Power amplifier with adaptive protection control circuit

Abstract

The utility model discloses a power amplifier with a self-adaptive protection control circuit. The power amplifier comprises an input circuit, a power amplifier power supply circuit, a power amplifier circuit, a power amplifier power supply voltage feedback circuit and a voltage comparator circuit, the input circuit is connected with commercial power input, and the output end is connected with the power amplifier power circuit; the power amplifier power supply circuit comprises a power amplifier power supply output end connected to the power amplifier circuit, a first input end connected to the input circuit and a second input end connected to the voltage comparator circuit, and the output voltage of the power amplifier power supply output end is jointly controlled by the first input end and the second input end; the power amplifier power supply voltage feedback circuit collects the load voltage of the power amplifier circuit and feeds back the load voltage to the voltage comparator circuit. According to the utility model, the power amplifier can be adjusted according to the real-time change of the load, so that the power amplifier is kept running in an adaptive power state, and a better dynamic response is achieved; and when the load end is short-circuited, the power supply can be quickly cut off for protection, and self-recovery can be realized after the short-circuit fault is eliminated, so that the self-adaptive protection control effect is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of audio processing circuits, in particular to a power amplifier with an adaptive protection control circuit. Background Art

[0002] Speakers are electronic devices that amplify audio signals and are used in many scenarios in people's lives and work. Based on the different working environments of the speakers, the functional requirements for the speakers will also vary. The power amplifier is a supporting device for the normal operation of the speaker system. In order to ensure the operation and safety of the power amplifier, the power amplifier is generally equipped with a protection circuit module structure. Despite this, the short-circuit protection mechanism of the power amplifier in the existing market is relatively simple, and most of them are short-circuit cut-off settings, that is, when a short-circuit fault is detected, the power supply is directly controlled to be cut off for protection. The adaptive functionality is poor, which is not conducive to improving the comprehensive performance of the power amplifier. Summary of the invention

[0003] In view of the above problems, the utility model provides a power amplifier with an adaptive protection control circuit. The technical solution of the utility model is:

[0004] A power amplifier with an adaptive protection control circuit comprises an input circuit, a power amplifier power supply circuit, a power amplifier circuit, a power amplifier power supply voltage feedback circuit and a voltage comparator circuit; the input circuit is connected to a mains input, and an output end is connected to the power amplifier power supply circuit; the power amplifier power supply circuit comprises a power amplifier power supply output end connected to the power amplifier circuit, a first input end connected to the input circuit and a second input end connected to the voltage comparator circuit, and an output voltage of the power amplifier power supply output end is jointly controlled by the first input end and the second input end; the power amplifier power supply voltage feedback circuit collects a load voltage of the power amplifier circuit and feeds it back to the voltage comparator circuit.

[0005] As a further illustration of the present utility model, the power amplifier power supply circuit is a transformer circuit.

[0006] Furthermore, the input circuit includes an input-end rectification and filtering circuit.

[0007] Furthermore, the power amplifier power supply circuit includes an output rectifier and filter circuit.

[0008] Furthermore, the power amplifier supply voltage feedback circuit is a photoelectric feedback circuit.

[0009] Furthermore, it also includes a relay protection circuit, which is connected to the power amplifier power supply voltage feedback circuit and is used to control the on and off of the power amplifier power supply output terminal.

[0010] Furthermore, the relay protection circuit uses a normally open contact of a relay to control the on and off of the power supply output terminal of the power amplifier.

[0011] Furthermore, it also includes a delay circuit, which is connected to the input circuit and the relay protection circuit and is used to control the relay protection circuit.

[0012] Beneficial effects of the utility model:

[0013] The utility model converts the real-time change of the load of the power amplifier circuit into a voltage feedback signal for feedback through the power amplifier power supply voltage feedback circuit, and can adjust the voltage and current of the power amplifier power supply output end according to the real-time change of the load of the power amplifier circuit, so that the power amplifier circuit keeps running in a power state adapted to its load, so as to achieve a better dynamic response effect by adaptively adapting to the actual load change of the power amplifier; on the other hand, if a short circuit occurs at the load end, the power supply of the power amplifier circuit can be quickly cut off for protection to avoid damage to the power amplifier, and the operation can be automatically restored after the short circuit fault is eliminated, thereby achieving an adaptive protection control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a power amplifier module with an adaptive protection control circuit of the utility model;

[0015] Figure 2 This is a circuit schematic diagram of the delay circuit of the utility model embodiment. DETAILED DESCRIPTION

[0016] Example:

[0017] The following is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0018] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0019] like Figure 1As shown, a power amplifier with an adaptive protection control circuit includes an input circuit, a power amplifier power supply circuit, a power amplifier circuit, a power amplifier power supply voltage feedback circuit and a voltage comparator circuit; the input circuit is connected to a mains input, and an output end is connected to the power amplifier power supply circuit; the power amplifier power supply circuit includes a power amplifier power supply output end connected to the power amplifier circuit, a first input end connected to the input circuit and a second input end connected to the voltage comparator circuit, and the output voltage of the power amplifier power supply output end is jointly controlled by the first input end and the second input end; the power amplifier power supply voltage feedback circuit collects the load voltage of the power amplifier circuit and feeds it back to the voltage comparator circuit.

[0020] In this embodiment, the AC power input outputs a driving voltage to the power amplifier circuit after passing through the power amplifier power circuit. During the operation of the power amplifier, the working current is compared with the input voltage by subtraction and then compared with the peak voltage of the power amplifier power circuit by addition, and then used to control the power supply output end of the power amplifier to realize the dynamic output function; the second input end of the power amplifier power circuit is also connected to the power amplifier power supply voltage feedback circuit to feed back the power supply voltage of the digital power amplifier to the power amplifier power circuit. The specific working principle of this embodiment is as follows: when the mains voltage input becomes lower, the current at the power amplifier power supply output end becomes larger accordingly, and the peak voltage of the power amplifier power supply circuit becomes lower accordingly. At this time, the value obtained by comparing the CMOS current with the mains input voltage is added to the peak voltage of the power amplifier power supply circuit to control the power amplifier power supply output end to achieve a constant output power function; when the power amplifier output power increases, the power amplifier power supply voltage feedback circuit detects a voltage increase, and the power amplifier power supply circuit accordingly adjusts the output voltage of the power amplifier power supply output end to decrease to achieve a dynamic function; when the power amplifier is not working, the power amplifier power supply voltage feedback circuit controls the power amplifier power supply circuit through an optical coupler to achieve output constant voltage power supply, so that the power amplifier circuit remains running in a power state adapted to its load, so as to be able to adapt to the actual load changes of the power amplifier and achieve a better dynamic response effect. When the load is short-circuited, the power amplifier supply voltage feedback circuit will feed back to the power amplifier power supply circuit, and the power amplifier power supply circuit will reduce the power amplifier loss of the power amplifier circuit to 0, thereby protecting the power amplifier. After the short circuit is restored, the power amplifier power supply circuit will restore the power output to the power amplifier circuit, thereby realizing adaptive protection control of the power amplifier.

[0021] As a feasible implementation method, the power amplifier power supply circuit in this embodiment adopts a transformer circuit, and an input rectifier and filter circuit is set on the primary side of the transformer circuit (that is, the input circuit side) to ensure the voltage stability of the primary side of the transformer circuit; an output rectifier and filter circuit is set on the secondary side of the transformer circuit (the power amplifier power supply circuit side) to ensure the stability of the voltage at the output end of the power supply.

[0022] Preferably, in this embodiment, the power amplifier supply voltage feedback circuit is a photoelectric feedback circuit, which isolates the load end and the power supply end of the power amplifier to prevent load short circuit from affecting the power supply control of the power amplifier and ensure the safe operation of the power amplifier.

[0023] Preferably, in this embodiment, the power amplifier with the adaptive protection control circuit also includes a relay protection circuit, and the relay protection circuit is connected to the power amplifier power supply voltage feedback circuit to control the on and off of the power amplifier power supply output terminal.

[0024] Preferably, in this embodiment, the relay protection circuit uses a normally open contact of a relay to control the on / off of the power supply output terminal of the power amplifier.

[0025] Preferably, in this embodiment, a delay circuit is further included, and the delay circuit is connected to the input circuit and the relay protection circuit, and is used to control the relay protection circuit. Figure 2 As shown, the delay circuit of this embodiment includes a NE555 chip U18, a power module, multiple resistors and multiple capacitors; the first pin of the NE555 chip U18 is grounded, the second pin of the NE555 chip U18 is connected to the power output end of the power module through a resistor R113, the second pin of the NE555 chip U18 is also connected to the feedback signal output end of the current sampling detection and driving circuit through a resistor R33, the second pin of the NE555 chip U18 is also grounded through a capacitor C20, and the third pin of the NE555 chip U18 is connected to the feedback signal output end of the mute circuit. The input end, the fourth pin of the NE555 chip U18 is connected to the power output end of the power module, one end of the resistor R95 is respectively connected to the second pin and the fourth pin of the NE555 chip U18, the other end of the resistor R95 is connected to the sixth pin of the NE555 chip U18 and the end is also grounded through the capacitor C22, the fifth pin of the NE555 chip U18 is grounded through the capacitor C24, the sixth pin of the NE555 chip U18 is connected to the seventh pin of the NE555 chip U18, and the eighth pin of the NE555 chip U18 is connected to the power output end of the power module. After the load short circuit relay performs disconnection protection, the delay circuit delays the connection of the relay protection circuit. If the load short circuit at the load end of the power amplifier is not released, the relay protection circuit disconnects the power supply of the power amplifier circuit again for protection; if the load short circuit at the load end of the power amplifier has been released, the normal operation of the power amplifier is restored, and the above-mentioned adaptive protection control effect of the power amplifier is achieved.

[0026] The above only describes the preferred embodiments of the utility model, which should not be construed as limiting the claims. The utility model is not limited to the above embodiments, and its specific structure is allowed to be changed. In short, all changes made within the protection scope of the independent claims of the utility model are within the protection scope of the utility model.

Claims

1. A power amplifier with an adaptive protection control circuit, characterized in that: It includes an input circuit, a power amplifier power supply circuit, a power amplifier circuit, a power amplifier power supply voltage feedback circuit and a voltage comparator circuit; the input circuit is connected to the mains input, and the output end is connected to the power amplifier power supply circuit; the power amplifier power supply circuit includes a power amplifier power supply output end connected to the power amplifier circuit, a first input end connected to the input circuit and a second input end connected to the voltage comparator circuit, and the output voltage of the power amplifier power supply output end is jointly controlled by the first input end and the second input end; the power amplifier power supply voltage feedback circuit collects the load voltage of the power amplifier circuit and feeds it back to the voltage comparator circuit.

2. The power amplifier with adaptive protection control circuit according to claim 1, characterized in that: The power amplifier power supply circuit is a transformer circuit.

3. The power amplifier with adaptive protection control circuit according to claim 2, characterized in that: The input circuit includes an input-end rectifying and filtering circuit.

4. The power amplifier with adaptive protection control circuit according to claim 2, characterized in that: The power amplifier power supply circuit includes an output rectifier and filter circuit.

5. The power amplifier with adaptive protection control circuit according to claim 2, characterized in that: The power amplifier supply voltage feedback circuit is a photoelectric feedback circuit.

6. The power amplifier with adaptive protection control circuit according to claim 1, characterized in that: It also includes a relay protection circuit, which is connected to the power amplifier power supply voltage feedback circuit and is used to control the on and off of the power amplifier power supply output terminal.

7. The power amplifier with adaptive protection control circuit according to claim 6, characterized in that: The relay protection circuit uses the normally open contact of the relay to control the on and off of the power supply output terminal of the power amplifier.

8. The power amplifier with adaptive protection control circuit according to claim 6, characterized in that: It also includes a delay circuit, which is connected to the input circuit and the relay protection circuit and is used to control the relay protection circuit.

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