JP2005341067A - Receiver and power cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constitute a receiver which has a practical electric wire of any length and receives radio wave signals efficiently. <P>SOLUTION: The receiver has an electric wire 2a having a plug 1 at one end to be connected to a commercial power line, a first filter 3a for blocking a current from a power source, but allowing the radio waves signals received with the electric wire 2a to pass and a signal receiver 5c for receiving the radio wave signals which is fed with power through the wire 2a and a power circuit 5a and connected to the wire 2a through the first filter 3a. It comprises a resonator circuit 4 resonant with radio waves between the plug 1 and the first filter 3a. The wire 2a between the resonator circuit 4 and the first filter 3a has a length tunable with the radio wave signals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a receiving apparatus that receives a radio signal using an electric wire of a power cord for supplying power as an antenna, and a power cord that receives a radio signal using an electric wire for power supply as an antenna.

  There is a receiving device such as a radio or a television receiver that can receive a radio signal by using a power cord connected to a commercial power source as an antenna. The receiving device is connected to the electric wire through a filter connected to a commercial power source and supplying a current to the power circuit of the tuner and a radio signal received by the electric wire and blocking a current from the power source. There is a tuner (Patent Document 1).

  According to the receiving apparatus configured as described above, the electric wire serves as an antenna that receives an FM, VHF, or UHF radio signal transmitted from a broadcasting station in addition to the original function of supplying current from the power supply to the power supply circuit. It has a function. The filter has a high impedance with respect to a commercial alternating current frequency of 50 Hz or 60 Hz, and functions as a low-impedance high-pass filter with respect to the frequency of the received radio wave signal. In the electric wire that receives the radio wave, the current from the power source is superimposed on the radio signal generated by the radio wave, but the current from the power source is cut off by the filter, and only the radio signal is input to the tuner. Then, a predetermined radio signal is selected and received by the tuner.

Therefore, it is not necessary to install an antenna outdoors and to draw a coaxial cable or feeder line indoors from the antenna. Moreover, it is not necessary to set an indoor antenna.
JP 2002-151932 A

  However, in general, the optimum length of an electric wire for efficiently receiving a radio signal is approximately one-fourth the wavelength of the radio wave associated with the received radio signal or an integral multiple of the length. . If the length of the wire is set to the optimum length for receiving the radio signal, for example, if the length is set to the optimum length for receiving the VHF radio signal, the length of the wire is an integral multiple of about 45 cm. Length cannot be chosen freely. On the contrary, when the length of the electric wire is appropriately set to a length other than an integral multiple of 45 cm, the length of the electric wire functioning as an antenna deviates from the optimum length for tuning to the received radio signal, and the radio wave is efficiently transmitted. There was a problem that the signal could not be received.

  The present invention has been made in view of such circumstances, and by providing a resonant circuit that resonates with a received radio wave signal between a plug and a filter, a wire having a practically arbitrary length is provided. It is an object of the present invention to provide a receiving device and a power cord that can efficiently receive a radio signal.

  It is another object of the present invention to provide a receiving device and a power cord that can realize a resonance circuit with a simple configuration by receiving a radio signal that resonates in parallel by connecting a capacitor and a coil in parallel to an electric wire. .

  Furthermore, by inserting the resonance circuit so that the length of the electric wire between the resonance circuit and the filter is about one-fourth of the wavelength of the radio wave related to the received radio signal, the radio signal can be efficiently transmitted. Another object of the present invention is to provide a receiving apparatus capable of receiving.

  Furthermore, another object of the present invention is to provide a receiving device that can efficiently receive a radio signal by setting the resonant frequency of the resonant circuit to one of the frequency bands of FM, VHF, or UHF radio signals. Objective.

  A receiving device according to the present invention includes an electric wire having a plug connected to a power source at one end, a filter that allows a radio signal received by the electric wire to pass therethrough and cuts off a current from the power source, and the radio signal transmitted through the filter. And a signal receiving unit that receives the signal, a resonance circuit that resonates with the radio signal is provided between the plug and the filter, and a length of an electric wire between the resonance circuit and the filter is It is characterized in that it is tuned to a radio signal.

  In the receiving device according to the present invention, the resonance circuit is a capacitor and a coil connected in parallel to the electric wire.

  In the receiving apparatus according to the present invention, the length of the electric wire between the resonance circuit and the filter is set to a length that is approximately one-fourth of the wavelength of the radio wave related to the radio signal that resonates in the resonance circuit. And

  In the receiving apparatus according to the present invention, the resonance frequency of the resonance circuit is any of 76 MHz to 222 MHz or 470 MHz to 764 MHz.

  A power cord according to the present invention is a power cord comprising a plug connected to a power source, an electric wire having the plug at one end, and a filter that allows a radio signal received by the electric wire to pass therethrough and cuts off a current from the power source. One or a plurality of resonance circuits that resonate with the radio signal are provided between the plug and the filter, and the length of the electric wire between the resonance circuit and the filter is set to a length that is tuned to the radio signal. And

  In the power cord according to the present invention, the resonance circuit is a capacitor and a coil connected in parallel to the electric wire.

  In the present invention, when the resonance circuit resonates with the radio signal, the impedance of the resonance circuit is theoretically infinite with respect to the radio signal received by the electric wire, and the radio signal received between the resonance circuit and the plug resonates. There is no passage from the circuit to the filter side. Accordingly, the wire portion between the resonance circuit and the filter substantially functions as an antenna regardless of the length of the wire between the resonance circuit and the plug. In addition, since the length of the electric wire between the resonance circuit and the filter is a length that synchronizes with the radio signal, the radio signal can be efficiently received by the electric wire.

  In the present invention, since the resonance circuit is a capacitor and a coil connected in parallel to the electric wire, the resonance circuit can be configured with a simple configuration. When the radio signal received by the electric wire resonates in parallel, the impedance of the resonance circuit is theoretically infinite with respect to the radio signal. Therefore, radio wave signals can be efficiently received regardless of the length of the electric wire between the plug and the resonance circuit.

  In the present invention, since the length of the electric wire between the resonance circuit and the filter is approximately one quarter of the wavelength of the electric wave related to the received radio signal, the radio signal is transmitted by the electric wire between the resonance circuit and the filter. Tunes well. Therefore, radio wave signals can be received efficiently.

  In the present invention, the resonance frequency of the resonance circuit is any one of FM, VHF, and UHF. Therefore, the resonance circuit resonates with respect to the FM, VHF, or UHF radio signal, and the radio signal can be received efficiently.

  In the receiving device and the power cord according to the present invention, the length of the electric wire between the plug and the capacitor can be freely set, and the electric wave signal is provided by the electric wire with the electric wire having any practical length. Can be received efficiently.

  In the receiving apparatus and the power cord according to the present invention, radio signals can be efficiently received with a simple configuration.

  In the receiving apparatus according to the present invention, the radio signal is satisfactorily tuned by the electric wire between the resonance circuit and the filter, so that the radio signal can be received efficiently.

  In the receiving apparatus according to the present invention, FM, UHF, or VHF radio signals can be efficiently received by resonance of the resonance circuit.

(Embodiment 1)
Hereinafter, a receiver and a power cord according to the present invention will be described in detail with reference to the drawings showing the best mode for carrying out the invention. FIG. 1 is a schematic diagram illustrating a receiving device and a power cord according to the first embodiment. A receiving apparatus according to the present invention includes a plug 1 connected to a commercial power source (not shown), electric wires 2a and 2b having the plug 1 at one end, filters 3a and 3b, a resonance circuit 4, a power circuit 5a, and an impedance converter. 5b and a signal receiving unit 5c. Reference numeral 5 denotes a housing of the receiving device. In the housing 5, an appropriate point A of the electric wire 2a is connected to the signal input terminal of the signal receiving unit 5c via the first filter 3a and the impedance converting unit 5b. Similarly, the appropriate point B of the electric wire 2b is connected to the ground terminal of the signal receiving unit 5c through the second filter 3b and the impedance conversion unit 5b in the housing 5.

A resonance circuit 4 formed by connecting a capacitor 4a and a coil 4b in parallel is interposed in the electric wire 2a between the plug 1 and the first filter 3a. The capacitance of the capacitor 4a and the inductance of the coil 4b are determined so as to resonate in parallel with the received radio wave signal. For example, in the case of a receiving device that receives a radio signal of 76 to 90 MHz, which is the frequency band of FM broadcasting, the parallel resonance frequency may be set to an intermediate frequency of 76 to 90 MHz, 83 MHz. Since the parallel resonance frequency is 1 / {2π · (LC) ^1/2 }, the capacitance of the capacitor 4a may be 10 pF and the inductance of the coil 4b may be 0.33 μH.

  The length d of the electric wire 2a between the resonance circuit 4 and the first filter 3a is a length that is tuned to a received radio wave signal, specifically, a length that is approximately a quarter of the wavelength of the radio wave related to the received radio signal. It is. In the case of an 83 MHz radio wave, the wavelength of the radio wave is about 360 cm, so the length d is set to 360 cm / 4 = about 90 cm.

  The first filter 3a and the second filter 3b are high-pass filters that cut off a 50 Hz or 60 Hz current supplied from a commercial power source and pass a radio signal received by the electric wire 2a, for example, a radio signal having a frequency of 76 to 90 MHz. is there. The radio signal induced in the electric wire 2a that has received the radio wave and the current from the commercial power source are separated by the first filter 3a, and only the separated radio signal reaches the impedance converter 5b.

  The impedance converter 5b matches the impedance of the two electric wires 2a and 2b connecting the filters 3a and 3b and the impedance converter 5b with the impedance of the coaxial cable connecting the impedance converter 5b and the signal receiver 5c. It is an impedance matching element.

  The signal receiving unit 5c extracts the radio signal of the channel selected by the signal receiving unit 5c from the radio signal input from the impedance conversion unit 5b, converts it to an intermediate frequency, and outputs the intermediate signal to an IF signal processing unit (not shown) It is.

  The power supply circuit 5a includes a transformer that transforms the voltage of power supplied from the commercial power supply through the two electric wires 2a and 2b into a predetermined voltage, a rectifier circuit that rectifies the current, and a smoothing circuit that smoothes the rectified current. Prepare. The smoothed current is supplied to the receiving device including the signal receiving unit 5c.

  The operation of the receiving apparatus and the power cord configured as above will be described. The electric wire 2a and the electric wire 2b included in the receiving device supply power from a commercial power supply of 50 Hz or 60 Hz to the power supply circuit 5a and function as an antenna that receives a radio signal. When the plug 1 is connected to a power source, power is supplied from the plug 1 to the signal receiving unit 5c through the two electric wires 2a and 2b and the power supply circuit 5a. When the electric wire 2a receives a radio wave transmitted from a broadcasting station, a radio signal corresponding to the radio wave is induced in the electric wire 2a, and a current supplied from a commercial power source is superimposed on the radio signal in the electric wire 2a. . The current from the power source and the radio signal are separated by the first filter 3a, and only the radio signal is input to the signal receiving unit 5c. Therefore, the current supplied from the power supply is not input to the signal receiving unit 5c.

  By the way, when the frequency of the radio wave signal induced in the electric wire 2a, that is, the frequency of the radio wave matches the resonance frequency of the resonance circuit 4, the radio signal resonates in parallel in the resonance circuit 4, and therefore The impedance of the resonance circuit 4 becomes theoretically infinite. Then, the radio wave signal induced between the first filter 3a and the plug 1 does not pass through the resonance circuit 4, and the electric wire portion between the resonance circuit 4 and the first filter 3a substantially functions as an antenna. Further, since the length of the electric wire portion is approximately one-fourth the wavelength of the electric wave related to the received electric wave signal, the electric wave signal is tuned in the electric wire portion. Therefore, the receiving device and the power cord according to the present invention can better receive the radio signal by the electric wire 2a than the receiving device or the power cord that does not include the resonance circuit 4.

  In the present invention, the radio wave signal can be efficiently received by the electric wire between the resonance circuit 4 and the first filter 3a regardless of the length of the electric wire between the resonance circuit 4 and the plug 1. The length between 4 and the plug 1 can be set to a practical arbitrary length, and a radio signal can be efficiently received.

  In the present embodiment, the capacitance of the capacitor and the inductance of the coil are determined so as to be tuned to the FM radio signal, and the length d of the wire is set. Alternatively, it may be designed to tune to UHF or other radio signals.

  In the present embodiment, the power cord includes a filter, but a filter may be provided on the signal receiving unit side of the receiving device.

  FIG. 2 is a schematic diagram showing a modification of the receiving apparatus according to Embodiment 1. The receiving apparatus according to the present invention further includes an amplifying unit 5d that amplifies the radio signal output from the impedance converting unit 5b. The radio signal amplified by the amplifying unit 5d is input to the switching unit 5e, and the switching unit 5e outputs the input radio signal to the signal receiving unit 5c. The switching unit 5e includes an antenna terminal 5f to which a radio signal received by the external antenna 6 is input, and switches between a radio signal input from the amplifying unit 5d and a radio signal input from the antenna terminal 5f. Output to the receiver 5c. Since the configuration of the receiving apparatus according to another modification is the same as the configuration illustrated in FIG. 1, the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the receiving apparatus configured as described above, by switching the switching unit 5e, it is possible to switch between reception of a radio signal by the external antenna 6 connected to the antenna terminal 5f and reception by the electric wire 2a. When the switching unit 5e is switched and a radio signal is received by the electric wire 2a, the radio signal received by the electric wire 2a is amplified by the amplifying unit 5d and output to the signal receiving unit 5c. When the switching unit 5e is switched and a radio signal is received by the external antenna 6, the radio signal received by the external antenna 6 is output to the signal receiving unit 5c via the switching unit 5e.

  Accordingly, even when the receiving apparatus shown in FIG. 1 is used in an area where the radio wave is weak so that the radio signal cannot be satisfactorily received, the radio signal is satisfactorily received using the electric wire or the external antenna. It becomes possible.

(Embodiment 2)
FIG. 3 is a schematic diagram illustrating a receiving device and a power cord according to the second embodiment. The power cord according to the present invention includes a first resonance circuit 104 and a second resonance circuit 140 interposed between the plug 1 and the filter 3a in order to efficiently receive two types of radio waves belonging to different frequency bands. ing.

  The first resonance circuit 104 is the first capacitor 104a and the first coil 104b that are connected in parallel in the middle of the electric wire 2a as in the first embodiment, but the parallel resonance frequency is different. Here, the parallel resonance frequency of the first resonance circuit 104 is determined so as to resonate in parallel with a VHF radio signal, for example, a 156 MHz radio signal. Specifically, the capacitance of the first capacitor 104a may be 5 pF, and the inductance of the first coil 104b may be 0.21 μH. The length d1 of the electric wire 2a between the first resonance circuit 104 and the first filter 3a is a length tuned to a radio wave signal related to a radio wave of 156 MHz. Specifically, since the wavelength of the 156 MHz radio wave is about 192 cm, the length d1 is set to 192/4 = about 48 cm.

  The second resonance circuit 140 is a second capacitor 140a and a second coil 140b that are connected in parallel to the electric wire 2a between the first resonance circuit 104 and the first filter 3a. The parallel resonance frequency of the second resonance circuit 140 is determined so as to resonate in parallel with a radio signal of a UHF radio wave, for example, a 617 MHz radio wave. Specifically, the capacitance of the second capacitor 140a may be 1 pF, and the inductance of the second coil 140b may be 0.06 μH. The length d2 of the electric wire 2a between the second resonance circuit 140 and the second filter 3b is a length that is tuned to the received 617 MHz radio signal. Specifically, since the wavelength of the radio wave of 617 MHz is about 48.6 cm, the length d2 of the electric wire 2a is set to 48.6 / 4 = about 12 cm.

  Since the configuration of the other receiving apparatus according to the second embodiment is the same as the configuration shown in the first embodiment, the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.

  The operation of the receiving apparatus and the power cord configured as above will be described. First, similarly to the first embodiment, since the radio wave signal induced in the electric wire 2a that has received the radio wave transmitted from the broadcasting station resonates in parallel in the second resonance circuit 140, the second resonance circuit 140 and the first filter The electric wire part between 3a functions as an antenna substantially. Since the length d2 of the electric wire portion is tuned to the UHF radio signal, the UHF radio signal can be efficiently received.

  Further, among the radio signals induced in the electric wire 2a, the VHF radio signal that resonates in parallel with the first resonance circuit 104 does not resonate in parallel with the second resonance circuit 140, and therefore, between the first resonance circuit 104 and the first filter 3a. The electric wire portion substantially functions as an antenna. Since the length d1 of the electric wire portion is tuned to the VHF radio signal, the VHF radio signal can be efficiently received.

  Therefore, the receiving apparatus and the power cord according to Embodiment 2 can efficiently receive radio signals of VHF and UHF having different frequency bands.

  In this embodiment, the power cord is provided with a filter, but a filter may be provided on the signal receiving unit side of the receiving device.

FIG. 3 is a schematic diagram illustrating a receiving device and a power cord according to the first embodiment. 6 is a schematic diagram showing a modification of the receiving apparatus according to Embodiment 1. FIG. 6 is a schematic diagram illustrating a receiving device and a power cord according to Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plug 2a, 2b Electric wire 4a Capacitor 4b Coil 4 Resonance circuit 3a 1st filter 3b 2nd filter 104 1st resonance circuit 140 2nd resonance circuit 5 Case 5a Power supply circuit 5b Impedance conversion part 5c Signal receiving part 5d Amplification part 5e Switching Part 5f Antenna terminal

Claims (6)

An electric wire having a plug connected to a power source at one end, a filter that allows a radio signal received by the electric wire to pass therethrough and cuts off a current from the power source, and a signal receiving unit that receives the radio signal via the filter In a receiving device comprising:
One or more resonant circuits that resonate with the radio signal are provided between the plug and the filter,
A receiving apparatus, wherein a length of an electric wire between the resonance circuit and the filter is set to a length tuned to the radio signal. The resonant circuit is:
The receiving device according to claim 1, wherein the receiving device is a capacitor and a coil connected in parallel to the electric wire.   The length of the electric wire between the said resonance circuit and the said filter is made into the length of about 1/4 of the wavelength of the electromagnetic wave which concerns on the electromagnetic wave signal resonated by the said resonance circuit. 2. The receiving device according to 2.   4. The receiving device according to claim 1, wherein a resonance frequency of the resonance circuit is any one of 76 MHz to 222 MHz or 470 MHz to 764 MHz. In a power cord comprising a plug connected to a power source, an electric wire having the plug at one end, and a filter that allows a radio signal received by the electric wire to pass therethrough and cuts off a current from the power source,
One or more resonant circuits that resonate with the radio signal are provided between the plug and the filter,
The power cord according to claim 1, wherein the length of the electric wire between the resonance circuit and the filter is set to be tuned to the radio signal. The resonant circuit is:
The power cord according to claim 5, wherein the power cord is a capacitor and a coil connected in parallel to the electric wire.

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