CN2899358Y

CN2899358Y - High-frequency loundspeaker protector

Info

Publication number: CN2899358Y
Application number: CN 200620058056
Authority: CN
Inventors: 黄钦荣
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-04-20
Filing date: 2006-04-20
Publication date: 2007-05-09
Anticipated expiration: 2016-04-20

Abstract

The utility model discloses a high frequency loudspeaker protector. Wherein, a thyristor is of a parallel connection to a filter capacitor at the input terminal of high audio frequency, and serial-connected divider resistances are connected to the thyristor in parallel, meanwhile a current-limiting resistance is connected between the junction of the serial-connected divider resistances and the controlling terminal of the thyristor. A protecting circuit adopts thyristor as switching element and is of quick response, and can retain a high-resistance state, so the power and audio quality to the loudspeaker can not be influenced. The basic cross frequency of the frequency divider and the sensitivity can not affected, the frequency divider can still adjust the cross frequency and the sensitivity to adapt to the requirements of different high frequency loudspeakers, and the protecting circuit can still provide a best protection. Furthermore, the protecting circuit is of high antivibration and overloading capacities, good applicability, and can restrain the rising of overloading peak voltage and counter-electromotive of the power amplifier, loudspeaker, and frequency-dividing inductance to make the whole acoustics system work more safely and reliably.

Description

The loudspeaker protector

Technical field

The utility model relates to a kind of overload protecting circuit.Especially a kind of overload protecting circuit that is applicable to sound equipment alt loudspeaker.

Background technology

In sound system, loudspeaker are audio outlet terminals, and higher if tonequality is pursued, its cost is also higher relatively.In use, if the power output of power amplifier is excessive, produce under the situations such as self-excitation amplification or human operational error owing to positive feedback as high, middle pitch, loudspeaker need bear higher driving voltage and bigger drive current, when power output surpasses the peak power of loudspeaker, loudspeaker will be burnt, and cause very big loss.Therefore corresponding protection circuit need be set to prevent burning of loudspeaker, present this protective circuit has following several form: 1, adopt temperature-sensitive, piezo-resistance; 2, adopt the protection bulb; 3, the protective circuit of relay system.The protection action of above circuit is all slower; especially temperature-sensitive, piezo-resistance start and recovery process all needs several seconds to tens seconds, can not play effective protective effect; and must reduce its input power below half, device just can recover normal operating conditions.

Summary of the invention

The purpose of this utility model is to provide a kind of response time soon, not influence replaying effect, loudspeaker protector simple in structure and with low cost.

The utility model is to realize above-mentioned purpose like this:

The loudspeaker protector is characterized in that comprising and high pitch audio input end filter capacitor controllable silicon in parallel that controllable silicon is parallel with the divider resistance that is in series, and also has current-limiting resistance to be connected between the junction and silicon controlled control end of series connection divider resistance.

The beneficial effects of the utility model are: protective circuit adopts controllable silicon as switch element, and the response time is fast, under normal circumstances keeps high-impedance state, does not influence the power and the tonequality that output to loudspeaker; This circuit generally is linked in the high pitch frequency divider, basic part-frequency point and not influence of design sensitivity to frequency divider, frequency divider still can be as required carries out stepless adjustment adapting to the demand of different loudspeakers to part-frequency point and sensitivity, and protective circuit still reaches the best protection effect; The antivibration and the overload capacity of circuit is strong, accommodation is wide; Can suppress power amplifier, loudspeaker, the overload crest voltage of frequency division inductance and raising up of back electromotive force, reduced the instructions for use of frequency division element and printed circuit board (PCB), feed back to power amplification back electromotive force wherein simultaneously and also obtain restriction, make whole sound system work more safe and reliable.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified:

Fig. 1 is circuit theory diagrams of the present utility model.

Embodiment

With reference to Fig. 1; the loudspeaker protector; comprise the controllable silicon Q1 in parallel with high pitch audio input end filter capacitor C1, controllable silicon Q1 is parallel with divider resistance R3, the R4 that is in series, and also has current-limiting resistance R6 to be connected between the control end of the junction of series connection divider resistance R3, R4 and controllable silicon Q1.Because audio signal is an alternate electrical signal, so controllable silicon Q1 adopts bidirectional triode thyristor.Resistance R 3, R4 form bleeder circuit, calculate the conducting voltage of setting controllable silicon Q1 as required, and just the protection voltage of protector is lower than this protection voltage, and protector is failure to actuate, and prevent to be burnt otherwise start protection loudspeaker SP.Current-limiting resistance R6 is used to limit the electric current of controllable silicon Q1 control end, prevents that the excessive back of electric current from being burnt.When the control end voltage of controllable silicon Q1 is lower than trigger voltage, controllable silicon Q1 is the high resistant cut-off state, and the high pitch audio power directly is loaded on the loudspeaker SP, and protective circuit is to power output and not influence of tonequality.Overtension when the high pitch audio frequency; when the control end voltage of controllable silicon Q1 surpasses trigger voltage; controllable silicon Q1 conducting; audio signal forms the loop through controllable silicon Q1 and consumes; the voltage that is loaded on the loudspeaker SP obtains cutting down; prevented loudspeaker SP because overvoltage is burnt, because response time of controllable silicon Q1 generally can reach the microsecond level, so the reaction of protective circuit is very rapid, reliable.

Consider rising with temperature; certain drift can take place in the parameter of electronic component; the parameter that mainly is controllable silicon Q1 changes; next is that divider resistance value R3, R4 change; thereby cause protecting the drift of voltage; therefore divider resistance R3 is parallel with thermo-compensator R5, realizes the compensation of balance adjustment protection voltage, reduces drift value.Guarantee under the situation that operational environment changes, to reduce the error of protection voltage.

In addition, after controllable silicon Q1 conducting, audio signal be equivalent to directly from an input behind frequency divider filter capacitor C1, controllable silicon Q1 directly and another input join, most of power output of audio signal will be loaded on the filter capacitor C1, may cause burning or the damage of power amplifier of filter capacitor C1 like this.Therefore be connected with the filter capacitor C1 of high pitch audio input end after controllable silicon Q1 is in series with load resistance R1, the R2 that is in parallel, even like this after the controllable silicon Q1 conducting, audio signal need be passed through filtering capacitor C 1, load resistance R1, R2 and controllable silicon Q1, most power output will be loaded on load resistance R1, the R2, as long as suitably set rated power and the resistance of load resistance R1, R2 as required, be unlikely to have influence on the operate as normal of filter capacitor C1 and power amplifier.

Claims

1. loudspeaker protector; it is characterized in that comprising the controllable silicon (Q1) in parallel with the filter capacitor (C1) of high pitch audio input end; controllable silicon (Q1) is parallel with the divider resistance (R3, R4) that is in series, and also has current-limiting resistance (R6) to be connected between the control end of the junction of series connection divider resistance (R3, R4) and controllable silicon (Q1).

2. loudspeaker protector according to claim 1 is characterized in that controllable silicon (Q1) is a bidirectional triode thyristor.

3. loudspeaker protector according to claim 1 and 2 is characterized in that divider resistance (R3) is parallel with thermo-compensator (R5).

4. loudspeaker protector according to claim 1 and 2 is characterized in that controllable silicon (Q1) is in series with load resistance (R1, the R2) back that is in parallel and is connected with the filter capacitor (C1) of high pitch audio input end.