Automatic control amplifier circuit structure suitable for voice signal input amplitude

Abstract

The present invention provides an automatic control power amplifier circuit suitable for voice signal input amplitude, characterized in that it comprises: an amplifier circuit, a voltage stabilizing circuit, an input circuit, a control power supply circuit and a power amplifier circuit, wherein the input circuit is connected in series with the amplifier circuit; the amplifier circuit is connected in series with the control power supply circuit and the power amplifier circuit; the control power supply circuit is connected in parallel with the power amplifier circuit; the ground terminal of the voltage stabilizing circuit is connected to the ground terminal of the input circuit, and the power supply terminal of the voltage stabilizing circuit and the power supply terminal of the control power supply circuit are simultaneously connected to a 12V power supply. The present invention solves the technical problem that when there is no signal input to a general power amplifier circuit, the power supply is always maintained, the environmental noise and the internal noise of the machine will be transmitted through the power amplifier circuit, and the broadcasting speaker has noise output when there is no signal input by automatically controlling the power amplifier circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of power amplifier circuits, and in particular to an automatic control power amplifier circuit structure suitable for voice input amplitude. Background Art

[0002] The voice input function in the prior art needs to use a manual button to realize the broadcast function, which will lead to the inconvenience and geographical restrictions of the broadcast, and if the broadcast is always powered on, it will cause a waste of resources.

[0003] After searching, the patent document CN204314648U discloses a speaker power control system based on audio signal detection, including an audio amplifier circuit, an audio signal conversion circuit, a microcontroller and a speaker power control circuit connected in sequence, the audio amplifier circuit includes a differential input audio power amplifier, the audio signal conversion circuit includes a photoelectric isolator, a first inverter and a second inverter connected in sequence, the speaker power control circuit includes a solid-state relay, the input end of the differential input audio power amplifier inputs a voice signal, its output end is connected to the photoelectric isolator input end, the photoelectric isolator output end is connected to the first inverter input end, the second inverter input end is connected to the first inverter output end, its output end is connected to the microcontroller, the solid-state relay input end is connected to the microcontroller, and its output end is connected to the AC power supply of the speaker. However, the disadvantage of the prior art is that the audio signal is detected to control the power supply to the speaker, and the detection of the audio signal usually uses an audio transformer to amplify and detect the audio signal. This method will greatly reduce the amplitude of the voice signal, causing voice distortion and affecting the conversation effect.

[0004] Therefore, it is necessary to develop a method that allows the local duty room to broadcast to the local area by pressing the "local broadcast" button when not talking to the main control room. And when making local broadcasts, if there is a call from the main control room, it will also be transmitted through the loudspeaker at the same time, and the duty officer can release the local broadcast button to broadcast. Summary of the invention

[0005] In view of the defects in the prior art, an object of the present invention is to provide an automatic control power amplifier circuit suitable for voice signal input amplitude.

[0006] According to the present invention, an automatic control power amplifier circuit suitable for voice signal input amplitude includes: an amplifier circuit, an input circuit, a control power supply circuit and a power amplifier circuit.

[0007] The input circuit is connected in series with the amplifier circuit; the amplifier circuit is connected in series with the power supply circuit and the power amplifier circuit; and the power supply circuit is connected in parallel with the power amplifier circuit.

[0008] Preferably, it also includes a voltage stabilizing circuit, the ground terminal of the voltage stabilizing circuit is connected to the ground terminal of the input circuit, and the power supply terminal of the voltage stabilizing circuit and the power supply terminal of the power supply circuit are simultaneously connected to a 12V power supply.

[0009] Preferably, the input circuit includes a transient voltage suppression diode TVS, a capacitor C1, a capacitor C2, a resistor R12, a capacitor C6, a resistor R13 and a capacitor C17.

[0010] One end of the transient voltage suppression diode TVS is connected to the capacitor C1, and the other end is connected to the capacitor C2;

[0011] One end of the capacitor C1 is connected in series with the resistor R12, and a capacitor C6 is provided between the resistor R12 and the resistor R13;

[0012] One end of the resistor R13 is connected to the capacitor C17.

[0013] Preferably, the amplifier circuit includes a voltage follower reverse comparator U1A, a variable resistor VR1, a capacitor C3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C8, a variable resistor VR3, a capacitor C37, a capacitor C4, and an inductor L1.

[0014] One end of the variable resistor VR1 is connected to the resistor R13 of the input circuit, and the other end is connected to the capacitor C3;

[0015] One end of the resistor R1 is connected to the capacitor C3, and the other end is connected to the inverting input terminal 2;

[0016] One end of the non-inverting input terminal 3 is connected to the capacitor C5, and one end of the capacitor C5 is grounded;

[0017] Resistor R3 is connected in parallel with capacitor C5, and resistor R3 is connected in series with resistor R2;

[0018] One end of the resistor R2 is connected to the capacitor C4, and the capacitor C4 is connected in parallel with the capacitor C37;

[0019] One end of the capacitor C37 is grounded, and the other end is connected to the inductor L1, and the inductor L1 is connected to a power supply;

[0020] One end of the resistor R4 is connected to the inverting input terminal, and the other end is connected to one end of the resistor R5 and one end of the voltage follower inverting comparator U1A;

[0021] The other end of the resistor R5 is connected to the capacitor C8, and the capacitor C8 is connected in parallel with the variable resistor VR3;

[0022] The positive power supply terminal is grounded, and the negative power supply terminal is connected to the other end of the resistor R2;

[0023] The power supply output is connected to a voltage follower inverting comparator U1A.

[0024] Preferably, the power amplifier circuit includes a mono audio power amplifier integrated circuit U2, the mono audio power amplifier integrated circuit U2 has an operating voltage of 60V and an output power of 25W.

[0025] Preferably, the mono audio power amplifier integrated circuit U2 includes an eighth capacitor C8, a variable resistor VR3, a capacitor C9, a capacitor C10, a capacitor C11, a resistor R6, a resistor R7, a resistor R8, a capacitor C12, a capacitor C13, a resistor R9, a capacitor C14, a resistor R10, a resistor R11, a capacitor C16 and a capacitor C15.

[0026] The capacitor C8 is connected in parallel with the variable resistor VR3, and one end of the variable resistor VR3 is grounded;

[0027] Capacitor C9 is arranged between variable resistor VR3 and capacitor C10;

[0028] After capacitor C11 is connected in parallel with resistor R7, one end is grounded and the other end is connected to resistor R6;

[0029] One end of the resistor R6 is connected to the capacitor C12, and the capacitor C12 is grounded;

[0030] Resistor R6 is connected in series with resistor R7, one end of resistor R8 is connected to capacitor C11, and the other end is connected to the positive phase input terminal;

[0031] The positive power supply terminal is connected to the capacitor 12, and the negative power supply terminal is grounded;

[0032] One end of the capacitor C15 is connected to the output end, and the other end of the capacitor C15 is connected to the voice signal output carrier;

[0033] Capacitor C14 is connected in series with resistor R10, resistor R11 is connected in series with capacitor C16, capacitor C14 and resistor R10 are connected in parallel with resistor R11 and capacitor C16;

[0034] One end of the resistor R9 is connected to the circuit between the negative phase input terminal and the capacitor C14, and the other end is connected to the circuit between the output terminal and the resistor R11.

[0035] Preferably, the control power supply circuit includes a diode D1, a diode D2, a capacitor C23, a photocoupler U1B, a voltage V1 and a relay J1.

[0036] When a voice signal is input to the amplifier circuit, the band is detected through diodes D1 and D2, and the DC signal charges capacitor C23. When the level of the positive input terminal 5 pin of the photocoupler U1B is higher than that of the negative input terminal 6 pin, the output terminal 7 pin outputs a high level, the voltage V1 is turned on, and the relay J1 is energized to supply power to the mono audio power amplifier integrated circuit U2 in the power amplifier circuit;

[0037] When there is no voice signal input to the amplifier circuit, the level of the negative input terminal 6 of the optocoupler U1B is higher than that of the positive input terminal 5, the output terminal 7 outputs a low level, the voltage V1 is cut off, and the relay J1 is released, which cuts off the power to the mono audio power amplifier integrated circuit U2 in the power amplifier circuit and mutes the speaker.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention solves the technical problem that when there is no signal input, the power supply of the general power amplifier circuit is always maintained, the environmental noise and the noise inside the machine are transmitted through the power amplifier circuit, and the broadcast speaker has noise output when there is no signal input through the automatic control power amplifier circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0041] Figure 1 It is a schematic diagram of a power amplifier circuit in the present invention;

[0042] Figure 2 It is a schematic diagram of the input circuit and the amplifying circuit in the present invention;

[0043] Figure 3 It is a schematic diagram of the control power supply circuit in the present invention;

[0044] Figure 4 It is a schematic diagram of a voltage stabilizing circuit in the present invention;

[0045] Figure 5 It is a simplified overall frame line schematic diagram of the present invention. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0047] like Figure 1-Figure 5As shown, the present invention provides an automatic control power amplifier circuit structure suitable for voice input amplitude, including an amplifier circuit 2, an input circuit 1, a control power circuit 4, a voltage stabilizing circuit 5 and a power amplifier circuit 3, wherein the input circuit 1 is connected in series with the amplifier circuit 2; the amplifier circuit 2 is connected in series with the control power circuit 4 and the power amplifier circuit 3; the control power circuit 4 is connected in parallel with the power amplifier circuit 3; the ground terminal of the voltage stabilizing circuit 5 is connected to the ground terminal of the input circuit 1, and the power supply terminal of the voltage stabilizing circuit 5 and the power supply terminal of the control power circuit 4 are simultaneously connected to a 12V power supply.

[0048] Further, the input circuit 1 includes a transient voltage suppression diode TVS, a capacitor C1, a capacitor C2, a resistor R12, a capacitor C6, a resistor R13 and a capacitor C17, one end of the transient voltage suppression diode TVS is connected to the capacitor C1, and the other end is connected to the capacitor C2, and the capacitor C2 is grounded; one end of the capacitor C1 is connected in series with the resistor R12, and a capacitor C6 is provided between the resistor R12 and the resistor R13, and the capacitor C6 is grounded; one end of the resistor R13 is connected to the capacitor C17, and the capacitor C17 is grounded.

[0049] Furthermore, the amplifier circuit 2 includes a voltage follower reverse comparator U1A, a variable resistor VR1, a capacitor C3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C8, a variable resistor VR3, a capacitor C37, a capacitor C4, and an inductor L1. One end of the variable resistor VR1 is connected to the resistor R13 of the input circuit, and the other end is connected to the capacitor C3; one end of the resistor R1 is connected to the capacitor C3, and the other end is connected to the inverting input terminal 2; one end of the non-inverting input terminal 3 is connected to the capacitor C5, and one end of the capacitor C5 is grounded; the resistor R3 and the capacitor C5 In parallel, resistor R3 is connected in series with resistor R2; one end of resistor R2 is connected to capacitor C4, and capacitor C4 is connected to capacitor C37 in parallel; one end of capacitor C37 is grounded, and the other end is connected to inductor L1, and inductor L1 is connected to the power supply; one end of resistor R4 is connected to the inverting input end, and the other end is connected to one end of resistor R5 and one end of voltage follower reverse comparator U1A; the other end of resistor R5 is connected to capacitor C8, and capacitor C8 is connected to variable resistor VR3 in parallel; the positive power supply end is grounded, and the negative power supply end is connected to the other end of resistor R2; the power supply output end is connected to the voltage follower reverse comparator U1A.

[0050] Furthermore, the power amplifier circuit 3 includes a mono audio power amplifier integrated circuit U2, the working voltage of the mono audio power amplifier integrated circuit U2 is 60V, and the output power is 25W. The mono audio power amplifier integrated circuit U2 includes an eighth capacitor C8, a variable resistor VR3, a capacitor C9, a capacitor C10, a capacitor C11, a resistor R6, a resistor R7, a resistor R8, a capacitor C12, a capacitor C13, a resistor R9, a capacitor C14, a resistor R10, a resistor R11, a capacitor C16 and a capacitor C15. The capacitor C8 is connected in parallel with the variable resistor VR3, and one end of the variable resistor VR3 is grounded; the capacitor C9 is arranged between the variable resistor VR3 and the capacitor C10; the capacitor C11 is connected in parallel with the resistor R7, and one end is grounded, and the other end is connected to the resistor R6; one end of the resistor R6 is connected in parallel with the capacitor C12 The resistor R6 is connected in series with the resistor R7, one end of the resistor R8 is connected to the capacitor C11, and the other end is connected to the positive phase input terminal; the positive power supply terminal is connected to the capacitor 12, and the negative power supply terminal is grounded; one end of the capacitor C15 is connected to the output terminal, and the other end of the capacitor C15 is connected to the voice signal output carrier; the capacitor C14 is connected in series with the resistor R10, the resistor R11 is connected in series with the capacitor C16, and the capacitor C14 and the resistor R10 are connected in parallel with the resistor R11 and the capacitor C16; one end of the resistor R9 is connected to the circuit between the negative phase input terminal and the capacitor C14, and the other end is connected to the circuit between the output terminal and the resistor R11.

[0051] Furthermore, the control power supply circuit 4 includes a capacitor C7, a resistor R16, a diode D1, a diode D2, a resistor R17, a diode D3, a capacitor C23, a diode D4, a resistor R18, a variable resistor VR4, a resistor R19, a photocoupler U1B, a resistor R20, a diode D5, a diode D6, a voltage V1 and a relay J1. One end of the resistor R16 is connected to the capacitor C7, and the other end is connected to the diode D2; the diode D1 is connected to the circuit between the resistor R16 and the diode D2; one end of the resistor R17 is connected to the diode D1, and the other end is connected to the diode D2; the diode D3 is connected in parallel with the resistor R17; the capacitor C23 is connected in parallel with diode D3, one end of capacitor C23 is connected to positive phase input terminal 5 pin, and the other end is connected to diode D4; diode D4 is connected in parallel with variable resistor VR4, one end of variable resistor VR4 is connected to resistor R18, and resistor R18 is connected to 12V power supply; the other end of variable resistor VR4 is connected to R19, and R19 is grounded; variable resistor VR4 is connected to negative phase input terminal 6 pin; output terminal 7 pin is connected to one end of photoelectric coupler U1B, and the other end of photoelectric coupler U1B is connected to diode D5, diode D6, and voltage V1 in sequence; one end of voltage V1 is grounded, and the other end is connected to diode D7, and relay J1 is connected in parallel with diode D7.

[0052] When a voice signal is input to the amplifier circuit 2, the band is detected through the diodes D1 and D2, and the DC signal charges the capacitor C23. When the level of the positive input terminal 5 pin of the photocoupler U1B is higher than that of the negative input terminal 6 pin, the output terminal 7 pin outputs a high level, the voltage V1 is turned on, and the relay J1 is energized to supply power to the mono audio power amplifier integrated circuit U2 in the power amplifier circuit;

[0053] When there is no voice signal input to the amplifier circuit 2, the level of the negative input terminal 6 of the optocoupler U1B is higher than that of the positive input terminal 5, the output terminal 7 outputs a low level, the voltage V1 is cut off, and the relay J1 is released, which cuts off the power to the mono audio power amplifier integrated circuit U2 in the power amplifier circuit and mutes the speaker.

[0054] To go further, the voltage stabilizing circuit 5 includes a transformer T, a bridge stack, a capacitor C24, a voltage U3, an inductor coil L2, a diode D8, a capacitor C25, a capacitor C26, a resistor R21 and a diode D9, the second coil of the transformer is connected to the first end and the third end of the bridge stack, the second end of the bridge stack is grounded, the fourth end of the bridge stack is connected to one end of the capacitor C24, and the other end of the capacitor C24 is connected to the input port VIN; the output port OUT is connected to the inductor coil L2, the diode D8 is connected to the circuit between the output port OUT and the inductor coil L2, the capacitor C25 is connected in parallel with the diode D8, one end of the capacitor C25 is connected to the output port OUT, and the other end is grounded; the capacitor C26 is connected in parallel with the resistor R21, and the resistor R21 is connected in series with the diode D9. The buck regulator has high efficiency, does not require an external heat sink, has a large drive current, and has excellent load adjustment capabilities.

[0055] The circuit of the present invention has an automatic mute function after 10 seconds without signal input, which solves the technical problem that when there is no signal input, the general power amplifier circuit keeps power supply all the time, the environmental noise and the noise inside the machine will be transmitted through the power amplifier circuit, and the broadcast speaker has noise output when there is no signal input.

[0056] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0057] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. An automatic control power amplifier circuit suitable for voice signal input amplitude, characterized in that: include: an amplifier circuit (2), an input circuit (1), a control power supply circuit (4) and a power amplifier circuit (3), The input circuit (1) is connected in series with the amplifier circuit (2); The amplifier circuit (2) is connected in series with the control power supply circuit (4) and the power amplifier circuit (3); The control power supply circuit (4) is connected in parallel with the power amplifier circuit (3); It also includes a voltage stabilizing circuit (5), the ground end of the voltage stabilizing circuit (5) is connected to the ground end of the input circuit, and the power supply end of the voltage stabilizing circuit (5) and the power supply end of the control power supply circuit (4) are simultaneously connected to a 12V power supply. The input circuit (1) comprises a transient voltage suppression diode TVS, a capacitor C1, a capacitor C2, a resistor R12, a capacitor C6, a resistor R13 and a capacitor C17, One end of the transient voltage suppression diode TVS is connected to the capacitor C1, and the other end is connected to the capacitor C2; One end of the capacitor C1 is connected in series with the resistor R12, and a capacitor C6 is provided between the resistor R12 and the resistor R13; One end of the resistor R13 is connected to the capacitor C17. The amplifier circuit (2) comprises a voltage follower reverse comparator U1A, a variable resistor VR1, a capacitor C3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C8, a variable resistor VR3, a capacitor C37, a capacitor C4, and an inductor L1. One end of the variable resistor VR1 is connected to the resistor R13 of the input circuit, and the other end is connected to the capacitor C3; One end of the resistor R1 is connected to the capacitor C3, and the other end is connected to the inverting input terminal 2; One end of the non-inverting input terminal 3 is connected to the capacitor C5, and one end of the capacitor C5 is grounded; Resistor R3 is connected in parallel with capacitor C5, and resistor R3 is connected in series with resistor R2; One end of the resistor R2 is connected to the capacitor C4, and the capacitor C4 is connected in parallel with the capacitor C37; One end of the capacitor C37 is grounded, and the other end is connected to the inductor L1, and the inductor L1 is connected to a power supply; One end of the resistor R4 is connected to the inverting input terminal, and the other end is connected to one end of the resistor R5 and one end of the voltage follower inverting comparator U1A; The other end of the resistor R5 is connected to the capacitor C8, and the capacitor C8 is connected in parallel with the variable resistor VR3; The positive power supply terminal is grounded, and the negative power supply terminal is connected to the other end of the resistor R2; The power supply output is connected to a voltage follower inverting comparator U1A.

2. The automatic control power amplifier circuit suitable for voice signal input amplitude according to claim 1, characterized in that: The power amplifier circuit (3) comprises a mono audio power amplifier integrated circuit U2. The mono audio power amplifier integrated circuit U2 has an operating voltage of 60V and an output power of 25W.

3. The automatic control power amplifier circuit suitable for voice signal input amplitude according to claim 2, characterized in that: The mono audio power amplifier integrated circuit U2 includes an eighth capacitor C8, a variable resistor VR3, a capacitor C9, a capacitor C10, a capacitor C11, a resistor R6, a resistor R7, a resistor R8, a capacitor C12, a capacitor C13, a resistor R9, a capacitor C14, a resistor R10, a resistor R11, a capacitor C16 and a capacitor C15. The capacitor C8 is connected in parallel with the variable resistor VR3, and one end of the variable resistor VR3 is grounded; The capacitor C9 is arranged between the variable resistor VR3 and the capacitor C10; The capacitor C11 is connected in parallel with the resistor R7, one end of which is grounded, and the other end is connected to the resistor R6; One end of the resistor R6 is connected to the capacitor C12, and the capacitor C12 is grounded; The resistor R6 is connected in series with the resistor R7, one end of the resistor R8 is connected to the capacitor C11, and the other end is connected to the positive phase input terminal; The positive power supply terminal is connected to the capacitor 12, and the negative power supply terminal is grounded; One end of the capacitor C15 is connected to the output end, and the other end of the capacitor C15 is connected to the voice signal output carrier; The capacitor C14 is connected in series with the resistor R10, the resistor R11 is connected in series with the capacitor C16, and the capacitor C14 and the resistor R10 are connected in parallel with the resistor R11 and the capacitor C16; One end of the resistor R9 is connected to the circuit between the negative phase input terminal and the capacitor C14, and the other end is connected to the circuit between the output terminal and the resistor R11.

4. The automatic control power amplifier circuit suitable for voice signal input amplitude according to claim 1, characterized in that: The control power supply circuit (4) comprises a diode D1, a diode D2, a capacitor C23, a photoelectric coupler U1B, a voltage V1 and a relay J1. When a voice signal is input to the amplifier circuit (2), the band is detected through diodes D1 and D2, and the DC signal charges capacitor C23. When the level of the positive input terminal 5 pin of the photocoupler U1B is higher than that of the negative input terminal 6 pin, the output terminal 7 pin outputs a high level, the voltage V1 is turned on, and the relay J1 is energized to supply power to the mono audio power amplifier integrated circuit U2 in the power amplifier circuit; When there is no voice signal input to the amplifier circuit (2), the level of the negative input terminal 6 of the optocoupler U1B is higher than that of the positive input terminal 5, and the output terminal 7 outputs a low level, the voltage V1 is cut off, and the relay J1 is released, and the mono audio power amplifier integrated circuit U2 in the power amplifier circuit is powered off, and the speaker is muted.

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