Sound power amplifier protection system

Abstract

The utility model relates to the technical field of sound equipment, and provides a sound equipment power amplifier protection system, in a power amplifier protection circuit, a first end of a resistor R31 is connected with a left channel output end I of a power amplifier circuit, a second end of the resistor R31 is connected with a loudspeaker I through a first normally closed output of a relay K1, and a second end of the resistor R31 is connected with an input end of an optocoupler U6 through a resistor R33; the first output end of the optocoupler U6 is connected with the emitting electrode of the triode Q1, the second output end of the optocoupler U6 is connected with the first input end of the relay K1, the first end of the resistor R32 is connected with the first right channel output end of the power amplifier circuit, the second end of the resistor R32 is connected with the second loudspeaker by being connected with the second normally-closed output end of the relay K1, and the first end of the resistor R32 is connected with the input end of the optocoupler U7 through the resistor R34. The first output end of the optocoupler U7 is connected with the emitting electrode of the triode Q1, and the second output end is connected with the input end of the relay K1. According to the technical scheme, damage to the loudspeaker caused by abnormity of the power amplifier circuit is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of sound equipment, specifically, relates to a sound equipment power amplifier protection system. BACKGROUND

[0002] The sound equipment is mainly composed of a sound source, a single-chip microcomputer, a power amplifier and a sound box. These devices are often quite expensive, so the excellent protection circuit of the sound equipment cannot be ignored when designing high-quality sound equipment. The sound equipment power amplifier system is an important part of modern audio equipment, which is responsible for amplifying the weak signal in the sound source input circuit to a sufficient level to drive the loudspeaker to produce sound. However, during the power amplification process, due to various factors such as power supply voltage fluctuation, load change, component aging, etc., the power amplifier circuit may produce abnormal output such as overload, short circuit, etc. These abnormal outputs not only reduce the sound quality, but also may cause damage to the loudspeaker and other components. SUMMARY

[0003] The utility model provides a sound equipment power amplifier protection system, solve the technical problem that the power amplifier circuit damages the sound equipment in prior art when abnormal output.

[0004] The technical scheme of the utility model is as follows:

[0005] A sound equipment power amplifier protection system, comprising a power supply circuit and control circuit, power amplifier circuit, power amplifier protection circuit and loudspeaker connected in turn, the control circuit is connected with sound source input circuit still, the power supply circuit is the whole system power supply, the power amplifier protection circuit includes resistance R31, resistance R32, resistance R33, resistance R34, resistance R35, triode Q1, photoelectric coupler U6, photoelectric coupler U7 and relay K1, the base of triode Q1 is connected control circuit through resistance R35, the collector connects power supply, the first end of resistance R31 is connected left channel output end one of power amplifier circuit, the second end is connected the first common end of relay K1, the first normally closed end of relay K1 is connected loudspeaker one, the second end of resistance R31 is still connected the input end of photoelectric coupler U6 through resistance R33, the first output end of photoelectric coupler U6 is connected the emitter of triode Q1, the second output end is connected the first input end of relay K1, the first end of resistance R32 is connected right channel output end one of power amplifier circuit, the second end is connected the second common end of relay K1, the second normally closed end of relay K1 is connected loudspeaker two, the first end of resistance R32 is still connected the input end of photoelectric coupler U7 through resistance R34, the first output end of photoelectric coupler U7 is connected the emitter of triode Q1, the second output end is connected the first input end of relay K1, the second input end of relay K2 is grounded.

[0006] Further, the power amplifier protection circuit further comprises a diode D4, a cathode of the diode D4 is connected to a first input end of the relay K1, and an anode of the diode D4 is connected to a second input end of the relay K1.

[0007] Further, the power amplifier circuit comprises a power amplifier chip U4, an inductor L18, an inductor L19, an inductor L20 and an inductor L21, a SD pin, a LINP pin and a RINP pin of the power amplifier chip U4 are connected to the control circuit, an OUTNL pin of the power amplifier chip U4 is connected to a left channel output end one of the power amplifier circuit in series with the inductor L19 and then connected to the power amplifier protection circuit, an OUTPL pin of the power amplifier chip U4 is connected to a left channel output end two of the power amplifier circuit in series with the inductor L18 and then connected to a loudspeaker, an OUTNR pin of the power amplifier chip U4 is connected to a right channel output end one of the power amplifier circuit in series with the inductor L20 and then connected to the power amplifier protection circuit, and an OUTPR pin of the power amplifier chip U4 is connected to a right channel output end two of the power amplifier circuit in series with the inductor L21 and then connected to the loudspeaker.

[0008] Further, the control circuit comprises a control chip U2, a DAC-L pin of the control chip U2 is connected to the LINP pin of the power amplifier chip U4, a DAC-R pin of the control chip U2 is connected to the RINP pin of the power amplifier chip U4, an A20 pin of the control chip U2 is connected to the SD pin of the power amplifier chip U4, and a B6 pin of the control chip U2 is connected to the resistor R35.

[0009] Further, the control circuit comprises a control chip U2, a DAC-L pin of the control chip U2 is connected to the LINP pin of the power amplifier chip U4, a DAC-R pin of the control chip U2 is connected to the RINP pin of the power amplifier chip U4, an A20 pin of the control chip U2 is connected to the SD pin of the power amplifier chip U4, and a B6 pin of the control chip U2 is connected to the resistor R35.

[0010] The working principle and beneficial effects of the utility model are as follows:

[0011] The utility model discloses a kind of protection mechanisms for power amplifier, which can avoid the damage of speaker caused by abnormal power amplifier circuit, and improve the stability and reliability of sound system.

[0012] The utility model will be further described in detail in combination with the drawings and specific embodiments. DRAWINGS

[0013] Figure 1 It is the circuit diagram of power amplifier protection circuit in the utility model;

[0014] Figure 2 It is the circuit diagram of power amplifier circuit in the utility model;

[0015] Figure 3 It is the circuit diagram of control circuit in the utility model;

[0016] Figure 4 It is the circuit diagram of optical fiber circuit in the utility model. SPECIFIC EMBODIMENT

[0017] The technical solutions in the embodiments of the utility model will be clearly and completely described in combination with the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor are involved in the scope of the utility model protection.

[0018] Embodiment 1

[0019] The embodiment proposes a kind of sound power amplifier protection system, including power supply circuit and sequentially connected control circuit, power amplifier circuit, power amplifier protection circuit and speaker, control circuit is also connected with sound source input circuit, power supply circuit is the power supply of entire system.

[0020] As Figure 1As shown, the power amplifier protection circuit includes resistors R31, R32, R33, R34, R35, a triode Q1, optocouplers U6, U7, and a relay K1. The base of the triode Q1 is connected to the control circuit through the resistor R35, the collector is connected to the power supply, the first end of the resistor R31 is connected to the left channel output end of the power amplifier circuit, the second end is connected to the first common end of the relay K1, the first normally closed end of the relay K1 is connected to a speaker, the second end of the resistor R31 is also connected to the input end of the optocoupler U6 through the resistor R33, the first output end of the optocoupler U6 is connected to the emitter of the triode Q1, and the second output end is connected to the first input end of the relay K1. The first end of the resistor R32 is connected to the right channel output end of the power amplifier circuit, the second end is connected to the second common end of the relay K1, the second normally closed end of the relay K1 is connected to a speaker, the first end of the resistor R32 is also connected to the input end of the optocoupler U7 through the resistor R34, the first output end of the optocoupler U7 is connected to the emitter of the triode Q1, and the second output end is connected to the first input end of the relay K1. The second input end of the relay K2 is grounded.

[0021] In this embodiment, an optoelectronic isolation control method is adopted. Two optocouplers are needed to sample the positive and negative half cycles, and two channels are responsible for half a cycle. As long as half a cycle signal is sampled, current sampling can be completed. The relay K1 is a double-switch relay, and the two output switches control the connection of the two speakers and the power amplifier circuit.

[0022] In normal operation, the control circuit outputs a high-level ON / OFF signal to drive the triode Q1 to conduct. When the output of the power amplifier circuit is overloaded or short-circuited, the voltage drop generated across R31 and R32 is limited by R33 and R34, and the positive half-cycle signal makes U6 conduct, and the negative half-cycle signal makes U7 conduct, driving the relay K1 to conduct, and then the normally closed end and the common end of the relay K1 are disconnected, cutting off the connection between the power amplifier circuit and the speakers.

[0023] In one embodiment, the sound source input circuit connected to the control circuit includes a storage circuit or a memory card interface circuit, which can be used through networking download or external memory card. The way of providing sound sources is not limited in this scheme.

[0024] Further, the power amplifier protection circuit further includes a diode D4, the cathode of the diode D4 is connected to the first input end of the relay K1, and the anode of the diode D4 is connected to the second input end of the relay K1.

[0025] In this embodiment, when the relay is disconnected, a reverse electromotive force will be generated in the coil. If this reverse voltage directly acts on the relay coil, it may cause damage to the electromagnet. After connecting the diode in parallel, when the relay is disconnected, the diode can dissipate this part of energy, avoiding damage to the relay coil by the reverse voltage.

[0026] As Figure 2 shown, the power amplifier circuit includes power amplifier chip U4, inductor L18, inductor L19, inductor L20, inductor L21, the SD pin, LINP pin and RINP pin of power amplifier chip U4 are connected to the control circuit, the OUTNL pin of power amplifier chip U4 is connected to the power amplifier protection circuit after being connected in series with inductor L19 and serving as the left channel output end one of the power amplifier circuit, the OUTPL pin of power amplifier chip U4 is connected to the loudspeaker after being connected in series with inductor L18 and serving as the left channel output end two of the power amplifier circuit, the OUTNR pin of power amplifier chip U4 is connected to the power amplifier protection circuit after being connected in series with inductor L20 and serving as the right channel output end one of the power amplifier circuit, and the OUTPR pin of power amplifier chip U4 is connected to the loudspeaker after being connected in series with inductor L21 and serving as the right channel output end two of the power amplifier circuit.

[0027] In the embodiment, the LINP pin and RINP pin of power amplifier chip U4 are respectively the left channel input and right channel input of the sound source, and the sound source data obtained from the control chip is processed through power amplifier chip U4 to drive the loudspeaker to play.

[0028] As Figure 3 shown, the control circuit includes control chip U2, the DAC-L pin of control chip U2 is connected to the LINP pin of power amplifier chip U4, the DAC-R pin of control chip U2 is connected to the RINP pin of power amplifier chip U4, the A20 pin of control chip U2 is connected to the SD pin of power amplifier chip U4, and the B6 pin of control chip U2 is connected to resistor R35.

[0029] Further, the system further includes an optical fiber circuit.

[0030] As Figure 4 shown, the optical fiber circuit includes optical fiber interface OPT1, resistor R37, capacitor C32, capacitor C34 and inductor L7, the input end of optical fiber interface OPT1 is connected to the A30 pin of control chip U2 through capacitor C32, the input end of optical fiber interface OPT1 is also grounded through resistor R37, the power supply end of optical fiber interface OPT1 is connected to the power supply through inductor L7, and the power supply point of optical fiber interface OPT1 is also grounded through capacitor C34. In the embodiment, the sound can be downloaded through the optical fiber circuit.

[0031] The above is only a preferred embodiment of the utility model, and is not used to limit the utility model, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An audio power amplifier protection system, characterized by, The power supply circuit, the control circuit, the power amplifier circuit, the power amplifier protection circuit and the speaker are sequentially connected, the control circuit is further connected with the sound source input circuit, the power supply circuit supplies power for the whole system, the power amplifier protection circuit comprises resistors R31, R32, R33, R34, R35, a triode Q1, optical couplings U6 and U7 and a relay K1, the base of the triode Q1 is connected with the control circuit through the resistor R35, the collector is connected with the power supply, the first end of the resistor R31 is connected with the left channel output end one of the power amplifier circuit, the second end is connected with the first common end of the relay K1, the first normally closed end of the relay K1 is connected with the speaker one, the second end of the resistor R31 is further connected with the input end of the optical coupling U6 through the resistor R33, the first output end of the optical coupling U6 is connected with the emitter of the triode Q1, the second output end is connected with the first input end of the relay K1, the first end of the resistor R32 is connected with the right channel output end one of the power amplifier circuit, the second end is connected with the second common end of the relay K1, the second normally closed end of the relay K1 is connected with the speaker two, the first end of the resistor R32 is further connected with the input end of the optical coupling U7 through the resistor R34, the first output end of the optical coupling U7 is connected with the emitter of the triode Q1, the second output end is connected with the first input end of the relay K1, the second input end of the relay K1 is grounded.

2. The audio power amplifier protection system of claim 1, wherein The power amplifier protection circuit further comprises a diode D4, the cathode of the diode D4 is connected with the first input end of the relay K1, the anode of the diode D4 is connected with the second input end of the relay K1.

3. The protection system for audio power amplifier according to claim 1, characterized in that, The power amplifier circuit comprises a power amplifier chip U4, inductors L18, L19, L20 and L21, the SD pin, the LINP pin and the RINP pin of the power amplifier chip U4 are connected with the control circuit, the OUTNL pin of the power amplifier chip U4 is connected with the power amplifier protection circuit as the left channel output end one of the power amplifier circuit after being connected in series with the inductor L19, the OUTPL pin of the power amplifier chip U4 is connected with the speaker as the left channel output end two of the power amplifier circuit after being connected in series with the inductor L18, the OUTNR pin of the power amplifier chip U4 is connected with the power amplifier protection circuit as the right channel output end one of the power amplifier circuit after being connected in series with the inductor L20, and the OUTPR pin of the power amplifier chip U4 is connected with the speaker as the right channel output end two of the power amplifier circuit after being connected in series with the inductor L21.

4. The protection system for audio power amplifier according to claim 3, characterized in that, The control circuit comprises a control chip U2, the DAC-L pin of the control chip U2 is connected with the LINP pin of the power amplifier chip U4, the DAC-R pin of the control chip U2 is connected with the RINP pin of the power amplifier chip U4, the A20 pin of the control chip U2 is connected with the SD pin of the power amplifier chip U4, and the B6 pin of the control chip U2 is connected with the resistor R35.

5. The protection system for an audio power amplifier according to claim 4, wherein Also included is an optical fiber circuit, which includes an optical fiber interface OPT1, a resistor R37, a capacitor C32, a capacitor C34 and an inductor L7. The input end of the optical fiber interface OPT1 is connected to the A30 pin of the control chip U2 through the capacitor C32. The input end of the optical fiber interface OPT1 is also grounded through the resistor R37. The power supply end of the optical fiber interface OPT1 is connected to a power supply through the inductor L7. The power supply point of the optical fiber interface OPT1 is also grounded through the capacitor C34.

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