H-type power amplifier voltage switching circuit

Abstract

The utility model discloses a voltage switching circuit for an H-type power amplifier. The voltage switching circuit comprises an audio conversion circuit, a plurality of power output modules and a plurality of power output terminals, the input end of the audio conversion circuit is connected with a preceding-stage audio signal; the input end of the power output module is connected with the output end of the audio conversion circuit, the output end of the power output module is connected between two adjacent power output terminals, and the loudspeaker is connected between the output end of the audio conversion circuit and the power output terminals; the power output module comprises an output detection circuit, a shaping drive circuit, a switching circuit and a bootstrap circuit; through the structure, the voltage of the power amplifier can be dynamically switched, the complete conduction of the MOS tube can be ensured, and different power section power supply requirements can be switched along with the frequency response of music.

Description

Technical Field

[0001] The utility model relates to the technical field of high-power professional power amplifiers, in particular to a class H power amplifier voltage switching circuit. Background Art

[0002] Since Class H amplifiers are very effective in reducing the problem of high heat generation when the amplifier plays at low and medium powers, Class H amplifiers are currently used in high-power professional amplifiers. The power supply voltage and current of high-power amplifiers are relatively high, so this voltage switching circuit requires a power tube with high speed and high current to control it. Usually, high-power transistors are used for control. Since the current of the transistor is not very large, the switching speed is slow. If MOS tubes are used for switching, the advantages of fast switching speed, high current and low conduction internal resistance can be achieved. However, the GS voltage of the MOS tube must be above 10V for full conduction, making it impossible for the existing voltage switching circuit to ensure that the MOS tube is fully conducted while ensuring fast switching speed. Therefore, there is an urgent need for a Class H amplifier voltage switching circuit. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems in the prior art. To this end, the present invention proposes a class H power amplifier voltage switching circuit.

[0004] An embodiment of the present invention solves the technical problem by adopting a technical solution: a class H power amplifier voltage switching circuit, comprising an audio conversion circuit, a plurality of power output modules, and a plurality of power output terminals; the input end of the audio conversion circuit is connected to the front-stage audio signal; the input end of the power output module is connected to the output end of the audio conversion circuit, and the output end is connected between two adjacent power output terminals; and a speaker is connected between the output end of the audio conversion circuit and the power output terminals;

[0005] The power output module includes an output detection circuit, a shaping drive circuit, a switching circuit and a bootstrap circuit;

[0006] The output detection circuit is connected between the output terminal of the audio conversion circuit and the shaping drive circuit, and is used to detect the amplitude of the output signal;

[0007] The output end of the shaping drive circuit is connected to the output end of the bootstrap circuit and the input end of the switching circuit respectively, so as to drive the switching circuit;

[0008] The switching circuit is connected between two adjacent power output terminals;

[0009] The input end of the bootstrap circuit is connected to the next-stage power output module to provide a conduction voltage for the switching circuit.

[0010] As one of the preferred embodiments of the present utility model, the output detection circuit includes a diode D13, capacitors C7-8, a resistor R13, a resistor R16 and a resistor R19. The anode of the diode D13 is connected to the output end of the audio conversion circuit, the cathode of the diode D13 is respectively connected to one end of the capacitor C7, one end of the resistor R13 and one end of the resistor R16, the other end of the capacitor C7 is respectively connected to one end of the capacitor C8, the other end of the resistor R16, one end of the resistor R19 and the shaping drive circuit, the other end of the resistor R13 is connected to one of the two adjacent power output terminals, and the other end of the capacitor C8 and the other end of the resistor R19 are connected to the other of the two adjacent power output terminals.

[0011] As one of the preferred embodiments of the present utility model, the shaping drive circuit includes diodes D10-11, diodes D14-16, diode D18, resistor R12, resistor R14, resistor R17-18, resistor R20-21, capacitor C5 and transistor Q7-10, the anode of diode D15 is connected to the output detection circuit, the cathode of diode D15 is connected to the anode of diode D16 and the anode of diode D10, the cathode of diode D16 is connected to the base of transistor Q9 and one end of resistor R20, the cathode of diode D10 is connected to one end of resistor R14 and the collector of transistor Q9, the other end of resistor R14 is connected to the cathode of diode D11 and the cathode of diode D14, the anode of diode D11 is connected to one end of resistor R12 and the base of transistor Q7, and resistor R1 The other end of transistor D2 is connected to the emitter of transistor Q7, the collector of transistor Q8, and the bootstrap circuit. The anode of diode D14 is connected to the collector of transistor Q7, one end of resistor R17, and one end of resistor R21. The other end of resistor R17 is connected to one end of capacitor C5, the base of transistor Q8, and the base of transistor Q10. The other end of capacitor C5 is connected to one of two adjacent power output terminals. The emitter of transistor Q8 is connected to the emitter of transistor Q10 and one end of resistor R18. The other end of resistor R18 is connected to the switching circuit. The cathode of diode D18 is connected to the bootstrap circuit. The anode of diode D18, the other end of resistor R20, the other end of resistor R21, the emitter of transistor Q9, and the collector of transistor Q10 are connected to the other of the two adjacent power output terminals.

[0012] As one of the preferred embodiments of the present utility model, the bootstrap circuit includes a transistor Q6, a resistor R15, a diode D9 and a capacitor C6, the collector of the transistor Q6 is connected to one end of the resistor R15 and one of the two adjacent power output terminals, the other end of the resistor R15 is connected to the base of the transistor Q6 and the shaping drive circuit, the emitter of the transistor Q6 is connected to one end of the capacitor C6 and the shaping drive circuit via the diode D9, and the other end of the capacitor C6 is connected to the shaping drive circuit.

[0013] As one of the preferred embodiments of the present invention, the audio conversion circuit includes resistors R23-26 and transistors Q1-2, one end of the resistor R23 is connected to the pre-stage audio signal and one end of the resistor R25, the other end of the resistor R23 is connected to the base of the transistor Q1, the other end of the resistor R25 is connected to the base of the transistor Q2, the collector of the transistor Q1 and the collector of the transistor Q2 are connected to the power output module, the emitter of the transistor Q1 is connected to the emitter of the transistor Q2 via the resistor R24 and the resistor R26, and the resistor R24 and the resistor R26 are jointly connected to the speaker.

[0014] As one of the preferred embodiments of the present utility model, the number of power output modules is 4 and the number of power output terminals is 6.

[0015] The beneficial effects of the present invention are as follows: a Class H power amplifier voltage switching circuit includes an audio conversion circuit, multiple power output modules and multiple power output terminals; the input end of the audio conversion circuit is connected to the front-stage audio signal; the input end of the power output module is connected to the output end of the audio conversion circuit, and the output end is connected between two adjacent power output terminals, and the speaker is connected between the output end of the audio conversion circuit and the power output terminal; the power output module includes an output detection circuit, a shaping drive circuit, a switching circuit and a bootstrap circuit; through the above structure, the voltage of the power amplifier can be dynamically switched, which can ensure that the MOS tube is fully conductive and can also switch to different power supply requirements according to the frequency response of the music. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 The following is a circuit schematic diagram of a class H power amplifier voltage switching circuit;

[0018] Figure 2 This is a schematic diagram of the first part of a voltage switching circuit for a Class H power amplifier;

[0019] Figure 3 The second part of the circuit schematic diagram of a class H power amplifier voltage switching circuit;

[0020] Figure 4 The third part of a circuit schematic diagram of a class H power amplifier voltage switching circuit;

[0021] Figure 5 The fourth part of the circuit schematic diagram of a class H power amplifier voltage switching circuit;

[0022] Figure 6 This is the circuit schematic diagram of the audio conversion circuit. DETAILED DESCRIPTION

[0023] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention 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 overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0024] In the description of this utility model, "above," "below," and "within" are understood to be exclusive of the number indicated, while "above," "below," and "within" are understood to be inclusive of the number indicated. The use of "first" and "second" is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, or implicitly specifying the number or order of the technical features indicated.

[0025] In the description of the present invention, it should be understood that descriptions involving orientations, 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. They 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. Therefore, they cannot be understood as limitations on the present invention.

[0026] In this utility model, unless otherwise expressly defined, terms such as "disposed," "installed," and "connected" should be interpreted broadly. For example, they may refer to direct connection or indirect connection through an intermediate medium; fixed connection or detachable connection or integral molding; mechanical connection; internal communication between two components or interaction between two components. Those skilled in the art can reasonably determine the specific meanings of these terms in this utility model based on the specific content of the technical solution.

[0027] Reference Figures 1 to 6 A class H power amplifier voltage switching circuit includes an audio conversion circuit 10, a plurality of power output modules 20, and a plurality of power output terminals 30; the input end of the audio conversion circuit 10 receives a pre-stage audio signal; the input end of the power output module 20 is connected to the output end of the audio conversion circuit 10, and the output end is connected between two adjacent power output terminals 30; and the speaker is connected between the output end of the audio conversion circuit 10 and the power output terminals 30;

[0028] The power output module 20 includes an output detection circuit 21, a shaping drive circuit 22, a switching circuit 23 and a bootstrap circuit 24;

[0029] The output detection circuit 21 is connected between the output terminal of the audio conversion circuit 10 and the shaping drive circuit 22, and is used to detect the amplitude of the output signal;

[0030] The output end of the shaping driving circuit 22 is connected to the output end of the bootstrap circuit 24 and the input end of the switching circuit 23 respectively, so as to drive the switching circuit 23;

[0031] The switching circuit 23 is connected between two adjacent power output terminals 30;

[0032] An input end of the bootstrap circuit 24 is connected to the next-stage power output module 20 for providing a conduction voltage for the switching circuit 23 .

[0033] In this utility model, the working principle is as follows:

[0034] ① In the audio conversion circuit 10, the audio conversion circuit 10 includes resistors R23-26 and transistors Q1-2. One end of the resistor R23 is connected to the pre-stage audio signal and one end of the resistor R25. The other end of the resistor R23 is connected to the base of the transistor Q1. The other end of the resistor R25 is connected to the base of the transistor Q2. The collector of the transistor Q1 and the collector of the transistor Q2 are connected to the power output module 20. The emitter of the transistor Q1 is connected to the emitter of the transistor Q2 via the resistor R24 and the resistor R26. The resistor R24 and the resistor R26 are connected to the speaker together.

[0035] Specifically, the center point of resistor R23 and resistor R25 is the input point of the front-stage audio, which is amplified by the power tube and output to the speaker. The speaker output is transmitted to four power output modules 20 (20a, 20b, 20c and 20d).

[0036] ②Reference Figure 1 The power output terminals 30 are set to 6, namely V50+, V100+, V150+, V50-, V100- and V150-. The speaker output is transmitted to 4 output detection circuits 21. Specifically, the output detection circuit 21 in the power output module 20b and the output detection circuit 21 in the power output module 20d are positive and negative voltage level 1 detection, and the output detection circuit 21 in the power output module 20a and the output detection circuit 21 in the power output module 20c are positive and negative voltage level 2 detection.

[0037] ③ Assume that the voltage is divided into three sections, namely ±50, ±100, ±150V; Figure 3 Take the medium power output module 20b as an example to illustrate:

[0038] In the output detection circuit 21, the output detection circuit 21 includes a diode D13, capacitors C7-8, a resistor R13, a resistor R16, and a resistor R19. The anode of the diode D13 is connected to the output end of the audio conversion circuit 10, and the cathode of the diode D13 is respectively connected to one end of the capacitor C7, one end of the resistor R13, and one end of the resistor R16. The other end of the capacitor C7 is respectively connected to one end of the capacitor C8, the other end of the resistor R16, one end of the resistor R19, and the shaping drive circuit 22. The other end of the resistor R13 is connected to one of the two adjacent power output terminals 30 (V100A+), and the other end of the capacitor C8 and the other end of the resistor R19 are connected to the other of the two adjacent power output terminals 30 (V50A+). The diode D13 undergoes a 7.5V voltage drop and then divides the voltage with the resistor R13, the resistor R16, and the resistor R19. The capacitors C7 and C8 are used for filtering.

[0039] ④ In the shaping drive circuit 22, the shaping drive circuit 22 includes a diode D10-11, a diode D14-16, a diode D18, a resistor R12, a resistor R14, a resistor R17-18, a resistor R20-21, a capacitor C5 and a transistor Q7-10. The anode of the diode D15 is connected to the output detection circuit 21, the cathode of the diode D15 is connected to the anode of the diode D16 and the anode of the diode D10, the cathode of the diode D16 is connected to the base of the transistor Q9 and one end of the resistor R20, the cathode of the diode D10 is connected to one end of the resistor R14 and the collector of the transistor Q9, the other end of the resistor R14 is connected to the cathode of the diode D11 and the cathode of the diode D14, the anode of the diode D11 is connected to one end of the resistor R12 and the base of the transistor Q7, and the other end of the resistor R12 is connected to the base of the transistor Q The emitter of transistor Q7, the collector of transistor Q8, and the bootstrap circuit 24 are connected. The anode of diode D14 is connected to the collector of transistor Q7, one end of resistor R17, and one end of resistor R21. The other end of resistor R17 is connected to one end of capacitor C5, the base of transistor Q8, and the base of transistor Q10. The other end of capacitor C5 is connected to one of two adjacent power output terminals 30 (V100A+). The emitter of transistor Q8 is connected to the emitter of transistor Q10 and one end of resistor R18. The other end of resistor R18 is connected to the switching circuit 23. The cathode of diode D18 is connected to the bootstrap circuit 24. The anode of diode D18, the other end of resistor R20, the other end of resistor R21, the emitter of transistor Q9, and the collector of transistor Q10 are connected to the other of the two adjacent power output terminals 30 (V50A+).

[0040] When the level at the speaker output reaches 33V, diode D15 is turned on, and the voltage is applied to the base of transistor Q9 through diode D16. Transistor Q9 is turned on, pulling down the voltage on resistor R14, and then the base level of transistor Q7 is pulled down through diode D11, thereby turning on transistor Q7. After transistor Q7 is turned on, the voltage on resistor R17 is pulled up. After the push-pull amplification composed of transistors Q8 and Q10, the gate of MOS tube V2 is driven through resistor R18, and MOS tube V2 is turned on. At this time, the power supply voltage of the power tube of the power amplifier rises from 50V+ to 100V+, and the power of the power amplifier rapidly increases by 4 times.

[0041] ⑤ In the bootstrap circuit 24, the bootstrap circuit 24 includes a transistor Q6, a resistor R15, a diode D9 and a capacitor C6. The collector of the transistor Q6 is connected to one end of the resistor R15 and one of the two adjacent power output terminals 30. The other end of the resistor R15 is connected to the base of the transistor Q6 and the shaping drive circuit 22. The emitter of the transistor Q6 is connected to one end of the capacitor C6 and the shaping drive circuit 22 via the diode D9. The other end of the capacitor C6 is connected to the shaping drive circuit 22.

[0042] After the DS terminal of MOS tube V2 is turned on, the voltage difference between the G terminal and the S terminal decreases, and the power supply of transistor Q7 and transistor Q8 is 14V. The 14V voltage is obtained by charging capacitor C6 through diode D9 after the 100V voltage is dropped by transistor Q6. When MOS tube V2 is turned on, the voltage of V50A+ terminal will rise to 100V. The negative terminal of capacitor C6 is connected to V50A+ terminal. Therefore, the positive terminal voltage of capacitor C6 will be 14V higher than 100V. , that is, 114V. Since the output level of the power amplifier is a sine wave signal, when the level signal is negative, the MOS tube V2 is cut off, and the V50A+ end drops to 50V. At this time, 100V continues to drop to 14V to charge the capacitor C6, and this cycle continues; the G pole of the MOS tube V2 is always higher than the S pole by 10-14V. The GS of the MOS tube V2 can be fully turned on with a voltage of 10-14V, and the GS of the MOS tube V2 will not be damaged by causing the GS of the MOS tube V2 to exceed 20V.

[0043] ⑥ Similarly, the power output module 20a works in the same way, with the difference being that when the voltage rises from 100V to 150V, the GS voltage of the MOS tube V1 also increases by 10-14V, reaching 164V.

[0044] The power output module 20c increases the voltage from -50V to -100V, and the GS voltage of the MOS tube V3 also increases by 10-14V to -114V.

[0045] The power output module 20d increases the -100V to -150V, and the GS voltage of the MOS tube V4 also increases by 10-14V to -164V.

[0046] ⑦ The advantage of the present invention is that the voltage of the power amplifier can be dynamically switched through the above structure, which can ensure that the MOS tube is fully turned on, and can also switch to different power supply requirements according to the frequency response of the music.

[0047] In one embodiment, the switching circuit 23 includes a MOS transistor V2, the gate of which is connected to the shaping drive circuit 22, the drain of which is connected to one of two adjacent power output terminals 30, and the source of which is connected to the audio conversion circuit 10 and the other of the two adjacent power output terminals 30. The switching circuit 23 is used to switch the supply voltage required for different power levels and to open or close the multi-stage power supply system according to the actual required output power. The switching process is fast and accurate, ensuring that the switching transition does not affect the power amplifier and is not distorted.

[0048] Of course, the present invention is not limited to the above-mentioned embodiments. Those skilled in the art 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 class H power amplifier voltage switching circuit, characterized in that: The invention comprises an audio conversion circuit (10), a plurality of power output modules (20) and a plurality of power output terminals (30); the input end of the audio conversion circuit (10) is connected to the front-stage audio signal; the input end of the power output module (20) is connected to the output end of the audio conversion circuit (10), and the output end is connected between two adjacent power output terminals (30); and the speaker is connected between the output end of the audio conversion circuit (10) and the power output terminal (30); The power output module (20) comprises an output detection circuit (21), a shaping drive circuit (22), a switching circuit (23) and a bootstrap circuit (24); The output detection circuit (21) is connected between the output end of the audio conversion circuit (10) and the shaping drive circuit (22) and is used to detect the amplitude of the output signal; The output end of the shaping drive circuit (22) is respectively connected to the output end of the bootstrap circuit (24) and the input end of the switching circuit (23), and is used to drive the switching circuit (23); The switching circuit (23) is connected between two adjacent power output terminals (30); The input end of the bootstrap circuit (24) is connected to the power output module (20) of the next stage, and is used to provide a conduction voltage for the switching circuit (23).

2. The class H power amplifier voltage switching circuit according to claim 1, wherein: The output detection circuit (21) includes a diode D13, capacitors C7-8, a resistor R13, a resistor R16, and a resistor R19. The anode of the diode D13 is connected to the output end of the audio conversion circuit (10), the cathode of the diode D13 is respectively connected to one end of the capacitor C7, one end of the resistor R13, and one end of the resistor R16. The other end of the capacitor C7 is respectively connected to one end of the capacitor C8, the other end of the resistor R16, one end of the resistor R19, and the shaping drive circuit (22). The other end of the resistor R13 is connected to one of the two adjacent power output terminals (30), and the other end of the capacitor C8 and the other end of the resistor R19 are connected to the other of the two adjacent power output terminals (30).

3. The class H power amplifier voltage switching circuit according to claim 1, wherein: The shaping drive circuit (22) includes a diode D10-11, a diode D14-16, a diode D18, a resistor R12, a resistor R14, a resistor R17-18, a resistor R20-21, a capacitor C5, and a transistor Q7-10. The anode of the diode D15 is connected to the output detection circuit (21), the cathode of the diode D15 is connected to the anode of the diode D16 and the anode of the diode D10, the cathode of the diode D16 is connected to the base of the transistor Q9 and one end of the resistor R20, the cathode of the diode D10 is connected to one end of the resistor R14 and the collector of the transistor Q9, the other end of the resistor R14 is connected to the cathode of the diode D11 and the cathode of the diode D14, the anode of the diode D11 is connected to one end of the resistor R12 and the base of the transistor Q7, and the other end of the resistor R12 is connected to the emitter of the transistor Q7. , the collector of the transistor Q8 and the bootstrap circuit (24), the anode of the diode D14 is connected to the collector of the transistor Q7, one end of the resistor R17 and one end of the resistor R21, the other end of the resistor R17 is connected to one end of the capacitor C5, the base of the transistor Q8 and the base of the transistor Q10, the other end of the capacitor C5 is connected to one of the two adjacent power output terminals (30), the emitter of the transistor Q8 is connected to the emitter of the transistor Q10 and one end of the resistor R18, the other end of the resistor R18 is connected to the switching circuit (23), the cathode of the diode D18 is connected to the bootstrap circuit (24), the anode of the diode D18, the other end of the resistor R20, the other end of the resistor R21, the emitter of the transistor Q9 and the collector of the transistor Q10 are connected to the other of the two adjacent power output terminals (30).

4. The class H power amplifier voltage switching circuit according to claim 1, wherein: The bootstrap circuit (24) includes a transistor Q6, a resistor R15, a diode D9 and a capacitor C6, wherein the collector of the transistor Q6 is connected to one end of the resistor R15 and one of the two adjacent power output terminals (30), the other end of the resistor R15 is connected to the base of the transistor Q6 and the shaping drive circuit (22), the emitter of the transistor Q6 is connected to one end of the capacitor C6 and the shaping drive circuit (22) via the diode D9, and the other end of the capacitor C6 is connected to the shaping drive circuit (22).

5. The class H power amplifier voltage switching circuit according to claim 1, wherein: The audio conversion circuit (10) includes resistors R23-26 and transistors Q1-2, one end of the resistor R23 is connected to the pre-stage audio signal and one end of the resistor R25, the other end of the resistor R23 is connected to the base of the transistor Q1, the other end of the resistor R25 is connected to the base of the transistor Q2, the collector of the transistor Q1 and the collector of the transistor Q2 are connected to the power output module (20), the emitter of the transistor Q1 is connected to the emitter of the transistor Q2 via the resistor R24 and the resistor R26, and the resistor R24 and the resistor R26 are connected to the speaker.

6. The class H power amplifier voltage switching circuit according to claim 1, wherein: The number of the power output modules (20) is set to four, and the number of the power output terminals (30) is set to six.

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