted. This embodiment attempts to electrically perform the signal processing cycle shown in Figure 3. That is, according to No. 611, a tojinsu ring is provided which has a primary winding m10 which acts as an inductor which acts for signal suppression, and a secondary winding m10 which acts as an impedance control of this primary winding 1 m (b). , one end of the primary winding 11) is connected to one side of the input signal source (1), and the other end is connected to one side between the capacitors.
A transistor forming a pair at one end of the secondary winding (d),
The other end of the winding (d) is connected to each emitter of the resistor (d) through the resistor (d). Connect to each collector of Sakaki. Also, the pace of the transistor is connected to the collector between the transistors, the emitter between the transistors is connected to the collector of the transistor, the pace of the transistor is connected to the collector of the transistor, and the emitter between the transistors is connected to the collector of the transistor. It is connected to the collector of the star, and the so-called Darlington connection configuration is used between the star and the star. The base of the transistor α is connected to the collector between the transistors through the resistor 1, and the emitter between the transistors is 2.
It is connected to the other end of the next winding and also to the emitter of the tosynister 6◇. A capacitor is connected between the pace between the first transistor and the emitter of the second transistor, and a capacitor is connected between the first transistor's pace and the emitter of the second transistor. The base between the two synchronizers is provided on the secondary side of the Zener diode and the coil α, and is connected to the pace of the synchronistor (self) through the 92nd winding ring and between the Zener diodes.
Note that the intermediate tap taken out from the winding ring is connected to ground, that is, to the other side of the input signal source (1). and,
One end of the winding ring and the other side of the input signal source (1) are connected in parallel with a resistor ■, a capacitor, and a diode P@, while the other end of the winding ring and the other side of the input signal source (1) are connected in parallel. A resistor ■, a capacitor ■, and a diode are installed in parallel between the two. Furthermore, a resistor branch, a capacitor, and a resistor (2) are connected in series to both ends of the input signal source (1), and a diode and a capacitor (2) are connected in parallel to this resistor (1). The connection point between the capacitor and the resistor is connected to the collector of the transistor 1, and is also connected to the pace K of the transistor 1 through the resistor 1. Similarly, the incoming signal source (1
), a series K resistor ■, a capacitor wire, and a resistor (
C) is connected, a diode (from) and a capacitor (to) are connected across this resistor (c), and a capacitor Q
The connection point between the resistor (c) and the resistor (c) is connected to the collector between the transistors, and is also connected to the resistor's pace K via the resistor (1). Next, the circuit operation of this stripe diagram 6 will be explained. In the case of normal operation where the input signal from the input signal source (1) is small, in the positive half cycle of input No. 1, the syn resistor is turned on by the signal obtained through the circuit such as resistor No. 1 and capacitor (to). However, since the transistor turns on due to this K, both ends of the secondary winding InI (I4 are formed into a closed circuit through the transistor collector path and the resistor, while the input signal is in the negative half cycle. When K is a signal obtained through a circuit such as a resistor ring and a capacitor, the circuit between the synchronizers and the resistor is turned on, and both ends of the secondary winding are connected between the resistors and the resistor. An intermediate circuit is formed through the collector-emitter path of the register.In other words, in the case of a normal input signal, the register is always in the on state.(B), 輔, and 1 are in the ON state, so the winding - forms a closed circuit. The impedance seen from the primary side of the transformer is approximately zero, and the impedance of the speaker o4 side seen from the input signal source (1) remains unchanged.Therefore, the signal from the input signal source <<1>> is It is supplied to the speaker (self) without being affected by the primary winding Im (d).Next, an excessive input signal is supplied and the voltage generated in the winding 1Kll is applied to the siener diode and the like. When the voltage exceeds a predetermined voltage that is substantially determined, the transistor ring turns on in the positive half cycle, while transistor ■ turns on in the negative half cycle, turning the husband transistors .1 and -, 1 off. As a result, the closed circuit of the secondary winding lI!- is opened, so the inductance of the primary winding k becomes large, and the input signal source (1 Subika seen from the side (
The impedance on the (self) side will effectively increase by K.
Due to this increase in impedance on the speaker side, the input signal (current) is suppressed, and the speaker (6) receives an excessive input signal (
Electric tlt. ) will be protected. In addition, in this case, the value of the filter coil α is the initial setting value because the secondary winding 111mK secondary current does not flow under normal operating conditions where the input signal is small, and the input signal is excessive. Therefore, when the voltage across the coil α increases, a current flows through the winding Mff4 as described above.As a result, the L component of the coil a1, the impedance, decreases, and the current flowing through the speaker (6) decreases. flows through this coil α in a shunted manner, and this κ also protects the speaker (b) from an excessive input signal (current).

In addition, in this circuit, if the switching circuits such as transistors, etc. are suddenly turned on and off, the secondary current flowing through the secondary winding @KJ of the transistor will also change rapidly, which may cause a back electromotive force on the primary side. However, in order to make this as small as possible, the switch circuit should have an appropriate time constant and the rate of change of the secondary current should be made small. For example, if you choose a large value for the capacitor, @, and resistor 1, you can reduce the clustering rate, but if you increase the value of resistor 1, a large resistor will be inserted on the secondary side of the transformer 1. This goes against the purpose of short circuiting. Therefore, the resistor-
Make it as small as possible and set it so that it has an appropriate time constant in the friend state. FIG. 7 shows a third embodiment of the present invention, and in the embodiment of FIG. 6 described above, the transistor. (The power supply for the switch paths such as 14 etc. can be obtained from the input signal 9, but in this embodiment, a separate power supply is provided. In other words, DC power supplies t◆ and (to) are provided, and the DC power supply When the positive side of G◆ is connected to the collector between the two resistors through the resistor (C), it is connected to one end of the K resistor, and the negative side is connected to the other side of the input signal source (1). The positive side of the power supply (c) is connected to the other side of the input signal source (1), and the negative side is connected to the collector of the transistor via resistor n and to one end of resistor 1.Other configurations are as follows. This is the same as in Figure 6. In the case of this short circuit, when the input signal is a normal one, the DC power supply switch ◆K, the cytosynister, and one are turned on and the secondary winding (6) is turned on. Turn on the synchronizer and 1 from the current power supply (c) K to make the winding (6) an intermediate circuit, and if there is an excessive input signal, turn on the transistor and Iυ to connect the transistor and the transistor. . In Fig. 7, the coil α and K also shunt the current flowing to the speaker (B) when an excessive input signal occurs, thereby providing protection from the excessive input signal (current) of the speaker (self). FIG. 8 shows a fourth embodiment of the present invention. In this figure, parts corresponding to those in FIG. The signal source that short-circuits the winding ring is removed after the transformer.In other words, in the same figure, a resistor fe and (to ) are connected to each other, and the other end of the resistor (c) is connected to the anode side of the Zener diode shaft via a capacitor, and the other end of the resistor wire is connected between the Zener diodes via a capacitor (9). The cathode side is connected to κ.Therefore, in this case, the filter coil α wheel is connected in parallel with the speaker (6) in the normal state without providing any secondary winding.Other configurations are shown in Figure 7. With this configuration, it is possible to obtain substantially the same effects as the embodiments shown in FIGS. 6 and 7 in this embodiment.In addition, in the case of this embodiment, the filter coil DIK2 There is no change in the L component because there is no flow of current, and there is an advantage that no waveform distortion occurs.Figure 9 shows a fifth embodiment of the present invention. If no overload occurs, install a secondary winding 1 corresponding to the coil α, and connect a K Zener diode ■. 1 is connected, and when the voltage induced in winding 1 when an excessive input signal exceeds a certain predetermined voltage, both ends of the Zener diode ring, 1 and 2 are short-circuited. When this winding II-1 is short-circuited and current flows, the inductance of the coil (11) decreases and the impedance decreases, and the excessive current flowing to the speaker (6) is diverted through this coil α. This prevents problems such as disconnection of the speaker coil (6).In this way, in this embodiment, it is possible to protect the speaker from excessive input signals (current) with an extremely simple circuit configuration. be.

As described above, according to the present invention, the inductor is arranged at a position where at least the signal supplied to the speaker can be suppressed, and the impedance of this inductor is controlled according to the signal level supplied to the speaker, thereby preventing excessive input. Since the signal is suppressed from being supplied to the speaker, the speaker system can be reliably protected from excessive input signals without completely cutting off the human power current. In addition,
In the above-mentioned embodiments, the present invention has been explained by taking as an example the case where it is applied to the tweeter section of the speaker system, but it goes without saying that it can also be applied to other parts such as the woofer section and the squabble section at the same time.

This invention can also be applied to other circuits that require such functionality.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing an example of a conventional speaker system.
2 is a diagram showing the circuit characteristics of FIG. 1, FIG. 3 is a circuit configuration diagram showing an embodiment of the present invention, FIG. 4 is a side view showing an example of the main part of FIG. 3, and FIG. This figure is a side view showing another example of the main part of FIG. 3, and FIGS. 6 to 9 are circuit diagrams showing other embodiments of the present invention. Between is a filter capacitor, α umbrella is a filter coil,
The wheels and rings are toshins, the shaft is i-ku, (from), the wheel is a variable yoke, (to) is the lever, (to) is the coil motor,
(To), 輔, @ is the secondary winding, (B) is the rectifier circuit, 1--
・--1-between-■ is Toshin Jisuji, 14. Between, ■, and one are diener diodes. -597 598

Claims (1)

[Claims] 1. an inductor arranged at a position where at least a signal to the speaker can be suppressed; a signal detection means for detecting the signal supplied to the speaker; and an impedance level control of the inductor according to the output level of the #slang detection means. A speaker protection circuit characterized in that the impedance of the inductor is changed to suppress the signal sent to the speaker when a large input signal is received.
2. Using windings connected in series with the speaker κ and equipped with a wire that forms a substantial magnetic path between the κ and the speaker κ as an inductor.
kNupika protection circuit according to claim 1. 3. The inductor control means is arranged in correspondence with the inductor, and is interlocked with a 92nd order winding, a first variable pitcher on which a #2ndary winding ring is arranged, and the first variable pitcher, and the winding A drive for selectively inserting the first and 20th variable gears in accordance with the output level K of the signal detecting means and the second variable gear which is not provided with the gears K of the yoke of the inductor. 3. A speaker protection circuit according to claim 2, comprising means. 4. The inductor control means includes a secondary winding arranged corresponding to the inductor, and a switch circuit arranged in series with the secondary winding, which opens and closes the secondary winding according to the output level of the signal detection means. A speaker protection circuit according to claim 2, comprising: 5. A speaker protection circuit according to claim 1, which uses a filter coil of a speaker system as an inductor. Claim 5: The inductor control means comprises a secondary winding arranged corresponding to the inductor, and a plurality of constant voltage elements arranged in opposite polarity between the secondary windings.
Speaker protection circuit as described in section.