CN219960825U - Isolated microphone signal acquisition circuit - Google Patents
Isolated microphone signal acquisition circuit Download PDFInfo
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- CN219960825U CN219960825U CN202320729397.2U CN202320729397U CN219960825U CN 219960825 U CN219960825 U CN 219960825U CN 202320729397 U CN202320729397 U CN 202320729397U CN 219960825 U CN219960825 U CN 219960825U
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- 239000003990 capacitor Substances 0.000 claims abstract description 78
- 101000795624 Homo sapiens Pre-rRNA-processing protein TSR1 homolog Proteins 0.000 claims abstract description 15
- 102100031564 Pre-rRNA-processing protein TSR1 homolog Human genes 0.000 claims abstract description 15
- 238000002955 isolation Methods 0.000 claims description 19
- 238000001914 filtration Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000003321 amplification Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000012636 effector Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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Abstract
The utility model relates to the technical field of microphones and provides an isolated microphone signal acquisition circuit which comprises an amplifying circuit, an isolating circuit and a power supply circuit, wherein the input end of the amplifying circuit is used as the input end of the acquisition circuit and used for receiving microphone signals, the output end of the amplifying circuit is connected with sound card equipment through the isolating circuit, the power supply circuit is used for supplying power to the amplifying circuit, the isolating circuit comprises an isolating transformer TSR1, a resistor R5 and a capacitor C4, the input end of the isolating transformer TSR1 is connected with the output end of the amplifying circuit after sequentially passing through the resistor R5 and the capacitor C4, and the output end of the isolating transformer TSR1 is connected with the sound card equipment. After the processing of the isolating circuit, the ground loops of the main board ground signal of the on-demand system and the input signal of the microphone are cut off, and the digital noise of the main board of the on-demand system can not influence the acquisition signal of the microphone. The accuracy of a microphone signal acquisition circuit in the on-demand system is improved, and the influence of noise on a user is reduced.
Description
Technical Field
The utility model relates to the technical field of microphones, in particular to an isolated microphone signal acquisition circuit.
Background
The current KTV use scene improves the voice interaction experience with the user, and besides singing, the microphone can also be used for scoring the intonation. In order to realize the function, the KTV on-demand system firstly collects microphone signals of a user, and then enters the KTV on-demand system after amplification and filtering treatment. However, in actual use, the existing KTV on-demand system is provided with different brands/models of effectors due to the fact that the microphone signal acquisition circuit is not provided with an isolation circuit, so that the situation that obvious noise is heard on a sound box only by connecting microphone signals is found, and meanwhile, the sound level scoring, sound control game and voice functions of the system are triggered by large probability errors, so that the user experience is seriously influenced.
Disclosure of Invention
The utility model provides an isolated microphone signal acquisition circuit, which solves the technical problem that a KTV on-demand system in the prior art can hear obvious noise on a sound box only by connecting microphone signals.
The technical scheme of the utility model is as follows:
an isolated microphone signal acquisition circuit is used for an on-demand system and comprises an amplifying circuit, an isolating circuit and a power supply circuit, wherein the input end of the amplifying circuit is used as the input end of the acquisition circuit and used for receiving microphone signals, the output end of the amplifying circuit is connected with sound card equipment through the isolating circuit, the power supply circuit is used for supplying power to the amplifying circuit, the isolating circuit comprises an isolating transformer TSR1, a resistor R5 and a capacitor C4, the input end of the isolating transformer TSR1 sequentially passes through the resistor R5 and the capacitor C4 and then is connected with the output end of the amplifying circuit, and the output end of the isolating transformer TSR1 is connected with the sound card equipment.
The working principle and the beneficial effects of the utility model are as follows:
in the utility model, an isolation circuit is added on the basis of the original signal acquisition circuit, and after the acquired microphone signal is amplified, the microphone signal is output to a sound card in the on-demand system through the isolation circuit for subsequent processing. After the processing of the isolating circuit, the ground loops of the main board ground signal of the on-demand system and the input signal of the microphone are cut off, and the digital noise of the main board of the on-demand system can not influence the acquisition signal of the microphone. The accuracy of a microphone signal acquisition circuit in the on-demand system is improved, and the influence of noise on a user is reduced.
Drawings
FIG. 1 is a circuit diagram of a isolation circuit of the present utility model;
FIG. 2 is a circuit diagram of an amplifying circuit according to the present utility model;
fig. 3 is a circuit diagram of a power supply circuit according to the present utility model.
Detailed Description
The technical solutions of the embodiments of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
Example 1
The embodiment provides an isolated microphone signal acquisition circuit for an on-demand system, which comprises an amplifying circuit, an isolating circuit and a power supply circuit, wherein the input end of the amplifying circuit is used as the input end of the acquisition circuit and is used for receiving microphone signals, the output end of the amplifying circuit is connected with sound card equipment through the isolating circuit, and the power supply circuit is used for supplying power to the amplifying circuit.
In this embodiment, an isolation circuit is added on the basis of the original signal acquisition circuit, after the acquired microphone signal is amplified, the amplified microphone signal is output to a sound card in the on-demand system through the isolation circuit for subsequent processing, and the sound card has a built-in ADC function, so that the amplified and filtered microphone signal can be directly acquired. After the processing of the isolating circuit, the ground loops of the main board ground signal of the on-demand system and the input signal of the microphone are cut off, and the digital noise of the main board of the on-demand system can not influence the acquisition signal of the microphone.
As shown in fig. 1, the isolation circuit includes an isolation transformer TSR1, a resistor R5 and a capacitor C4, where an input end of the isolation transformer TSR1 sequentially passes through the resistor R5 and the capacitor C4 and then is connected to an output end of the amplifying circuit, and an output end of the isolation transformer TSR1 is connected to the sound card device.
After the microphone input signal is processed by the amplifying circuit, the amplitude is greatly improved, and the maximum output amplitude is probably close to the peak-to-peak value of 10V. The signal is transmitted to the sound card of the on-demand system through the isolation processing of the isolation transformer TSR1, so that the physical isolation of the signal is realized. Wherein, the capacitor C4 and the resistor R5 are filtering effects.
Further, the isolation circuit further comprises a resistor R6 and a capacitor C5, a first end of the resistor R6 is connected with the output end of the isolation transformer TSR1, a second end of the resistor R6 is connected with the sound card device, a first end of the capacitor C5 is connected with a second end of the resistor R6, and a second end of the capacitor C5 is grounded.
In this embodiment, since the amplified microphone signal is subjected to the isolation transformer, the noise will be affected to some extent, and thus the signal output from the isolation transformer is output to the sound card after the first-order low-pass filtering process composed of the resistor R6 and the capacitor C5.
As shown in fig. 2, the amplifying circuit includes an operational amplifier U1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2, and a capacitor C3, wherein a first in-phase input end of the operational amplifier U1 is connected to the first end of the resistor R1, a second end of the resistor R1 is connected to the microphone through the capacitor C1, a second end of the resistor R1 is grounded through the resistor R2, a first inverting input end of the operational amplifier U1 is connected to a first output end of the operational amplifier U1, a first output end of the operational amplifier U1 is sequentially connected to a second inverting input end of the operational amplifier U1 after passing through the capacitor C2 and the resistor R3, a second inverting input end of the operational amplifier U1 is connected to a second output end of the operational amplifier U1 after being on demand, and the resistor R4 is connected to the second inverting input end of the operational amplifier U1 in parallel.
In this embodiment, the first set of input and output in the operational amplifier U1 is used as a follower, and the second set of input and output is used as an inverting amplifier circuit. The microphone input signal is amplified and filtered through the second group of input and output after being processed through the first group of input and output in the blocking capacitor C1 and the operational amplifier U1. The amplification factor of the circuit is mainly determined by the ratio of the resistor R3 to the resistor R4, and is adjusted according to the matched microphone equipment.
Further, the power supply circuit comprises a driver U2, a transformer T1, a capacitor C8, a diode D1, a diode D2, a capacitor C9, a capacitor C10 and a capacitor C13, wherein a power supply end of the driver U2 is connected with a 5V power supply, an output end of the driver U2 is connected with a primary side of the transformer T1, a first end of a secondary side of the transformer T1 is connected with the first end of the capacitor C8, a second end of the secondary side of the transformer T1 is grounded, a second end of the capacitor C8 is connected with an anode of the diode D1, an anode of the diode D1 is connected with a cathode of the diode D2, an anode of the diode D2 is grounded, a cathode of the capacitor C13 is grounded, the capacitor C9 and the capacitor C10 are connected in parallel with the capacitor C13, and the cathode of the diode D1 is powered by the amplifying circuit.
In this embodiment, the driver U2 is an H-bridge driver of a power supply circuit, and a primary side controller is built in the chip. The driver can provide the highest driving power of 3W, a transformer T1 at the rear end is driven (the turns ratio of a primary coil and a secondary coil can be adjusted according to the actual voltage requirement), and then +15V power supply VDD15V is obtained through voltage doubling of a rear-end diode D1 and a diode D2 and filtering of a capacitor C9, a capacitor C10 and a capacitor C13 to supply power to an operational amplifier circuit of a rear-end signal acquisition circuit. The power supply circuit in the utility model can also realize the physical isolation between the 5V power supply and the amplifying circuit.
Further, the power supply circuit further comprises a capacitor C15, a diode D3, a diode D4, a capacitor C11, a capacitor C12 and a capacitor C14, wherein a first end of the capacitor C15 is connected with a first end of a secondary side of the transformer T1, a second end of the capacitor C15 is connected with a cathode of the diode D4, a cathode of the diode D4 is connected with an anode of the diode D3, a cathode of the diode D3 is grounded, a cathode of the capacitor C14 is connected with an anode of the diode D4, an anode of the capacitor C14 is grounded, the capacitor C11 and the capacitor C12 are connected in parallel with the capacitor C14, and an anode of the diode D4 supplies power for the amplifying circuit.
In this embodiment, although the power consumption of the amplifying circuit is relatively small, the signal to noise ratio and dynamic range of the microphone signal acquisition circuit are further improved by the aid of the circuit, and the power supply circuit provides positive and negative power supplies for the operational amplifier. the-15V power supply VEE15V is obtained through voltage doubling of the rear-end diode D3 and the diode D4 and filtering of the capacitor C11, the capacitor C12 and the capacitor C14 and is supplied to an operational amplifier circuit of the rear-end signal acquisition circuit for power supply.
The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the utility model.
Claims (5)
1. An isolated microphone signal acquisition circuit for an on-demand system is characterized by comprising an amplifying circuit, an isolating circuit and a power supply circuit, wherein the input end of the amplifying circuit is used as the input end of the acquisition circuit and used for receiving microphone signals, the output end of the amplifying circuit is connected with sound card equipment through the isolating circuit, the power supply circuit is used for supplying power to the amplifying circuit, the isolating circuit comprises an isolating transformer TSR1, a resistor R5 and a capacitor C4, the input end of the isolating transformer TSR1 sequentially passes through the resistor R5 and the capacitor C4 and then is connected with the output end of the amplifying circuit, and the output end of the isolating transformer TSR1 is connected with the sound card equipment.
2. The isolated microphone signal acquisition circuit of claim 1, further comprising a resistor R6 and a capacitor C5, wherein a first end of the resistor R6 is connected to the output terminal of the isolation transformer TSR1, a second end of the resistor R6 is connected to the sound card device, a first end of the capacitor C5 is connected to the second end of the resistor R6, and a second end of the capacitor C5 is grounded.
3. The isolated microphone signal acquisition circuit according to claim 1, wherein the amplifying circuit comprises an operational amplifier U1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2 and a capacitor C3, wherein a first in-phase input end of the operational amplifier U1 is connected to the first end of the resistor R1, a second end of the resistor R1 is connected to the microphone through the capacitor C1, a second end of the resistor R1 is grounded through the resistor R2, a first inverting input end of the operational amplifier U1 is connected to a first output end of the operational amplifier U1, a first output end of the operational amplifier U1 sequentially passes through the capacitor C2 and the resistor R3 and then is connected to a second inverting input end of the operational amplifier U1, a second inverting input end of the operational amplifier U1 is connected to a second output end on demand through the capacitor C3, and a second inverting input end of the operational amplifier U1 is connected in parallel with the capacitor C4 as an input end of the operational amplifier U1.
4. The isolated microphone signal acquisition circuit of claim 1, wherein the power supply circuit comprises a driver U2, a transformer T1, a capacitor C8, a diode D1, a diode D2, a capacitor C9, a capacitor C10 and a capacitor C13, wherein a power supply terminal of the driver U2 is connected to a 5V power supply, an output terminal of the driver U2 is connected to a primary side of the transformer T1, a first terminal of a secondary side of the transformer T1 is connected to a first terminal of the capacitor C8, a second terminal of the transformer T1 is grounded, a second terminal of the capacitor C8 is connected to an anode of the diode D1, an anode of the diode D1 is connected to a cathode of the diode D2, an anode of the diode D2 is grounded, a cathode of the capacitor C13 is connected to a cathode of the diode D1, a cathode of the capacitor C13 is grounded, and the capacitor C9 and the capacitor C10 are connected in parallel to the capacitor C13, and a second terminal of the transformer T1 is an amplifier.
5. The isolated microphone signal acquisition circuit of claim 4, wherein the power supply circuit further comprises a capacitor C15, a diode D3, a diode D4, a capacitor C11, a capacitor C12, and a capacitor C14, wherein a first end of the capacitor C15 is connected to a first end of the secondary side of the transformer T1, a second end of the capacitor C15 is connected to a cathode of the diode D4, a cathode of the diode D4 is connected to an anode of the diode D3, a cathode of the diode D3 is grounded, a cathode of the capacitor C14 is connected to an anode of the diode D4, an anode of the capacitor C14 is grounded, the capacitor C11 and the capacitor C12 are connected in parallel to the capacitor C14, and an anode of the diode D4 supplies power to the amplifying circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320729397.2U CN219960825U (en) | 2023-03-27 | 2023-03-27 | Isolated microphone signal acquisition circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320729397.2U CN219960825U (en) | 2023-03-27 | 2023-03-27 | Isolated microphone signal acquisition circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219960825U true CN219960825U (en) | 2023-11-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320729397.2U Active CN219960825U (en) | 2023-03-27 | 2023-03-27 | Isolated microphone signal acquisition circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219960825U (en) |
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2023
- 2023-03-27 CN CN202320729397.2U patent/CN219960825U/en active Active
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