High-power power amplifier output short circuit and output direct current protection circuit

Abstract

The utility model discloses an output short circuit and output direct current protection circuit for a high-power power amplifier. The output short circuit and output direct current protection circuit comprises a switching module, a current detection module, a direct current detection module and a control module, the switching module is provided with an action part and a control part, the action part is connected with the pre-stage circuit through the current detection module and serves as a power amplifier output end, and the loudspeaker is connected into the action part; the current detection module is connected with the control module; the direct current detection module is connected with the power amplifier output end and the control module. The control module is connected with the control part; the control module can control the action part to cut off a loop between the loudspeaker and the output end of the power amplifier through the control part when the current detection module detects a short-circuit signal and / or the direct-current detection module detects a direct-current signal; through the structure, output short circuit protection and output direct current protection can be realized, so that the loudspeaker is protected, fire disasters are prevented, and the practicability is very good.

Description

Technical Field

[0001] The utility model relates to the field of high-power professional power amplifiers, in particular to a high-power power amplifier output short circuit and output direct current protection circuit. Background Art

[0002] Since the output power of high-power professional amplifiers is relatively large, the output terminals of the amplifiers are generally at the back, which can easily cause short circuits when connecting speaker cables. If the speaker cables are accidentally short-circuited during wiring, the power tube fuse and other components of the amplifier will be burned out. At the same time, since the output power of high-power amplifiers is large, reaching hundreds or thousands of watts, if there are individual components inside the amplifier that are defective, causing the circuit to output DC, the DC voltage will burn the speakers, and many speakers are made of wood, which can easily cause fires. Therefore, there is an urgent need for a high-power amplifier output short-circuit and output DC protection circuit. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a high-power amplifier output short circuit and output DC protection circuit.

[0004] An embodiment of the utility model adopts a technical solution to solve its technical problem: a high-power amplifier output short circuit and output DC protection circuit, including a switching module, a current detection module, a DC detection module and a control module;

[0005] The switching module has an action part and a control part. The action part is connected to the front-stage circuit via the current detection module and serves as the output end of the power amplifier. The speaker is connected to the action part.

[0006] The current detection module is connected to the control module;

[0007] The DC detection module is connected to the power amplifier output terminal and the control module respectively;

[0008] The control module is connected with the control unit;

[0009] The control module can control the action unit to cut off the loop between the speaker and the output terminal of the power amplifier through the control unit when the current detection module detects a short circuit signal and / or the DC detection module detects a DC signal.

[0010] As one of the preferred embodiments of the present utility model, the switching module is set as a relay K1, the coil of the relay K1 constitutes an action part, and the coil of the relay K1 constitutes a control part.

[0011] As one of the preferred embodiments of the utility model, the current detection module includes a resistor R22, a resistor R24, a resistor R27 and a capacitor C9, one end of the resistor R22 is respectively connected to one end of the previous stage circuit and one end of the resistor R24, the other end of the resistor R22 is respectively connected to one end of the capacitor C9, one end of the resistor R27 and the control module, and the other end of the capacitor C9 is respectively connected to the other end of the resistor R27, the other end of the resistor R24, the other end of the previous stage circuit and the action part.

[0012] As one of the preferred embodiments of the utility model, the DC detection module includes a resistor R7, a resistor R16, a capacitor C3 and a capacitor C7, one end of the resistor R7 is connected to the output end of the power amplifier, the other end of the resistor R7 is respectively connected to one end of the capacitor C3, one end of the resistor R16 and the control module, and the other end of the capacitor C3 is respectively connected to the other end of the resistor R16 and the GND end via the capacitor C7.

[0013] The beneficial effects of the utility model are as follows: a high-power power amplifier output short-circuit and output DC protection circuit, comprising a switching module, a current detection module, a DC detection module and a control module; the switching module has an action part and a control part, the action part is connected to the front-stage circuit via the current detection module and serves as the power amplifier output end, and the speaker is connected to the action part; the current detection module is connected to the control module; the DC detection module is respectively connected to the power amplifier output end and the control module; the control module is connected to the control part; the control module can control the action part to cut off the loop between the speaker and the power amplifier output end through the control part when the current detection module detects a short-circuit signal and / or the DC detection module detects a DC signal; the above structure can realize output short-circuit protection and output DC protection, thereby protecting the speaker and preventing the occurrence of fire, and has very good practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0015] Figure 1 It is a circuit schematic diagram of a high-power amplifier output short circuit and output DC protection circuit;

[0016] Figure 2 This is the circuit schematic diagram of the switching module;

[0017] Figure 3 It is the circuit schematic diagram of the current detection module;

[0018] Figure 4 It is a circuit schematic diagram of the first part of a high-power amplifier output short circuit and output DC protection circuit;

[0019] Figure 5The second part of the circuit schematic diagram of a high-power amplifier output short circuit and output DC protection circuit. DETAILED DESCRIPTION

[0020] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0021] In the description of the present utility model, the meaning of "more than" is more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0022] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0024] Reference Figures 1 to 5 , a high-power amplifier output short circuit and output DC protection circuit, comprising a switching module 10, a current detection module 20, a DC detection module 30 and a control module 40;

[0025] The switching module 10 has an action part 11 and a control part 12. The action part 11 is connected to the front-stage circuit via the current detection module 20 and serves as the output end of the power amplifier. The speaker is connected to the action part 11.

[0026] The current detection module 20 is connected to the control module 40;

[0027] The DC detection module 30 is connected to the power amplifier output terminal and the control module 40 respectively;

[0028] The control module 40 is connected to the control unit 12;

[0029] When the current detection module 20 detects a short circuit signal and / or the DC detection module 30 detects a DC signal, the control module 40 can control the action unit 11 through the control unit 12 to cut off the circuit between the speaker and the output terminal of the power amplifier.

[0030] In this utility model, the working principle is as follows:

[0031] ① The level signal of the front-stage circuit passes through the resistor R23 and the resistor R25 and enters the power tube Q1 and the power tube Q2 for amplification. When the amplified level is output, it is connected to the switching module 10. As a preferred embodiment of the switching module 10, the switching module 10 is configured as a relay K1, and the coil of the relay K1 constitutes the action part 11, and the coil of the relay K1 constitutes the control part 12. That is, when the amplified level is output, it is connected to the relay K1 and then to the output terminal to control the circuit of the speaker terminal.

[0032] ② In the case of output short circuit protection, as a preferred embodiment of the current detection module 20, the current detection module 20 includes a resistor R22, a resistor R24, a resistor R27 and a capacitor C9, one end of the resistor R22 is respectively connected to one end of the front stage circuit and one end of the resistor R24, the other end of the resistor R22 is respectively connected to one end of the capacitor C9, one end of the resistor R27 and the control module 40, the other end of the capacitor C9 is respectively connected to the other end of the resistor R27, the other end of the resistor R24, the other end of the front stage circuit and the action unit 11; specifically, when the power amplifier output terminal is short-circuited, the current of the power tube Q1 will generate an abnormally large current, and when the large current flows through the resistor R24, the resistor R The voltage difference across 24 will increase and be conducted to C+ through resistor R22, so that the voltage between C+ and FB increases. When the voltage between C+ and FB is greater than 0.7V, transistor Q8 is turned on, so that there is current in pins 1-2 of the optocoupler U1, and pins 3-4 of the optocoupler U1 are turned on. The voltage at point A decreases, and the potential at point B is reduced through diode D3. Transistor Q3 starts to conduct, pulling down the voltage at point MUTE. After the voltage at point MUTE becomes low, the base of transistor Q5 loses voltage and is cut off, and transistor Q10 is also cut off. There is no current in the coil of relay K1, and the contact of relay K1 is disconnected, so that the output of the power amplifier is disconnected, which plays a role in short-circuit protection.

[0033] ③ When outputting DC protection, as a preferred embodiment of the DC detection module 30, the DC detection module 30 includes a resistor R7, a resistor R16, a capacitor C3 and a capacitor C7, one end of the resistor R7 is connected to the output end of the power amplifier, the other end of the resistor R7 is respectively connected to one end of the capacitor C3, one end of the resistor R16 and the control module 40, and the other end of the capacitor C3 is respectively connected to the other end of the resistor R16 and the GND end through the capacitor C7; specifically, the FB end is the output of the power amplifier. Under normal circumstances, the audio signal output by the power amplifier It is an AC level. When the AC level passes through resistor R7, capacitor C3, capacitor C7, and resistor R16, the AC level will be short-circuited and discharged. When the power amplifier outputs a DC level due to unexpected reasons, the DC level charges capacitor C3 and capacitor C7 through resistor R7, causing the voltage across capacitor C3 and capacitor C7 to increase. When the voltage increases by more than 0.7V, transistor Q9 is turned on. At this time, transistor Q9 will pull down the MUTE point, thereby turning off transistor Q5 and transistor Q10, and relay K1 is turned off, disconnecting the power amplifier output.

[0034] ④ The advantage of the utility model is that the output short circuit protection and output DC protection can be achieved through the above structure, thereby protecting the speaker and preventing the occurrence of fire, and it has very good practicality.

[0035] Of course, the present invention is not limited to the above-mentioned embodiments, and technicians familiar with the field may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. A high-power amplifier output short circuit and output DC protection circuit, characterized in that: It comprises a switching module (10), a current detection module (20), a DC detection module (30) and a control module (40); The switching module (10) comprises an action part (11) and a control part (12); the action part (11) is connected to the front-stage circuit via the current detection module (20) and serves as an output end of the power amplifier; and the speaker is connected to the action part (11); The current detection module (20) is connected to the control module (40); The DC detection module (30) is respectively connected to the power amplifier output end and the control module (40); The control module (40) is connected to the control unit (12); The control module (40) can control the action unit (11) to cut off the circuit between the speaker and the output end of the power amplifier through the control unit (12) when the current detection module (20) detects a short-circuit signal and / or the DC detection module (30) detects a DC signal.

2. A high-power amplifier output short circuit and output DC protection circuit according to claim 1, characterized in that: The switching module (10) is configured as a relay K1, the coil of the relay K1 constitutes the action unit (11), and the coil of the relay K1 constitutes the control unit (12).

3. A high-power amplifier output short circuit and output DC protection circuit according to claim 1, characterized in that: The current detection module (20) comprises a resistor R22, a resistor R24, a resistor R27 and a capacitor C9, one end of the resistor R22 is respectively connected to one end of the front-stage circuit and one end of the resistor R24, the other end of the resistor R22 is respectively connected to one end of the capacitor C9, one end of the resistor R27 and the control module (40), and the other end of the capacitor C9 is respectively connected to the other end of the resistor R27, the other end of the resistor R24, the other end of the front-stage circuit and the action unit (11).

4. A high-power amplifier output short circuit and output DC protection circuit according to claim 1, characterized in that: The DC detection module (30) comprises a resistor R7, a resistor R16, a capacitor C3 and a capacitor C7, one end of the resistor R7 is connected to the output end of the power amplifier, the other end of the resistor R7 is respectively connected to one end of the capacitor C3, one end of the resistor R16 and the control module (40), and the other end of the capacitor C3 is respectively connected to the other end of the resistor R16 and the GND end via the capacitor C7.

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