KR20040007161A - Circuit for Eliminating Pop-noise for Use in Wireless Microphone Receiver - Google Patents

Abstract

PURPOSE: A circuit for removing the pop-noise of wireless mike transceiver is provided to simplify the configuration of the circuits by removing or muting the generation of pop-noise. CONSTITUTION: A circuit for removing the pop-noise of wireless mike transceiver includes a power supply(210), a power switch(212), a power charge unit(220), a mike receiver(270), an audio output unit(280), a power transmission part(240), a noise removing unit(260), an operational switch unit(250) and a switch driving part(230). The power supply(210) supplies the power. The power charge unit(220) delays the supply or the short of the power by a predetermined time by charging the power to a predetermined amount. The audio output unit(280) outputs the audio signal from the mike receiver(210) as an audible voice. The power transmission part(240) transmits the power transmitted from the power supply(210) to the mike receiver(270). The operational switch unit(250) shorts the operation to remove the pop-noise of the noise removing unit(260). And, the switch driving part(230) shorts the switch operation of the operational switch unit(250).

Description

Circuit for Eliminating Pop-noise for Use in Wireless Microphone Receiver

The present invention relates to a pop-noise cancellation circuit of a wireless microphone transceiver. More particularly, the present invention relates to a semiconductor switching device for pop-noise generated from a receiver when a wireless microphone receiver is turned on and off when a wireless microphone transceiver is used. It relates to a pop-noise cancellation circuit of a wireless microphone transceiver which can be removed by the operation of.

In using a wireless microphone transceiver, a wireless microphone transmitter (usually called a wireless microphone) is designed to be used while the user is free to move the position. However, the wireless microphone receiver is installed near the amplifier and used in a fixed position. . At this time, whenever the power of the wireless microphone receiver is turned on and off, a surge occurs instantly to generate a 'squeak' or 'beep-big' sound, that is, pop-noise, which surprises people around it and operates the wireless microphone device. Also, in order to operate normally, there was an inconvenience to perform an operation to stabilize the amplifier unit.

1 is a block diagram showing the internal configuration of a conventional wireless microphone receiver.

The conventional wireless microphone receiver includes an RF front end unit 110, a second intermediate frequency amplifier 120, an IF filter 122, a demodulator 124, a voice signal amplifier 126, a voice signal output switch 128, a low frequency filter. 130, an output line 132, a control signal band pass 134, an expander 136, an audio signal amplifier 138, and a CPU 140.

The RF front end unit 110 includes a helical filter 111 for receiving a high frequency transmitted from a wireless microphone transmitter, a high frequency amplifier 112 for amplifying a high frequency received by the helical filter 111 to a predetermined level, and a high frequency. In the first intermediate frequency converter 113 and the first intermediate frequency converter 113 for mixing the high frequency amplified by the amplifying unit 112 and converting the high frequency amplified by the VCO 117 into a first intermediate frequency. A first intermediate frequency amplifier 114 for amplifying the converted first intermediate frequency to a predetermined level, a PLL 118 generating an oscillation frequency according to a control signal, and a first local oscillation according to an oscillation frequency generated in the PLL 118 The second local oscillator 119 generates the first intermediate frequency amplified by the VCO 117 generating the frequency, the second local oscillator 119 generating the second local oscillation frequency, and the first intermediate frequency amplifier 114. 10.7 MH by mixing with a second local oscillation frequency a second intermediate frequency converter 115 generating a second intermediate frequency of z and an intermediate frequency (IF) filter 116 extracting a second intermediate frequency of 10.7 MHz converted by the second intermediate frequency converter 115. .

The second intermediate frequency amplifier 120 amplifies the second intermediate frequency of 10.7 MHz extracted from the IF filter 116 in the RF front end 110 to a predetermined level, and the IF filter 122 converts the second intermediate frequency amplifier ( The second intermediate frequency of 10.7 MHz amplified by 120 is once again extracted, and the demodulator 124 demodulates the second intermediate frequency of 10.7 MHz extracted by the IF filter 122 into a voice signal and a control signal.

The voice signal amplifier 126 amplifies the voice signal demodulated by the demodulator 124 to a predetermined level, and the voice signal output switch 128 switches on / off under the control of the CPU 140 to perform the voice signal amplifier 126. A) and outputs the amplified voice signal, and the low frequency filter 130 passes only the low frequency signal among the voice signals output through the voice signal output switch 128.

The expander 136 restores the low frequency signal passed through the low frequency filter 130 to the voice signal, and the voice signal amplifier 138 amplifies the voice signal restored by the expander 136 and outputs the audio signal, and a control signal band. The passer 134 passes only the control signal among the signals demodulated by the demodulator 124.

The CPU 140 extracts the control signal passed through the control signal band pass 134 and controls the on / off operation of the voice signal output switch 128 to remove pop-noise generated by the carrier wave. do. At this time, the RF level meter output of the demodulator 124 is connected to the analog input terminal of the CPU 140 by the RF level meter output line 132.

Referring to the operation of the conventional wireless microphone receiver configured as described above are as follows.

First, when a user inputs a voice to a wireless microphone transmitter, the microphone converts the user's voice into an electric voice signal, amplifies the converted electric voice signal to a predetermined level, and compresses the amplified voice signal. The microphone generates a square wave control signal corresponding to an inaudible frequency of 33 KHz to 40 KHz higher than the audible frequency, modulates it together with the voice signal, and transmits the signal at a high frequency.

Then, the RF front end 110 of the wireless microphone receiver receives the high frequency transmitted from the wireless microphone transmitter and extracts the second intermediate frequency of 10.7 MHz by the IF filter 116 to the second intermediate frequency amplifier 120. Output

The second intermediate frequency amplifier 120 amplifies the second intermediate frequency of 10.7 MHz to a predetermined level, and the IF filter 122 again amplifies the second intermediate frequency of 10.7 MHz amplified by the second intermediate frequency amplifier 120. Once extracted, the demodulator 124 demodulates the second intermediate frequency of 10.7 MHz extracted from the IF filter 116 into a speech signal and a control signal, and the speech signal amplifier 126 demodulates the speech signal demodulated by the demodulator 124. Boost a certain level.

At this time, the control signal band passer 134 passes only the control signal by using a large frequency difference between the audio signal and the control signal demodulated by the demodulator 124.

Accordingly, the CPU 140 controls the audio signal output switch 128 to be turned on in accordance with the extraction of the control signal passed through the control signal bandpass 134 to generate the voice signal by the voice signal output switch 128. Output to the low frequency filter 130.

Then, the low frequency filter 130 passes only the low frequency signal among the voice signals output to the voice signal output switch 128 that is operated on and controlled by the CPU 140, and the expander 136 passes through the low frequency filter 130. The low frequency signal is restored to a speech signal, and finally, the speech signal amplifier 138 amplifies the speech signal restored by the expander 136 and outputs the audio signal.

That is, in the conventional wireless microphone receiver, the voice signal output switch 128 is initially set to the off state so that pop-noise generated due to an unmodulated high frequency carrier wave initially transmitted when the wireless microphone transmitter is turned on does not come out. After removing the control signal, which is modulated and transmitted together with the voice signal, the voice signal output switch 128 is turned on to recognize the reception of the voice signal and output the voice signal as original audio.

The conventional wireless microphone receiver configured as described above has a complicated circuit configuration for removing or muting pop-noise, and is expensive in manufacturing due to the large equipment scale.

Accordingly, there has been a demand for a method for simplifying a circuit configuration for removing or muting pop-noise in a wireless microphone receiver and for lowering the cost by configuring a small device size.

In order to meet the above-described demands, the present invention provides a wireless radio apparatus capable of eliminating pop-noise generated at a receiver when a wireless microphone receiver is turned on and off by using a wireless microphone transceiver. The purpose is to provide a pop-noise cancellation circuit of a microphone transceiver.

1 is a block diagram showing the internal configuration of a conventional wireless microphone receiver;

2 is a circuit diagram schematically showing a configuration of a pop-noise cancellation circuit of a wireless microphone transceiver according to an embodiment of the present invention;

3 is a block diagram schematically showing an internal configuration of a wireless microphone transmitter;

4 is an operational waveform diagram for each configuration of the wireless microphone transceiver.

<Description of Symbols for Main Parts of Drawings>

110: RF front end portion 120: second intermediate frequency amplifier

122: IF filter 124: demodulator

126: voice signal amplifier 128: voice signal output switch

130: low frequency filter 132: output line

134: control signal bandpass 136: expander

138: voice signal amplifier 140: CPU

200: wireless microphone receiver 210: power unit

212: power switch 220: power charging unit

230: switching driver 240: power transmission unit

250: operation switching unit 260: noise removing unit

270: microphone receiving unit 280: audio output unit

300: wireless microphone transmitter 302: microphone

304: amplitude limiting and voice signal amplifier 306: compression unit

308: voice signal modulation degree control unit 310: voltage controlled oscillator

312: high frequency power amplifier 314: high frequency band filter

316: band pass filter 318: control signal amplitude adjusting unit

320: phase locked loop 322: power switch

324: battery power 326: microprocessor

Reg: Three-terminal regulator C1 ~ C11: Capacitor (capacitor)

R1 to R8: resistors D1, D3: diodes

D2: Double Diode SP: Speaker

TR1: PNP type transistor TR2: NPN type transistor

In order to achieve the above object, the present invention is provided with a wireless microphone for inputting a voice signal, the pop-noise generated when the power of the wireless microphone receiver for receiving a voice signal transmitted from the wireless microphone on and off (Pop- In the pop-noise cancellation circuit of a wireless microphone transceiver capable of removing noise, a power supply unit 210 for supplying power, a power switch 212 for intermittent supply of power from the power supply unit 210, and the power supply unit A power charging unit 220 for charging a predetermined amount of power supplied from the power supply 210 to delay the supply or shutdown of the power for a predetermined time, and receives a voice signal transmitted from the wireless microphone, and the power switch 212 Outputting the audio signal received by the microphone receiver 270 and the microphone receiver 270 as an audible sound when the pop-noise is generated on / off An audio output unit 280, a power transmission unit 240 for transferring the power supplied from the power supply unit 210 to the microphone receiver 270, switching by the power applied from the power transmission unit 240 An operation removing unit 260 for removing the pop-noise generated by the microphone receiver 270 and an operation switching unit 250 for controlling an operation of removing the pop-noise of the noise removing unit 260. ), And a switching driver 230 for interrupting the switching operation of the operation switching unit 250.

In addition, in order to achieve the above object, the present invention, the wireless microphone 300 for inputting a voice signal, the power supply unit 210 for supplying power, the power switch 212 to control the supply of power from the power supply unit 210 ), A microphone receiver 270 that receives a voice signal transmitted from the wireless microphone 300 and generates pop-noise when the power switch 212 is turned on or off, and the voice received by the microphone receiver 270. In the pop-noise cancellation circuit of a wireless microphone transceiver having an audio output unit 280 for outputting a signal as an audible sound, the power supply is charged by charging a predetermined amount of power from the power source 210. The power charging unit 220 for delaying the time, the power transmission unit 240 for transmitting the power supplied from the power supply unit 210 to the microphone receiver 270, the emitter is grounded, the base PNP transistor TR1 is connected to the power transmission unit 240, and the power is output to the collector, the emitter is grounded, and the collector of the PNP transistor TR1 is connected to the base via a resistor 6 R6. And a collector connected to the base of the NPN transistor TR2 to which the microphone receiver 270 and the audio output unit 280 are connected, and the base of the PNP transistor TR1 to adjust a base potential. And a switching driver 230 for interrupting the switching operation of the transistor TR1.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

2 schematically illustrates a configuration of a pop-noise cancellation circuit of a wireless microphone transceiver according to an embodiment of the present invention.

The wireless microphone receiver 200 according to the present invention includes a power supply unit 210, a power switch 212, a power charging unit 220, a switching driver 230, a power transmission unit 240, an operation switching unit 250, and noise reduction. Rejection 260, microphone receiving unit 270, audio output unit 280.

The power supply unit 210 supplies power to the wireless microphone receiver 200. The power switch 212 interrupts the power supply from the power supply unit 210 on or off. The power charging unit 220 charges a certain amount of power from the power supplied from the power supply unit 210 to delay supply or interruption of power for a predetermined time.

The power transmission unit 240 transmits the power supplied from the power supply unit 210 to the operation switching unit 250 to apply the power to the microphone receiver 270. The operation switching unit 250 interrupts the on or off switching operation to transfer the power applied from the power transmission unit 240 to the noise removing unit 260. The noise removing unit 260 is switched by the power applied from the power transmission unit 240 to remove the pop-noise generated by the microphone receiver 270.

The microphone receiver 270 receives a voice signal wirelessly transmitted from the wireless microphone 300 to be described later, and the audio output unit 280 outputs the voice signal received by the microphone receiver 270 as an audible sound. The switching driver 230 causes the off switching operation of the first switching unit 250 to be executed quickly.

The power switch 212 is connected to the power charging unit 220 by the diode 1 (D1). Capacitor 2 (C ₂ ) is connected in parallel to the power charging unit 220 between the connection point a and the ground. The power charging unit 220 is a positive output three-terminal regulator (Reg) is connected to the connection point (a) line, the oscillation prevention capacitor (C ₃ , C ₄ ) of approximately 0.1 사이 between the connection point (a) line and the ground ) Is connected in parallel to the regulator (Reg). When using more than 40% of the rated current, be sure to install and use a radiator (not shown). The three-terminal regulator Reg receives power from the power switch 212 and outputs 8 V as an output. Capacitor 5 (C ₅ ) is connected in parallel between the output terminal of the three-terminal regulator (Reg) and ground.

The minimum input voltage of the three-terminal regulator (Reg) must be at least 2.5 높아 higher than the output voltage, and if the voltage between the input and output is extremely small, it cannot be operated by the ripple generated in the smoothing circuit and the large ripple noise in the output ) Occurs. It is necessary to secure the input voltage of the regulator in consideration of the change of the voltage applied from the power supply unit 210 by about -10%. When the voltage between the input and output needs to be reduced for low power consumption, the voltage between the input and output is 0.2V. Use a low drop-out type regulator that can operate at ~ 0.5 V.

The power transmission unit 240 is connected so that power from the power charging unit 220 is applied to the operation switching unit 250 through the resistor 2 (R ₂ ) and the resistor 3 (R ₃ ) in series, and on each connection line. Capacitor 8 (C ₈ ) and diode 3 (D ₃ ) are connected in parallel between and ground. Of course, the power transmission unit 240 may be configured to have the same different function as that of the embodiment of the present invention.

The operation switching unit 250 includes a PNP transistor TR1 and a resistor 5 (R5), and the resistor 2 (R ₂ ) of the power transmission unit 240 is connected to the base of the PNP transistor TR1. In addition to the connection of the resistor 3 (R ₃ ) and the switching driver 230 is connected, the emitter (Emitter) is a resistor 4 (R ₄ ) in parallel with the connection of the resistor 2 (R ₂ ) and the resistor 3 (R ₃ ). Is connected, and resistor 5 (R ₅ ) is connected and grounded at this connection point. The noise collector 260 is connected to the collector of the PNP transistor TR1 through a resistor 6 (R ₆ ). Of course, the operation switching unit 250 may also be configured by using another semiconductor switching element instead of the PNP transistor TR1.

The noise canceller 260 is composed of an NPN transistor TR2, an emitter is grounded, a base is connected to an operation switching unit 250, and a collector is connected to a microphone receiver 270 and an audio output unit 280. have. That is, the noise removing unit 260 is operated by the base of the PNP type transistor TR1 being supplied from the operation switching unit 250 so that the pop-noise generated by the microphone receiver 270 passes through the emitter stage from the collector stage. Flow to ground eliminates pop-noise. Of course, the noise removing unit 260 may also be configured using other semiconductor switching elements having the same function instead of the NPN transistor TR2.

The switching driver 230 includes a pair diode D2 having the same current direction, and an anode of the left diode A of the pair diode D2 is connected to the power switch 212 and the power charger 220. The anode of the right diode (I) is connected to the base of the PNP type transistor TR1 of the operation switching unit 250. Capacitor 9 (C ₉ ) is connected and grounded at this connection point. A resistor 1 (R1) is connected to the cathode of the pair of diodes D2 and is grounded, and a capacitor 7 (C ₇ ) and a grounded capacitor 6 (C ₆ ) are connected in parallel with the pair of diodes D2.

The audio output unit 280 has a resistor 7 (R7), a capacitor 11 (C ₁₁ ), and a speaker SP connected in series on a connection line with the noise removing unit 260, and is parallel between the connection line and the ground. The resistor 7 (R7) and capacitor 10 (C ₁₀ ) are connected.

3 is a block diagram schematically illustrating an internal configuration of a wireless microphone transmitter for transmitting a voice signal to a wireless microphone receiver as a wireless signal.

The wireless microphone transmitter 300 includes a microphone 302, an amplitude limiting and voice signal amplifier 304, a compression unit 306, a voice signal modulation control unit 308, a voltage controlled oscillator 310, and a high frequency power amplifier ( 312), high frequency band filter 314, band pass filter 316, control signal magnitude adjuster 318, phase locked loop 320, power switch 322, battery power 324, microprocessor 326 And the like.

The microphone 302 converts the user's voice into an electrical voice signal, and the amplitude limitation and voice signal amplifier 304 limits and amplifies the electrical voice signal converted in the microphone 302 to a constant level.

The compression unit 306 compresses the amplitude signal and the speech signal amplified by the speech signal amplifier 304, the speech signal modulation degree adjuster 308 adjusts the modulation degree of the speech signal compressed by the compression unit 306, The voltage controlled oscillator (VCO) 310 is referred to as a VCO 310 and modulates a voice signal and a control signal of which modulation degree is controlled by a voice signal modulation degree adjusting unit 308 into a carrier wave to output a high frequency wave.

The high frequency power amplifier 312 amplifies the high frequency output from the VCO 310 to a predetermined level, and the high frequency band filter 314 filters a predetermined band of the high frequency amplified by the high frequency power amplifier 312 and passes the band. The filter 316 converts a square wave control signal corresponding to an inaudible frequency (33 KHz to 40 KHz) into a sine wave control signal.

The control signal amplitude adjusting unit 318 adjusts the magnitude of the sinusoidal control signal converted by the band pass filter 316, and the phase locked loop (PLL) 320 is referred to as the voice signal and A carrier for modulating the control signal is generated and output to the VCO 310, and the power switch 322 opens and closes the power of the high frequency power amplifier 312.

The battery power source 324 supplies power in each of the above configurations, and the microprocessor 326 generates a square wave control signal corresponding to an inaudible frequency of 33 KHz to 40 KHz, and transmits a high frequency carrier to provide a fixed time difference. The generated control signal is modulated together with the voice signal to control high frequency transmission.

Next, the preferred operation of the wireless microphone transceiver configured as described above will be described in detail with reference to the operation waveform diagram shown in FIG.

First, when the user turns on the wireless microphone transmitter 300, the PLL 320 generates a carrier wave for modulating a voice signal under the control of the microprocessor 326, and then the VCO 310 generates the carrier wave. An unmodulated high frequency carrier wave is transmitted to the wireless microphone receiver 200 via a high frequency power amplifier 312 and a high frequency band filter 314.

Then, in the wireless microphone receiver 200 in which the power switch 212 is initially turned off, the user turns on the power switch 212 of the wireless microphone receiver 200 to transmit an unmodulated high frequency carrier wave transmitted from the wireless microphone transmitter 300. It is then ready to receive the voice signal.

When the power switch 212 is in the off state, the points A, B, and C are both low level, and the power charging unit 220 is not yet charged, so it is low level.

When the user turns on the power switch 212 of the wireless microphone receiver 200 as shown in (a) of FIG. 4, the power is supplied from the power supply unit 210 to the power charging unit 220 and the switching driver 230. Is applied.

When the power switch 212 is turned on, the power charging unit 220 is charged to each of the capacitors C2 to C5 until the power level becomes high as shown in FIG. When power is applied from the power switch 212, the switching driver 230 operates the left diode of the double diode D2 so that a current flows from the anode to the ground via the cathode.

When the power switch 212 is turned on as shown in (d) of FIG. 4, the power is applied from the ground to the emitter of the PNP transistor TR1 so that the point A is at a high level. At this time, the point B connected to the base of the PNP transistor TR1 is until the power charging unit 220 is fully charged and the high level power is applied through the power transmission unit 240 as shown in FIG. Low level.

Therefore, while the power switch 212 is turned on and the power charging unit 220 is charged with power, the emitter of the PNP type transistor TR1 is in the high level state and the base is in the low level state. As shown in (e), the power is turned on, and the power output to the collector side is applied to the base of the NPN transistor TR2 via the resistor 6 (R6).

When the NPN transistor TR2 of the noise removing unit 260 is operated as shown in FIG. 4F, current flows from the emitter side to the collector side. At this time, since the pop-noise generated by the microphone receiver 270 is connected to the emitter terminal of the NPN transistor TR2, the pop-noise flows to the ground through the collector side.

That is, when the power switch 212 is turned on, the PNP transistor TR1 and the NPN transistor TR2 are operated until the power charging unit 220 is charged to the high level state, thereby operating the microphone receiver 270. The action of removing pop-noise generated at

On the other hand, as shown in (b) of FIG. 4, when the power is charged to the power charging unit 220 to be in the high level state, the high level power passes through the power transmission unit 240 to form the PNP transistor ( Is applied to the base of TR1). That is, when the power charged in the power charging unit 220 is in the high level state, the point B connected to the base of the PNP transistor TR1 in the operation switching unit 250 as shown in FIG. 4C is at a high level. It becomes a state. Therefore, since a high level power is applied to the base terminal of the PNP transistor TR1, the operation of the PNP transistor TR1 is stopped as shown in FIG.

As the operation of the PNP transistor TR1 is stopped, the point C on the collector side becomes a low level state, so that the base of the NPN transistor TR2 becomes a low level state as shown in FIG. ) Also stops.

As the operation of the noise remover 260 is stopped, the voice signal applied from the microphone receiver 270 is transmitted to the audio output unit 280. In this case, when a user inputs a voice using the wireless microphone transmitter 300, the wireless microphone transmitter 300 transmits a voice signal to the wireless microphone transmitter 300 and receives the audio signal from the microphone receiver 270 of the wireless microphone receiver 200. 280) to output an audible sound.

Next, the operation of the wireless microphone transmitter 300 will be described.

When the user's voice is input into the microphone 302 of the wireless microphone transmitter 300, the microphone 302 converts the user's voice into an electrical voice signal, and the amplitude limiting and voice signal amplifier 304 has a microphone 302. Limit and amplify the electric speech signal converted at the predetermined level, and the compression unit 306 compresses the speech signal amplified by the amplitude limiting and speech signal amplifier 304 and adjusts the voice signal modulation degree 308. Adjusts the modulation degree of the speech signal compressed by the compression unit 306.

Here, the microprocessor 326 controls the PLL 320 and the VCO 310 to transmit an unmodulated high frequency carrier wave, and then, for about 1 to 2 seconds, has a higher audible frequency of 20 Hz to 20 KHz corresponding to a voice signal. A square wave control signal corresponding to an inaudible frequency of 33 KHz to 40 KHz is generated, modulated with an audio signal, and controlled to transmit a high frequency wave.

That is, when the microprocessor 326 generates a control signal, the band pass filter 316 converts the square wave control signal corresponding to the inaudible frequency of 33 KHz to 40 KHz generated by the microprocessor 326 into a sinusoidal control signal. Subsequently, the control signal amplitude adjusting unit 318 adjusts the magnitude of the sinusoidal control signal converted by the band pass filter 316.

Subsequently, when the control signal adjusted by the control signal magnitude adjusting unit 318 is input to the VCO 310 together with the voice signal whose modulation degree is adjusted by the voice signal modulation degree adjusting unit 308, the VCO 310 receives the voice. The signal and the control signal are modulated by the carrier wave generated by the PLL 320 and output to the high frequency power amplifier 312 as a high frequency wave.

Subsequently, the high frequency power amplifier 312 is supplied with power by the power switch 322 which has been controlled by the microprocessor 326 to amplify the high frequency output from the VCO 310 to a constant level, and the high frequency band. The filter 314 radiates the high frequency amplified by the high frequency power amplifier 312 to the outside by the antenna Ant.

The voice signal radiated wirelessly from the wireless microphone transmitter 300 is received by the microphone receiver 270 of the wireless microphone receiver 200, and is transmitted from the microphone receiver 270 to the audio output unit 280 to the speaker SP. By audible sound.

After using the wireless microphone transceiver as described above, the user turns off the power switch 322 of the wireless mouse transmitter 300 and turns off the power switch 212 of the wireless microphone receiver 200.

When the user turns off the power switch 212 as shown in (a) of FIG. 4, the supply of power is stopped from the power supply unit 210, and the power charged in the power charging unit 220 is stored in FIG. 4 (b). As described above, the electric power is discharged from the time when the power switch 212 is turned off.

When the power switch 212 is turned off to stop the supply of power from the power supply unit 210, the left diode A of the double diode D2 in the switching driver 230 stops driving and is at the high point state. High-level power is applied to the anode of the right diode (B) that is connected to flow through the cathode to ground. Therefore, the point B of the high level state connected to the base of the PNP type transistor TR1 of the operation switching unit 250 by the switching driver 230 rapidly advances to the low level state. That is, the point B connected to the base of the PNP transistor TR1 is switched to the low level state until the power supply of the power charging unit b is discharged to a low level state as shown in FIG.

Point A connected to the emitter of the PNP type transistor TR1 is in a high level until point B becomes a low level state as shown in FIG. 4 (d), and then all the power of the power charging unit 220 is discharged. The point becomes low level from the moment the point becomes low level.

That is, as shown in (e) and (f) of FIG. 4, the PNP type transistor TR1 of the operation switching unit 250 from the time when the power switch 212 is turned off until the point B and the point A both become low level states. And the NPN type transistor TR2 is operated as the PNP type transistor TR1 is operated so that the pop-noise generated by the microphone receiver 270 when the power switch 212 is turned off is NPN type. It flows through the transistor TR2 to ground and is removed.

According to an embodiment of the present invention, a wireless microphone transceiver capable of removing the pop-noise generated by the receiver when the wireless microphone receiver is turned on and off when the wireless microphone transceiver is used, is operated by a semiconductor switching element. Pop-noise cancellation circuits can be realized.

The present invention is not limited to the above embodiments, and various modifications and changes can be made by those skilled in the art without departing from the technical scope of the present invention.

As described above, according to the present invention, the circuit configuration is simplified by eliminating or muting pop-noise generated when the power source is turned on or off by using a semiconductor switching element in the wireless microphone transceiver. It can be configured as. In addition, by applying the manufacturing cost of the wireless microphone transceiver at low cost, the selling price can be lowered.

Claims (16)

A wireless microphone having a wireless microphone for inputting a voice signal, and configured to remove pop-noise generated when the wireless microphone receiver for receiving a voice signal transmitted from the wireless microphone is turned on and off. In the pop-noise cancellation circuit of the transceiver, A power supply unit 210 for supplying power; A power switch 212 intermittent to supply power from the power supply 210; A power charger 220 for charging a predetermined amount of power from the power supplied by the power supply 210 to delay supply or interruption of the power for a predetermined time; A microphone receiver 270 which receives a voice signal transmitted from the wireless microphone and generates the pop-noise when the power switch 212 is turned on or off; An audio output unit 280 for outputting an audio signal received by the microphone receiver 270 as an audible sound; A power transmission unit 240 for transferring power supplied from the power supply unit 210 to the microphone receiver 270; A noise removing unit 260 for switching the pop-noise generated by the microphone receiving unit 270 by switching by the power applied from the power transmitting unit 240; An operation switching unit 250 for controlling an operation of removing the pop-noise of the noise removing unit 260; And Switching driver 230 to interrupt the switching operation of the operation switching unit 250 Pop-noise cancellation circuit of the wireless microphone transceiver, characterized in that it comprises a. The method of claim 1, The power switch 212 is connected to the power charging unit 220 by a diode 1 (D1), and a capacitor 2 (C ₂ ) is parallel to the power charging unit 220 between the connection point a and the ground. Connected to The power charging unit 220 is a positive output three-terminal regulator (Reg) is connected to the connection point (a) line, the oscillation prevention capacitor (C ₃ , C ₄ ) between the connection point (a) line and the ground is the three Connected in parallel to the terminal regulator (Reg), The three-terminal regulator (Reg) is a power input from the power switch 212 and output a constant voltage to the output, the capacitor 5 (C ₅ ) is connected in parallel between the output terminal and the ground of the three-terminal regulator (Reg) Pop-noise cancellation circuit of a wireless microphone transceiver, characterized in that. The method of claim 1, The operation switching unit 250 is composed of a PNP transistor TR1, Resistor 2 (R ₂ ) and resistor 3 (R ₃ ) of the power transmission unit 240 are connected to the base of the PNP transistor TR1, and the switching driver 230 is connected. Resistor 4 (R ₄ ) is connected in parallel to the connection between 2 (R ₂ ) and the resistor 3 (R ₃ ), and resistor 5 (R ₅ ) is connected between the connection point and the ground, and the PNP transistor The noise removing unit 260 is connected to the collector of TR1 via a resistor 6 (R ₆ ), The noise removing unit 260 is composed of an NPN transistor TR2, The emitter of the NPN transistor TR2 is grounded, a base is connected to the operation switching unit 250, and a collector is connected to the microphone receiver 270 and the audio output unit 280. Pop-noise cancellation circuit in wireless microphone transceiver. The method of claim 1, The power transmission unit 240 is connected so that power is supplied from the power charging unit 220 to the operation switching unit 250 through resistors 2 (R ₂ ) and 3 (R ₃ ) in series. A pop-noise cancellation circuit of a wireless microphone transceiver, characterized in that capacitor 8 (C ₈ ) and diode 3 (D ₃ ) are connected in parallel between the connection line and ground. The method of claim 1, The audio output unit 280 has a resistor 7 (R7), a capacitor 11 (C ₁₁ ), and a speaker SP connected in series on a connection line with the noise removing unit 260, and between the connection line and ground. Resistor 7 (R7) and capacitor 10 (C ₁₀ ) are connected in parallel to the pop-noise cancellation circuit of a wireless microphone transceiver. The method of claim 1, The operation switching unit 250 is a pop-noise cancellation circuit of a wireless microphone transceiver, characterized in that consisting of one of the FET or MOSFET. The method of claim 1, The noise canceling unit (260) is a pop-noise cancellation circuit of a wireless microphone transceiver, characterized in that consisting of one of the FET or MOSFET. The method of claim 3, wherein When the power switch 212 is turned on, the emitter terminal of the PNP transistor TR1 is in a high level state, and the base terminal of the PNP transistor TR1 is charged with the power of the power charging unit 220. Pop-noise cancellation circuit of a wireless microphone transceiver characterized by being in a low level until it is in a high level. The method of claim 3, wherein When the power switch 212 is turned on, the PNP transistor TR1 and the NPN transistor TR2 operate, and when the power of the power charger 220 is charged to a high level state, the PNP Pop-noise cancellation circuit of a wireless microphone transceiver, characterized in that the operation of the transistor type TR1 and the NPN transistor TR2 is stopped. The method of claim 3, wherein When the power switch 212 is turned off, the power charged in the power charger 220 is discharged, and when the power of the power charger 220 is discharged to a low level state, the PNP type transistor TR1 is discharged. The emitter of is in a low level state, and when the power charging unit 220 is discharged to a low level state, the base of the PNP transistor TR1 also becomes a low level state. The PNP transistor TR1 and the NPN transistor TR2 are operated from when the power switch 212 is turned off until the emitter of the PNP transistor TR1 is at a low level. -Noise cancellation circuit of wireless microphone transceiver. A wireless microphone 300 for inputting a voice signal, a power supply unit 210 for supplying power, a power switch 212 for intermittent supply of power from the power supply unit 210, and a voice transmitted from the wireless microphone 300. A microphone receiver 270 that receives a signal and generates pop-noise when the power switch 212 is turned on or off, and an audio output unit 280 for outputting an audio signal received by the microphone receiver 270 as an audible sound. A pop-noise cancellation circuit of a wireless microphone transceiver comprising: A power charging unit 220 for charging a predetermined amount of power supplied from the power supply unit 210 to delay the supply of the power for a predetermined time period; A power transmission unit 240 for transferring power supplied from the power supply unit 210 to the microphone receiver 270; An emitter is grounded, a base is connected to the power transmission unit 240, and a PNP transistor (TR1) for outputting power to a collector; The emitter is grounded and a collector of the PNP transistor TR1 is connected to the base via a resistor 6 (R6), and the collector is an NPN transistor in which the microphone receiver 270 and the audio output unit 280 are connected. (TR2); And A switching driver 230 connected to the base of the PNP transistor TR1 to regulate a base potential to interrupt the switching operation of the PNP transistor TR1. Pop-noise cancellation circuit of the wireless microphone transceiver, characterized in that it comprises a. The method of claim 11, The power switch 212 is connected to the power charging unit 220 by a diode 1 (D1), and a capacitor 2 (C ₂ ) is parallel to the power charging unit 220 between the connection point a and the ground. Connected to The power charging unit 220 is a positive output three-terminal regulator (Reg) is connected to the connection point (a) line, the oscillation prevention capacitor (C ₃ , C ₄ ) between the connection point (a) line and the ground is the three Connected in parallel to the terminal regulator (Reg), The three-terminal regulator (Reg) is a power input from the power switch 212 and output a constant voltage to the output, the capacitor 5 (C ₅ ) is connected in parallel between the output terminal and the ground of the three-terminal regulator (Reg) Pop-noise cancellation circuit of a wireless microphone transceiver, characterized in that. The method of claim 11, The power transmission unit 240 is connected so that power is supplied from the power charging unit 220 to the operation switching unit 250 through resistors 2 (R ₂ ) and 3 (R ₃ ) in series. A pop-noise cancellation circuit of a wireless microphone transceiver, characterized in that capacitor 8 (C ₈ ) and diode 3 (D ₃ ) are connected in parallel between the connection line and ground. The method of claim 11, When the power switch 212 is turned on, the emitter terminal of the PNP transistor TR1 is in a high level state, and the base terminal of the PNP transistor TR1 is charged with a high power supply of the power charging unit 220. The pop-noise cancellation circuit of a wireless microphone transceiver, which is in a low level until it is in a level state. The method of claim 11, When the power switch 212 is turned on, the PNP transistor TR1 and the NPN transistor TR2 operate, and when the power of the power charger 220 is charged to a high level state, the PNP Pop-noise cancellation circuit of a wireless microphone transceiver, characterized in that the operation of the transistor type TR1 and the NPN transistor TR2 is stopped. The method of claim 11, When the power switch 212 is turned off, the power charged in the power charger 220 is discharged, and when the power of the power charger 220 is discharged to a low level state, the PNP type transistor TR1 is discharged. The emitter of is in a low level state, and when the power charging unit 220 is discharged to a low level state, the base of the PNP transistor TR1 also becomes a low level state. The PNP transistor TR1 and the NPN transistor TR2 are operated from when the power switch 212 is turned off until the emitter of the PNP transistor TR1 is at a low level. -Noise cancellation circuit of wireless microphone transceiver.