An ultra-low impedance power amplifier circuit for driving a horn

Abstract

The application relates to an ultra-low impedance power amplifier circuit for driving a loudspeaker, which comprises a front-stage module and a back-stage module electrically connected with the front-stage module. The back-stage module receives a control signal from the front-stage module and adjusts the control signal to regulate the output power of the loudspeaker. The back-stage module comprises a first signal modulation unit, a first signal processing unit electrically connected with the first signal modulation unit, a second signal modulation unit arranged in parallel with the first signal modulation unit, a second signal processing unit electrically connected with the second signal modulation unit, a protection circuit unit connected between the first and second signal processing units, and a signal output unit electrically connected with the first and second signal processing units. The power amplifier circuit can directly use battery voltage without a power supply voltage boosting circuit, improves the power supply use efficiency, and can increase the output power.

Description

Technical Field

[0001] This invention relates to the field of damping technology, and in particular to an ultra-low impedance power amplifier circuit for driving a loudspeaker. Background Technology

[0002] The output power, efficiency, gain, and linearity of a power amplifier are directly determined by the source impedance of its input matching network and the load impedance of its output matching network. Therefore, the source impedance and load impedance of a power amplifier are crucial to its design.

[0003] For loudspeakers, the intensity or volume of the output sound often needs to be adjusted, and the greater the adjustment range, the better. However, the impedance of existing power amplifier circuits is generally relatively high, which limits the range of sound adjustment. Summary of the Invention

[0004] In view of this, the present invention provides an ultra-low impedance power amplifier circuit for driving a speaker that can solve the above problems.

[0005] An ultra-low impedance power amplifier circuit for driving a loudspeaker includes a preamplifier module and a power amplifier module electrically connected to the preamplifier module. The power amplifier module receives and adjusts a control signal from the preamplifier module to regulate the loudspeaker's output power. The power amplifier module includes a first signal modulation unit, a first signal processing unit electrically connected to the first signal modulation unit, a second signal modulation unit connected in parallel with the first signal modulation unit, a second signal processing unit electrically connected to the second signal modulation unit, a protection circuit unit connected between the first and second signal processing units, and a signal output unit electrically connected to the first and second signal processing units.

[0006] Further, the first signal modulation unit includes a first amplifier U22B, a capacitor C29 and a resistor R1 electrically connected in sequence to the output terminal of the first amplifier U22B, a second amplifier U21B, a resistor R4 connected to the output terminal of the second amplifier U21B, and a third amplifier U20B connected to the resistor R4. The positive terminal of the first amplifier U22B is grounded, the output terminal of the second amplifier U21B is connected to the negative terminal of the third amplifier U20B and the negative terminal of the third amplifier U20B is grounded, the negative terminal of the second amplifier U21B is connected to the positive terminal of the third amplifier U20B, and two capacitors C28 and C12 and two diodes Z7 and Z8 are connected in parallel between the output terminal and the negative terminal of the second amplifier U21B.

[0007] Furthermore, both diodes Z7 and Z8 are Zener diodes, and the negative terminals of the two diodes Z7 and Z8 are connected together.

[0008] Furthermore, the second signal modulation unit includes a fourth amplifier U21A, a fifth amplifier U20A connected to the output terminal of the fourth amplifier U21A, the positive terminal of the fourth amplifier U21A being electrically connected to the signal output unit, and two capacitors C27 and C11 and two diodes Z5 and Z6 connected in parallel between the output terminal and the negative terminal of the fourth amplifier U21A.

[0009] Furthermore, both diodes Z5 and Z6 are Zener diodes, and the negative terminals of the two diodes Z5 and Z6 are electrically connected.

[0010] Furthermore, the first signal processing unit includes a first processor B23 electrically connected to the output of the first signal modulation unit, and two first MOS transistors Q1 and Q2 respectively connected to the high-level pin and low-level pin of the first processor B23. The gates of the first and second MOS transistors Q1 and Q2 are connected to the first processor B23, the drains are grounded, and the sources are connected to the signal output unit.

[0011] Furthermore, both the first and second MOSFETs, Q1 and Q2, are N-type MOSFETs.

[0012] Furthermore, the second signal processor includes a second processor B24 electrically connected to the output terminal of the second signal modulation unit, and two third MOS transistors Q3 and Q4 respectively connected to the high-level pin and low-level pin of the second processor B24. The gates of the third and fourth MOS transistors Q3 and Q4 are connected to the second processor B24, the drains are grounded, and the sources are connected to the signal output unit. The third and fourth MOS transistors Q3 and Q4 are both N-type MOS transistors.

[0013] Furthermore, the protection circuit unit includes a first transistor Q10 electrically connected to the first processor B23, and a second transistor Q9 electrically connected to the first transistor Q10. The emitter of the first transistor Q10 is connected to the power supply pin of the first processor B23, the collector is connected to the power supply, the base is connected to the collector of the second transistor Q9, the emitter of the second transistor Q9 is grounded, and the base is connected to the anode of a Zener diode Z3. The cathode of the Zener diode Z3 is grounded.

[0014] Furthermore, the signal output unit includes a high-level terminal connected to the preamplifier module, two low-level terminals respectively connected to the high-level terminal, the speaker electrically connected between the high-level terminal and the low-level terminal, a first inductor L2 connected between the output terminal of the first signal processing unit and the low-level terminal, a second inductor L1 connected between the output terminal of the second signal processing unit and the low-level terminal, a capacitor C6 electrically connected between the first inductor L2 and ground, and a capacitor C15 connected between the second inductor L1 and ground.

[0015] Compared with the prior art, the ultra-low impedance power amplifier circuit for driving a speaker provided by the present invention includes a preamplifier module and a power amplifier module electrically connected to the preamplifier module. The power amplifier module receives control signals from the preamplifier module and adjusts them to regulate the output power of the speaker. The power amplifier module includes a first signal modulation unit, a first signal processing unit electrically connected to the first signal modulation unit, a second signal modulation unit connected in parallel with the first signal modulation unit, a second signal processing unit electrically connected to the second signal modulation unit, and a protection circuit connected between the first and second signal processing units. The system includes a unit and a signal output unit electrically connected to the first and second signal processing units. The first and second signal modulation units modulate the signals from the front-end module into digital pulse signals, thereby driving the processors of the first and second signal processing units to work. In turn, the processors drive the four MOS transistors Q1 / Q4 / Q3 / Q2 to work and drive the speaker. This eliminates the need for a power boost circuit and allows the use of battery voltage, improving power efficiency. At the same time, it can increase the output power, such as 500W to 1000W, which can drive ultra-low impedance speakers of 1OHM-0.1OHM. Attached Figure Description

[0016] Figure 1 The present invention provides a circuit diagram of a preamplifier module for an ultra-low impedance power amplifier circuit used to drive a speaker.

[0017] Figure 2 The present invention provides a circuit diagram of the power stage unit of an ultra-low impedance power amplifier circuit for driving a loudspeaker. Detailed Implementation

[0018] The following provides a more detailed description of specific embodiments of the present invention. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the scope of protection of the present invention.

[0019] like Figures 1 to 2The diagram shown is a circuit diagram of an ultra-low impedance power amplifier circuit for driving a loudspeaker provided by the present invention. The ultra-low impedance power amplifier circuit for driving a loudspeaker includes a preamplifier module 10 and a power amplifier module 20 electrically connected to the preamplifier module 10. It is conceivable that the ultra-low impedance power amplifier circuit for driving a loudspeaker also includes other functional modules, such as power supplies, transformer modules, etc., which are technologies known to those skilled in the art and will not be described in detail here.

[0020] The preamplifier module 10 is a common circuit module for driving the speaker, including a signal generation circuit, a comparison module, a power supply module, etc., which are existing technologies and will not be described in detail here. Specifically, the signal generation circuit is used to generate a circuit that controls the speaker's sound output according to user instructions or program instructions. The comparison module is used to obtain the amplification or reduction ratio by comparing the parameter values ​​of the sound signal generated by the signal generation circuit with set parameter values, thereby achieving the purpose of power amplification. The power supply module is used to provide power to the power-consuming electronic components such as chips and MOSFETs in the power amplifier circuit, and also to provide power to other functional circuits. Its specific circuit composition is as follows: Figure 1 As shown, it will not be elaborated further here.

[0021] The downstream module 20 includes a first signal modulation unit 21, a first signal processing unit 22 electrically connected to the first signal modulation unit 21, a second signal modulation unit 23 connected in parallel with the first signal modulation unit 21, a second signal processing unit 24 electrically connected to the second signal modulation unit 23, a protection circuit unit 25 connected between the first and second signal processing units 22 and 24, and a signal output unit 26 electrically connected to the first and second signal processing units 22 and 24. It is conceivable that the downstream module 20 also includes a compatibility circuit module for compatibility with the upstream module 10. This compatibility circuit module allows the downstream module 20 to adapt to various upstream modules 10.

[0022] The first signal modulation unit 21 is used to modulate the input sound signal, that is, to modulate the input triangular wave signal into a pulse digital signal, so as to drive the first signal processing unit 22 to work. Specifically, the first signal modulation unit 21 includes a first amplifier U22B, a capacitor C29 and a resistor R1 electrically connected in sequence to the output terminal of the first amplifier U22B, a second amplifier U21B, a resistor R4 connected to the output terminal of the second amplifier U21B, and a third amplifier U20B connected to the resistor R4. The positive terminal of the first amplifier U22B is grounded, the output terminal of the second amplifier U21B is connected to the negative terminal of the third amplifier U20B, and the negative terminal of the third amplifier U20B is grounded. The negative terminal of the second amplifier U21B is connected to the positive terminal of the third amplifier U20B, and two capacitors C28 and C12 and two diodes Z7 and Z8 are connected in parallel between the output terminal and the negative terminal of the second amplifier U21B. Of course, the first signal modulation unit 21 also includes other auxiliary electronic components, such as resistors, which will not be described in detail here. Both diodes Z7 and Z8 are Zener diodes, and the negative terminals of the two diodes Z7 and Z8 are connected together.

[0023] The second signal modulation unit 23 has the same function as the first signal modulation unit 21. The combined action of the two signal modulation units 21 and 23 can modulate the triangular wave signal into a continuous digital pulse signal with four intervals. The second signal modulation unit 23 includes a fourth amplifier U21A and a fifth amplifier U20A connected to the output of the fourth amplifier U21A. The positive terminal of the fourth amplifier U21A is electrically connected to the second signal output unit 24. Two capacitors C27 and C11 and two diodes Z5 and Z6 are connected in parallel between the output and negative terminals of the fourth amplifier U21A. Both diodes Z5 and Z6 are Zener diodes, and their negative terminals are electrically connected. Of course, the second signal modulation unit 23 also includes other auxiliary electronic components, such as resistors, which will not be described in detail here.

[0024] The first signal processing unit 22 processes the pulse digital signal output from the first signal modulation unit 21 to automatically adjust the dead zone of the data pulse signal, thereby expanding the adjustment range of the power amplifier and achieving lower impedance power output without the need for a power supply boost circuit. The first signal processing unit 22 includes a first processor B23 electrically connected to the output of the first signal modulation unit 21, and two MOSFETs, a first MOSFET Q1 and a second MOSFET Q2, respectively connected to the high-level and low-level pins of the first processor B23. The gates of the first and second MOSFETs Q1 and Q2 are connected to the first processor B23, their drains are grounded, and their sources are connected to the signal output unit. Both the first and second MOSFETs Q1 and Q2 are N-type MOSFETs.

[0025] The second signal processor 24 has the same function as the first signal processing unit 22, processing two of the four pulse signals. The second signal processor 24 includes a second processor B24 electrically connected to the output of the second signal modulation unit 23, and two third MOSFETs Q3 and Q4 respectively connected to the high-level and low-level pins of the second processor B24. The gates of the third and fourth MOSFETs Q3 and Q4 are connected to the second processor B24, their drains are grounded, and their sources are connected to the signal output unit. Both the third and fourth MOSFETs Q3 and Q4 are N-type MOSFETs.

[0026] The protection circuit unit 25 is used to protect the first and second processors B23 and B24 so that they can operate normally and are not burned out by sudden peak voltage. The protection circuit unit 25 includes a first transistor Q10 electrically connected to the first processor B23 and a second transistor Q9 electrically connected to the first transistor Q10. The emitter of the first transistor Q10 is connected to the power supply pin of the first processor B23, the collector is connected to the power supply, the base is connected to the collector of the second transistor Q9, the emitter of the second transistor Q9 is grounded, and the base is connected to the anode of a Zener diode Z3. The cathode of the Zener diode Z3 is grounded.

[0027] The signal output unit 26 is connected to the first and second signal processing units 22 and 24 to drive the speaker to emit sound according to user requirements, based on the signals processed by the first and second signal processing units 22 and 24. The signal output unit 26 includes a high-level terminal 261 connected to the preamplifier module 10 and two low-level terminals 262 electrically connected to the first and second signal processing units 22 and 24, respectively. The speaker is electrically connected between the high-level terminal 261 and the low-level terminal 261. A first inductor L2 is connected between the output terminal of the first signal processing unit 22 and the low-level terminal 262, and a second inductor L1 is connected between the output terminal of the second signal processing unit 24 and the low-level terminal 262. A capacitor C6 is electrically connected between the first inductor L2 and ground, and a capacitor C15 is connected between the second inductor L1 and ground.

[0028] Compared with the prior art, the ultra-low impedance power amplifier circuit for driving a speaker provided by the present invention includes a preamplifier module 10 and a power amplifier module 20 electrically connected to the preamplifier module 10. The power amplifier module 20 receives control signals from the preamplifier module 10 and adjusts them to regulate the output power of the speaker. The power amplifier module 20 includes a first signal modulation unit 21, a first signal processing unit 22 electrically connected to the first signal modulation unit 21, a second signal modulation unit 23 connected in parallel with the first signal modulation unit 21, a second signal processing unit 24 electrically connected to the second signal modulation unit 23, a protection circuit unit 25 connected between the first and second signal processing units 22 and 24, and a signal output unit 26 electrically connected to the first and second signal processing units 22 and 24. The signals from the front-end module 10 are modulated into digital pulse signals by the first and second signal modulation units 21 and 23, thereby driving the processors of the first and second signal processing units 22 and 24 to work, and then driving the four MOS transistors Q1, Q4, Q3 and Q2 to work to drive the speaker. This eliminates the need for a power boost circuit and allows the use of battery voltage directly, improving power efficiency. At the same time, it can increase the output power, such as 500W to 1000W, which can drive ultra-low impedance speakers of 1OHM-0.1OHM.

[0029] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions or improvements within the spirit of the present invention are covered within the scope of the claims of the present invention.

Claims

1. An ultra-low impedance power amplifier circuit for driving a loudspeaker, characterized by: The low-impedance power amplifier circuit for driving the loudspeaker comprises a front-stage module and a back-stage module electrically connected with the front-stage module, the back-stage module receives the control signal from the front-stage module and adjusts the control signal to regulate the output power of the loudspeaker, the back-stage module comprises a first signal modulation unit, a first signal processing unit electrically connected with the first signal modulation unit, a second signal modulation unit arranged in parallel with the first signal modulation unit, a second signal processing unit electrically connected with the second signal modulation unit, a protection circuit unit connected between the first and second signal processing units, and a signal output unit electrically connected with the first and second signal processing units, the first signal modulation unit comprises a first amplifier U22B, a capacitor C29, a resistor R1, a second amplifier U21B connected in sequence with the output terminal of the first amplifier U22B, a resistor R4 connected with the output terminal of the second amplifier U21B, a third amplifier U20B connected with the resistor R4, the positive electrode of the first amplifier U22B is grounded, the output terminal of the second amplifier U21B is connected with the negative electrode of the third amplifier U20B and the negative electrode of the third amplifier U20B is grounded, the negative electrode of the second amplifier U21B is connected with the positive electrode of the third amplifier U20B, two capacitors C28 and C12 and two diodes Z7 and Z8 connected in parallel are connected between the output terminal and the negative electrode of the second amplifier U21B, the negative electrodes of the two diodes Z7 and Z8 are electrically connected together, the second signal modulation unit comprises a fourth amplifier U21A and a fifth amplifier U20A connected with the output terminal of the fourth amplifier U21A, the positive electrode of the fourth amplifier U21A is electrically connected with the signal output unit, two capacitors C27 and C11 and two diodes Z5 and Z6 connected in parallel are connected between the output terminal and the negative electrode of the fourth amplifier U21A, the negative electrodes of the two diodes Z5 and Z6 are electrically connected together.The first signal processing unit comprises a first processor B23 electrically connected to the output of the first signal modulation unit, and a first MOS tube Q1 and a second MOS tube Q2 respectively connected to the high level pin and the low level pin of the first processor B23, the gate of the first and second MOS tubes Q1, Q2 being connected to the first processor B23, the drain being grounded, and the source being connected to the signal output unit. The second signal processing unit comprises a second processor B24 electrically connected to the output of the second signal modulation unit, and a third MOS tube Q3 and a fourth MOS tube Q4 respectively connected to the high level pin and the low level pin of the second processor B24, the gate of the third and fourth MOS tubes Q3, Q4 being connected to the second processor B24, the drain being grounded, and the source being connected to the signal output unit. The third and fourth MOS tubes Q3, Q4 are both N-type MOS tubes.

2. The ultra-low impedance power amplifier circuit for driving a horn of claim 1, wherein: Both diodes Z7 and Z8 are voltage stabilizing diodes.

3. The ultra-low impedance power amplifier circuit for driving a horn of claim 1, wherein: Both diodes Z5 and Z6 are voltage stabilizing diodes.

4. The ultra-low impedance power amplifier circuit for driving a horn of claim 1, wherein: Both the first and second MOS tubes Q1 and Q2 are N-type MOS tubes.

5. The ultra-low impedance power amplifier circuit for driving a horn of claim 1, wherein: The protection circuit unit comprises a first transistor Q10 electrically connected to the first processor B23, and a second transistor Q9 electrically connected to the first transistor Q10, the emitter of the first transistor Q10 is connected to the power supply pin of the first processor B23, the collector is connected to the power supply, the base is connected to the collector of the second transistor Q9, the emitter of the second transistor Q9 is grounded, and the base is connected to the anode of a voltage stabilizing diode Z3, and the cathode of the voltage stabilizing diode Z3 is grounded.

6. The ultra-low impedance power amplifier circuit for driving a horn of claim 1, wherein: The signal output unit comprises a high-level end connected to the front-stage module, two low-level ends respectively connected to the high-level end, the loudspeaker is electrically connected between the high-level end and the low-level end, the output end of the first signal processing unit is connected with the first inductor L2 between the low-level end, the output end of the second signal processing unit is connected with the second inductor L1 between the low-level end, the first inductor L2 is connected with the capacitor C6 between the ground, and the second inductor L1 is connected with the capacitor C15 between the ground.

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