KR20020084530A - Apparatus for transmitting and receiving voi ce in the subway - Google Patents

Abstract

PURPOSE: A voice transceiving device in a train is provided to modulate an electrical voice signal of a monitor installed in a public area to a wireless microphone frequency, to transmit the signal through a helical antenna, and to receive the signal in a personal receiver. CONSTITUTION: A transmitter(5) modulates a specific frequency of a crystal oscillating circuit(11) and a voice signal of a voice signal input unit(12) in a high frequency modulating circuit(13), and amplifies the modulated frequency and the signal in a high frequency amplifying circuit(14), then filters the amplified signal in a low pass filter(15) to transmit the signal through a transmission antenna(16). A receiver(31) comprises as follows. A receiving antenna(33) receives the signal from the transmitter(5). A high frequency amplifying circuit(34) amplifies the signal. A crystal oscillating circuit(35) generates a specific frequency. A local oscillating circuit(36) converts a difference frequency of the crystal oscillating circuit(35) to an intermediate frequency(IF). A filter circuit(37) filters the IF. An IF circuit(38) demodulates the filtered IF. An amplifier(39) amplifies the demodulated signal to convert the signal as a voice.

Description

Apparatus for transmitting and receiving voi ce in the subway}

The present invention relates to a voice transmission and reception device in an electric vehicle, and more particularly, to modulate an electric voice signal from a monitor in a public place such as an electric vehicle or a waiting room by transmitting a helical antenna at a specific power output by modulating an electric voice signal to a wireless microphone frequency. The present invention relates to a voice transmission / reception apparatus in an electric vehicle for receiving it in a portable receiver.

The subway is currently the most used mode of public transportation, but you can't watch videos on the subway. Therefore, much attention is being paid to improving the quality of the subway, and in the near future, it will be possible to watch TV-like videos in the subway. However, some people do not want video information in public places such as subways, so it is difficult to provide voice information through speakers in subways.

In addition, the technology for receiving video and voice information in the subway is introduced in Korean Utility Model Registration Application No. 20-2000-0023375, "Multimedia Broadcasting System in Subway."

In Korean Utility Model Application No. 20-2000-0023375, "Multimedia Broadcasting System in Subway", radio waves are transmitted using FM radio frequency (88-108 MHz). However, when transmitting radio waves at the FM radio frequency in this way, the "wireless equipment using weak radio wave" standard (output within 500m of 3m) shall be applied. In this case, since the transmission and reception distance of the radio wave is less than 3m, the installation interval should be within the installation interval of the transmitter within 3m, the second harmonic has a lot of interference caused by the cross-modulation, there is a problem that the FM radio unique broadcast reception is disturbed.

Accordingly, it is an object of the present invention to provide a voice transmission and reception apparatus in an electric vehicle that can provide voice information of a moving picture to a receiver carried by each individual so that only those who want to listen to the voice information of a moving picture in a public place such as a subway. .

Another object of the present invention is to provide a voice transmission and reception apparatus in an electric vehicle that satisfies the radio wave method and has a long transmission and reception distance.

An example of an apparatus for transmitting and receiving a voice in an electric vehicle according to the present invention for achieving the above object is a transmitter for modulating and transmitting a voice signal from a monitor installed in a subway to a predetermined frequency, and each of the signals for modulating the signal of the transmitter into voice. Characterized in that the receiver is configured to carry the individual.

The transmitter synthesizes and modulates a specific frequency generated by a crystal oscillation circuit and a voice signal provided through a voice signal input unit in a high frequency modulation circuit to amplify the high frequency amplification circuit, and after filtering the amplified signal by a low pass filter, a transmission antenna It is characterized in that for transmitting the signal through.

In addition, the transmitter is a terminal type, the printed circuit board printed circuits are embedded in the shield case, the audio signal input unit is provided on one side of the shield case, the antenna jack on which the transmission antenna is mounted on the voice signal input unit Is disposed, and the DC jack is disposed below the sex signal input unit.

The receiver includes a reception antenna for receiving a transmission signal from a transmitter, a high frequency amplification circuit for amplifying the received signal, a crystal oscillation circuit for generating a specific frequency, and a difference frequency between an input signal frequency and a frequency supplied from the crystal oscillation circuit. A local oscillation circuit for converting to a constant intermediate frequency, a filter circuit for filtering the intermediate frequency, an intermediate frequency circuit for demodulating the filtered intermediate frequency, an amplifier and an earphone for converting the signal into voice by amplifying the demodulated signal It is characterized by.

The crystal oscillator circuit is characterized in that the frequency of the turned-on channel is provided to the local oscillator circuit when the switch is turned on in any one of channel 1 and channel 2.

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

1 is a block diagram showing a voice transmission and reception apparatus in an electric vehicle according to the present invention.

2 is a schematic diagram illustrating the transmitter of FIG.

3A is a plan view of the receiver of FIG.

3B is a side view of the receiver of FIG. 1.

* Description of Signs of Main Parts of Drawings *

5 transmitter 11 crystal oscillation circuit

12: audio signal input unit 13: high frequency modulation circuit

14: high frequency amplification circuit 15: low pass filter

16: transmitting antenna 31: receiver

33: reception antenna 43: high frequency amplification circuit

35: crystal oscillation circuit 36: local oscillation circuit

37: filter circuit 38: intermediate frequency circuit

39: amplifier 40: earphone

Referring to FIG. 1, the apparatus for transmitting and receiving voice in an electric vehicle according to the present invention includes a transmitter 5 for modulating and transmitting a voice signal from a monitor (not shown) installed in a subway to a predetermined frequency, and transmitting a signal from the transmitter. It consists of a receiver 31 carried by each individual to be modulated.

The transmitter 5 receives a specific frequency (for example, 217. 4 MHz or 217.8 MHz) generated by a crystal oscillatory circuit 11 and a voice signal provided through the voice signal input unit 12. The synthesized modulated signal is then amplified by the high frequency amplification circuit 14, and the amplified signal is filtered by a low pass filter 15 and then propagated through the transmission antenna 16.

In addition, as shown in FIG. 2, the transmitter 5 has a terminal form, and a printed circuit board 20 on which circuits are printed is embedded in a shield case 21, and an audio signal input unit 12 is provided. Is provided at one side of the shield case 21, an antenna jack 22, on which the transmission antenna 16 is mounted, is disposed above the voice signal input unit 12, and below the voice signal input unit 12. DC jack 23 is disposed.

The voice signal input unit 12 has a 5-pin terminal form, and the transmission antenna 16 is preferably a helical antenna.

The receiver 31 includes a reception antenna 33 for receiving a transmission signal of the transmitter 5, a high frequency amplifier circuit 34 for amplifying the received signal, and 10.7 less than a specific frequency (for example, 217.4 MHz or 217.8 MHz). Crystal oscillation circuit 35 for generating 206.7 MHz or 207.1 MHz, and local oscillation for converting the difference between the input signal frequency and the frequency supplied from the crystal oscillation circuit 35 (10.7 MHz) to an intermediate frequency. A circuit 36, a filter circuit 37 for filtering the intermediate frequency, an intermediate frequency circuit 38 for demodulating the filtered intermediate frequency, and a demodulated signal to amplify the signal. It consists of an amplifier 39 and earphone 40 to convert to.

The crystal oscillation circuit 35 has a frequency of the turned-on channel when the switch 43 is turned on in one of the first channel (CH1; 206.7 MHz) and the second channel (CH1; 207.1 MHz). Is provided.

3A and 3B, the receiver 31 is in the form of a terminal and includes a power volume switch 42, a channel selection switch 43, and an earphone hole 44 on the upper surface 41. do.

The receiver 31 configured as described above operates as follows.

When the receiver portable terminal selects the first channel CH1, when the signal received through the reception antenna 33 and the 206.7 MHz frequency provided by the crystal oscillation circuit 35 are input to the local oscillation circuit 36, the local oscillation circuit 36 is input. Modulates to a differential frequency of 10.7 MHz, the intermediate frequency circuit 38 demodulates the original signal at an intermediate frequency that is the differential frequency, and amplifies the demodulated signal from the amplifier 39 and the earphone 40. To voice.

An apparatus for transmitting and receiving voice in an electric vehicle according to the present invention configured as described above operates as follows.

When the voice signal from the monitor installed in the subway is modulated and transmitted by the transmitter 5 at a predetermined frequency (for example, 217. 4 MHz or 217.8 MHz), the signal is received by the receiver 31 carried by each individual. The receiver mobile can listen to the voice information through the earphone 43. At this time, the receiver mobile can select the channel (CH1 or CH2) to select the desired voice information.

As described above, the transmission and reception apparatus of the electric vehicle according to the present invention provides the audio information of the video to the receiver which each individual carries so that only the person who wants to listen to the audio information of the video broadcasted through the monitor in a public place such as subway. It is effective.

Claims (5)

A transmitter 5 comprising a transmitter 5 for modulating and transmitting a voice signal from a monitor installed in a subway at a predetermined frequency, and a receiver 31 for carrying each person modulating the signal of the transmitter into voice. Transceiver. The method of claim 1, The transmitter 5 synthesizes and modulates a specific frequency generated by the crystal oscillation circuit 11 and a voice signal provided through the voice signal input unit 12 in the high frequency modulation circuit 13 to amplify the high frequency amplification circuit 14. And transmitting the signal through a transmission antenna (16) after filtering the amplified signal by a low pass filter (15). The method according to claim 1 or 2, The transmitter 5 is in the form of a terminal, a printed circuit board 20 on which circuits are printed is embedded in the shield case 21, and an audio signal input unit 12 is provided at one side of the shield case 21. An antenna jack 22 having a transmission antenna 16 mounted on the voice signal input unit 12 is disposed, and a DC jack 23 is disposed below the voice signal input unit 12. Transceiver. The method of claim 1, The receiver 31 includes a reception antenna 33 for receiving a transmission signal of the transmitter 5, a high frequency amplification circuit 34 for amplifying the received signal, a crystal oscillation circuit 35 for generating a specific frequency, Local oscillation circuit 36 for converting the difference frequency of the input signal frequency and the frequency supplied from the crystal oscillation circuit 35 to a constant intermediate frequency, a filter circuit 37 for filtering the intermediate frequency and the filtered intermediate frequency And a demodulating intermediate frequency circuit (38), and an amplifier (39) and an earphone (40) for amplifying the demodulated signal and converting the signal into voice. The method of claim 4, wherein The crystal oscillation circuit 35 is characterized in that the frequency of the turned-on channel is provided to the local oscillation circuit 35 when the switch 43 is turned on in any one of the first channel (CH1) and the second channel (CH2). Transceivers in electric vehicles.