KR20010004955A - Wireless mike transceiver mute controller by micom control - Google Patents

Abstract

PURPOSE: An apparatus for controlling a wireless microphone transceiver mute is provided to transceive a non-modulation carrier and a modulation carrier to a transceiving unit at one to two second time intervals when a transceiver power is turned off, by using a 33-40Khz frequency higher than an audio frequency, so as to remove on/off noises of a microphone power. CONSTITUTION: A wireless microphone transceiving circuit comprises as follows. A band pass filter(8) changes a square wave into a sine wave. A control signal size controller(9) controls a size of the band pass filter to transmit a control signal to a modulation input terminal of a voltage control oscillator(VCO). A phase locked loop(PLL) and the VCO decide high frequency carrier frequencies by a data signal of a CPU, and oscillate the high frequency carrier frequencies. A high frequency amplifier amplifies the high frequencies. A high frequency band filter reduces an unwanted copying of the high frequencies. A power switch and a battery power switch power of the high frequency power amplifier. A wireless microphone receiver comprises as follows. A helical filter(21) receives a transmitted propagation. A high frequency amplifier(22) amplifies an output signal of the helical filter(21). A PLL(28) decides a frequency by a CPU(38). A VCO(27) oscillates a voltage of the PLL(28). A first intermediate frequency(IF) converter(23) inputs signals from the amplifier(22) and the VCO(27), and converts the signals into IF signals. A first IF amplifier(24) amplifies the converted IF signals. A second local oscillator(29) makes a second 10.7MHz IF. A second frequency converter(25) inputs signals of the second local oscillator(29) and the first IF amplifier(24), and converts the signals into second IFs. IF filters(26,31) extract the second 10.7MHz IF. A 10.7MHz IF amplifier(30) amplifies signals between the IF filters(26,31). A demodulator(32) demodulates an audio signal. A voice signal amplifier(33) amplifies a voice output signal of the demodulator(32). An audio output switch(34) is controlled by the CPU(38). A low frequency filter(35) passes low frequency signals only. An expander(39) restores a sound signal compressed in a transmitter. A control signal band pass circuit(36) controls the output signal of the demodulator(32). A radio frequency(RF) level meter output line(37) is transmitted to the CPU(38) from the demodulator(32).

Description

Wireless microphone transceiver mute controller by micom control {Wireless mike transceiver mute controller by micom control}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless microphone transceiver, and more particularly, to a wireless microphone transceiver mute control apparatus by a microprocessor control capable of removing transmission on / off noise generated when the wireless microphone is turned on / off.

When using a conventional wireless microphone, the receiver is installed close to the amplifier unit, its position is fixed, and the microphone transmitter with the built-in battery is used by the user to freely move the moving position. A momentary “click” was heard from the receiver, which surprised everyone around them.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to transmit a control signal higher than an audible frequency whose frequency is adjusted by soft, and transmits a control signal at a time difference from a high frequency carrier when the microphone transmitter is turned on or off. It modulates the receiver control signal and removes the noise by adjusting the receiver muting time by reading the constant magnitude of the RF level DC voltage obtained only when there is a high frequency input from the receiving demodulator.

1 is a view showing the configuration of a wireless microphone transmitter of the present invention

2 is a view showing the configuration of a wireless microphone receiver of the present invention

<Explanation of symbols for main parts of drawing>

1: microphone 3: compression

5: VCO 6: high frequency power amplifier

7: High frequency band filter 8: Band pass filter

10: PLL 11: power switch

12: Battery power 13,38: CPU

20: RF front end 26, 31: IF filter

32: demodulator 35: low frequency filter

36: control signal bandpass 39: expander

40: sound signal amplifier and power mute

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

1 is a diagram illustrating a transmitter of a wireless microphone of the present invention, wherein a microphone 1 for amplifying an input voice signal, an amplitude limiter and a voice signal amplifier 2 for limiting and amplifying a signal of the microphone 1 are shown in FIG. And a compression unit (3) for compressing the audio signal through the amplitude limiter and the audio signal amplifier (2), a variable resistance portion (4) for controlling the audio signal modulation degree, and a square wave generated by the CPU (13). A band pass filter 8 for converting to a sine wave, a control signal magnitude adjusting unit 9 for controlling the size of the band pass filter 8 and transmitting it to the modulation input terminal of the VCO 5, and the CPU 13 The high frequency carrier frequency is determined by the data signal, and the PLL 10 and VCO 5 oscillate, the high frequency amplifier 6 connected to the VCO 5 to amplify the high frequency, and the high frequency to reduce unnecessary radiation. Opening the power supply of the band pass filter 7 and the said high frequency power amplifier 6 It is composed of a power switch 11 and a battery power supply 12 for supplying power, and reference numeral 20 in the figure is an RF front end.

2 shows a transmitter of the wireless microphone of the present invention, a helical filter 21 for receiving a transmitted radio wave, a high frequency amplifier 22 for amplifying a received signal through the helical filter 21, The PLL 28 whose frequency is determined by the CPU 38, the VCO 27 oscillating voltage by the PLL 28, and the signals of the high frequency amplifier 22 and the VCO 27 are received. A first intermediate frequency converter 23 for converting an intermediate frequency, a first intermediate frequency amplifier 24 for amplifying a signal of the first intermediate frequency converter 23, and a second for producing a second intermediate frequency of 10.7 MHz A second frequency converter 25 that receives a signal from a local oscillator 29, the second local oscillator 29 and the first intermediate frequency amplifier 24, and converts the second frequency; and a second intermediate frequency 10.7 MHz. 10.7 MHz intermediate frequency for amplifying a signal between an intermediate frequency (IF) filter 26 (31) and an intermediate frequency filter (26) (31) for extracting A demodulator 32 connected to an amplifier 30, an output terminal of the intermediate frequency filter 31 for demodulating an audio signal, an audio signal amplifier 33 for amplifying an audio output signal of the demodulator 32, and a CPU; An audio output switch 34 controlled by (38), a low frequency filter (35) for passing only low frequency signals in a signal through the audio output switch (34), and a low frequency filter (35) connected to and compressed by a transmitter An expander 39 for restoring a sound signal, an acoustic signal amplifier and a power supply muting unit 40 connected to an output terminal of the expander 39, and a control signal band passer for controlling the output signal of the demodulator 32; And an RF level meter output line 37 which is transmitted from the demodulator 32 to the CPU 38.

Referring to the operation of the present invention configured as described above is as follows.

First, as shown in FIG. 1, a receiver mute control signal higher than a voice signal is modulated and transmitted to a high frequency carrier from a transmitter embedded in a microphone, and the receiver is controlled by opening and closing the signal with a certain time difference when the high frequency carrier is turned on and off. .

That is, when the user speaks by holding the microphone, the voice signal is induced in the microphone 1, and the VCO 5 passes through the amplifier 2, the compression unit 3, and the voice signal modulation control unit 4. In this case, a specific frequency within 33KHz-40KHz, which can be arbitrarily generated by the CPU 13, is adjusted by the bandpass filter 8 and the control signal size adjusting unit 9 for adjusting the size. The FM signal is input to the VCO 5 modulation stage together with the voice signal.

In order to modulate the control signal to the high frequency carrier, the power supply of the high frequency power amplifying unit 6 is supplied to the VCO 5 and the PLL 10 after the carrier frequency is transmitted to the VCO 5 and the PLL 10 when the transmitter is turned on. The power switch 11 controlled by the &quot; on &quot; is turned on to radiate only the unmodulated high frequency to the antenna via the high frequency band filter 7.

Therefore, the mute control signal is oscillated in the CPU 13 after 1-2 seconds of the first unmodulated high frequency emission, and the modulation is applied to the high frequency carrier via the band pass filter 8 and the control signal magnitude adjusting unit 9.

On the other hand, as shown in Figure 2, the receiving unit receives this radio wave through the antenna and demodulates the demodulator 32 via the RF front end 20, and then the audio signal and the control signal has a significant difference between the respective frequencies By using the control signal bandpass 36, the control signal is extracted and input only to the input port of the CPU 38, and the RF level meter output 37 of the demodulator 32 is input to the analog input of the CPU 38. To enter.

At this time, the audio output switch 34 is turned off so that the FM noise, that is, the "shooting" sound is not output.

When the transmitter is turned on and a high frequency unmodulated carrier is first received, the FM amplifier is removed from the FM amplifier after a while, and the audio output switch 34 remains off until this time.

After a few seconds, when the mute control signal from the transmitter is input to the CPU 38 via the control signal band pass 36, the audio signal received by turning on the audio output switch 34 in the CPU 38 is a low frequency filter. And output through the expander 39, the expander 39, the acoustic signal amplifier and the power supply muting section 40.

As described above, the present invention can remove the microphone power on / off noise by transmitting and receiving an unmodulated carrier wave and a modulated wave at a time difference of 1-2 seconds when the transmitter power is turned on / off at a frequency of 33-40 KHz higher than the audible frequency at the transceiver. It can be effective.

Claims (1)

A microphone 1 for amplifying an input voice signal, an amplitude limiter and a voice signal amplifier 2 for limiting and amplifying a signal of the microphone 1, a compression unit 3 for compressing a voice signal, and a voice signal modulation diagram A band pass filter 8 for converting the square wave generated by the variable resistance resistor 4 and the CPU 13 into a sine wave, and controlling the size of the band pass filter 8 to transmit it to the modulation input terminal of the VCO 5. A high frequency carrier frequency is determined by the control signal magnitude adjusting unit 9 and the data signal of the CPU 13, and the high frequency carrier frequency is connected to the PLL 10 and the VCO 5 and the VCO 5 to oscillate. A wireless microphone transmitter comprising an amplifier 6, a high frequency band filter 7 for reducing unnecessary radiation of high frequencies, a power switch 11 for opening and closing the power of the high frequency power amplifier 6, and a battery power source 12; ; Helical filter 21 for receiving the transmitted radio wave, high frequency amplifier 22 for amplifying the output signal of the helical filter, PLL 28 whose frequency is determined by CPU 38, and PLL 28 The first intermediate frequency converter 23 and the first intermediate frequency converter 23 for converting an intermediate frequency by receiving signals from the VCO 27, the high frequency amplifier 22, and the VCO 27 having oscillated voltages. Of the first intermediate frequency amplifier 24, the second local oscillator 29 for making the second intermediate frequency 10.7 MHz, the second local oscillator 29 and the first intermediate frequency amplifier 24 Between the second frequency converter 25 for receiving a signal and converting the second frequency, the intermediate frequency filter 26 and 31 for extracting the second intermediate frequency 10.7 MHz, and the intermediate frequency filter 26 and 31. A 10.7 MHz intermediate frequency amplifier 30 for amplifying a signal, a demodulator 32 connected to an output terminal of the intermediate frequency filter 31 for demodulating an audio signal, Only a low frequency signal is passed in the signal through the audio signal switch 33 controlled by the CPU 38, the audio signal switch 33 which amplifies the audio output signal of the demodulator 32, and the audio output switch 34. A low frequency filter 35, an expander 39 connected to the low frequency filter 35 to recover a compressed sound signal from a transmitter, an acoustic signal amplifier and a power muting unit 40 connected to an output terminal of the expander 39, A wireless microphone receiver comprising a control signal band passer (36) for controlling an output signal of the demodulator (32) and an RF level meter output line (37) transmitted from the demodulator (32) to the CPU (38); Wireless microphone transceiver mute control device by the microcomputer control, characterized in that consisting of.