A power amplifier device

Abstract

The application provides a power amplifier device, comprising: a power amplifier circuit, a temperature measurement module, a control module, a feedback control circuit; the input end of the power amplifier circuit is connected with a signal source, and the output end of the power amplifier circuit is connected with a playing device; the temperature measurement module collects a temperature signal of the power amplifier circuit and transmits the temperature signal to the control module; the control module sends a control signal to the feedback control circuit according to the temperature signal; the feedback control circuit comprises a controlled resistance, the first end of the controlled resistance is connected with the input end of the power amplifier circuit, and the second end of the controlled resistance is grounded; the feedback control circuit controls the resistance value of the controlled resistance according to the control signal. The current temperature state of the power amplifier circuit is collected, the control module controls the feedback control circuit according to the temperature signal, adjusts the resistance value state of the controlled resistance, realizes the adjustment of the power amplifier circuit, accurately guarantees the safe and stable operation of the power amplifier device, and the power amplifier device can also avoid the pollution of the signal source and better protect the playing sound quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sound amplification equipment, in particular to a power amplifier device. BACKGROUND

[0002] The power amplifier device can amplify the signal source and then play through the playing device. The power amplifier device will generate heat during continuous use. Especially in some professional audio amplification scenes such as concerts, conferences, broadcasts, etc., the power amplifier device used has large power and large quantity, and the heat accumulates quickly. If the heat cannot be well dissipated due to environmental factors during use, the power amplifier device will be damaged.

[0003] To this end, the present application provides a power amplifier device capable of stable and safe operation. SUMMARY

[0004] The present application provides a power amplifier device to solve the defect that the power amplifier device is easy to accumulate heat and be damaged in the prior art.

[0005] The power amplifier device provided by the present application comprises a power amplifier circuit, a temperature measurement module, a control module and a feedback control circuit.

[0006] The input end of the power amplifier circuit is connected to a signal source, and the output end of the power amplifier circuit is connected to a playing device.

[0007] The temperature measurement module collects a temperature signal of the power amplifier circuit and transmits the temperature signal to the control module.

[0008] The control module sends a control signal to the feedback control circuit according to the temperature signal.

[0009] The feedback control circuit comprises a controlled resistor, a first end of the controlled resistor is connected to the input end of the power amplifier circuit, and a second end of the controlled resistor is grounded; the feedback control circuit controls the resistance value of the controlled resistor according to the control signal.

[0010] According to the power amplifier device provided by the present application, the control module is configured to:

[0011] In the case that the temperature signal is greater than a set threshold, a first level signal is sent to the feedback control circuit to make the feedback control circuit control the controlled resistor to be in a low resistance state.

[0012] In the case that the temperature signal is less than or equal to the set threshold, a second level signal is sent to the feedback control circuit to make the feedback control circuit control the controlled resistor to be in a high resistance state.

[0013] The feedback control circuit comprises a switching transistor, a light emitting diode and the controlled resistance;

[0014] The control end of the switching transistor is connected to the control module for receiving the control signal of the control module; the two controlled ends of the switching transistor are connected in series with the light emitting diode on the first power supply branch;

[0015] The controlled resistance is a photoresistor for receiving the light of the light emitting diode.

[0016] According to the power amplifier provided by the application, the second resistance is further connected in series on the first power supply branch close to the positive pole of the power supply.

[0017] According to the power amplifier provided by the application, the device further comprises a heat sink for dissipating heat for the power amplifier circuit; the temperature measuring module comprises a thermistor for collecting the temperature signal of the heat sink.

[0018] According to the power amplifier provided by the application, the temperature measuring module comprises a thermistor and a third resistance;

[0019] The thermistor and the third circuit are connected in series on the second power supply branch; the detection point between the thermistor and the third resistance is connected to the temperature signal pin of the control module.

[0020] According to the power amplifier provided by the application, the temperature measuring module further comprises a follower, the detection point is connected to the positive end of the follower, and the output end of the follower is connected to the temperature signal pin of the control module.

[0021] According to the power amplifier provided by the application, the control module determines the temperature of the power amplifier circuit according to the following formula:

[0022] V t =V c R c / (R c +R t );

[0023] Wherein, V t is the voltage of the detection point, V c is the power supply voltage of the second power supply branch, R c is the third resistance, R t is the thermistor, and R t is a function of the temperature.

[0024] The power amplifier device provided by the present application further comprises a first resistor, a first end of the first resistor being connected to the signal source, a second end of the first resistor being connected to an input end of the power amplifier circuit and a first end of the controlled resistor.

[0025] The power amplifier device provided by the present application further comprises a display module connected to the control module, for displaying the temperature of the power amplifier circuit.

[0026] The power amplifier device provided by the present application can collect the temperature signal of the power amplifier circuit through the temperature measurement module, so as to know the current temperature state of the power amplifier device, the control module can output the control signal according to the temperature signal and the control strategy, and the feedback control circuit can adjust the resistance state of the controlled resistor according to the control signal, so as to finally realize the adjustment of the power amplifier circuit, accurately guarantee the safe and stable operation of the power amplifier device, and the power amplifier device can also avoid the pollution of the signal source and better protect the sound quality of the played sound. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0028] Figure 1 is a structural schematic diagram of the power amplifier device provided by the present application;

[0029] Figure 2 is a circuit diagram example of the power amplifier device provided by the present application;

[0030] Figure 3 is a corresponding relationship example table of the thermistor and the temperature in the power amplifier device provided by the present application. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0032] The following will describe the power amplifier device provided by the present application in combination with Figures 1-3

[0033] Figure 1 is a structural schematic diagram of the power amplifier device provided by the present application, as​Figure 1 As shown in the figure, the power amplifier device comprises: a power amplifier circuit, a temperature measurement module, a control module, a feedback control circuit;

[0034] The input end of the power amplifier circuit is connected to a signal source, and the output end of the power amplifier circuit is connected to a playing device. The power amplifier device can amplify and output the signal source to obtain an amplified signal, and the playing device converts the amplified signal into sound energy to realize sound amplification. The playing device can be, for example, a sound box, a handheld loudspeaker amplifier, a fixed loudspeaker amplifier, or the like.

[0035] The temperature measurement module collects a temperature signal of the power amplifier circuit and transmits the temperature signal to the control module. The temperature measurement module can only comprise a signal collection circuit, and correspondingly, the temperature signal is an electric signal collected by the signal collection circuit according to the temperature state near the power amplifier circuit; or the temperature measurement module can comprise a signal collection circuit and a processing circuit, the processing circuit processes the electric signal collected by the signal collection circuit to generate the temperature signal, that is, the temperature signal at this time corresponds to an actual temperature meaning.

[0036] The control module comprises a temperature signal pin and a control signal pin, the temperature signal pin is connected to the temperature measurement module and used to receive the temperature signal, and the control signal pin is connected to the feedback control circuit and used to output a control signal to the feedback control circuit. The control module can generate a corresponding control signal according to the temperature signal. Specifically, a program can be burned in the control module, and the control module processes the temperature signal according to the program to generate the control signal.

[0037] The feedback control circuit comprises a controlled resistor, and the feedback control circuit controls the resistance value of the controlled resistor according to the control signal. The first end of the controlled resistor is connected to the input end of the power amplifier circuit, and the second end of the controlled resistor is connected to the ground (negative pole of the power supply or reference ground). It can be understood that, since the first end of the controlled resistor is connected to the input end of the power amplifier circuit, and the input end of the power amplifier circuit is connected to the signal source, the controlled resistor can play a shunt role for the signal source. When the controlled resistor is in a high resistance state, the shunt effect is weak, and the signal source connected to the input of the power amplifier circuit is basically not affected, and the power amplifier circuit can work normally; when the controlled resistor is in a low resistance state, the signal source is basically passed through the controlled resistor, that is, the controlled resistor plays a short-circuit effect for the power amplifier circuit, reduces the power of the power amplifier circuit, and reduces the heat accumulation.

[0038] In this embodiment, the temperature signal of the power amplifier circuit is collected by the temperature measurement module to facilitate understanding of the current temperature state of the power amplifier circuit, the control module outputs a control signal according to the temperature signal and a control strategy, and the feedback control circuit adjusts the resistance value state of the controlled resistor according to the control signal, so as to finally realize the adjustment of the power amplifier circuit and accurately ensure the safe and stable operation of the power amplifier device.

[0039] In addition, it needs to be explained that the power amplifier device of the present application does not use a temperature control switch to control the signal source input of the power amplifier circuit, because the temperature control switch has a large error, and the metal sheet of the temperature control switch is prone to mechanical wear and loss of life, and the service life is not long. The power amplifier device of the present application can more accurately and stably control the working state of the power amplifier device. The present application also does not use a switching transistor to directly control the signal source input, because when the switching transistor is directly used to control the signal source input, the non-linear voltage drop of the switching transistor will interfere with the signal source and pollute the sound quality of the played sound. The present application can better protect the sound quality.

[0040] Based on the above embodiments, in one embodiment, the control module is configured to;

[0041] In the case that the temperature signal is greater than the set threshold, a first level signal is sent to the feedback control circuit to make the feedback control circuit control the controlled resistance to be in a low resistance state;

[0042] In the case that the temperature signal is less than or equal to the set threshold, a second level signal is sent to the feedback control circuit to make the feedback control circuit control the controlled resistance to be in a high resistance state.

[0043] Specifically, a program can be burned into the control module to realize the above configuration. The above set threshold can be flexibly set and adjusted according to requirements, so that the signal source is cut off when a certain temperature is exceeded, the power of the power amplifier circuit is reduced, and the signal source is introduced when a certain temperature is exceeded, the power of the power amplifier device is improved. The first level signal and the second level signal are different level signals, for example, the first level signal is high, and the second level signal is low, and for example, the first level signal is low, and the second level signal is high.

[0044] Further, the feedback control circuit further comprises a D / A conversion module, which converts the control signal output by the control module into an analog control signal to adjust the power of the power amplifier circuit. For example, the switching transistor Q1 in Figure 2 is replaced by a D / A conversion module, and the power of the light-emitting diode is adjusted through the D / A conversion module, so as to adjust the resistance value of the controlled resistance, realize the shunt effect of the signal source, and thus the power of the power amplifier circuit can be smoothly adjusted.

[0045] Referring to Figure 2 , in one embodiment, the feedback control circuit comprises a switching transistor Q1, a light-emitting diode and a controlled resistance;

[0046] The control end of the switching transistor Q1 is connected to the control module for receiving the control signal of the control module; the two controlled ends of the switching transistor are connected in series with the light-emitting diode on the first power supply branch; the controlled resistance is a photoresistor for receiving the light of the light-emitting diode.

[0047] Specifically,Figure 2 Only one feasible solution is illustrated: the switching transistor Q1 is an NPN transistor, with its emitter connected to GND (ground, negative power supply), its base connected to the control module, its collector connected to the negative terminal of the LED, and the positive terminal of the LED connected to the positive terminal Vs of the first power supply. When the base of the transistor receives a high-level signal, the transistor conducts, the LED is energized and illuminates, making the controlled resistor low-resistance; when the base of the transistor receives a low-level signal, the transistor is cut off, the LED is de-energized, and the controlled resistor becomes high-resistance.

[0048] Understandably, based on the same approach, other types of switching transistors (thyristors, field-effect transistors) can be used with corresponding adjustments to the first power supply branch. For example, a PNP transistor can be used, with its emitter connected to the positive power supply terminal Vs, its base connected to the control module, its collector connected to the positive terminal of an LED, and the LED's negative terminal GND (ground, negative power supply terminal). When the base of the transistor receives a high-level signal, the transistor is cut off, the LED is de-energized, and the controlled resistor is in a high-resistance state; when the base of the transistor receives a low-level signal, the transistor is turned on, the LED is energized and illuminates, and the controlled resistor is in a low-resistance state.

[0049] The aforementioned light-emitting diode and controlled resistor constitute an optocoupler. Figure 2 The diagram illustrates an LCR optocoupler. The circuit described above can prevent electromagnetic interference, ensure fast response speed, high stability, and long service life of the power amplifier, and will not affect the quality of the signal source input to the power amplifier circuit, thus avoiding contamination of sound quality.

[0050] Still refer to Figure 2 In one embodiment, a second resistor R2 is connected in series on the side of the first power supply branch closest to the positive terminal of the power supply. The second resistor R2 is used to protect the first switching transistor and the light-emitting diode to prevent the device from being damaged by overload.

[0051] Based on any of the above embodiments, in one embodiment, the device further includes a heat sink for dissipating heat from the power amplifier circuit. The shape and position of the heat sink can be flexibly set according to requirements. The temperature measurement module includes a thermistor for acquiring the temperature signal of the heat sink.

[0052] Based on any of the above embodiments, in one embodiment, the temperature measuring module comprises a thermistor and a third resistor. The thermistor and the third resistor are connected in series on the second power supply branch. It can be understood that the "second power supply branch" is used to distinguish from the "first power supply branch" mentioned above. The voltage of the second power supply branch can be different from or the same as the voltage of the first power supply branch. The connection line between the thermistor and the third resistor has a detection point, which is connected to the temperature signal pin of the control module to input the temperature signal to the control module.

[0053] In the embodiment, the thermistor and the third resistor are connected in series on the second power supply branch, and the temperature is measured by detecting the divided voltage signal, which can reduce the power consumption of the temperature measuring module and improve the accuracy of temperature measurement.

[0054] Still referring to Figure 2 In one embodiment, the temperature measuring module further comprises a follower U1. The aforementioned detection point is connected to the positive terminal of the follower U1 (i.e. pin 3 of U1 in the schematic diagram), the output terminal of the follower U1 (i.e. pin 1 of U1 in the schematic diagram) is connected to the temperature signal pin of the control module, and the output terminal of the follower U1 is also connected to the negative terminal of the follower (i.e. pin 2 of U1 in the schematic diagram). Figure 2 Figure 2 In one embodiment, the temperature measuring module further comprises a follower U1. The aforementioned detection point is connected to the positive terminal of the follower U1 (i.e. pin 3 of U1 in the schematic diagram), the output terminal of the follower U1 (i.e. pin 1 of U1 in the schematic diagram) is connected to the temperature signal pin of the control module, and the output terminal of the follower U1 is also connected to the negative terminal of the follower (i.e. pin 2 of U1 in the schematic diagram). Figure 2 The output terminal of the follower U1 can output the same voltage as the positive terminal without causing interference to the temperature measuring module.

[0055] In the embodiment, the follower U1 separates the second power supply branch from the control module, so that the control module does not interfere with the voltage signal of the detection point, improving the accuracy of the temperature signal detection.

[0056] Still referring to Figure 2 In one embodiment, the control module determines the temperature of the power amplifier circuit according to the following formula:

[0057] V t = V c R c / (R c +R t );

[0058] wherein V t is the voltage of the detection point, V c is the voltage of the second power supply branch, R c is the third resistor, R t is the thermistor, and R t is a function of the temperature.

[0059] Specifically, the third resistor R c and the thermistor R t ​The power supply voltage of the second power supply branch is divided, and the above formula can be obtained according to the division relationship. In addition, the resistance of the thermistor R t is a function of temperature, for example, Figure 2 An example of a table of the corresponding relationship between the resistance of a thermistor and temperature is shown. According to the above formula and the corresponding relationship between the resistance of the thermistor R t and temperature, the corresponding relationship between V t and temperature can be determined, and then, during the temperature measurement, the measured V t can be used to determine the temperature of the power amplifier circuit.

[0060] Still referring to Figure 3 , in one embodiment, the power amplifier device further comprises a first resistor R1, a first end of the first resistor R1 being connected to the signal source, a second end of the first resistor R1 being connected to the input end of the power amplifier circuit and the first end of the controlled resistor. Specifically, the first resistor R1 can play a role of current limiting to prevent current overload from damaging the power amplifier device.

[0061] Based on any of the above embodiments, in one embodiment, the power amplifier device further comprises a display module connected to the control module, for displaying the temperature of the power amplifier circuit, so that the user can know the current temperature state of the power amplifier device and use the power amplifier device reasonably. The display module can be, for example, a digital tube, a display screen in Figure 2 Figure 2 , and the like.

[0062] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A power amplifier device, characterized in that, include: Power amplifier circuit, temperature measurement module, control module, feedback control circuit; The input terminal of the power amplifier circuit is connected to a signal source, and the output terminal of the power amplifier circuit is connected to a playback device. The temperature measurement module acquires the temperature signal of the power amplifier circuit and transmits the temperature signal to the control module; The control module sends a control signal to the feedback control circuit based on the temperature signal; The feedback control circuit includes a controlled resistor, the first end of which is connected to the input terminal of the power amplifier circuit, and the second end of which is grounded; the feedback control circuit controls the resistance value of the controlled resistor according to the control signal. The control module is configured as follows: When the temperature signal is greater than a set threshold, a first level signal is sent to the feedback control circuit so that the feedback control circuit controls the controlled resistor to be in a low-resistance state. When the temperature signal is less than or equal to the set threshold, a second level signal is sent to the feedback control circuit so that the feedback control circuit controls the controlled resistor to be in a high-resistance state. The feedback control circuit includes a switching transistor and a light-emitting diode; The control terminal of the switching transistor is connected to the control module and is used to receive the control signal from the control module; the two controlled terminals of the switching transistor are connected in series with the light-emitting diode in the first power supply branch. The controlled resistor is a photoresistor used to receive the light from the light-emitting diode; The temperature measurement module includes a thermistor and a third resistor; The thermistor and the third resistor are connected in series in the second power supply branch; the detection point between the thermistor and the third resistor is connected to the temperature signal pin of the controlled module. The temperature measurement module also includes a follower, the detection point is connected to the positive terminal of the follower, and the output terminal of the follower is connected to the temperature signal pin of the control module; The control module determines the temperature of the power amplifier circuit according to the following formula: V t =V c R c / (R c +R t ) ; Among them, V t V is the voltage at the detection point. c R is the supply voltage of the second power supply branch. c R is the resistance value of the third resistor. t It is the resistance value of the thermistor.

2. The power amplifier device according to claim 1, characterized in that, A second resistor is connected in series on the side of the first power supply branch closest to the positive terminal of the power supply.

3. The power amplifier device according to claim 1, characterized in that, The device also includes a heat sink for dissipating heat from the power amplifier circuit.

4. The power amplifier device according to claim 1, characterized in that, It also includes a first resistor, the first end of which is connected to the signal source, and the second end of which is connected to the input terminal of the power amplifier circuit and the first end of the controlled resistor.

5. The power amplifier device according to claim 1, characterized in that, It also includes a display module, which is connected to the control module and is used to display the temperature of the power amplifier circuit.

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