JP4359554B2 - Receiver - Google Patents

Description

  The present invention relates to a receiving apparatus for receiving a long wave standard radio wave including time information transmitted from a radio station.

  In Japan, the Kyushu station set up in Saga Prefecture and the Fukushima station set up in Fukushima Prefecture send time information, that is, a longwave standard radio wave with a time code. A so-called radio timepiece can receive accurate time display by receiving these radio waves and correcting the time.

  By the way, the frequency of the long-wave standard radio wave of the Kyushu station is 60 kHz, and the frequency of the long-wave standard radio wave of the Fukushima station is 40 kHz. Therefore, a receiving apparatus has been proposed that can receive both of these two long wave standard radio waves in order to present the correct time regardless of where the radio timepiece is installed (see Patent Document 1).

  FIG. 12 is a diagram for explaining an antenna unit included in the conventional receiving apparatus disclosed in Patent Document 1. In FIG. As shown in this figure, an antenna unit 100 constituting a conventional receiving apparatus includes an inductance element 101, a switch 102, and a capacitor 103 as main components.

  Here, the inductance element 101 includes a core 101a, a first winding 101b, and a second winding 101c. The first winding 101b is for 60 kHz, and the element value is set so that the resonance frequency of the parallel resonance circuit composed of the first winding 101b and the capacitor 103 is 60 kHz. The second winding 101c is set so that the parallel resonance frequency with the capacitor 103 is 40 kHz when connected in series with the first winding 101b.

  The switch 102 is a circuit for selecting the resonance frequency from either 40 kHz or 60 kHz. As described above, the capacitor 103 is a resonance capacitor, the resonance frequency with the first winding 101b is 60 kHz, and the first winding 101b and the second winding 101c are connected in series. The element value is set so that the resonance frequency of the output becomes 40 kHz.

  In a receiving apparatus including such an antenna unit, it is possible to selectively receive a 60 kHz or 40 kHz long wave standard radio wave by operating the switch 102.

JP 2003-60520 A (abstract, claim)

  By the way, in the antenna part shown in patent document 1, as shown in FIG. 13, about each of the 1st winding 101b and the 2nd winding 101c, the floating resulting from arrange | positioning adjacent to each other Capacitances (stray capacities) 110 and 111 are generated, and the resonance frequency may shift. When the resonance frequency is shifted as described above, there is a problem that sufficient reception sensitivity cannot be obtained and the time cannot be corrected accurately.

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a receiving apparatus capable of obtaining sufficient receiving sensitivity.

  In order to achieve the above-described object, the present invention is a receiver that selectively receives radio waves of a predetermined frequency using parallel resonance between a coil and a capacitor wound around a core. A first winding corresponding to the first frequency and a second winding wound around the core and corresponding to a second frequency lower than the first frequency by being connected in series with the first winding When receiving radio waves of the first frequency, the first winding and the capacitor constitute a parallel resonant circuit, and when receiving radio waves of the second frequency, the first and second connected in series Control means for performing control to form a parallel resonant circuit with two windings and a capacitor, and the first winding and the second winding are mutually connected when receiving either the first frequency or the second frequency. To the terminal that is not connected to the Has an output means for outputting a voltage appearing, the.

  It is possible to provide a receiving apparatus that can obtain sufficient receiving sensitivity.

  In addition to the above-described invention, another invention includes an adjustment core that is arranged close to the core and adjusts the element values of the first and second windings by adjusting the distance from the core. Have. For this reason, since it becomes possible to adjust an element value correctly, it becomes possible to raise receiving sensitivity.

  In another invention, in addition to the above-described invention, the adjusting core is arranged close to the winding side of the first winding and the second winding with the larger number of windings. For this reason, it is possible to increase the sensitivity with respect to the reception sensitivity with respect to the radio wave having a high frequency by increasing the sensitivity by boosting and to accurately adjust the element value with respect to the radio wave with a low frequency.

  ADVANTAGE OF THE INVENTION According to this invention, the receiver which can obtain sufficient receiving sensitivity can be provided.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration example of a receiving apparatus according to an embodiment of the present invention. As shown in this figure, the receiving apparatus includes an antenna unit 1, a receiving circuit 2, a control circuit 3, an operation unit 4, and a display device 5 as main components.

  Here, the antenna unit 1 transmits a long wave standard radio wave with a frequency of 60 kHz (corresponding to the first frequency) transmitted from the Kyushu station and a long wave standard radio wave with a frequency of 40 kHz (corresponding to the second frequency) transmitted from the Fukushima station. Either one is selectively received. A detailed configuration example of the antenna unit 1 will be described later.

  The reception circuit 2 extracts the reception signal supplied from the antenna unit 1 and outputs it to the control circuit 3.

  The control circuit (part of the control means) 3 is constituted by, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and is included in the time signal extracted by the receiving circuit 2 The corrected time information is displayed on the display device 5 in accordance with the time information. The control circuit 3 controls the antenna unit 1 and the receiving circuit 2 in accordance with a program stored in the ROM.

  The operation unit 4 includes, for example, a plurality of operation buttons, generates information corresponding to a user operation, and supplies the information to the control circuit 3.

  The display device 5 is configured by, for example, an LCD (Liquid Crystal Display) or the like, and displays information (time information or the like) supplied from the control circuit 3.

  FIG. 2 is a circuit diagram illustrating a configuration example of the antenna unit 1. As shown in this figure, the antenna unit 1 includes an inductance element 10, a switch 1a, and a capacitor 1b as main components.

  Here, the inductance element 10 includes a winding 10a (corresponding to the first winding) corresponding to 60 kHz and a winding 10b (second winding) corresponding to 40 kHz by being connected in series with the winding 10a. ) Is wound around the core 60. The screw core 40 (corresponding to the adjustment core) adjusts the element value by changing the gap with the core 60. The detailed configuration of the inductance element 10 will be described later.

  The switch 1a (a part of the control means) is connected to the upper terminal in the figure when receiving a 60 kHz long wave standard wave, and the lower terminal in the figure when receiving a 40 kHz long wave standard wave. Connected to. The connection direction of the switch 1a is controlled by the control circuit 3 shown in FIG.

  The capacitor 1b is a capacitor for parallel resonance. When the switch 1a is connected to the upper terminal, the capacitor 1b is connected in parallel with the winding 10a to resonate at 60 kHz, and when connected to the lower terminal. The windings 10a and 10b connected in series are connected in parallel and resonate at 40 kHz. The terminal 1c (corresponding to the output means) and the terminal 1d (corresponding to the output means) are terminals for connection to the receiving circuit 2.

  FIG. 3 is an exploded perspective view illustrating a configuration example of the inductance element 10 illustrated in FIG. 2. As shown in this figure, the inductance element 10 includes a case 20, a lid 30, a screw core 40, a coil bobbin 50, and a core 60 as main components.

  Here, the case 20 is made of, for example, plastic, ceramics, metal, or the like. A hole 22 into which the screw core 40 is inserted is formed on the left side (left side in the figure) of the case 20. A female screw that fits with the male screw of the screw core 40 is formed on the wall surface of the hole 22. A hole 21 into which the lid 30 is fitted is formed on the right side (right side in the drawing) of the case 20. Moreover, although not shown in this figure, the opening part in which the coil bobbin 50 by which the core 60 was fitted and the winding was wound was inserted in the lower surface (lower side of a figure) of case 20 25 is formed. Furthermore, a terminal 23 and a terminal 24 (not shown) for connecting an external circuit and an internal winding are provided in the lower left part of the case 20.

  The lid 30 is made of plastic, for example, and has a function of fixing the core 60 when fitted to the case 20. Further, a terminal 34 and a terminal 35 (not shown) for connecting an external circuit and an internal winding are provided at the lower part of the lid 30. A concave portion 33 is provided on the left side (left side in the figure) of the lid 30, and the end portion 62 of the core 60 is inserted and fixed in the concave portion 33. The insertion portion 31 of the lid 30 is inserted and fixed inside the case 20. Further, the exposed portion 32 is exposed to the outside of the case 20.

  The screw core 40 is made of a ferrite material or the like, like the core 60, and is used when adjusting the inductance value. Here, when adjusting the element value, the screw core 40 has a concave portion 41 for inserting a Phillips screwdriver formed on the left side (left side in the drawing). Further, on the side surface 42 of the screw core 40, a male screw that fits into the female screw formed on the wall surface of the hole 22 is formed.

  The coil bobbin 50 includes four flanges 53 to 56 having a “U” shape and connecting portions 51 and 52 for connecting these flanges 53 to 56. The collars 53 to 56 have cutout portions 53a to 56a, respectively, and the shaft portion 61 of the core 60 is inserted into the cutout portions 53a to 56a. The connecting portions 51 and 52 connect the flanges 53 to 56 to each other and prevent the first winding 10 a and the second winding 10 b from directly contacting the core 60. That is, since the connecting portions 51 and 52 are wider in the vertical direction (vertical direction in FIG. 3) than the shaft portion 61 of the core 60, the first winding 10a and the second winding 10b are connected. When wound on the parts 51 and 52, these windings are prevented from coming into contact with the core 60. In addition, the coil bobbin 50 and the flanges 53 to 56 are configured as an integral part (coil bobbin 50) having a “U” shape by connecting four flanges, and can be fitted into the core 60 from the lateral direction. As a result, the assembly can be simplified.

  The core 60 is made of a ferrite material or the like formed by firing a metal oxide. The core 60 is formed by a shaft portion 61 into which the coil bobbin 50 is inserted and left and right end portions 62 and 63.

  FIG. 4 is a perspective view showing an appearance of the inductance element 10 when the components shown in FIG. 3 are assembled. As shown in this figure, when the components shown in FIG. 3 are assembled, the insertion portion 31 of the lid 30 is inserted into the case 20 and the exposed portion 32 is exposed. Further, the screw core 40 is inserted into the hole 22.

  FIG. 5 is a cross-sectional view of the assembled inductance element 10 shown in FIG. 4 taken along A-A ′. As shown in this figure, the core 60 is fixed inside the case 20. A winding 10a corresponding to 60 kHz is wound between the collar 54 and the collar 55 and between the collar 55 and the collar 56 in two parts. In addition, a winding 10b corresponding to 40 kHz is wound between the flange 53 and the flange 54 when connected in series with the winding 10a. A screw core 40 is disposed on the left side of the core 60. By inserting a screwdriver or the like into the recess 41 and rotating it in a desired direction, the distance between the end 63 and the screw core 40 is adjusted, and the inductance value is adjusted. be able to. An opening 25 is provided on the lower surface of the case 20, and the core 60 is inserted from this portion during assembly.

  FIG. 6 is a diagram for explaining a winding method of the inductance element 10 according to the embodiment of the present invention. As shown in this figure, the inductance element 10 according to the embodiment of the present invention is wound with a winding 10a corresponding to 60 kHz divided into two places. That is, the winding wire 10a is wound around the region partitioned by the flange 56 and the flange 55 for 228 turns and wound around the region partitioned by the flange 55 and the flange 54 to form one winding. . The reason why the winding 10a is divided into two is to reduce the stray capacity. Further, a winding 10b connected in series with the winding 10a and corresponding to 40 kHz is wound in an area partitioned by the collar 53 and the collar 54 for 280 turns.

  FIG. 7 is a diagram illustrating the relationship between the position of the screw core 40 and the rate of change of the inductance value. In this figure, the curve indicated by “◯” indicates the rate of change of the inductance value of the winding 10a when the screw core 40 is disposed on the winding 10b side and the position thereof is moved, as shown in FIG. Yes. Further, as shown in FIG. 8, the curve indicated by “x” indicates the rate of change in the inductance value of the winding 10a when the screw core 40 is disposed on the winding 10a side and the position thereof is moved. Further, as shown in FIG. 8, the curve indicated by “Δ” indicates the winding 10 a and the winding when the screw core 40 is disposed on the winding 10 a side (or the winding 10 b side) and the position thereof is moved. The change rate of the inductance value when 10b is connected in series is shown. As shown in this figure, when adjusting the element value of the winding 10a, the rate of change is greater when the screw core 40 is arranged closer to the winding 10a. Therefore, in the inductance element 10 according to the present embodiment, the element value can be easily adjusted by disposing the screw core 40 near the winding 10a having a large number of turns.

  Next, a method for assembling the inductance element 10 of the above embodiment will be described.

  First, the shaft portion 61 of the core 60 is inserted into the notches 53a to 56a of the coil bobbin 50 shown in FIG. Next, the winding wire 10b is wound in three layers in the region surrounded by the flanges 53 and 54. Subsequently, as shown in FIG. 5, a part of the winding 10 a is wound in three layers around the area surrounded by the flanges 54 and 55, and the winding 10 a is wound around the area surrounded by the flanges 55 and 56. The remaining part of is wound on three layers.

  When the winding of the winding ends, the coil bobbin 50 and the core 60 wound with the winding are inserted into the case 20 from the opening 25 of the case 20 and fixed. And it inserts and fixes to the hole 21 of the case 20 so that the recessed part 33 of the lid | cover 30 may fit into the edge part 62. FIG. Subsequently, necessary portions of the windings 10a and 10b are connected to the terminals 23 and 24 and the terminals 34 and 35 by solder or the like.

  Next, the screw core 40 is inserted while rotating clockwise with respect to the hole 22. Then, the switch 1a and the capacitor 1b are connected, and the position of the screw core 40 is finely adjusted so as to resonate at 40 kHz in a state where the switch 1a is connected to the lower side (40 kHz side) of FIG. As will be described later, the receiving sensitivity for 60 kHz is higher than that for 40 kHz, and 40 kHz is often used as the main, so fine adjustment is performed so as to accurately resonate at 40 kHz. When the adjustment is finished, the lid 30 and the screw core 40 are fixed with an adhesive or the like, and the manufacturing process is finished.

  Next, the operation of the receiving apparatus shown in FIG. 1 will be described.

  When the operation of the receiving device including the inductance element 10 manufactured as described above is started, first, the control circuit 3 switches the switch 1a of the antenna unit 1 to the lower (40 kHz side) contact point in FIG. Connect to. As a result, as shown in FIG. 9A, a parallel resonance circuit having a resonance frequency of 40 kHz is formed between the winding 10a and winding 10b connected in series and the capacitor 1b. As a result, a 40 kHz long wave standard radio wave is captured and supplied to the receiving circuit 2.

  Here, as described above, in the manufacturing process, since the screw core 40 is adjusted so as to resonate accurately at 40 kHz, the resonance circuit shown in FIG. 9A resonates with high accuracy at 40 kHz. . Therefore, when the electric field strength of the 40 kHz long wave standard radio wave is sufficient in the environment where the receiving device is arranged, the radio wave can be captured with high sensitivity.

  In the receiving circuit 2, a 40kHz long wave standard radio wave is converted into an intermediate frequency, and then a time signal is extracted. The time signal extracted in this way is supplied to the control circuit 3. The control circuit 3 determines the reception state from the magnitude of the received signal. If the reception state is good, the control circuit 3 extracts time information from the time signal supplied from the reception circuit 2, and based on the time information. Then, the time of the internal clock is corrected, and the current time is displayed on the display device 5.

  On the other hand, when it is determined that the reception state at 40 kHz is bad, the connection of the switch 1a of the antenna unit 1 is changed to the upper side (60 kHz side) in FIG. As a result, as shown in FIG. 9B, a parallel resonant circuit having a resonant frequency of 60 kHz is formed between the winding 10a and the capacitor 1b, and a long-wave standard radio wave of 60 kHz is captured. At this time, as the output of the antenna unit 1, voltages appearing at the terminals of the winding 10 a and the winding 10 b that are not connected to each other are output, not at both ends of the capacitor 1 b constituting the resonance circuit. Here, since the winding 10a and the winding 10b are wound in the same direction around the same core 60, a voltage in the same direction as the voltage applied to the winding 10a is excited in the winding 10b. Will be.

  Here, the voltage excited in the winding 10b is determined according to the turns ratio of the winding 10a and the winding 10b and the coupling coefficient. In the present embodiment, the winding ratio is 556: 280 as shown in FIG. 6, and the coupling coefficient is about 0.5 according to actual measurement. Therefore, a voltage of about 25% of the voltage applied to the winding 10a is output to the winding 10b. For this reason, as shown in FIG. 9B, when the voltages appearing at the terminals of the winding 10a and the winding 10b that are not connected to each other are taken out as outputs, 1 of the voltage appearing at the winding 10a. A voltage of about 25 times is obtained. As a result, in the antenna unit 1 of the present embodiment, it is possible to increase the reception sensitivity as compared with the conventional antenna unit shown in FIG.

  FIG. 10 shows that the reception sensitivity [V / μT] with respect to the long-wave standard radio wave of 60 kHz when the output of the winding 10a is directly taken out (without boosting) and the winding 10a and the winding 10b are not connected to each other. It is a figure which shows the measured value of the receiving sensitivity with respect to the 60kHz long wave standard radio wave when the voltage which each appears in the terminal of the side is taken out as an output (in the case of pressure | voltage rise). As shown in this figure, the receiving sensitivity when the voltage appearing at the terminals of the winding 10a and the winding 10b that are not connected to each other is taken out as an output is about 4.5 [V / μT], When the voltage appearing on the winding 10a is taken out as it is, the receiving sensitivity is about 3.5 [V / μT]. Therefore, as described above, the reception sensitivity can be increased by about 30% when boosted as compared to when boost is not performed.

  As described above, when the reception sensitivity is increased by boosting, it is possible to obtain a sufficient reception signal even when the resonance frequency slightly deviates from 60 kHz. As a result, a sufficient received signal can be obtained at 60 kHz even when the element value is set to resonate at 40 kHz using the screw core 40 in the manufacturing process.

  The reception signal captured by the antenna unit 1 in this way is supplied to the reception circuit 2. In the receiving circuit 2, a 60kHz long wave standard radio wave is converted into an intermediate frequency, and then a time signal is extracted.

  As in the case described above, the control circuit 3 extracts time information from the time signal supplied from the receiving circuit 2, corrects the time of the internal clock based on the time information, and sets the current time on the display device 5. indicate. Note that if the reception status of both the 40 kHz and 60 kHz radio waves is not good, the control circuit 3 displays an error on the display device 5, for example.

  As described above, according to the receiving apparatus according to the embodiment of the present invention, even when the element value is set to resonate at 40 kHz, sufficient reception sensitivity is obtained by boosting to 60 kHz. It becomes possible.

  The above embodiment is merely an example, and there are various other modified embodiments. For example, as shown in FIG. 11, a winding 10c may be newly provided to add a boosting effect. That is, in the example of FIG. 11, when a 40 kHz long wave standard radio wave is received, the reception signal obtained by the parallel resonance of the winding 10a and the winding 10b connected in series with the capacitor 1b is boosted by the winding 10c. And output. When receiving a 60 kHz long wave standard radio wave, the reception signal obtained by parallel resonance of the winding 10a and the capacitor 1b is boosted and output by both the coil 10b and the winding 10c. According to such a configuration, it is possible to further improve the reception sensitivity. In the example of FIG. 11, the winding 10 c is wound around the screw core 40, but it may be wound around the opposite side of the screw core 40 or between the winding 10 a and the winding 10 b. Is possible.

  In the embodiment described above, the winding 10a and the winding 10b are wound in three layers, but the number of layers other than this (two layers or four or more layers) may be used.

  In the above embodiment, the flanges 53 to 56 are connected to each other by the connecting portions 51 and 52. However, a part or all of each of the flanges 53 to 56 is a single structure, and the core 60 is used. It is good also as a structure which inserts and fixes each to. Moreover, it is also possible to set it as the structure which does not provide the collars 53-56 depending on the case.

  In addition, the core 60 has been described by taking a rectangular shape as an example, but a core having a cylindrical shape can also be used. It is also possible to use a core that does not have the end portions 62 and 63.

  Further, although the screw core 40 is provided on the winding 10a side, it can be provided on the winding 10b side. It is also possible to provide one screw core for each of the winding wire 10a and the winding wire 10b. In that case, fine adjustment can be performed by adjusting two screw cores as compared to the case of one screw core. Further, by independently adjusting the respective screw cores, the winding 10a and the winding 10b can be adjusted independently. Moreover, although the recessed part 41 of the screw core 40 was made into the plus shape, it can also be made into a minus shape.

  In the above embodiments, the case where the windings corresponding to 60 kHz and 40 kHz are provided has been described as an example, but it goes without saying that the windings corresponding to other frequencies can be provided. Absent.

  The receiving apparatus of the present invention can be used for a radio timepiece that receives a long wave standard radio wave.

It is a block diagram which shows the structural example of the receiver which concerns on embodiment of this invention. It is a figure which shows the detailed structural example of the antenna part shown in FIG. FIG. 3 is an exploded perspective view showing a detailed configuration example of the inductance element shown in FIG. 2. It is a perspective view which shows the external appearance at the time of assembling the inductance element shown in FIG. FIG. 5 is a cross-sectional view showing a cross section when the inductance element shown in FIG. 4 is cut along A-A ′. It is a figure which shows the number of turns of the winding of an inductance element. It is a figure which shows the relationship between the position of a screw core, and the change rate of element value L. FIG. It is a figure for demonstrating the position of the screw core in the figure shown in FIG. FIGS. 3A and 3B are diagrams illustrating an equivalent circuit of the antenna unit illustrated in FIG. 2, in which FIG. 2A is an equivalent circuit when receiving a 40 kHz long wave standard radio wave, and FIG. It is. It is a figure which shows the receiving sensitivity with respect to the 60kHz long wave standard radio wave of the antenna part shown in FIG. It is a figure which shows the other structural example of an antenna part. It is a figure which shows the structural example of the antenna which comprises the conventional receiver. It is a figure explaining the stray capacity which arises in the antenna shown in FIG.

Explanation of symbols

1a switch (part of control means)
1c, 1d terminals (output means)
3 Control circuit (part of control means)
10 Inductance element 10a Winding (first winding)
10b Winding (second winding)
40 Screw core (adjustment core)
60 cores

Claims (3)

In a receiving device that selectively receives radio waves of a predetermined frequency using parallel resonance between a coil wound around a core and a capacitor,
A first winding corresponding to a first frequency wound around the core;
A second winding wound around the core and corresponding to a second frequency lower than the first frequency by being connected in series with the first winding;
When receiving the radio wave of the first frequency, the first winding and the capacitor constitute a parallel resonant circuit, and when receiving the radio wave of the second frequency, the first connected in series. Control means for performing control to form a parallel resonant circuit by the first and second windings and the capacitor;
Output means for outputting voltages appearing at terminals of the first winding and the second winding that are not connected to each other when receiving either the first frequency or the second frequency; ,
A receiving apparatus comprising:   2. The adjusting core according to claim 1, further comprising an adjusting core that is disposed in proximity to the core and adjusts element values of the first and second windings by adjusting a distance from the core. Receiver device.   3. The receiving device according to claim 2, wherein the adjustment core is disposed in proximity to a winding having a larger number of windings among the first and second windings.

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