A power supply circuit system for a high-power 6000W digital power amplifier

Abstract

The present invention discloses a power circuit system of a high-power 6000W digital power amplifier, wherein the power supply adopts PFC and half-bridge switching power supply technology, and the power supply adopts overcurrent and overvoltage protection. The first bridge rectifier and filter circuit of the present invention is connected to the AC input, and the rectified DC enters the flyback switching power supply circuit. The output power is rectified and filtered to supply power to the power control circuit, the PFC circuit, and the half-bridge switching power supply circuit. After the power control circuit is powered on, the soft switch start circuit is controlled to connect the main power supply line. The input power supply of the present invention adopts a soft switch design, and uses a weak current to control the input strong current part, and the components of the impact current protection are short-circuited by a relay, so that additional useless power loss is avoided when working at high power. The power driver chip is powered by a flyback switching power supply, so that the power driver chip can work stably when working at high power.

Description

Technical Field

[0001] The present invention relates to a power amplifier device, and more particularly to a high-power switching power supply based on a PFC of an audio device. Background Art

[0002] Audio amplifiers are widely used in life. Power amplifiers are referred to as power amplifiers. Their main function is to amplify the weak signal input by the sound source equipment and drive the speaker of the sound box to make sound. At this time, a stable and good power supply is essential for professional power amplifier equipment. Professional power amplifiers are generally used for conferences, performances, halls, venues, and halls. The power needs to be large enough. The design is mainly based on large output power, perfect protection circuits, and good heat dissipation. Considering power, impedance, distortion, dynamics, and different usage ranges and control adjustment functions, the circuit design and production process are also different. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art. The power supply adopts PFC and half-bridge switching power supply technology, and the power supply adopts over-current and over-voltage protection.

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

[0005] A power circuit system for a high-power 6000W digital power amplifier comprises a first bridge rectifier filter circuit, the first bridge rectifier filter circuit is connected to an AC input, the rectified DC enters a flyback switching power supply circuit, the output power is rectified and filtered to supply power to a power control circuit, a PFC circuit, and a half-bridge switching power supply circuit, and the power control circuit controls a soft switch start circuit to connect to a main power supply line after being powered on;

[0006] The AC power is input to the first bridge rectifier filter circuit, and the flyback switching power supply circuit is started through the manually closed soft switch circuit. After the power control circuit obtains power, the soft switch start circuit is turned on. The AC power passes through the power-on surge current protection circuit, the second bridge rectifier filter circuit, and the PFC circuit, and then reaches the half-bridge switching power supply circuit, and is boosted and output by the transformer isolation output circuit to output the main power supply and various auxiliary power supplies.

[0007] Further, the input end of the first bridge rectifier and filter circuit is connected to the AC input, the output end of the first bridge rectifier and filter circuit is connected to the power control circuit through the flyback switching power supply circuit, the input end of the soft switch starting circuit is connected to the AC input and the power control circuit, the flyback switching power supply circuit is connected to the soft switch starting circuit, the output end of the soft switch starting circuit is connected to the half-bridge switching power supply circuit after passing through the switch impact current protection circuit, the second bridge rectifier and filter circuit, and the PFC circuit in sequence, the input end of the half-bridge switching power supply circuit is connected to the flyback switching power supply circuit, the output end of the half-bridge switching power supply circuit is connected to the transformer isolation output circuit, the output end of the transformer isolation output circuit is connected to the auxiliary power supply 1 rectifier and filter circuit, the main power supply bridge rectifier and filter circuit, and the auxiliary power supply 2 rectifier and filter circuit, the output end of the auxiliary power supply 1 rectifier and filter circuit is connected to the switch impact current protection circuit, and the output ends of the main power supply bridge rectifier and filter circuit and the auxiliary power supply 2 rectifier and filter circuit are connected to the DC output.

[0008] Further, the auxiliary power supply 1 rectifier and filter circuit drives the transistor Q3 and transistor Q12 of the half-bridge switching power supply circuit after rectification and filtering, and then the relay RY2 coil of the soft switch start circuit is energized and closed, and the resistors R3, R4 and the thermistor PR1 on the switch inrush current protection circuit are short-circuited to reduce losses;

[0009] The voltage induced by the rectifier and filter circuit of auxiliary power supply 2 is based on the negative voltage of the main power supply. After rectification and filtering, the voltage is stabilized to obtain a +12V / -VCC voltage, and the DC output is used for other circuits.

[0010] In some embodiments, the second bridge rectifier filter circuit includes: a PNP transistor Q15, diodes D29, D30, D31, and D32 in the second bridge rectifier filter circuit constitute a bridge rectifier circuit bridge, diodes D29, D30, D31, and D32 constitute a bridge arm circuit, one diagonal of the bridge arm is connected to the emitter E of the PNP transistor Q15, and the other diagonal of the bridge arm is connected to the negative electrode of the polarity capacitor C156; the emitter E of the PNP transistor Q15 is connected to the positive electrode of the polarity capacitor C155, the negative electrode of the polarity capacitor C155 is connected to the positive electrode of the polarity capacitor C156, the positive electrode of the polarity capacitor C156 is grounded, and the negative electrode of the polarity capacitor C156 is connected to the power supply -85V; parallel resistors R123A, R123B, R124A, and R124B are connected between the emitter E and the base B of the PNP transistor Q15; the base B of the PNP transistor Q15 is connected to the power supply +85V through R51;

[0011] The polar capacitor C155 is connected in parallel with a resistor R92 and a light emitting diode D63, and the cathode of the light emitting diode D63 is grounded; the polar capacitor C156 is connected in parallel with a resistor R93 and a light emitting diode D62, and the cathode of the light emitting diode D62 is connected to a power supply -85V;

[0012] The power from the secondary winding of transformer T2 of the half-bridge switching power supply circuit passes through the bridge stack rectifier circuit bridge (diodes D29, D30, D31, D32) in the second bridge rectifier filter circuit, and then filtered by polarity capacitor C155 and polarity capacitor C156 to obtain positive and negative main voltages. The size of the load is detected by connecting resistors R123~R124 (composed of parallel resistors R123A, R123B, R124A, R124B) in series with the positive main voltage (power supply +85V) and using PNP transistor Q15 to detect the voltage drop on the resistor; When the load is too heavy, the PNP transistor Q15 is turned on, and the collector C of the PNP transistor Q15 is connected to (reaches) the base B of the NPN transistor Q16 through the resistor R90, the positive and negative electrodes of the diode D6, and the resistor R29. The base B of the NPN transistor Q16 is grounded after passing through the capacitor C105, and the collector C of the NPN transistor Q16 is connected to the power supply +12V. The emitter E of the NPN transistor Q16 is connected to the LIMIT terminal through the positive and negative electrodes of the diode D55 and the resistor R95, providing a trigger model to the compression circuit, which reduces the output by compressing the input signal.

[0013] The half-bridge switching power supply circuit uses a totem pole driving method to drive the power MOS tube, a fast diode is connected in parallel to the driving resistor, a fast diode and an RC absorption circuit are connected in parallel to the drain and source of the MOS tube, and a resistor is connected in parallel to the gate and source of the MOS tube.

[0014] In some embodiments, the PFC circuit is driven by a PFC driver chip U8 in a totem pole manner to drive two parallel NMOS tubes (NMOS tube Q4, NMOS tube Q5), and the pin 3 of the PFC driver chip U8 is connected to the source S of the NMOS tube Q4 and the NMOS tube Q5 after passing through a resistor R1 and parallel resistors R11 to R18; the pin 4 of the PFC driver chip U8 is connected to the drain D of the NMOS tube Q4 and the NMOS tube Q5 after passing through a resistor R64, a resistor R63, and an inductor L2; the source S of the NMOS tube Q4 and the NMOS tube Q5 is grounded, and the drain D of the NMOS tube Q4 and the NMOS tube Q5 is connected to VCC after passing through the positive and negative electrodes of the diode BD2; a resistor R21 is connected in parallel to the gate G and the source S of the NMOS tube Q4, and a resistor R22 is connected in parallel to the gate G and the source S of the NMOS tube Q5;

[0015] Pin 7 of the PFC driver chip U8 is connected to the emitter E of the NPN transistor Q2 in the flyback switching power supply circuit through the resistor R10, and the collector C of the NPN transistor Q2 is connected to the +15V-PRI terminal (that is, pin 7 of the PFC driver chip U8 is connected to the +15V-PRI terminal through the resistor R10 and the NPN transistor Q2), and pin 8 of the PFC driver chip U8 is connected to the base B of the NPN transistor Q1 and the base B of the PNP transistor Q14; the emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q14 are connected, and the emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q14 are connected to the gate G of the NMOS tube Q4 through the driving resistor R19, and the emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q14 are connected to the gate G of the NMOS tube Q5 through the driving resistor R20.

[0016] Further, the driving resistor R19 and the driving resistor R20 are respectively connected in parallel with a fast diode D18 and a fast diode D19, the anode of the fast diode D18 is connected to the gate G of the NMOS tube Q4, and the anode of the fast diode D19 is connected to the gate G of the NMOS tube Q5; the gate G and the source S of the NMOS tube Q4 and the NMOS tube Q5 are respectively connected in parallel with a resistor R21 and a resistor R22, and the drain D and the source S of the NMOS tube Q4 and the NMOS tube Q5 are respectively connected in parallel with a capacitor C16 and a capacitor C22. Capacitor C17 and resistors R11-R18 are connected in parallel to the source S of NMOS tube Q4 and the source S of NMOS tube Q5, and resistors R11-R18 are connected in parallel to serve as short-circuit protection for NMOS tube Q4 and NMOS tube Q5. The drain D of NMOS tube Q4 and the drain D of NMOS tube Q5 are connected to the positive electrode of fast diode BD2, and the negative electrode of fast diode BD2 is connected to VCC. Resistor R24 ​​and capacitor C20 are connected in series and then connected in parallel to fast diode BD2; the source S of NMOS tube Q5 is grounded.

[0017] In some embodiments, the half-bridge switching power supply circuit uses a totem pole method to drive the MOS tube, the driver chip U7 pin 2 and pin 3 are connected to +15V-PRI, and a low-power switching power supply is used for power supply. The driver chip U7 pin 14 is connected to +15V-PRI through the cathode-positive electrode of the diode D21, the source driver chip U7 pin 14 is connected to the power driver chip U7 pin 12 through the parallel capacitor C52 and the capacitor C53, the power driver chip U7 pin 13 is connected to the NPN transistor Q8 base and the PNP transistor Q7 base through the resistor R38, the power driver chip U7 pin 13 is connected to the optocoupler U2 pin 1 through the resistor R43, and the power driver chip U7 pin 11 is connected to the NP through the resistor R37. The base of the N transistor Q9 and the base of the PNP transistor Q6, the base of the NPN transistor Q9 and the base of the PNP transistor Q6 are connected to pin 1 of the optocoupler U3 through the resistor R44, the emitters of the NPN transistor Q8 and the PNP transistor Q7 are connected, the emitters of the NPN transistor Q8 and the PNP transistor Q7 are connected to the gate of the NMOS transistor Q10 through two parallel driving resistors R41 and R42, the fast diode D22 is connected in parallel to the driving resistor R41 and R42, the resistor R48 is connected in parallel between the gate and the source of the NMOS transistor Q10, and the fast diode D27 and an RC absorption circuit (resistor R54 in series with capacitor C57) are connected in parallel between the drain and the source of the NMOS transistor Q10.

[0018] Further, the emitter of the NPN transistor Q9 is connected to the emitter of the PNP transistor Q6, the emitter of the PN transistor Q9 and the emitter of the PNP transistor Q6 are connected to the gate of the NMOS transistor Q11 through the parallel driving resistor R39 and the driving resistor R40, the fast diode D23 is connected in parallel to the driving resistor R39 and the driving resistor R40, the resistor R47 is connected in parallel to the gate and source of the NMOS transistor Q11, the fast diode D28 and another RC absorption circuit (resistor R55 in series with capacitor C58) are connected in parallel to the drain and source of the NMOS transistor Q11, and the pins 8 and 9 of the power driver chip U7 are grounded;

[0019] The main winding J4 of transformer T2 is connected to pin 4 of high-frequency transformer T1, and pin 2 of high-frequency transformer T1 returns to the center point (CEN) of the main voltage through two parallel capacitors C61 and C62. The voltage of the secondary of high-frequency transformer T1 after bridge rectification is connected to pin 3 of comparator U5A, and pin 1 of comparator U5A is connected to pin 10 of power driver chip U7.

[0020] In some embodiments, in the main power bridge rectifier and filter circuit, the positive voltage after the main power is rectified and filtered is connected in series with a resistor, and the voltage drop on the resistor is detected by transistor Q15. When the load of the power supply is too high, the transistor Q15 drives the transistor Q16 to provide a signal to the compression circuit to compress the input signal and avoid output distortion.

[0021] The input power supply of the present invention adopts a soft switch design, and uses a weak current to control the input strong current part. When the switch surge current protection circuit processes the startup surge current, after the power supply starts normally, the surge current protection component is short-circuited through a relay, so that additional useless power loss is avoided when working at high power. The power supply driver chip is powered by a flyback switching power supply, so that the power supply driver chip can work stably when working at high power. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Shown is a circuit principle block diagram of the present invention;

[0023] Figure 2A Shown is a circuit diagram of a flyback switching power supply circuit of the present invention;

[0024] Figure 2B Shown is a circuit diagram of a soft switch starting circuit of the present invention;

[0025] Figure 2C Shown is a circuit diagram of a power supply control circuit of the present invention;

[0026] Figure 3 Shown is a circuit diagram of a PFC circuit of the present invention;

[0027] Figure 4 Shown is a circuit diagram of a half-bridge switching power supply circuit of the present invention;

[0028] Figure 5 Shown is a circuit diagram of a second bridge rectifier filter circuit of the present invention.

[0029] The following are the descriptions of the reference numerals:

[0030] First 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, second 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. DETAILED DESCRIPTION

[0031] 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.

[0032] The principle block diagram of the present invention is shown in the attached Figure 1The present invention comprises: a first bridge rectifier filter circuit 01, the input end of the first bridge rectifier filter circuit 01 is connected to an AC input, the output end of the first bridge rectifier filter circuit 01 is connected to a power control circuit 03 through a flyback switch power supply circuit 02, the input end of a soft switch start circuit 04 is connected to the AC input and the power control circuit 03, the flyback switch power supply circuit 02 is connected to the soft switch start circuit 04, and the output end of the soft switch start circuit 04 is sequentially connected to a switch surge current protection circuit 05, a second bridge rectifier filter circuit 06, and a PFC circuit 07. Connected to the half-bridge switching power supply circuit 08, the input end of the half-bridge switching power supply circuit 08 is connected to the flyback switching power supply circuit 02, the output end of the half-bridge switching power supply circuit 08 is connected, the output end of the transformer isolation output circuit 09 is connected to the auxiliary power supply 1 rectifier filter circuit 10, the main power supply bridge rectifier filter circuit 11, and the auxiliary power supply 2 rectifier filter circuit 12, the output end of the auxiliary power supply 1 rectifier filter circuit 10 is connected to the switch impact current protection circuit 05, and the output ends of the main power supply bridge rectifier filter circuit 11 and the auxiliary power supply 2 rectifier filter circuit 12 are connected to the DC output;

[0033] The AC input (AC power input) is input to the first bridge rectifier filter circuit 01, and the flyback switching power supply circuit 02 is started by manually closing the soft switch circuit 04. After the power control circuit 03 obtains the power, the relay of the soft switch start circuit 04 is turned on. The AC power is boosted after passing through the startup surge current protection circuit 05, the second bridge rectifier filter circuit 06, and the PFC circuit 07, and then reaches the half-bridge switching power supply circuit 08, and outputs the main power supply and various auxiliary power supplies through the transformer isolation output circuit 09.

[0034] Furthermore, the AC input first passes through the first bridge rectifier and filter circuit 01, and the rectified DC enters the flyback switching power supply circuit 02. The output power is rectified and filtered to supply power to the power control circuit 03, the PFC circuit 07, and the half-bridge switching power supply circuit 08. After the power control circuit 03 is powered on, it controls the soft switch start circuit 04 to connect the main power supply line.

[0035] The second bridge rectifier filter circuit 06 is shown in the attached Figure 5 The second bridge rectifier filter circuit 06 includes: a PNP transistor Q15, the emitter E of the PNP transistor Q15 is connected to the positive electrode of the polar capacitor C155, the negative electrode of the diode D29, and the negative electrode of the diode D31, the negative electrode of the polar capacitor C155 is connected to the positive electrode of the polar capacitor C156, the positive electrode of the polar capacitor C156 is grounded, and the negative electrode of the polar capacitor C156 is connected to the power supply -85V; parallel resistors R123A, R123B, R124A, and R124B are connected between the emitter E and the base B of the PNP transistor Q15; the base B of the PNP transistor Q15 is connected to the power supply +85V through R51;

[0036] The polar capacitor C155 is connected in parallel with a resistor R92 and a light emitting diode D63, and the cathode of the light emitting diode D63 is grounded; the polar capacitor C156 is connected in parallel with a resistor R93 and a light emitting diode D62, and the cathode of the light emitting diode D62 is connected to a power supply -85V;

[0037] The power from the secondary winding of transformer T2 of the half-bridge switching power supply circuit 08 passes through the bridge rectifier circuit bridge (bridge rectifier circuit: diodes D29, D30, D31, D32) in the second bridge rectifier filter circuit 06, and then is filtered by polarity capacitors C155 and C156 to obtain positive and negative main voltages. The positive main voltage (power supply +85V) is connected in series with resistors R123~R124 (composed of parallel resistors R123A, R123B, R124A, R124B), and the PNP transistor Q15 is used to detect the voltage drop on the resistor to detect the voltage carried. The size of the load; when the load is too heavy, the PNP transistor Q15 is turned on, and the collector C of the PNP transistor Q15 is connected to (reaches) the base B of the NPN transistor Q16 through the resistor R90, the positive pole-negative pole of the diode D6, and the resistor R29. The base B of the NPN transistor Q16 is grounded after passing through the capacitor C105, and the collector C of the NPN transistor Q16 is connected to the power supply +12V. The emitter E of the NPN transistor Q16 is connected to the LIMIT terminal through the positive pole-negative pole of the diode D55 and the resistor R95, providing a trigger model to the compression circuit, which reduces the output by compressing the input signal.

[0038] The half-bridge switching power supply circuit 08 uses a totem pole driving method to drive the power MOS tube, a fast diode is connected in parallel to the driving resistor, a fast diode and an RC absorption circuit are connected in parallel to the drain and source of the MOS tube, and a resistor is connected in parallel to the gate and source of the MOS tube.

[0039] The incoming AC power first passes through the first bridge rectifier filter circuit 01, and reaches the flyback switching power supply circuit 02. After the driving optocoupler IC1 is started, the secondary rectifier and filter of the transformer T3 obtains the VCC-PRI voltage, and the voltage of +15V-PRI and +5VP is obtained through voltage stabilization. The +5VP voltage supplies power to the power control circuit 03. After obtaining the power supply, the control chip controls the relay RY1 of the soft switch start circuit 04 to close. The AC power passes through the relay RY1 to reach the switch inrush current protection circuit 05, the second bridge rectifier filter circuit 06, and the PFC circuit 07, and then reaches the half-bridge switching power supply circuit 08. The transformer isolation output circuit 09 boosts the voltage, and the main power supply bridge rectifier filter circuit 11 rectifies and filters to obtain the main voltage and its auxiliary power supply.

[0040] The auxiliary power supply 1 rectifier filter circuit 10 drives the transistor Q3 and transistor Q12 of the half-bridge switch power supply circuit 08 after rectification and filtering, and then the relay RY2 coil of the soft switch start circuit 04 is energized and closed, and the resistors R3, R4 and the thermistor PR1 on the switch surge current protection circuit 05 are short-circuited to reduce losses;

[0041] The voltage induced by the rectification and filtering circuit 12 of the auxiliary power supply 2 is based on the negative voltage of the main power supply. After rectification and filtering, the voltage is stabilized to obtain a voltage of +12V / -VCC, and the DC output is used for other circuits.

[0042] In some embodiments, the input power adopts a soft switching design, using weak current to control the input strong current part. When the switch surge current protection circuit 05 processes the power-on surge current, after the power supply starts normally, the surge current protection components are short-circuited through a relay to avoid additional useless power loss when working at high power. The power driver chip is powered by a flyback switching power supply, which enables the power driver chip to work stably when working at high power.

[0043] See the attached for power on method Figure 2A , Attachment Figure 2B , Attachment Figure 2C , including a flyback switching power supply circuit 02, a power supply control circuit 03, and a soft switch start circuit 04. The AC input reaches the pins 1 and 3 of the socket J16, and reaches the socket J15 through the cable holder, and then reaches the fuse F1 and the thermistor PR2, and then enters the bridge rectifier filter bridge BD1 of the first bridge rectifier filter circuit 01. D20 in the bridge rectifier filter bridge BD1 is a gas discharge tube. When used in the 110VAC voltage range, when the power supply is 220VAC, the gas discharge tube D20 will act to break the fuse F1, which plays a protective role; when the switch connected to the plug interface CN3 is closed, the flyback switching power supply circuit 02 is started, and the three voltages of VCC-PRI, +15V-PRI and +5VP are obtained after rectification, filtering and voltage stabilization at the secondary end of the transformer T3. The secondary winding of the transformer T3 is grounded after passing through the positive and negative electrodes of the diode D42 and the capacitor C102. The secondary winding of the transformer T3 is rectified and filtered after passing through the positive and negative electrodes of the diode D42 and the capacitor C102. The secondary winding of the transformer T3 is grounded after passing through the positive and negative electrodes of the diode D42, the resistor R88 and the positive and negative electrodes of the light-emitting diode D53. The light-emitting diode D53 plays an indicating role.

[0044] The cathode of diode D42 is connected to the cathode of voltage regulator tube D54, the anode of voltage regulator tube D54 is connected to pin 1 of optocoupler IC1 through resistor R89, pin 5 of optocoupler IC1 is connected to the cathode of diode D41, the anode of diode D41 is connected to pin 4 of transformer T3, pin 4 of optocoupler IC1 is connected to pin 4 of flyback switching power supply driver chip U10, used for feedback, wherein +5VP voltage supplies power to power supply control chip U15 of power supply control circuit 03, and then pin 5 of power supply control chip U15 controls the closing of relay RY1 of soft switch start circuit 04 through transistor Q18, and the alternating current reaches resistor R3, resistor R4 and thermistor PR1 of switch inrush current protection circuit 05 after passing through relay RY1, and reaches second bridge rectifier filter circuit 06. Pins 1-2, 3-4, 1-3, and 2-4 of rectifier bridge D11 are connected in parallel with capacitors.

[0045] PFC circuit 07 see attached Figure 3 , PFC circuit 07 is driven by PFC driver chip U8 through totem pole mode to drive two parallel NMOS tubes (NMOS tube Q4, NMOS tube Q5), PFC driver chip U8 pin 3 is connected to the source S of NMOS tube Q4, NMOS tube Q5 through resistor R1, resistor R11 ~ R18; PFC driver chip U8 pin 4 is connected to the drain D of NMOS tube Q4, NMOS tube Q5 through resistor R64, resistor R63, inductor L2; the source S of NMOS tube Q4, NMOS tube Q5 is grounded, and the drain D of NMOS tube Q4, NMOS tube Q5 is connected to VCC through the positive and negative electrodes of diode BD2; the gate G and source S of NMOS tube Q4 are connected in parallel with resistor R21, and the gate G and source S of NMOS tube Q5 are connected in parallel with resistor R22.

[0046] After the PFC driver chip U8 is powered on and started, the output is from the pin 8 of the PFC driver chip U8, and the PFC MOS tube is driven in a totem pole manner. The resistor R188 and the light-emitting diode D56 act as indicators. The resistors R11 to R18 act as short-circuit protection for the PFC NMOS tubes Q4 and Q5. Fast diodes D18 and D19 are connected in parallel to their driving resistors, and resistors R21 and R22 are connected in parallel between the gate and source of the NMOS tubes Q4 and Q5, respectively. Capacitors C16 and C17 are connected in parallel between the drain and source of the NMOS tubes Q4 and Q5, respectively. The resistor R24 ​​and capacitor C20 of the RC absorption circuit are connected in parallel to the fast diode BD2 for rectification.

[0047] Pin 7 of the PFC driver chip U8 is connected to the emitter E of the NPN transistor Q2 in the flyback switching power supply circuit 02 through the resistor R10, and the collector C of the NPN transistor Q2 is connected to the +15V-PRI terminal (that is, pin 7 of the PFC driver chip U8 is connected to the +15V-PRI terminal through the resistor R10 and the NPN transistor Q2), and pin 8 of the PFC driver chip U8 is connected to the base B of the NPN transistor Q1 and the base B of the PNP transistor Q14; the emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q14 are connected, and the emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q14 are connected to the gate G of the NMOS tube Q4 through the driving resistor R19, and the emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q14 are connected to the gate G of the NMOS tube Q5 through the driving resistor R20.

[0048] In some embodiments, the driving resistor R19 and the driving resistor R20 are respectively connected in parallel with a fast diode D18 and a fast diode D19, the anode of the fast diode D18 is connected to the gate G of the NMOS tube Q4, and the anode of the fast diode D19 is connected to the gate G of the NMOS tube Q5; the gate G and the source S of the NMOS tube Q4 and the NMOS tube Q5 are respectively connected in parallel with a resistor R21 and a resistor R22, and the drain D and the source S of the NMOS tube Q4 and the NMOS tube Q5 are respectively connected in parallel with a capacitor C16. And capacitor C17, resistors R11~R18 are connected in parallel and connected to the source S of NMOS tube Q4 and the source S of NMOS tube Q5. Resistors R11~R18 are connected in parallel to serve as short-circuit protection of NMOS tube Q4 and NMOS tube Q5. The drain D of NMOS tube Q4 and the drain D of NMOS tube Q5 are connected to the positive electrode of fast diode BD2, and the negative electrode of fast diode BD2 is connected to VCC. Resistor R24 ​​and capacitor C20 are connected in series and connected in parallel to fast diode BD2; the source S of NMOS tube Q5 is grounded.

[0049] Half-bridge switching power supply circuit 08 See attached Figure 4, the half-bridge switching power supply circuit 08 uses a totem pole method to drive the MOS tube. The driver chip U7 pin 2 and pin 3 are connected to +15V-PRI, and a small power switching power supply is used for power supply. The driver chip U7 pin 14 is connected to +15V-PRI through the cathode-positive pole of the diode D21. The source driver chip U7 pin 14 is connected to the power driver chip U7 pin 12 through the parallel capacitor C52 and capacitor C53. The power driver chip U7 pin 13 is connected to the base of the NPN transistor Q8 and the base of the PNP transistor Q7 through the resistor R38. The power driver chip U7 pin 13 is connected to the optocoupler U2 pin 1 through the resistor R43. The power driver chip U7 pin 11 is connected to the NPN transistor through the resistor R37. The base of Q9 and the base of PNP transistor Q6, the base of NPN transistor Q9 and the base of PNP transistor Q6 are connected to pin 1 of optocoupler U3 through resistor R44, the emitters of NPN transistor Q8 and PNP transistor Q7 are connected, the emitters of NPN transistor Q8 and PNP transistor Q7 are connected to the gate of NMOS tube Q10 through two parallel driving resistors R41 and driving resistor R42, the fast diode D22 is connected in parallel to the driving resistor R41 and the driving resistor R42, the resistor R48 is connected in parallel between the gate and source of NMOS tube Q10, and the fast diode D27 and the RC absorption circuit (composed of a resistor R54 and a capacitor C57 connected in series) are connected in parallel between the drain and source of NMOS tube Q10.

[0050] The half-bridge switching power supply circuit 08 has over-temperature / over-voltage / over-current protection, DC protection, and uses a temperature control switch to achieve thermal protection automatic shutdown, power limitation, hiccup protection, temperature reduction self-start, Reset protection, power-on reset, and software reset. The power driver chip U7 pins 2 and 3 are powered by the flyback switching power supply circuit 02, which makes the power supply of the driver chip stable during high-power output. The power driver chip U7 pins 13 and 11 drive the totem poles through driving resistors R38 and R37 to indirectly drive the NMOS tubes Q10 and N The MOS tube Q11 and the NMOS tube driving resistor R54 and the driving resistor R55 are connected in parallel with the fast diode D27 and the fast diode D28 respectively. The fast diode D27 and the diode D28 are connected in parallel between the drain and the source of the NMOS tube Q10 and the NMOS tube Q11 respectively. The RC absorption circuits R54-C57 (resistor R54 is connected in series with capacitor C57) and R55-C58 (resistor R55 is connected in series with capacitor C58) are connected in parallel between the drain and the source of the NMOS tube Q10 and the NMOS tube Q11 respectively.

[0051] The gate and source of the NMOS tube Q10 and the NMOS tube Q11 are connected in parallel with resistors R47 and R48 respectively. Pin 12 of the power driver chip U7 is output to the main winding J3 of the transformer T2. The parallel resistors R56 and R57 are current detection resistors. The current detection resistor is connected to the source of the NMOS tube Q11. The current detection resistor is connected to pin 3 of the comparator U5A through the resistor R53 and the positive and negative electrodes of the diode D37. Pin 1 of the comparator U5A is connected to pin 10 of the power driver chip U7 to achieve overcurrent protection.

[0052] The main winding J4 of the main transformer T2 on the half-bridge switching power supply circuit 08 flows through the primary of the high-frequency transformer T1, and is connected to the pin 3 of the comparator U5 through the positive and negative electrodes of the diode D39 after rectification and filtering at the secondary of the high-frequency transformer T1 to achieve overvoltage protection; the secondary winding pin 8 of the transformer T2 is rectified and filtered to supply power to the relay RY2, and the startup impact current protection component resistor R3, resistor R4, and thermistor PR1 are short-circuited to reduce the loss of useless power at high power.

[0053] The bases of transistors Q7 and Q8 are connected to pin 1 of optocoupler U2 through resistor R43, and pin 2 of optocoupler U2 is connected to pin 12 of power driver chip U7, which is used to detect the high-end drive of power driver chip U7, and the output result is connected from pin 3 of optocoupler U2 to pin 8 of power control chip U15 via resistor R45; the bases of transistors Q6 and Q9 are connected to pin 1 of optocoupler U3 through resistor R44, and pin 2 of optocoupler U3 is grounded, which is used to detect the low-end drive of power driver chip U7, and the output result is connected from pin 3 of optocoupler U3 to pin 7 of power control chip U15 via resistor R46, which is used to monitor the operating status of power driver chip U7.

[0054] In some embodiments, the emitter of the NPN transistor Q9 is connected to the emitter of the PNP transistor Q6, the emitter of the PN transistor Q9 and the emitter of the PNP transistor Q6 are connected to the gate of the NMOS transistor Q11 through the parallel driving resistor R39 and the driving resistor R40, the fast diode D23 is connected in parallel to the driving resistor R39 and the driving resistor R40, the resistor R47 is connected in parallel to the gate and source of the NMOS transistor Q11, the fast diode D28 and another RC absorption circuit (composed of a resistor R55 and a capacitor C58 connected in series) are connected in parallel to the drain and source of the NMOS transistor Q11, and the pins 8 and 9 of the power driver chip U7 are grounded;

[0055] The main winding J4 of transformer T2 is connected to pin 4 of high-frequency transformer T1, and pin 2 of high-frequency transformer T1 returns to the center point (CEN) of the main voltage through two parallel capacitors C61 and C62. The voltage of the secondary of high-frequency transformer T1 after bridge rectification is connected to pin 3 of comparator U5A, and pin 1 of comparator U5A is connected to pin 10 of power driver chip U7.

[0056] In some embodiments, in the main power bridge rectifier filter circuit 11, the positive voltage after the main power rectification and filtering is connected in series with a resistor, and the voltage drop on the resistor is detected by the transistor Q15 on the second bridge rectifier filter circuit 06. When the load of the power supply is too high, the transistor Q15 drives the transistor Q16 to provide a signal to the compression circuit to compress the input signal and avoid output distortion.

[0057] 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 circuit system for a high-power 6000W digital power amplifier, comprising: a first bridge rectifier filter circuit (01), characterized in that: The first bridge rectifier filter circuit (01) is connected to an AC input, and the rectified DC enters the flyback switch power supply circuit (02). The output power is rectified and filtered to supply power to the power control circuit (03), the PFC circuit (07), and the half-bridge switch power supply circuit (08). After the power control circuit (03) is powered on, it controls the soft switch start circuit (04) to connect the main power supply line; The AC power is input to the first 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, it is connected to the soft switch start circuit (04). The AC power passes through the startup surge current protection circuit (05), the second bridge rectifier filter circuit (06), and the PFC circuit (07), and then reaches the half-bridge switch power supply circuit (08). After the AC power is increased through the transformer isolation output circuit (09), the main power supply and various auxiliary power supplies are output; The input end of the first bridge rectifier filter circuit (01) is connected to the AC input, the output end of the first bridge rectifier filter circuit (01) is connected to the power control circuit (03) through the flyback switch power supply circuit (02), the input end of the soft switch start circuit (04) is connected to the AC input and the power control circuit (03), the flyback switch power supply circuit (02) is connected to the soft switch start circuit (04), the output end of the soft switch start circuit (04) is connected to the half-bridge switch power supply circuit (08) through the switch surge current protection circuit (05), the second bridge rectifier filter circuit (06), and the PFC circuit (07) in sequence, the input end of the half-bridge switch power supply circuit (08) is connected to the flyback switch power supply circuit (02), the output end of the half-bridge switch power supply circuit (08) is connected to the transformer isolation output circuit (09), the transformer isolation output circuit (09) The output end is connected to the auxiliary power supply 1 rectifier filter circuit (10), the main power supply bridge rectifier filter circuit (11), and the auxiliary power supply 2 rectifier filter circuit (12); the output end of the auxiliary power supply 1 rectifier filter circuit (10) is connected to the switch impact current protection circuit (05); the output ends of the main power supply bridge rectifier filter circuit (11) and the auxiliary power supply 2 rectifier filter circuit (12) are connected to the DC output; The second bridge rectifier filter circuit (06) The invention comprises: a PNP transistor Q15, diodes D29, D30, D31 and D32 in a second bridge rectifier filter circuit (06) form a bridge rectifier circuit bridge, diodes D29, D30, D31 and D32 form a bridge arm circuit, one diagonal of the bridge arm is connected to the emitter E of the PNP transistor Q15, and the other diagonal of the bridge arm is connected to the negative electrode of the polar capacitor C156; the emitter E of the PNP transistor Q15 is connected to the positive electrode of the polar capacitor C155, the negative electrode of the polar capacitor C155 is connected to the positive electrode of the polar capacitor C156, the positive electrode of the polar capacitor C156 is grounded, and the negative electrode of the polar capacitor C156 is connected to a power supply -85V; resistors R123A, R123B, R124A and R124B are connected in parallel between the emitter E and the base B of the PNP transistor Q15; the base B of the PNP transistor Q15 is connected to the power supply +85V through R51; The polar capacitor C155 is connected in parallel with a resistor R92 and a light emitting diode D63, and the cathode of the light emitting diode D63 is grounded; the polar capacitor C156 is connected in parallel with a resistor R93 and a light emitting diode D62, and the cathode of the light emitting diode D62 is connected to a power supply -85V; The power from the secondary winding of the transformer T2 of the half-bridge switching power supply circuit (08) passes through the bridge stack rectifier circuit bridge in the second bridge rectifier filter circuit (06), and then is filtered by polarity capacitors C155 and C156 to obtain positive and negative main voltages. The size of the load is detected by connecting resistors R123-R124 in series to the positive main voltage and using a PNP transistor Q15 to detect the voltage drop on the resistor. When the load is too heavy, the PNP transistor Q15 is turned on and the PNP transistor Q15 is turned on. The collector C of the tube Q15 is connected to the base B of the NPN transistor Q16 through the resistor R90, the positive and negative electrodes of the diode D6, and the resistor R29. The base B of the NPN transistor Q16 is grounded after passing through the capacitor C105. The collector C of the NPN transistor Q16 is connected to the power supply +12V. The emitter E of the NPN transistor Q16 is connected to the LIMIT terminal through the positive and negative electrodes of the diode D55 and the resistor R95, providing a trigger model to the compression circuit to reduce the output by compressing the input signal. The PFC circuit (07) is driven by a PFC driver chip U8 in a totem pole manner to drive two parallel NMOS tubes. The pin 3 of the PFC driver chip U8 is connected to the source S of the NMOS tubes Q4 and Q5 through a resistor R1 and resistors R11 to R18; the pin 4 of the PFC driver chip U8 is connected to the drain D of the NMOS tubes Q4 and Q5 through a resistor R64, a resistor R63 and an inductor L2; the source S of the NMOS tubes Q4 and Q5 is grounded, and the drain D of the NMOS tubes Q4 and Q5 is connected to VCC through the positive and negative electrodes of a diode BD2; a resistor R21 is connected in parallel to the gate G and source S of the NMOS tube Q4, and a resistor R22 is connected in parallel to the gate G and source S of the NMOS tube Q5; Pin 7 of the PFC driver chip U8 is connected to the emitter E of the NPN transistor Q2 in the flyback switching power supply circuit (02) through a resistor R10, the collector C of the NPN transistor Q2 is connected to the +15V-PRI terminal, and pin 8 of the PFC driver chip U8 is connected to the base B of the NPN transistor Q1 and the PNP transistor Q14; the emitter of the NPN transistor Q1 is connected to the emitter of the PNP transistor Q14, the emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q14 are connected to the gate G of the NMOS transistor Q4 through a driving resistor R19, and the emitter of the NPN transistor Q1 and the emitter of the PNP transistor Q14 are connected to the gate G of the NMOS transistor Q5 through a driving resistor R20; The half-bridge switching power supply circuit (08) uses a totem pole method to drive the MOS tube. Pins 2 and 3 of the power driver chip U7 are connected to +15V-PRI. A low-power switching power supply is used for power supply. Pin 14 of the power driver chip U7 is connected to +15V-PRI through the cathode-anode of the diode D21. Pin 14 of the power driver chip U7 is connected to pin 12 of the power driver chip U7 through capacitors C52 and C53 connected in parallel. Pin 13 of the power driver chip U7 is connected to the base of the NPN transistor Q8 and the base of the PNP transistor Q7 through resistor R38. Pin 13 of the power driver chip U7 is connected to pin 1 of the optocoupler U2 through resistor R43. Pin 11 of the power driver chip U7 is connected to pin 1 of the optocoupler U2 through resistor R37 is connected to the base of NPN transistor Q9 and the base of PNP transistor Q6, the base of NPN transistor Q9 and the base of PNP transistor Q6 are connected to pin 1 of optocoupler U3 through resistor R44, the emitters of NPN transistor Q8 and PNP transistor Q7 are connected, the emitters of NPN transistor Q8 and PNP transistor Q7 are connected to the gate of NMOS tube Q10 through two parallel driving resistors R41 and driving resistor R42, the fast diode D22 is connected in parallel to the driving resistor R41 and the driving resistor R42, the resistor R48 is connected in parallel between the gate and source of NMOS tube Q10, and the fast diode D27 and an RC absorption circuit are connected in parallel between the drain and source of NMOS tube Q10.

2. The power circuit system of a high-power 6000W digital power amplifier according to claim 1, characterized in that: The auxiliary power supply 1 rectifier and filter circuit (10) drives the transistor Q3 and transistor Q12 of the half-bridge switch power supply circuit (08) after rectification and filtering, and then the relay RY2 coil of the soft switch start circuit (04) is energized and closed, and the resistors R3, R4 and the thermistor PR1 on the switch surge current protection circuit (05) are short-circuited to reduce losses; The voltage induced by the auxiliary power supply 2 rectification and filtering circuit (12) is based on the negative voltage of the main power supply. After rectification and filtering, the voltage is stabilized to obtain a voltage of +12V / -VCC, and the DC output is used by other circuits.

3. The power circuit system of a high-power 6000W digital power amplifier according to claim 1, characterized in that: The driving resistor R19 and the driving resistor R20 are respectively connected in parallel with a fast diode D18 and a fast diode D19, the anode of the fast diode D18 is connected to the gate G of the NMOS tube Q4, and the anode of the fast diode D19 is connected to the gate G of the NMOS tube Q5; the gate G and the source S of the NMOS tube Q4 and the NMOS tube Q5 are respectively connected in parallel with a resistor R21 and a resistor R22, and the drain D and the source S of the NMOS tube Q4 and the NMOS tube Q5 are respectively connected in parallel with a capacitor C16 and a capacitor C22. C17, resistors R11~R18 are connected in parallel to the source S of NMOS tube Q4 and the source S of NMOS tube Q5, resistors R11~R18 are connected in parallel to serve as short-circuit protection for NMOS tube Q4 and NMOS tube Q5, the drain D of NMOS tube Q4 and the drain D of NMOS tube Q5 are connected to the positive electrode of fast diode BD2, the negative electrode of fast diode BD2 is connected to VCC, resistor R24 ​​and capacitor C20 are connected in series and then connected in parallel to the fast diode BD2; the source S of NMOS tube Q5 is grounded.

4. The power circuit system of a high-power 6000W digital power amplifier according to claim 1, characterized in that: The emitter of the NPN transistor Q9 is connected to the emitter of the PNP transistor Q6, the emitter of the PN transistor Q9 and the emitter of the PNP transistor Q6 are connected to the gate of the NMOS transistor Q11 through the parallel driving resistor R39 and the driving resistor R40, the fast diode D23 is connected in parallel to the driving resistor R39 and the driving resistor R40, the resistor R47 is connected in parallel to the gate and source of the NMOS transistor Q11, the fast diode D28 and another RC absorption circuit are connected in parallel to the drain and source of the NMOS transistor Q11, and the pins 8 and 9 of the power driver chip U7 are grounded; The main winding J4 of transformer T2 is connected to pin 4 of high-frequency transformer T1, and pin 2 of high-frequency transformer T1 returns to the center point of the main voltage through two parallel capacitors C61 and capacitor C62. The voltage of the secondary of high-frequency transformer T1 after bridge rectification is connected to pin 3 of comparator U5A, and pin 1 of comparator U5A is connected to pin 10 of power driver chip U7.

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