Energy storage circuit for passive control of loudspeaker and control method thereof

Abstract

The present invention discloses an energy storage circuit for passive control of a loudspeaker and a control method thereof, which is suitable for high-power and non-high-frequency loudspeakers. The energy storage circuit includes a frequency selection network, a rectification network, a DC-DC module, an energy storage element, and a management module. The frequency selection network, the rectification network, and the DC-DC module are connected in sequence to convert the changing energy in the loudspeaker into a suitable energy storage voltage and provide it to the energy storage element; the management module controls the DC-DC module according to the energy and energy storage voltage of the loudspeaker, and optimizes the performance of the control circuit. The present invention sets an energy storage circuit at the passive end of the loudspeaker connected to the audio amplifier circuit, which can provide a stable and reliable power supply to the control circuit of the passive end according to the audio signal conditions, thereby avoiding damage to the sound quality.

Description

Technical Field

[0001] The present invention relates to the field of electronic products, and in particular to an energy storage circuit for passive control of a loudspeaker and a control method thereof. Background Art

[0002] Speakers are ubiquitous in audio systems, from small, homemade sound systems to large alarm and broadcast systems. As electro-acoustic transducers, speakers' performance isn't as easily controlled as circuits. Furthermore, due to the uncertainty and drive characteristics of audio signals, speaker performance requires real-time monitoring. Therefore, improving audio system performance requires not only circuit innovation but also real-time monitoring and control based on speaker conditions.

[0003] However, as a conversion device, the speaker has unstable and discontinuous voltage and cannot power the attached monitoring and control circuits. In addition, improper energy loss in the speaker can easily seriously affect the sound quality.

[0004] Therefore, in order to effectively monitor and control the loudspeaker, it is necessary to provide an energy storage circuit for passive control of the loudspeaker. Summary of the Invention

[0005] To address the aforementioned technical issues, the present invention provides an energy storage circuit for passive loudspeaker control, suitable for high-power, low-frequency loudspeakers. The circuit comprises a frequency selection network, a rectifier network, a DC-DC module, an energy storage element, and a management module. The frequency selection network's input is connected to the loudspeaker, which is then sequentially connected to the rectifier network and the DC-DC module. The network outputs a shaped usable voltage to provide energy for the energy storage element. The management module controls the DC-DC module based on the loudspeaker's energy and the energy storage voltage of the energy storage element, and optimizes the control circuit's performance.

[0006] The frequency selection network is a low-frequency filter with a cut-off frequency lower than the highest value of the intermediate frequency in the audible sound frequency range of the human ear. The input end is connected to the speaker to obtain energy within the available frequency band, and the output end is connected to the rectifier network. The rectifier network shapes the voltage within the available frequency band into pulsating direct current, and the output end is connected to the input end of the DC-DC module for the DC-DC module to adjust the energy storage voltage. The DC-DC module converts the pulsating direct current into energy storage voltage according to the instructions of the management module. The control end is connected to the output end of the management module, and the output end is connected to the energy storage element to provide it with energy. The energy storage element is a supercapacitor, one end of which is connected to the output end of the DC-DC module and the other end is grounded.

[0007] The DC-DC module includes a switch tube, and the control end of the switch tube is the control end of the DC-DC module, which is connected to the output end of the management module.

[0008] The management module controls the DC-DC module and optimizes the performance of the control circuit based on the energy of the speaker and the energy storage voltage of the energy storage element, and includes a startup unit, a power control unit, and a drive unit. The startup unit acts as a temporary power source when the audio system is powered on or when the instantaneous energy provided by the speaker does not meet the required power. The startup unit includes a first diode, a second clamping diode, a third diode, a first resistor, and a small-capacity energy storage element. The positive electrode of the first diode is connected to the positive electrode of the small-capacity energy storage element, and the negative electrode is connected to the power supply terminal of the power control unit. The positive electrode of the second clamping diode is grounded, and the negative electrode is connected to the positive electrode of the small-capacity energy storage element. The positive electrode of the third diode is connected to the output terminal of the rectifier network, and the negative electrode is connected to one end of the first resistor. The other end of the first resistor is connected to the positive electrode of the small-capacity energy storage element and the first input terminal of the power management unit. The positive electrode of the small-capacity energy storage element is connected to the other end of the first resistor, and the negative electrode is grounded. The power control unit is used to control the static power consumption of the energy storage circuit and control the drive unit. The first input end is connected to the other end of the first resistor, the second input end is connected to the ungrounded end of the energy storage element via a voltage divider circuit, the power end is connected to the ungrounded end of the energy storage element and the cathode of the first diode via a fourth diode, and the output end is connected to one of the input ends of the drive unit. The drive unit is used to adjust the duty cycle of the switch tube in the DC-DC module according to the energy storage voltage, the energy provided by the speaker, and the control of the power control unit. It mainly includes a first operational amplifier, a first comparator, a second comparator, and an AND gate. The input end of the first operational amplifier is connected to the output end of the rectifier network and the ungrounded end of the energy storage element via a voltage divider circuit, the other input end is connected to reference voltage 1, and the output end is connected to one input end of the first comparator. The other input end of the first comparator is a triangular wave signal, and the output end is connected to one input end of the AND gate. The second comparator has one input end directly connected to the ungrounded end of the energy storage element, the other input end is connected to reference voltage 2, and the output end enable signal is connected to the other input end of the AND gate. The output end of the AND gate is connected to the control end of the DC-DC module.

[0009] When the input end of the power control unit detects that the output of the rectifier network is 0, that is, the speaker has no energy and the audio system is turned off, the enable signal is low, that is, the drive unit is turned off.

[0010] The present invention also provides a method for controlling an energy storage circuit for passive control of a loudspeaker, comprising the following S1-S4.

[0011] S1: When the speaker is first started or receives low-frequency energy, a small-capacity energy storage element provides temporary power to the management module.

[0012] S2: The power control module detects the energy received by the speaker and controls the switch of the driving module;

[0013] S2.1: When the power control module detects that the speaker receives energy, it turns on the driving module;

[0014] S2.2: When the power control module detects that the speaker does not receive energy, it turns off the driving module.

[0015] S3: The driving module generates a changing PWM signal;

[0016] S3.1: The driving module generates a PWM signal using the signal received by the speaker as an input signal and the energy storage voltage on the energy storage element as a feedback signal;

[0017] S3.2: The power control module limits the circuit current by limiting the maximum duty cycle of the PWM signal generated by the driving module according to the energy storage voltage on the energy storage element.

[0018] S4: The DC-DC module switches according to the signal from the driving module to control the energy storage of the energy storage element.

[0019] The energy storage circuit for passive speaker control described in the present invention can be set at the passive end of the speaker connected to the audio amplifier circuit. According to the audio signal situation, a stable power supply is provided to the control circuit of the passive end, thereby avoiding damage to the sound quality and realizing effective protection and control of the audio system.

[0020] In order to make the above contents of the present invention more clearly understood, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a system block diagram of an energy storage circuit for passive control of a loudspeaker according to the present invention;

[0023] Figure 2 A circuit diagram of the drive unit according to the present invention;

[0024] Numbers in the figure:

[0025] 10: frequency selection network; 20: rectifier network; 30: DC-DC module; 40: energy storage element;

[0026] 50: Management module; 501: Power control unit; 502: Drive unit;

[0027] D1: first diode; D2: second clamping diode; D3: third diode; D4: fourth diode

[0028] R1: first resistor; C1: small capacity energy storage element; A1: first operational amplifier;

[0029] A2: first comparator; A3: second comparator; 5021: AND gate. DETAILED DESCRIPTION

[0030] To make the purposes, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in a variety of different configurations. Therefore, the detailed description of the embodiments of the present invention provided in the drawings below is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0031] See also Figure 1, a system block diagram of an energy storage circuit for passive loudspeaker control according to the present invention. It includes a frequency selection network 10, a rectifier network 20, a DC-DC module 30, an energy storage element 40, and a management module 50. The input of the frequency selection network 10 is connected to the loudspeaker, and is sequentially connected to the rectifier network 20 and the DC-DC module 30. It outputs a shaped usable voltage to provide energy to the energy storage element 40. The management module 50 controls the DC-DC module 30 and optimizes the control circuit performance based on the loudspeaker's energy and the energy storage voltage of the energy storage element 40. The frequency selection network 10 is a low-frequency filter, with its input connected to the loudspeaker and its output connected to the rectifier network 20. The output of the rectifier network 20 is connected to the input of the DC-DC module 30, allowing the DC-DC module 30 to adjust the energy storage voltage. The control end of the DC-DC module 30 is connected to the output of the management module 50, and its output is connected to the energy storage element 40. The energy storage element 40 is a supercapacitor, with one end connected to the output of the DC-DC module 30 and the other end grounded. The management module 50 includes a startup unit, a power control unit 501, and a drive unit 502. The startup unit includes a first diode D1, a second clamping diode D2, a third diode D3, a first resistor R1, and a small-capacity energy storage element C1; the anode of the first diode D1 is connected to the anode of the small-capacity energy storage element C1, and the cathode is connected to the power supply terminal Vs of the power control unit 501; the anode of the second clamping diode D2 is grounded, and the cathode is connected to the anode of the small-capacity energy storage element C1; the anode of the third diode D3 is connected to the output terminal of the rectifier network 20, and the cathode is connected to one end of the first resistor R1; the other end of the first resistor R1 is connected to the anode of the small-capacity energy storage element C1 and the first input terminal of the power management unit 501; the anode of the small-capacity energy storage element C1 is connected to the other end of the first resistor R1, and the cathode is grounded. The power control unit 501 has a first input terminal connected to the other end of the first resistor R1, a second input terminal connected to the ungrounded end of the energy storage element 40 via a voltage divider circuit, a power terminal connected to the ungrounded end of the energy storage element 40 and the cathode of the first diode D1 via a fourth diode D4, and an output terminal connected to one of the input terminals of the drive unit 502. The other input terminal of the drive unit 502 is connected to the output terminal of the rectifier network 20, a feedback terminal connected to the ungrounded end of the energy storage element 40 via a voltage divider circuit, and an output terminal connected to the control terminal of the DC-DC module 30.

[0032] See also Figure 2, is a circuit diagram of the drive unit described in the present invention. The drive unit 502 primarily comprises a first operational amplifier A1, a first comparator A2, a second comparator A3, and an AND gate 5021. The first operational amplifier A1 has an input connected to the ungrounded end of the energy storage element 40 via a voltage divider circuit, another input connected to a reference voltage Vref1, and an output connected to an input of the first comparator A2. The first comparator A2 has a triangular wave signal as its other input, and its output connected to an input of the AND gate 5021. The second comparator A3 has one input connected to the ungrounded end of the energy storage element 40, another input connected to a reference voltage Vref2, and an output enabling signal connected to the other input of the AND gate 5021. The output of the AND gate 5021 is connected to the control terminal of the DC-DC module 30.

[0033] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A tank circuit for passive control of a loudspeaker, characterized in that: The system comprises a frequency selection network, a rectification network, a DC-DC module, an energy storage element, and a management module; the input end of the frequency selection network is connected to a speaker, and is sequentially connected to the rectification network and the DC-DC module, and outputs a shaped usable voltage; the management module controls the DC-DC module and optimizes the control circuit performance according to the energy of the speaker and the energy storage voltage of the energy storage element; The frequency selection network is a low-frequency filter with a cut-off frequency lower than the highest value of the intermediate frequency in the audible sound frequency range of the human ear, an input end of which is connected to a speaker, and an output end of which is connected to the rectifier network; The rectifier network shapes the voltage within the available frequency band into pulsating direct current, and the output end is connected to the input end of the DC-DC module for the DC-DC module to adjust the energy storage voltage; The DC-DC module includes a switch tube, a control end of which is connected to the output end of the management module, and an output end of which is connected to the energy storage element to provide energy for it; The energy storage element is a supercapacitor, one end of which is connected to the output end of the DC-DC module and the other end is grounded; The management module includes a starting unit, a power control unit and a driving unit; the starting unit includes a first diode, a second clamping diode, a third diode, a first resistor and a small-capacity energy storage element; the positive electrode of the first diode is connected to the positive electrode of the small-capacity energy storage element, and the negative electrode is connected to the power supply end of the power control unit; the positive electrode of the second clamping diode is grounded, and the negative electrode is connected to the positive electrode of the small-capacity energy storage element; the positive electrode of the third diode is connected to the output end of the rectifier network, and the negative electrode is connected to one end of the first resistor; the other end of the first resistor is connected to the positive electrode of the small-capacity energy storage element and the first input end of the power control module; the positive electrode of the small-capacity energy storage element is connected to the other end of the first resistor, and the negative electrode is grounded.

2. The energy storage circuit for passive control of a loudspeaker according to claim 1, wherein: The power control unit is used to control the static power consumption of the energy storage circuit and control the driving unit, with a first input end connected to the other end of the first resistor, a second input end connected to the ungrounded end of the energy storage element via a voltage divider circuit, a power end connected to the ungrounded end of the energy storage element and the cathode of the first diode via a fourth diode, and an output end connected to one of the input ends of the driving unit; the driving unit is used to adjust the duty cycle of the switch tube in the DC-DC module according to the energy storage voltage, the energy provided by the speaker and the control of the power control unit, and mainly includes a first operational amplifier, a first comparator, a second comparator and an AND gate; the input end of the first operational amplifier is connected to the output end of the rectifier network and the ungrounded end of the energy storage element via a voltage divider circuit, the other input end is connected to reference voltage 1, and the output end is connected to an input end of the first comparator; the other input end of the first comparator is a triangular wave signal, and the output end is connected to an input end of the AND gate; one input end of the second comparator is directly connected to the ungrounded end of the energy storage element, the other input end is connected to reference voltage 2, and the output end enable signal is connected to the other input end of the AND gate; the output end of the AND gate is connected to the control end of the DC-DC module; When the input end of the power control unit detects that the output of the rectifier network is 0, that is, the speaker has no energy and the audio system is turned off, the enable signal is low, that is, the drive unit is turned off.

3. A control method for a tank circuit for passive speaker control according to claim 2, characterized in that: include: S1: When the system is first started or when the speaker receives low-frequency energy, a small-capacity energy storage element provides temporary power to the management module. S2: The power control module detects the energy received by the speaker and controls the switch of the driving unit; S2.1: When the power control module detects that the speaker receives energy, it turns on the driving unit; S2.2: When the power control module detects that the speaker does not receive energy, it turns off the driving unit; S3: the driving unit generates a changing PWM signal; S3.1: The drive unit generates a PWM signal using the signal received by the speaker as an input signal and the energy storage voltage on the energy storage element as a feedback signal; S3.2: The power control module limits the circuit current by limiting the maximum duty cycle of the PWM signal generated by the drive unit according to the energy storage voltage on the energy storage element; S4: The DC-DC module switches according to the signal of the driving unit to control the energy storage of the energy storage element.

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