A power amplifier circuit system of a high-power 6000W digital power amplifier

Abstract

The present invention discloses a power amplifier circuit system of a high-power 6000W digital power amplifier, which is composed of a PWM pulse width modulation circuit and an MCU control unit, and performs voltage detection / online control and temperature control. The output end of the transformer isolation output circuit of the present invention is respectively connected to the auxiliary power supply 2 rectifier filter circuit, the auxiliary power supply 3 rectifier filter circuit, and the auxiliary power supply 4 rectifier filter circuit, and the output end of the auxiliary power supply 2 rectifier filter circuit is connected to the main power supply bridge rectifier filter circuit and the PWM drive power supply circuit; the output end of the auxiliary power supply 3 rectifier filter circuit is connected to the +5V auxiliary power supply circuit through the ±12V auxiliary power supply circuit, and the input end of the fan power supply output circuit is respectively connected to the auxiliary power supply 4 rectifier filter circuit and the MCU control unit. The power amplifier of the present invention is arranged in a double-layer board, and the assembly method is that two PCBs are plugged in through the pin and socket mode, and are uniformly locked on the U-shaped heat sink, which has good heat dissipation effect and good sound quality fidelity effect.

Description

Technical Field

[0001] The invention relates to a power amplifier power supply device, in particular to a pulse width modulated high-power digital power amplifier. Background Art

[0002] Audio amplifiers are widely used in life. Power amplifiers are referred to as amplifiers. Their main function is to amplify the weaker signal input by the sound source equipment and generate a large enough current to drive the speaker to reproduce the sound. After amplifying the audio electrical signal, it drives the speaker of the speaker to make a sound. Professional amplifiers are generally used for conferences, performances, halls, venues, and halls. The design is based on large output power, perfect protection circuits, and good heat dissipation. The performance of the audio amplifier directly affects the sound quality of the entire speaker. There are often situations such as sound distortion. At present, speaker amplifiers have different powers, and different places use amplifiers of different powers. How to improve the design of signal processing in the amplifier to make it suitable for the needs of various occasions is what this article wants to discuss. Considering power, impedance, distortion, dynamics, different use ranges and control adjustment functions, different amplifiers are also different in internal signal processing, circuit design and production technology. Professional amplifiers are generally used for conferences, performances, halls, venues, and halls. The design is based on large output power, perfect protection circuits, and good heat dissipation. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art. The present invention adopts a PWM pulse width modulation circuit and an MCU control unit. The MCU control unit is controlled by an MCU single chip computer to perform voltage detection / online control, start / shutdown detection control, output mode / output power detection control, temperature control, and two-stage acceleration control of a fan.

[0004] To achieve the above purpose, a power amplifier circuit system of a high-power 6000W digital power amplifier of the present invention adopts the following technical solutions:

[0005] A power amplifier circuit system of a high-power 6000W digital power amplifier comprises an A-bridge rectifier filter circuit, wherein the input end of the A-bridge rectifier filter circuit is connected to an AC input, and the output end of the A-bridge rectifier filter circuit is connected to a power control circuit and a half-bridge switch power circuit through a flyback switch power circuit; the input end of a soft switch start circuit is connected to an AC input, and the output end of the soft switch start circuit is connected to a transformer isolation output circuit after sequentially passing through a switch impact current protection circuit, a B-bridge rectifier filter circuit, a PFC circuit, and a half-bridge switch power circuit, and the soft switch start circuit is respectively connected to a flyback switch power circuit and a power control circuit, the input end of an auxiliary power supply 1 rectifier filter circuit is connected to a transformer isolation output circuit, and the output end of the auxiliary power supply 1 rectifier filter circuit is connected to a switch impact current protection circuit;

[0006] The output end of the transformer isolation output circuit is respectively connected to the auxiliary power supply 2 rectifier filter circuit, the auxiliary power supply 3 rectifier filter circuit, and the auxiliary power supply 4 rectifier filter circuit, and the output end of the auxiliary power supply 2 rectifier filter circuit is connected to the main power supply bridge rectifier filter circuit and the PWM drive power supply circuit; the output end of the auxiliary power supply 3 rectifier filter circuit is connected to the +5V auxiliary power supply circuit through the ±12V auxiliary power supply circuit, and the input end of the fan power supply output circuit is respectively connected to the auxiliary power supply 4 rectifier filter circuit and the MCU control unit;

[0007] The AC input (AC input) is connected to the A bridge rectifier filter circuit, and the flyback switching power supply circuit is started through the manually closed soft switch start circuit. After the power control circuit obtains the power, the relay of the soft switch start circuit is turned on. The AC is boosted by the startup inrush current protection circuit, the B bridge rectifier filter circuit, and the PFC circuit, and then reaches the half-bridge switching power supply circuit. The main power supply and various auxiliary power supplies are output through the transformer isolation output circuit to power the PWM drive power supply circuit (amplifier PWM drive), start the amplifier, and the weak signal passes through the audio compression circuit to reach the digital amplifier PWM pulse width modulation circuit for amplification and output through the LC filter circuit. The channel output power is up to 3000W / 4 ohms. At the same time, the +5V auxiliary power supply circuit (auxiliary power supply) supplies power to the MCU control unit. The temperature detection circuit detects the temperature in the circuit to control the compression of the input signal and the voltage output by the fan power output circuit.

[0008] The output end of the transformer isolation output circuit is connected to the main power bridge rectifier filter circuit, and the output end of the main power bridge rectifier filter circuit is connected to the LC filter circuit through the digital power amplifier PWM pulse width modulation circuit. The output end of the LC filter circuit provides a 3000W / 4 ohm channel output;

[0009] In some embodiments, the input end of the audio compression circuit is connected to the signal input, the output end of the audio compression circuit is connected to the digital power amplifier PWM pulse width modulation circuit, the output end of the temperature detection circuit is respectively connected to the MCU control unit and the audio compression circuit, and the input end of the MCU control unit is connected to the +5V auxiliary power supply circuit.

[0010] The positive voltage after rectification and filtering in the main power bridge rectifier filter circuit is connected in series with a resistor, and the voltage drop on the resistor is detected by the temperature detection circuit. When the load of the power supply is too high, the MCU control unit provides a signal to the audio compression circuit to compress the input signal to avoid output distortion.

[0011] Furthermore, the digital power amplifier PWM pulse width modulation circuit includes two groups of digital power amplifier PWM power amplifier units, and the first group of digital power amplifier PWM power amplifier units is provided with an over-temperature protection circuit (see attached Figure 2A), the power supply +5V-D is grounded through the resistor R448 and the thermistor PR400, and the voltage drop of the thermistor PR400 is detected by the microcontroller U16 pin 40 and pin 42 of the MCU control unit. The thermistor PR400 is located next to the power amplifier NMOS tube. The digital power amplifier PWM pulse width modulation circuit is distributed on the upper circuit board, and the remaining circuits are arranged on the lower circuit board. The entire circuit is assembled on the U-shaped heat sink, which has good heat dissipation conditions and is also easy to assemble and repair. The first group of digital power amplifier PWM power amplifier unit pulse width modulation chip Pin 15 of U201 is connected to the positive main power supply J1 interface after passing through resistor R218, pin 9 of pulse width modulation chip U201 is connected to the negative main power supply J2 interface, pin 14 of pulse width modulation chip U201 is connected to the gate G of NMOS tube FET202 after passing through resistor R220, pin 13 of pulse width modulation chip U201 is connected to the source S of NMOS tube FET202 and the drain D of NMOS tube FET203, pin 13 of pulse width modulation chip U201 outputs the power amplifier signal, and the drain D of NMOS tube FET202 is connected to the positive main power supply J1 interface.

[0012] Further, in some embodiments, the pulse width modulation chip U201 pin 16 of the digital power amplifier PWM pulse width modulation circuit is connected to the drain D of the NMOS tube FET202 through the resistor R504 and the positive electrode and negative electrode of the diode D206 in sequence, the resistor R216 is connected in parallel to the pulse width modulation chip U201 pin 16 and pin 13, one end of the resistor R215 is connected to the positive electrode of the diode D206, and the other end of the resistor R215 is connected to the pulse width modulation chip U201 pin 15, and an RC absorption circuit is connected in parallel between the drain D of the NMOS tube FET202 and the source S of the NMOS tube FET203, and the RC absorption circuit is composed of a series The second group of digital power amplifier PWM power amplifier unit circuits are the same as the first group of digital power amplifier PWM power amplifier units. The digital power amplifier PWM pulse width modulation circuit is connected to interfaces J9, J10, J12, J7, 11, and J8 of other lines through interfaces J1, J2, J3, J4, J5, and J6.

[0013] Further, in some embodiments, the control chip U16 pin 38 of the MCU control unit is connected to the power supply +5V; the control chip U16 pin 44 is connected to the inductor L5, which is connected to the main power supply positive voltage detection; the control chip U16 pin 1 is connected to the inductor L8, which is connected to the output negative terminal voltage detection, the control chip U16 pin 3 is connected to the inductor L9, which is connected to the output positive terminal voltage OUT1+ detection, the control chip U16 pin 5 and pin 7 are connected to the interface COM1 for program download and update; the control chip U16 pin 12 is connected to the power supply +5V through the resistor R178 and the cathode-positive pole of the light-emitting diode D81.

[0014] Further, in some embodiments, the fan connection circuit of the MCU control unit includes an NPN transistor Q13, the control chip U16 pin 18 is connected to the NPN transistor Q13 base B through the inductor L3, the positive and negative electrodes of the diode D4, and the resistor R67, the control chip U16 pin 19 is connected to the NPN transistor Q13 base B through the inductor L4, the positive and negative electrodes of the diode D5, and the resistor R68, the NPN transistor Q13 emitter E is grounded, and the NPN transistor Q13 collector C is connected to the fan interface FAN.

[0015] Further, in some embodiments, pin 30 of the control chip U16 is connected to the base B of the NPN transistor Q22 through a resistor R145, the emitter E of the NPN transistor Q22 is connected to the positive electrode of the light-emitting diode D82, the negative electrode of the light-emitting diode D82 is grounded, and the collector of the NPN transistor Q22 is connected to the power supply +12V through a resistor R146; pin 31 and pin 34 of the control chip U16 are connected to the resistor R121 to the base of the transistor Q20 through diodes D45 and D44.

[0016] Further, in some embodiments, the compression chip IC2 pin 1 of the audio compression circuit is connected to the optocoupler U18 pin 3 and the switch tube (bidirectional thyristor) D78 pin 3 through resistors R161 and R165, the optocoupler U18 pin 4 is connected to the power supply +12V terminal through resistor R159, the control chip U16 pin 21 of the MCU control unit is connected to the positive electrode of the diode D76 through resistor R187, and the pin 23 is connected to the positive electrode of the diode D76 through resistor R186, the control chip U16 pin 22 is connected to the positive electrode of the diode D75 through resistor R185, and the pin 24 is connected to the positive electrode of the diode D75 through resistor R184, the cathode of the diode D75 and the cathode of the diode D76 are connected to the optocoupler U18 pin 1, and the optocoupler U18 pin 2 is grounded.

[0017] Further, in some embodiments, pin 2 of the compression chip IC2 is connected to the +12V terminal of the power supply through resistor R166, pin 3 of the compression chip IC2 is grounded through resistor R167, pin 4 of the compression chip IC2 is connected to pin 2 of the op amp U20A through resistor R169, pin 5 of the compression chip IC2 is connected to pin 3 of the op amp U20A, the output of pin 1 of the op amp U20A is connected to pin 3 of the comparator U19A and pin 5 of the comparator U19B through resistor R164, and pin 1 of the comparator U19A and pin 7 of the comparator U19B are connected to the positive pole of the switching tube (bidirectional thyristor) D78.

[0018] The power amplifier of the present invention is arranged in a double-layer board, the digital power amplifier PWM pulse width modulation circuit is distributed on the upper circuit board (PCB board), and the other circuits are arranged on the lower circuit board. The layout is reasonable, and the assembly method is that two PCBs are plugged in through pin headers and sockets, and are uniformly locked on a U-shaped heat sink, which has good heat dissipation effect and good sound quality fidelity effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Shown is a circuit principle block diagram of the present invention;

[0020] Figure 2 The figure shows a circuit diagram of a first group of digital power amplifier digital power amplifier PWM power amplifier units of the digital power amplifier PWM pulse width modulation circuit of the present invention;

[0021] Figure 2A Shown is a circuit diagram of an over-temperature protection circuit and an interface part of the first group of digital power amplifier PWM power amplifier units of the present invention;

[0022] Figure 3 1 is a circuit diagram of a digital power amplifier PWM pulse width modulation circuit of the present invention;

[0023] Figure 4A Shown is a circuit diagram of the MCU control unit of the present invention;

[0024] Figure 4B Shown is a circuit diagram of the detection circuit of the present invention;

[0025] Figure 4C Shown is a circuit diagram of a fan connection circuit of an MCU control unit of the present invention;

[0026] Figure 5 Shown is a circuit diagram of the audio compression circuit of the present invention.

[0027] The following are the descriptions of the reference numerals:

[0028] A bridge rectifier filter circuit 01, flyback switching power supply circuit 02, power supply control circuit 03, soft switch start circuit 04, switch impact current protection circuit 05, B bridge rectifier filter circuit 06, PFC circuit 07, half-bridge switching power supply circuit 08, transformer isolation output circuit 09, auxiliary power supply 1 rectifier filter circuit 10, main power supply bridge rectifier filter circuit 11, auxiliary power supply 2 rectifier filter circuit 12, PWM drive power supply circuit 13, digital power amplifier PWM pulse width modulation circuit 14, LC filter circuit 15, auxiliary power supply 3 rectifier filter circuit 16, ±12V auxiliary power supply circuit 17, +5V auxiliary power supply circuit 18, MCU control unit 19, audio compression circuit 20, temperature detection circuit 21, auxiliary power supply 4 rectifier filter circuit 22, fan power supply output circuit 23. DETAILED DESCRIPTION

[0029] In order to further understand the features, technical means and specific objectives and functions achieved by the present invention, and analyze the advantages and spirit of the present invention, a further understanding is obtained through the following detailed description of the present invention in combination with the accompanying drawings and specific implementation methods.

[0030] The principle block diagram of the present invention is shown in Figure 1 The present invention includes an A bridge rectifier filter circuit 01, wherein the input end of the A bridge rectifier filter circuit 01 is connected to an AC input, and the output end of the A bridge rectifier filter circuit 01 is connected to a power control circuit 03 and a half-bridge switch power circuit 08 through a flyback switch power circuit 02; the input end of a soft switch start circuit 04 is connected to an AC input, and the output end of the soft switch start circuit 04 is connected to a transformer isolation output circuit 09 after sequentially passing through a switch impact current protection circuit 05, a B bridge rectifier filter circuit 06, a PFC circuit 07, and a half-bridge switch power circuit 08, and the soft switch start circuit 04 is respectively connected to the flyback switch power circuit 02 and the power control circuit 03, the input end of an auxiliary power supply 1 rectifier filter circuit 10 is connected to a transformer isolation output circuit 09, and the output end of the auxiliary power supply 1 rectifier filter circuit 10 is connected to a switch impact current protection circuit 05;

[0031] The output end of the transformer isolation output circuit 09 is connected to the main power bridge rectifier filter circuit 11, and the output end of the main power bridge rectifier filter circuit 11 is connected to the LC filter circuit 15 through the digital power amplifier PWM pulse width modulation circuit 14. The output end of the LC filter circuit 15 provides a 3000W / 4 ohm channel output;

[0032] The input end of the audio compression circuit 20 is connected to the signal input, the output end of the audio compression circuit 20 is connected to the digital power amplifier PWM pulse width modulation circuit 14, the output end of the temperature detection circuit 21 is respectively connected to the MCU control unit 19 and the audio compression circuit 20, and the input end of the MCU control unit 19 is connected to the +5V auxiliary power supply circuit 18.

[0033] The positive voltage after rectification and filtering of the main power bridge rectifier filter circuit 11 is connected in series with a resistor, and the voltage drop on the resistor is detected by the temperature detection circuit 21. When the load of the power supply is too high, the MCU control unit 19 provides a signal to the audio compression circuit 20 to compress the input signal to avoid output distortion.

[0034] The main power supply and various auxiliary power supplies supply power to the power amplifier PWM drive power supply circuit 13 to start the power amplifier. The weak signal passes through the audio compression circuit 20 and reaches the digital power amplifier PWM pulse width modulation circuit 14 for amplification and is output through the LC filter circuit 15 with a maximum power of 3000W / 4 ohms. At the same time, the auxiliary power supply supplies power to the MCU control unit 19. The temperature detection circuit 21 detects the temperature in the circuit to control the compression of the input signal and the voltage output by the fan power output circuit 23.

[0035] The output end of the transformer isolation output circuit 09 is respectively connected to the auxiliary power supply 2 rectifier filter circuit 12, the auxiliary power supply 3 rectifier filter circuit 16, and the auxiliary power supply 4 rectifier filter circuit 22; the output end of the auxiliary power supply 2 rectifier filter circuit 12 is connected to the main power supply bridge rectifier filter circuit 11 and the PWM drive power supply circuit 13; the output end of the auxiliary power supply 3 rectifier filter circuit 16 is connected to the +5V auxiliary power supply circuit 18 through the ±12V auxiliary power supply circuit 17, and the input end of the fan power supply output circuit 23 is respectively connected to the auxiliary power supply 4 rectifier filter circuit 22 and the MCU control unit 19.

[0036] The alternating current input (AC input) is input to the A bridge rectifier filter circuit 01, and the flyback switching power supply circuit 02 is started by manually closing the soft switch start circuit 04. After the power supply control circuit 03 obtains the power supply, the relay of the soft switch start circuit 04 is turned on. The alternating current is boosted by the startup inrush current protection circuit 05, the B bridge rectifier filter circuit 06, and the PFC circuit 07, and then reaches the half-bridge switching power supply circuit 08. The main power supply and various auxiliary power supplies are output through the transformer isolation output circuit 09, and the PWM drive power supply circuit 13 (power amplifier PWM drive) is powered to start the power amplifier. The weak signal passes through the audio compression circuit 20 and reaches the digital power amplifier PWM pulse width modulation circuit 14 for amplification, and is output through the LC filter circuit 15. The channel output power is up to 3000W / 4 ohms. At the same time, the +5V auxiliary power supply circuit 18 (auxiliary power supply) supplies power to the MCU control unit 19. The temperature detection circuit 21 detects the temperature in the line to control the compression of the input signal and the voltage output by the fan power supply output circuit 23.

[0037] The circuit diagram of the digital power amplifier PWM pulse width modulation circuit 14 is shown in the attached Figure 2 and attached Figure 3The digital power amplifier PWM pulse width modulation circuit 14 includes two groups of digital power amplifier PWM power amplifier units. The first group of digital power amplifier PWM power amplifier units includes a PWM pulse width modulation chip U201. The first group of digital power amplifier PWM power amplifier units is provided with an over-temperature protection circuit (see attached Figure 2A ), the power supply +5V-D is grounded through the resistor R448 and the thermistor PR400, and the voltage drop of the thermistor PR400 is detected by the pin 40 and pin 42 of the single-chip microcomputer U16 of the MCU control unit 19. The thermistor PR400 is located next to the power amplifier NMOS tube. The digital power amplifier PWM pulse width modulation circuit 14 is distributed on the upper circuit board, and the remaining circuits are arranged on the lower circuit board. The entire circuit is assembled on the U-shaped heat sink, which has good heat dissipation conditions and is also easy to assemble and maintain. The pulse width modulation of the first group of digital power amplifier PWM power amplifier units Pin 15 of chip U201 is connected to the positive main power supply J1 interface after passing through resistor R218, pin 9 of pulse width modulation chip U201 is connected to the negative main power supply J2 interface, pin 14 of pulse width modulation chip U201 is connected to the gate G of NMOS tube FET202 after passing through resistor R220, pin 13 of pulse width modulation chip U201 is connected to the source S of NMOS tube FET202 and the drain D of NMOS tube FET203, pin 13 of pulse width modulation chip U201 outputs the power amplifier signal, and the drain D of NMOS tube FET202 is connected to the positive main power supply J1 interface.

[0038] In some embodiments, the pulse width modulation chip U201 pin 16 of the digital power amplifier PWM pulse width modulation circuit 14 is connected to the drain D of the NMOS tube FET202 through the resistor R504 and the positive electrode-negative electrode of the diode D206 in sequence, the resistor R216 is connected in parallel to the pulse width modulation chip U201 pin 16 and pin 13, one end of the resistor R215 is connected to the positive electrode of the diode D206, and the other end of the resistor R215 is connected to the pulse width modulation chip U201 pin 15, and an RC absorption circuit is connected in parallel between the drain D of the NMOS tube FET202 and the source S of the NMOS tube FET203, and the RC absorption circuit The routing is composed of a capacitor C213, a resistor R222, a resistor R223, and a capacitor C226 connected in series. The pin 10 of the pulse width modulation chip U201 is connected to the source S of the NMOS tube FET203 through the resistor R253 and the positive-negative pole of the light-emitting diode DS201. The second group of digital power amplifier PWM power amplifier unit circuit is the same as the first group of digital power amplifier PWM power amplifier unit. When the signal is input, the signal of the second group of digital power amplifier PWM power amplifier unit is the inverse of the first group of digital power amplifier PWM power amplifier unit. In the output part, it is bridged and output after passing through the LC filter circuit 15, and the maximum power is 3000W / 4 ohms. The digital power amplifier PWM pulse width modulation circuit 14 is connected to the interfaces J9, J10, J12, J7, 11, and J8 of other lines through interfaces J1, J2, J3, J4, J5, and J6.

[0039] The circuit diagram of the MCU control unit 19 is shown in the attached Figure 4A , the control chip U16 pin 38 of the MCU control unit 19 is connected to the power supply +5V; the control chip U16 pin 44 is connected to the inductor L5, which is connected to the main power supply positive voltage detection; the control chip U16 pin 1 is connected to the inductor L8, which is connected to the output negative terminal voltage detection, the control chip U16 pin 3 is connected to the inductor L9, which is connected to the output positive terminal voltage detection, the control chip U16 pin 5 and pin 7 are connected to the interface COM1 for program download and update; the control chip U16 pin 12 is connected to the power supply +5V through the resistor R178 and the negative pole-positive pole of the light-emitting diode D81.

[0040] The fan connection circuit of the MCU control unit 19 includes an NPN transistor Q13. The control chip U16 pin 18 is connected to the base B of the NPN transistor Q13 through the inductor L3, the positive and negative electrodes of the diode D4, and the resistor R67, which is used for the fan acceleration circuit. The control chip U16 pin 19 is connected to the base B of the NPN transistor Q13 through the inductor L4, the positive and negative electrodes of the diode D5, and the resistor R68. The emitter E of the NPN transistor Q13 is grounded, and the collector C of the NPN transistor Q13 is connected to the fan interface FAN.

[0041] The output end of the fan power supply output circuit 23 (fan voltage rectification and filtering) is connected to the fan speed control circuit, and the input end of the fan speed control circuit is connected to the MCU control unit 19. The MCU control unit 19 controls the fan speed by receiving the voltage fed back by the thermistor.

[0042] Further, in some embodiments, pin 30 of the control chip U16 is connected to the base B of the NPN transistor Q22 through a resistor R145, the emitter E of the NPN transistor Q22 is connected to the positive electrode of the light-emitting diode D82, the negative electrode of the light-emitting diode D82 is grounded, and the collector of the NPN transistor Q22 is connected to the power supply +12V through a resistor R146; pin 31 and pin 34 of the control chip U16 are connected to the resistor R121 to the base of the transistor Q20 through diodes D45 and D44, which are used to control the shutdown of the PWM pulse width modulation chip U201 and the PWM pulse width modulation chip U203, and the control chip U16 is connected to a comparator for detecting the status of the PWM pulse width modulation chip.

[0043] The circuit diagram of the audio compression circuit 20 is shown in the attached Figure 5, the compression chip IC2 pin 1 of the audio compression circuit 20 is connected to the optocoupler U18 pin 3 and the switch tube (bidirectional thyristor) D78 pin 3 through the resistor R161 and the resistor R165, and the optocoupler U18 pin 4 is connected to the power supply +12V terminal through the resistor R159. The optocoupler U18 is used to control the input signal compression. The control chip U16 pin 21 of the MCU control unit 19 is connected to the positive electrode of the diode D76 through the resistor R187, and the pin 23 is connected to the positive electrode of the diode D76 through the resistor R186. The control chip U16 pin 22 is connected to the positive electrode of the diode D75 through the resistor R185, and the pin 24 is connected to the positive electrode of the diode D75 through the resistor R184. The cathode of the diode D75 and the cathode of the diode D76 are connected to the optocoupler U18 pin 1, and the optocoupler U18 pin 2 is grounded.

[0044] In some embodiments, pin 2 of compression chip IC2 is connected to the +12V terminal of power supply through resistor R166, pin 3 of compression chip IC2 is grounded through resistor R167, pin 4 of compression chip IC2 is connected to pin 2 of op amp U20A through resistor R169, pin 5 of compression chip IC2 is connected to pin 3 of op amp U20A, output of pin 1 of op amp U20A is connected to pin 3 of comparator U19A and pin 5 of comparator U19B through resistor R164, pin 1 of comparator U19A and pin 7 of comparator U19B are connected to the positive pole of switch tube (bidirectional thyristor) D78. When the main power supply load is too heavy, optocoupler U18 is turned on by transistor drive to play a compression role; when MCU control unit 19 receives the temperature detection circuit 21 to detect that the temperature of the power amplifier is too high, audio compression circuit 20 is controlled by control chip U16 to compress the audio input signal.

[0045] The above-described embodiments only express some implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A power amplifier circuit system of a high-power 6000W digital power amplifier, comprising: The invention comprises an A-bridge rectifier filter circuit (01), characterized in that the input end of the A-bridge rectifier filter circuit (01) is connected to an AC input, and the output end of the A-bridge rectifier filter circuit (01) is connected to a power control circuit (03) and a half-bridge switch power circuit (08) through a flyback switch power circuit (02); the input end of the soft switch start circuit (04) is connected to the AC input, and the output end of the soft switch start circuit (04) is connected to a transformer isolation output circuit (09) after sequentially passing through a switch surge current protection circuit (05), a B-bridge rectifier filter circuit (06), a PFC circuit (07), and a half-bridge switch power circuit (08); the soft switch start circuit (04) is respectively connected to the flyback switch power circuit (02) and the power control circuit (03); the input end of the auxiliary power supply 1 rectifier filter circuit (10) is connected to the transformer isolation output circuit (09), and the output end of the auxiliary power supply 1 rectifier filter circuit (10) is connected to the switch surge current protection circuit (05); The output end of the transformer isolation output circuit (09) is respectively connected to the auxiliary power supply 2 rectifier filter circuit (12), the auxiliary power supply 3 rectifier filter circuit (16), and the auxiliary power supply 4 rectifier filter circuit (22); the output end of the auxiliary power supply 2 rectifier filter circuit (12) is connected to the main power supply bridge rectifier filter circuit (11) and the PWM drive power supply circuit (13); the output end of the auxiliary power supply 3 rectifier filter circuit (16) is connected to the +5V auxiliary power supply circuit (18) through the ±12V auxiliary power supply circuit (17); the input end of the fan power supply output circuit (23) is respectively connected to the auxiliary power supply 4 rectifier filter circuit (22) and the MCU control unit (19); The AC power is input to the A bridge rectifier filter circuit (01), and the flyback switch power supply circuit (02) is started through the manually closed soft switch start circuit (04). After the power supply control circuit (03) obtains the power supply, the soft switch start circuit (04) is turned on. The AC power is boosted through the startup surge current protection circuit (05), the B bridge rectifier filter circuit (06), and the PFC circuit (07), and then reaches the half-bridge switch power supply circuit (08). The main power supply and various auxiliary power supplies are output through the transformer isolation output circuit (09), and the PWM drive power supply circuit (13) is powered to start the power amplifier. The weak signal passes through the audio compression circuit (20) and reaches the digital power amplifier PWM pulse width modulation circuit (14) for amplification and is output through the LC filter circuit (15). The channel output power is up to 3000W / 4 ohms. At the same time, the +5V auxiliary power supply circuit (18) supplies power to the MCU control unit (19). The temperature detection circuit (21) detects the temperature in the line to control the compression of the input signal and the voltage output by the fan power supply output circuit (23); The digital power amplifier PWM pulse width modulation circuit (14) comprises two groups of digital power amplifier PWM power amplifier units. The first group of digital power amplifier PWM power amplifier units is provided with an over-temperature protection circuit. The power supply +5V-D is grounded via a resistor R448 and a thermistor PR400. The voltage drop of the thermistor PR400 is detected by using pins 40 and 42 of a control chip U16 of an MCU control unit (19). The thermistor PR400 is located next to the power amplifier NMOS tube. The digital power amplifier PWM pulse width modulation circuit (14) is distributed on an upper circuit board, and the remaining circuits are arranged on a lower circuit board. The entire circuit is assembled on a U-shaped heat sink. Pin 15 of the pulse width modulation chip U201 of the first group of digital power amplifier PWM power amplifier units is connected to the positive main power supply J1 interface after passing through resistor R218, pin 9 of the pulse width modulation chip U201 is connected to the negative main power supply J2 interface, pin 14 of the pulse width modulation chip U201 is connected to the gate G of the NMOS tube FET202 after passing through resistor R220, pin 13 of the pulse width modulation chip U201 is connected to the source S of the NMOS tube FET202 and the drain D of the NMOS tube FET203, pin 13 of the pulse width modulation chip U201 outputs the power amplifier signal, and the drain D of the NMOS tube FET202 is connected to the positive main power supply J1 interface.

2. The power amplifier circuit system of a high-power 6000W digital power amplifier according to claim 1, characterized in that: The output end of the transformer isolation output circuit (09) is connected to the main power bridge rectifier filter circuit (11), and the output end of the main power bridge rectifier filter circuit (11) is connected to the LC filter circuit (15) through the digital power amplifier PWM pulse width modulation circuit (14), and the output end of the LC filter circuit (15) provides a 3000W / 4 ohm channel output; The input end of the audio compression circuit (20) is connected to the signal input, the output end of the audio compression circuit (20) is connected to the digital power amplifier PWM pulse width modulation circuit (14), the output end of the temperature detection circuit (21) is respectively connected to the MCU control unit (19) and the audio compression circuit (20), and the input end of the MCU control unit (19) is connected to the +5V auxiliary power supply circuit (18).

3. The power amplifier circuit system of a high-power 6000W digital power amplifier according to claim 1, characterized in that: The pulse width modulation chip U201 pin 16 of the digital power amplifier PWM pulse width modulation circuit (14) is connected to the drain D of the NMOS tube FET202 through the resistor R504 and the positive electrode and negative electrode of the diode D206 in sequence, the resistor R216 is connected in parallel to the pin 16 and the pin 13 of the pulse width modulation chip U201, one end of the resistor R215 is connected to the positive electrode of the diode D206, and the other end of the resistor R215 is connected to the pin 15 of the pulse width modulation chip U201, and an RC absorption circuit is connected in parallel between the drain D of the NMOS tube FET202 and the source S of the NMOS tube FET203, and the RC absorption circuit is composed of a series capacitor C 213, a resistor R222 and a resistor R223, and a capacitor C226. The pin 10 of the pulse width modulation chip U201 is connected to the source S of the NMOS tube FET203 through the resistor R253 and the positive and negative electrodes of the light emitting diode DS201. The second group of digital power amplifier PWM power amplifier unit circuits is the same as the first group of digital power amplifier PWM power amplifier units. The digital power amplifier PWM pulse width modulation circuit (14) is connected to the interfaces J9, J10, J12, J7, 11, and J8 of other lines through interfaces J1, J2, J3, J4, J5, and J6.

4. The power amplifier circuit system of a high-power 6000W digital power amplifier according to claim 1, characterized in that: The control chip U16 pin 38 of the MCU control unit (19) is connected to the power supply +5V; the control chip U16 pin 44 is connected to the inductor L5, which is connected to the main power supply positive voltage detection; the control chip U16 pin 1 is connected to the inductor L8, which is connected to the output negative terminal voltage detection, the control chip U16 pin 3 is connected to the inductor L9, which is connected to the output positive terminal voltage OUT1+ detection, the control chip U16 pin 5 and pin 7 are connected to the interface COM1 for program download and update; the control chip U16 pin 12 is connected to the power supply +5V through the resistor R178 and the cathode-positive pole of the light-emitting diode D81.

5. The power amplifier circuit system of a high-power 6000W digital power amplifier according to claim 4, characterized in that: The fan connection circuit of the MCU control unit (19) comprises an NPN transistor Q13, a control chip U16 pin 18 is connected to the base B of the NPN transistor Q13 via an inductor L3, a diode D4 anode-cathode, and a resistor R67, a control chip U16 pin 19 is connected to the base B of the NPN transistor Q13 via an inductor L4, a diode D5 anode-cathode, and a resistor R68, an emitter E of the NPN transistor Q13 is grounded, and a collector C of the NPN transistor Q13 is connected to a fan interface FAN.

6. The power amplifier circuit system of a high-power 6000W digital power amplifier according to claim 4, characterized in that: The pin 30 of the control chip U16 is connected to the base B of the NPN transistor Q22 through the resistor R145, the emitter E of the NPN transistor Q22 is connected to the positive electrode of the light-emitting diode D82, the negative electrode of the light-emitting diode D82 is grounded, and the collector of the NPN transistor Q22 is connected to the power supply +12V through the resistor R146; the pin 31 and pin 34 of the control chip U16 are connected to the resistor R121 to the base of the transistor Q20 through the diodes D45 and D44.

7. The power amplifier circuit system of a high-power 6000W digital power amplifier according to claim 1, characterized in that: Pin 1 of the compression chip IC2 of the audio compression circuit (20) is connected to pin 3 of the optocoupler U18 and pin 3 of the switch tube D78 through resistors R161 and R165, pin 4 of the optocoupler U18 is connected to the +12V terminal of the power supply through resistor R159, pin 21 of the control chip U16 of the MCU control unit (19) is connected to the positive electrode of the diode D76 through resistor R187, pin 23 is connected to the positive electrode of the diode D76 through resistor R186, pin 22 of the control chip U16 is connected to the positive electrode of the diode D75 through resistor R185, pin 24 is connected to the positive electrode of the diode D75 through resistor R184, the cathode of the diode D75 and the cathode of the diode D76 are connected to pin 1 of the optocoupler U18, and pin 2 of the optocoupler U18 is grounded.

8. The power amplifier circuit system of a high-power 6000W digital power amplifier according to claim 7, characterized in that: The pin 2 of the compression chip IC2 is connected to the +12V terminal of the power supply through the resistor R166, the pin 3 of the compression chip IC2 is grounded through the resistor R167, the pin 4 of the compression chip IC2 is connected to the pin 2 of the op amp U20A through the resistor R169, the pin 5 of the compression chip IC2 is connected to the pin 3 of the op amp U20A, the output of the pin 1 of the op amp U20A is connected to the pin 3 of the comparator U19A and the pin 5 of the comparator U19B through the resistor R164, and the pin 1 of the comparator U19A and the pin 7 of the comparator U19B are connected to the positive pole of the switch tube D78.

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