JP2019066346A - Radio clock - Google Patents

Abstract

To provide a radio clock capable of performing precise battery management depending on executed operation content.SOLUTION: A satellite radio watch 1 comprises: a secondary cell 42; a receive circuit 20 that receive the power supplied from the secondary cell 42 to execute a reception operation receive a signal from the outside; and a control circuit 30 that is configured to integrate the voltage drop estimated count every time when a predetermined operation content in the received operations is executed by a predetermined value depending on the operation content, and when the voltage drop estimated count is an upper limit count value or more, to stop the received operation.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a radio controlled watch.

  A satellite radio clock that performs time correction based on time signals from GPS (Global Positioning System) satellites and a standard radio clock that performs time correction based on time signals called long wave standard radio waves transmitted from a standard radio transmission station A radio wave watch is known. Many radio wristwatches operate with built-in rechargeable batteries, but relatively large amounts of power are consumed, especially during reception of time signals. Therefore, a relatively large voltage drop occurs in the internal battery of the radio-controlled watch during the reception operation of the time signal. Then, when the battery remaining amount is low, if such a large voltage drop occurs, there is a possibility that the built-in processor, which performs an essential operation such as holding the current time, becomes inoperable, causing a system down.

  In this respect, when the satellite radio wave watch disclosed in Patent Document 1 below can not receive the signal from the satellite within the upper limit time, it immediately stops the reception operation and displays a message indicating reception failure. At this time, in order to suppress the drop of the battery voltage, the above upper limit time is changed according to the current value of the battery voltage.

Patent No. 5614548 gazette

  Here, the drop rate of the battery voltage during the receiving operation is not constant, and differs for each period during the receiving operation. Specifically, the receiving operation includes the capturing operation and the tracking operation, and the drop speed of the battery voltage in the period in which the capturing operation is performed is faster than the period in which the tracking operation is performed. Therefore, in the battery management of Patent Document 1, even if the upper limit time has elapsed, the battery voltage does not drop excessively depending on the operation content executed during that time, and it is necessary to stop the reception operation. On the other hand, even if the upper limit time has not passed, depending on the operation performed during that time, the battery voltage may drop excessively and system shutdown may occur.

  The present invention has been made in view of the above problems, and an object thereof is to provide a radio controlled watch capable of performing more precise battery management according to the executed operation content.

(1) A built-in battery, a receiving circuit which receives a power supply from the built-in battery, and executes a receiving operation for receiving a signal from the outside, and each time a predetermined operation content of the receiving operation is executed, A control circuit which integrates the voltage drop estimated count value by a predetermined value determined in advance according to the operation content and stops the reception operation when the voltage drop estimated count value becomes equal to or more than the upper limit count value Radio clock.

  (2) In (1), the reception operation includes an acquisition operation for acquiring the signal, and the control circuit performs the voltage drop estimation count value according to the acquisition operation each time the acquisition operation is performed. A radio controlled clock that integrates by predetermined values determined in advance.

  (3) In (1), the reception operation includes an acquisition operation for acquiring the signal, and the control circuit performs the voltage drop estimation count value each time a predetermined operation content of the acquisition operation is performed. A radio controlled watch that integrates by predetermined values determined in advance according to predetermined operation contents of the capture operation.

  (4) In (3), the receiving operation further includes a tracking operation which is executed after the capturing operation and tracks the signal, and the control circuit performs the tracking operation every time a predetermined operation content of the tracking operation is executed. A radio controlled watch, which integrates the voltage drop estimated count value by predetermined values which are predetermined according to predetermined operation contents of the tracking operation.

  (5) The radio controlled watch according to any one of (1) to (4), wherein the predetermined operation content is determined corresponding to a predetermined period of the execution period of the reception operation.

  (6) In any one of (1) to (5), further including a voltage sensor that outputs voltage data of the internal battery at the start of the reception operation, and the upper limit count value is based on the voltage data. A radio clock to be determined.

  (7) The radio controlled watch according to (6), further including a temperature sensor for outputting temperature data of the internal battery at the start of the reception operation, wherein the upper limit count value is determined based on the temperature data.

  (8) The radio controlled watch according to (7), further including a memory that stores a plurality of candidates for the upper limit count value in association with the combination of the temperature data and the voltage data.

  (9) In (8), the memory has a plurality of candidates for the upper limit count value when performing the reception operation for time measurement, and the upper limit count when performing the reception operation for positioning. A radio controlled watch, which stores a plurality of value candidates in association with a combination of the temperature data and the voltage data.

  (10) The radio controlled watch according to (8) or (9), wherein the width of the range of the temperature data associated with each of the plurality of candidates for the upper limit count value is narrower as the range relates to a lower temperature.

  (11) In any one of (1) to (5), a voltage sensor that outputs voltage data of the internal battery at the start of the reception operation, and temperature data of the internal battery at the start of the reception operation A radio controlled watch, further comprising: a memory for storing a plurality of candidates of the predetermined predetermined value in association with a combination of the temperature sensor and the combination of the temperature data and the voltage data.

  (12) In any one of (1) to (11), when the execution time of the reception operation exceeds the upper limit time, the control circuit determines whether the estimated voltage drop count value is equal to or greater than the upper limit count value. A radio controlled watch that stops the reception operation regardless of.

It is a top view which shows an example of the external appearance of the satellite radio wristwatch which concerns on 1st Embodiment. It is a structure block diagram which shows the internal structure of the satellite radio wristwatch which concerns on 1st Embodiment. It is a figure which shows the voltage transition of a secondary battery roughly. It is a figure which shows the outline | summary of the voltage transition of the secondary battery in, when a receiving circuit performs acquisition operation | movement continuously for every temperature of a secondary battery. It is a figure which shows an example of an upper limit count table in the case of performing reception operation for time measurement in 1st Embodiment. It is a figure shown about an example of integration of voltage drop presumed count value in a 1st embodiment. It is a figure shown about an example of integration of voltage drop presumed count value in a 1st embodiment. It is a flowchart which shows control of the microcontroller in 1st Embodiment. It is a figure which shows an example of an upper limit count table in the case of performing reception operation for time measurement in 2nd Embodiment. It is a figure shown about an example of integration of voltage drop presumed count value in a 2nd embodiment. It is a figure shown about an example of integration of voltage drop presumed count value in a 2nd embodiment. It is a flowchart which shows control of the microcontroller in 2nd Embodiment. It is a figure which shows an example of an upper limit count table in the case of performing reception operation for positioning. It is a figure which shows an example of an upper limit count table in the case of performing reception operation for positioning.

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

  The satellite radio-controlled wristwatch 1 according to the first embodiment receives a radio wave including time information, and corrects the time kept by itself using the time information included in the received radio wave. FIG. 1 is a plan view showing an example of the appearance of the satellite radio-controlled watch according to the first embodiment. FIG. 2 is a configuration block diagram showing an internal configuration of the satellite radio-controlled watch according to the first embodiment. As shown in these figures, the satellite radio-controlled watch 1 includes an antenna 10, a receiving circuit 20, a DCDC converter 23, a control circuit 30, a vibrator 38, a power supply unit 40, and a drive mechanism 50. It is comprised including the time display part 51, the pointer | guide 52, the dial 53, and the operation part 60.

  The antenna 10 receives a satellite signal transmitted from a satellite as a radio wave including time information. In the first embodiment in particular, the antenna 10 is a patch antenna that receives radio waves of about 1.6 GHz frequency transmitted from GPS satellites. GPS is a type of satellite positioning system, and is realized by a plurality of GPS satellites orbiting the earth. Each of these GPS satellites is equipped with a highly accurate atomic clock, and periodically transmits satellite signals including time information clocked by the atomic clock.

  The receiving circuit 20 decodes the satellite signal received by the antenna 10, and outputs a bit string (received data) indicating the content of the satellite signal obtained as a result of the decoding. Specifically, the receiving circuit 20 is configured to include a high frequency circuit (RF circuit) 21 and a decoding circuit 22. The output voltage of the secondary battery 42 which is an internal battery is converted into a predetermined voltage by the DCDC converter 23, and the converted voltage is supplied to the receiving circuit 20 as a power supply voltage.

  The high frequency circuit 21 is an integrated circuit operating at a high frequency, and amplifies and detects an analog signal received by the antenna 10 to convert it into a baseband signal. The decoding circuit 22 is an integrated circuit that performs baseband processing, decodes the baseband signal output from the high frequency circuit 21 and generates a bit string indicating the content of data received from the GPS satellite. Output. In addition, the decoding circuit 22 includes a correlator 22a that correlates with the satellite signal when capturing a satellite, and a tracking circuit 22b for tracking the satellite. The correlator 22a and the tracking circuit 22b are activated when the acquisition operation of the reception operation described later is started. Then, when the correlator 22a correlates with the satellite number of the satellite signal, correlation data regarding the satellite number and timing is sent to the tracking circuit 22b. When acquisition of the target satellite is completed, the operation of the correlator 22a is stopped. Then, the tracking circuit 22b tracks the satellite based on the satellite number and the timing sent from the correlator 22a.

  The dial 53 of the satellite radio-controlled wristwatch 1 is provided with a reception status indication 61 indicating the status of the reception circuit 20, for example, by the characters "OK", "NG" and "RX". While the second hand 52c indicates the letter "RX" during reception of the satellite signal, and then the reception circuit 20 succeeds in receiving the satellite signal, the second hand 52c indicates the letter "OK", and then resumes normal movement. . If the satellite signal reception fails, the second hand 52c resumes normal movement after the second hand 52c indicates the character "NG".

The control circuit 30 is a circuit that controls various circuits and mechanisms included in the satellite radio-controlled watch 1 and includes a microcontroller 31, a motor drive circuit 35, an oscillation circuit 36, and a temperature sensor 37. . The microcontroller 31 includes an arithmetic unit 32 and a RAM (Random
An access memory (ROM) 33, a read only memory (ROM) 34, and a counter 39 are included, and the control circuit 30 is configured of, for example, one integrated circuit.

  Arithmetic unit 32 performs various information processing in accordance with a program stored in ROM 34. Details of processing performed by the calculation unit 32 in the first embodiment will be described later. The RAM 33 functions as a work memory of the arithmetic unit 32, and data to be processed by the arithmetic unit 32 is written. Particularly in the first embodiment, a bit string (received data) representing the content of the satellite signal received by the receiving circuit 20 is sequentially written to the buffer area in the RAM 33, and the values of various variables for control are held. In the first embodiment, the counter 39 counts a voltage drop estimated count value corresponding to the operation content of the reception operation described later.

  The oscillation circuit 36 supplies a clock signal used at the time inside the satellite radio watch 1. Arithmetic unit 32 obtains the internal time based on the clock signal supplied from oscillation circuit 36, and determines the time (display time) to be displayed on time display unit 51.

  The oscillation circuit 36 is electrically connected to an external vibrator 38 such as a crystal vibrator. Since the oscillation frequency of the vibrator 38 has temperature dependence, the oscillation circuit 36 performs a temperature compensation operation to make the frequency of the clock signal generated by itself constant. Specifically, when the microcontroller 31 acquires temperature data of the vibrator 38 measured by the temperature sensor 37, the microcontroller 31 transmits a compensation signal to the oscillation circuit 36 so as to make the frequency of the clock signal constant. . The oscillation circuit 36 changes the oscillation frequency of the oscillator 38 according to the compensation signal, thereby making the oscillation frequency of the oscillator 38 and the frequency of the clock signal output from the oscillation circuit 36 constant regardless of the temperature.

  The temperature sensor 37 acquires temperature data by measuring the state of the temperature sensitive device. For example, the temperature sensor 37 may be configured to include a CR oscillator, and the oscillation frequency of the CR oscillator can be measured, and temperature data can be obtained from the oscillation frequency thus obtained.

  Here, as shown in FIG. 1, the temperature sensor 37 is built in a corner of the control circuit 30 which is an integrated circuit. In the case of the satellite radio-controlled wristwatch 1, a vibrator 38 is disposed next to a circular secondary battery 42 in plan view, and a temperature sensor 37 is provided at a corner formed by the secondary battery 42 and the vibrator 38. The corner portion of the control circuit 30 provided is disposed, whereby the temperature sensor 37 approaches not only the vibrator 38 but also the secondary battery 42. The secondary battery 42, the vibrator 38, and the temperature sensor 37 are all disposed in an area (upper side in FIG. 1) of the bisector α passing through the center of the watch (the position of the rotation axis of the pointer 52). In FIG. 1, the bisector α passes through the positions of 3 o'clock and 9 o'clock, but the bisector α may pass through the center of the watch and be any straight line that bisects the dial plate 53 in plan view. When the secondary battery 42 is large in size, the center 42a of the secondary battery 42 may be located in the above one side region of the bisector α, and a part of the peripheral portion is on the other side. It is also good. Other elements, for example, the portion other than the temperature sensor 37 of the control circuit 30, the antenna 10, the receiving circuit 20, the DCDC converter 23 and the like may be disposed on either side of the dividing line α. , An antenna 10, a receiving circuit 20, and an arrangement of the DCDC converter 23. Due to the above arrangement of the secondary battery 42, the vibrator 38 and the temperature sensor 37, the temperature data output from the temperature sensor 37 not only indicates the temperature of the vibrator 38 but also indicates the temperature of the secondary battery 42. It can also be used as The temperature sensor 37 does not have to be built in the control circuit 30, and may be an independent device. Alternatively, the temperature sensor 37 may be incorporated in another device. In any case, the temperature sensor 37 is disposed in the vicinity of the secondary battery 42 and the vibrator 38. Further, the temperature of the vibrator 38 and the temperature of the secondary battery 42 may be detected by separate sensors.

  The motor drive circuit 35 outputs a drive signal for driving a motor included in the drive mechanism 50 in accordance with the display time determined by the calculation unit 32. Thus, the display time generated by the microcontroller 31 is displayed on the time display unit 51.

  In the satellite radio-controlled wristwatch 1 according to the first embodiment, the operation unit 32 corrects the internal time measured by the clock signal supplied from the oscillation circuit 36 based on the satellite signal received by the reception circuit 20. .

  The power supply unit 40 supplies power necessary for the operation to each unit in the satellite radio watch 1, such as the reception circuit 20, the control circuit 30, and the drive mechanism 50. The power supply unit 40 includes a solar cell 41, a secondary cell 42, and a switch Sw1.

  The solar cell 41 is disposed, for example, under the dial plate 53 which is a light-transmissive thin plate, and generates electric power by external light such as sunlight emitted to the satellite radio watch 1, and generates generated electric power as a secondary The battery 42 is supplied.

  The secondary battery 42 includes a rechargeable battery such as a lithium ion battery and a battery management circuit that manages charging and discharging of the battery such as the lithium ion battery, and stores the power generated by the solar battery 41. Then, the stored electric power is supplied to each unit that needs the electric power, such as the receiving circuit 20, the control circuit 30, and the driving mechanism 50. Further, the battery management circuit described above includes a voltage sensor (not shown) that detects the voltage of the main body of the secondary battery 42, and voltage data detected by this voltage sensor is notified to the microcontroller 31.

  The secondary battery 42 is connected in parallel to the solar cell 41 via the switch Sw1 connected in series. Specifically, the positive electrode of the solar cell 41 and the positive electrode of the secondary battery 42 are connected via the switch Sw1. The solar cell 41 supplies power to the secondary cell 42 while the switch Sw1 is on.

  Here, since the reception of the satellite signal by the reception circuit 20 consumes a relatively large power, the power supply from the DCDC converter 23 to the reception circuit 20 is controlled by the switch Sw2 output from the control circuit 30. The microcontroller 31 saves power by supplying power to the receiving circuit 20 with the switch Sw2 turned on only when necessary. For example, the microcontroller 31 supplies power to the reception circuit 20 at a time determined every day, and supplies power to the reception circuit 20 when a reception operation is performed by the operation unit 60. Further, the microcontroller 31 supplies power to the receiving circuit 20 when it is presumed that the power generation amount of the solar cell 41 is large and the possibility that the antenna 10 disposed under the dial 53 is facing the satellite is high. You may

  Hereinafter, an operation in which power is supplied from the secondary battery 42 to the receiving circuit 20 and the receiving circuit 20 receives a satellite signal is referred to as a receiving operation. The receiving operation includes a capturing operation and a tracking operation. The acquisition operation is an operation for extracting one of the signals multiplexed by CDMA (Code Division Multiple Access), and more specifically, a C / A code (Coarse / Acquisition code) corresponding to one signal. By multiplying the received signal, it is an operation to extract a correlated signal in the correlator 22a. When there are a plurality of correlated signals, the signal with the highest correlation may be selected. Generally, it takes about 1 to 4 seconds for the capturing operation in the receiving operation for time measurement. The tracking operation is an operation of controlling the phase of the C / A code by the tracking circuit 22 in order to keep the C / A code synchronized with the C / A code of the satellite signal. Generally, it takes about 1 to 6 seconds for the tracking operation in the reception operation for time measurement. That is, in the reception operation for time measurement, it takes about 2 to 10 seconds per one operation.

  FIG. 3 is a diagram schematically showing voltage transition of the secondary battery. In FIG. 3, the reception operation period T in which the reception operation of the satellite signal is performed by the reception circuit 20 and the voltage transition of the secondary battery 42 during that period are shown. The reception operation period T is a period including a capture operation period T1 in which the capture operation is performed and a tracking operation period T2 in which the tracking operation is performed. Note that the capturing operation period T1 ends when capturing is successful or when the execution time of the capturing operation passes a predetermined upper limit time. Similarly, the tracking operation period T2 ends when the tracking is successful or when the execution time of the tracking operation passes a predetermined upper limit time.

  When the switch Sw2 is turned on by the microcontroller 31, the reception circuit 20 starts the acquisition operation of the reception operation of the satellite signal. As shown in FIG. 3, the voltage of the secondary battery 42 drops rapidly immediately after the start of the capture operation. Thereafter, the rapid voltage drop immediately after the start of energization of the reception circuit 20 converges, and the voltage of the secondary battery 42 recovers to some extent in the capturing operation period T1.

  Then, if acquisition is successful before the upper limit time of the acquisition operation has passed, the reception circuit 20 starts the tracking operation of the reception operation. In the tracking operation period T2, the voltage of the secondary battery 42 drops gently. Then, if the tracking is successful before the upper limit time of the tracking operation passes, the reception operation is completed, and at that time, the voltage of the secondary battery 42 is slightly recovered.

  Here, even when the reception operation is performed, reception of the satellite signal may fail depending on the reception environment or the like. In such a case, the reception operation is repeated. Such re-execution of the receiving operation is performed in each of the capturing operation and the tracking operation. For example, when acquisition is successful and the tracking operation is started and the satellite is lost during the tracking operation, the tracking operation is ended when the upper limit time has elapsed and the acquisition operation is started again. Also, if the acquisition operation is started and the satellite is lost during the acquisition operation, the acquisition operation is repeatedly performed each time the upper limit time elapses. As described above, when the capturing operation is performed a plurality of times, the voltage of the secondary battery 42 may excessively drop, and the voltage supplied to the microcontroller 31 may excessively drop. As a result, the reception operation can not be maintained, and there is a possibility that the reception may be stopped halfway. In addition, there is a risk that the system may be downed, such that a key operation such as holding the current time can not be performed.

  Further, the voltage drop amount (dropping speed) of the secondary battery 42 largely depends on the temperature of the secondary battery 42. Here, with reference to FIG. 4, the relationship between the voltage of the secondary battery 42 and the temperature of the secondary battery 42 will be described. FIG. 4 is a diagram showing an outline of voltage transition of the secondary battery when the receiving circuit continuously executes the capturing operation for each temperature of the secondary battery. Specifically, when the temperature of the secondary battery is high temperature (about 60 ° C.) is shown by a solid line, when normal temperature (about 24 ° C.) is shown by a broken line, and when low temperature (about -10 ° C.) is a two-dot chain line Indicated. As shown in the figure, the lower the temperature is, the larger the voltage drop amount of the secondary battery 42 is. FIG. 4 shows the outline of the transition of the voltage, and the actual waveform has a shape that largely falls as a whole while repeating the descent and recovery according to the capture operation.

  When the temperature of the secondary battery 42 is high, the amount of voltage drop is relatively small, so even if the trapping operation tends to cause a rapid voltage drop as shown in FIG. It is possible to execute multiple times. On the other hand, when the temperature of the secondary battery 42 is low, it can be said that it is necessary to limit the number of times of the capturing operation that can be repeatedly executed compared to the case where the temperature is high.

  In the first embodiment, in order to suppress the occurrence of the system down due to the excessive drop of the voltage of the secondary battery 42, the execution of the capture operation is limited as described below. Specifically, the control circuit 30 integrates the voltage drop estimated count value by one each time the capture operation is performed, and the voltage drop estimated count value becomes equal to or higher than the upper limit count value (threshold value Vth). In this case, it was decided to stop the reception operation. In the first embodiment, the voltage drop estimated count value is a value corresponding to a voltage estimated to drop each time the capture operation is performed.

  In the first embodiment, the voltage drop estimated count value is integrated by one for each capturing operation, but the present invention is not limited to this, and the value of the count-up may be changed as appropriate. . At that time, it is preferable to set the upper limit count value so that the reception operation is stopped when the voltage of the secondary battery 42 drops excessively.

  The upper limit count value is determined based on a table associated with the voltage and temperature of the secondary battery 42 stored in the ROM 34, as shown in FIG. FIG. 5 is a diagram showing an example of the upper limit count table in the case of executing the reception operation for time measurement in the first embodiment.

  In the first embodiment, in the battery management circuit of the secondary battery 42, the voltage of the secondary battery 42 main body at the start of the receiving operation is less than 2.0 V (voltage range 1), 2.0 V or more and less than 2.1 V (voltage) Range 2), 2.1 V or more and less than 2.4 V (voltage range 3), 2.4 V or more and less than 2.65 V (voltage range 4), 2.65 V or more and less than 2.7 V (voltage range 5), 2.7 V or more It is detected which of 2.8 V (voltage range 6), 2.8 V or more and less than 3.3 V (voltage range 7), or 3.3 V or more (voltage range 8). Then, the microcontroller 31 acquires voltage data detected by the voltage sensor.

  The temperature data detected by the temperature sensor 37 is, for example, in 0.1 degree increments, and the microcontroller 31 indicates that the temperature data at the start of the reception operation is, for example, less than -10 ° C (temperature range 1), -10. ° C to -5 ° C (temperature range 2), -5 ° C to less than 0 ° C (temperature range 3), 0 ° C to less than 5 ° C (temperature range 4), 5 ° C to less than 10 ° C (temperature range 5), 10 It is determined whether the temperature is in the range of 6 ° C. to less than 25 ° C. (temperature range 6), 25 ° C. to less than 40 ° C. (temperature range 7), or 40 ° C. or more (temperature range 8). Then, the microcontroller 31 acquires temperature data detected by the temperature sensor 37. The temperature range is set to be narrower as the temperature is lower. As a result, battery management can be performed more precisely at lower temperatures.

  The upper limit count table shown in FIG. 5 is stored in the ROM 34, and stores upper limit count candidates in association with each combination of voltage data and temperature data acquired by the microcontroller 31 as described above. is there. In the upper limit count table, as the voltage of the secondary battery 42 at the start of the reception operation is lower, the upper limit count value is made smaller. Further, the upper limit count value is reduced as the temperature range at the start of the reception operation becomes lower. A combination of temperature data and voltage data for which the receiving operation by the receiving circuit 20 is prohibited, that is, a flag indicating "prohibited" is stored in the upper limit count table for the upper limit count value "0" in the figure. It is good.

  Further, the microcontroller 31 may display the voltage detected by the voltage sensor. For example, a letter “L0” indicating a low voltage level, a letter “L1” indicating a medium voltage level, and a letter “L2” indicating a high voltage level are displayed on the dial 53, and the operation unit 60 is displayed. When a predetermined operation is performed, a pointer 52 such as a second hand 52c may indicate a character corresponding to voltage data sent from a voltage sensor. Here, “L0” is indicated in the case of voltage ranges 1 to 4, “L1” is indicated in the case of voltage ranges 5 and 6, and “L2” is indicated in the case of voltage ranges 7 and 8. . In the case of the low voltage level, voltage data is notified from the voltage sensor to the microcontroller 31 by four voltage ranges more than other voltage levels, and more precise battery management is possible.

  Further, the microcontroller 31 may display a temperature level (hereinafter referred to as temperature information) obtained by dividing the temperature detected by the temperature sensor 37 into levels for each predetermined range. Here, particularly when the watch is attached, there is a possibility that the temperature inside the watch and the temperature outside will be different values, but the temperature to be displayed may be the temperature inside the watch. Thus, the user can correctly recognize whether the environment is suitable for the reception operation. In addition, although the structure which mounts the temperature sensor for external temperature separately may be sufficient, it is good to make temperature shown at the time of receiving operation into temperature inside a timepiece. The temperature information may be displayed at all times, or may be displayed according to the operation of the operation unit 60. In the case of constant display, temperature measurement is performed in a predetermined cycle to update the display.

  In the first embodiment, the voltage drop estimated count value is integrated by one each time the capturing operation is started once. Then, when the estimated voltage drop count value becomes equal to or higher than the upper limit count value selected from the upper limit count table based on the voltage data and temperature data acquired by the microcontroller 31, the reception circuit 20 stops the reception operation. did. For example, in the case of the voltage range 6 to 7 and the temperature range 7, the upper limit count value to be selected is “8” (see FIG. 5), and the capture operation can be performed up to eight times. That is, if the acquisition operation is performed eight times and acquisition is still unsuccessful, the reception operation is stopped without executing the ninth acquisition operation.

  6 and 7 are diagrams showing an example of integration of the voltage drop estimated count value in the first embodiment.

  FIG. 6 shows an example in which the capturing operation is performed three times, and then the tracking operation is started, and the reception is successful. First, the counter 39 sets the estimated voltage drop count value to zero. Then, the reception operation is started and the capture operation is started to count up by one. As a result, the voltage drop estimated count value becomes one. Then, after the upper limit time (for example, 2 seconds) of the capture operation has elapsed, recapture is performed. Thus, the voltage drop estimated count value becomes 2 by 1 count up. Furthermore, after the upper limit time of the capture operation has elapsed, recapture is performed. As a result, the count is increased by one, and the estimated voltage drop count value is 3. Thereafter, acquisition is successful and tracking operation is started. Then, after tracking is successful, time data is acquired, and the reception operation is stopped.

  In the example shown in FIG. 6, the case where the selected upper limit count value is any of “3”, “5” and “8” is shown. If the selected upper limit count value is “1”, the reception operation is stopped without the second acquisition operation being started.

  FIG. 7 shows an example in which the acquisition operation is performed once and acquisition is successful, and then the tracking operation is started, and the satellite is lost during tracking and the acquisition operation is performed again. First, the counter 39 sets the estimated voltage drop count value to zero. Then, the capture operation is started and counted up by one. As a result, the voltage drop estimated count value becomes one. Then, after success in capturing before the upper limit time of the capturing operation has elapsed, the tracking operation is started. Furthermore, when the upper limit time (for example, 0.1 to 10 seconds) of the tracking operation has elapsed, reception of the satellite signal is not completed and tracking of the satellite can not be continued, and then the acquisition operation is started again. . When the capture operation is started again, it is incremented by one, and the estimated voltage drop count value is 2. Then, after capturing is successful, the tracking operation is started.

  In the example shown in FIG. 7, the case where the selected upper limit count value is any of “3”, “5”, and “8” is shown. If the selected upper limit count value is “1”, the reception operation is stopped without the second acquisition operation being started.

  The upper limit time of the reception operation may be further used as a condition for stopping the reception operation. For example, it is preferable to stop the reception operation when the execution time of the reception operation exceeds 80 seconds in total even if the voltage drop estimated count value is less than the upper limit count value with the upper limit of the reception operation being 80 seconds. . Even if the voltage drop estimated count value is less than the upper limit count value, the voltage of the secondary battery 42 may be excessively dropped if the execution time of the reception operation is extended to a certain extent (here, 80 seconds or more). It is because there is.

  FIG. 8 is a flow chart showing control of the microcontroller in the first embodiment. The control shown in the figure is executed when the reception timing of the satellite signal periodically arrives, or when the operation unit 60 instructs to receive the satellite signal.

  First, the microcontroller 31 acquires voltage data from the voltage sensor of the secondary battery 42, and acquires temperature data from the temperature sensor 37 (S101). Then, with reference to the upper limit count table, the upper limit count value Vth is acquired based on the acquired voltage data and temperature data (S102). At this time, when the acquired upper limit count value Vth is “0” (YES in S103), the prohibition flag is read, and the reception circuit 20 is not caused to execute the reception operation. That is, the reception prohibition process is performed (S104). At this time, it is preferable that a pointer such as the second hand 52 c indicates the character “NG” which is the reception state display 61. Alternatively, apart from "NG", a mark representing "prohibited" is provided on the dial 53 as the reception status display 61, and the pointer instructs the mark representing this "prohibited", whereby the user is prohibited from receiving operation. It may be configured to notify that effect. The temperature information described above may be displayed in addition to the "prohibit" instruction. The display of the temperature information may be only during the indication of "prohibit", and the display time may be continued until the predetermined temperature is reached. When the acquired upper limit count value is other than “0” (NO in S103), the microcontroller 31 turns on the switch SW2, and the reception circuit 20 starts the reception operation.

  If it is determined that the reception operation is to be started, the microcontroller 31 starts counting the time of the timer (S105), and the counter 39 sets the estimated voltage drop count value to 0 (S106). Thereafter, the capture operation is started (S107), and the voltage drop estimated count value is incremented by 1 with the start of the capture operation (S108). If the capture is successful before the upper limit time of the capture operation has elapsed (YES in S109), the tracking operation is started (S110). On the other hand, when the upper limit time of the capturing operation has passed (YES in S111) before the capture is successful (NO in S109), the timer time count passes the upper limit time (for example, 80 seconds) of the execution time of the receiving operation. If not (NO in S112) and the estimated voltage drop count value is less than the upper limit count value Vth (YES in S113), the capturing operation is started again (S107). On the other hand, if the total time count of the timer has exceeded the upper limit time of the reception operation execution time (YES in S112), or if the total voltage drop estimated count value is greater than or equal to the upper limit count value Vth (NO in S113) And stop the reception operation and perform reception failure processing (S114). In addition, when the acquisition of the satellite signal is successful before the tracking operation is started and the upper limit time of the tracking operation has elapsed (YES in S115), the reception success process is performed (S116). On the other hand, if the tracking fails (NO at S117) or the upper limit time of the tracking operation passes before the satellite signal acquisition succeeds (NO at S115) or if the upper limit time of the tracking operation elapses (YES at S118) Then, the capture operation is started again (S107) or the reception operation is stopped, and a reception failure process is performed (S114).

  According to the satellite radio-controlled watch 1 described above, the reception operation can be performed as much as possible without the voltage of the secondary battery 42 excessively dropping. As a result, it is possible to prevent the occurrence of a system down due to an excessive drop in the voltage supplied to the microcontroller 31, and to improve the accuracy of the reception success.

  Next, a second embodiment will be described with reference to FIGS. 9 to 12. FIG. 9 is a view showing an example of the upper limit count table in the case of executing the reception operation for time measurement in the second embodiment. FIG. 10 and FIG. 11 are diagrams showing an example of integration of the voltage drop estimated count value in the second embodiment. The basic configuration of the satellite radio-controlled wristwatch 1 in the second embodiment is the same as that of the first embodiment described with reference to FIGS. 1 to 4, and thus the description thereof will be omitted.

  In the first embodiment, an example is described in which the voltage drop estimated count value is integrated by one each time the capturing operation is started once. Here, as described above, the voltage drop speed is high during the capture operation, but the voltage of the secondary battery 42 is dropped although it is gentle during the tracking operation. In addition, even in the capturing operation period T1 during the capturing operation, the voltage drop speed is different immediately after the start of the capturing operation and in the subsequent operation. Therefore, in the second embodiment, in order to perform more precise battery management, each time a predetermined operation content of the reception operation is executed, voltage drop is performed by a predetermined value which is predetermined based on the operation content. The configuration is such that the estimated count value is integrated. In the second embodiment, the voltage drop estimated count value is a value corresponding to a voltage which is estimated to drop every time one predetermined operation content of the reception operation is performed. The predetermined operation content is determined corresponding to a predetermined period of the execution time of the reception operation.

  In the second embodiment, as predetermined operation content, operation content performed immediately after the start of the reception operation and performed in one second immediately after the start of the capture operation (hereinafter, also referred to as first operation content), capture operation The operation content is an operation other than the first operation content and is performed every two seconds (hereinafter also referred to as the second operation content), the operation content performed every one second of the tracking operation (hereinafter also referred to as the third operation content) Say). Then, predetermined values to be integrated are respectively set corresponding to the contents of the operations. Specifically, the voltage drop estimated count value is incremented by 1 when the first operation content is performed, and the voltage drop estimated count value is counted up by 3 when the second operation content is performed, and the third operation is performed. When the content is performed, the voltage drop estimated count value is incremented by one. As described above, the voltage drop estimated count value integrated per unit time is set larger as the operation content of the voltage drop amount is larger.

  Then, the ROM 34 stores the upper limit count table shown in FIG. 9 so as to correspond to such a counting method.

  In FIG. 10, in the capturing operation period T1, the voltage drop estimated count value is incremented by one immediately after the start of the receiving operation and one second after the start of the capturing operation (after completion of the first operation), After 2 seconds have elapsed (after the second operation is completed), the voltage drop estimated count value is incremented by 3 and after 2 seconds (after the second operation is completed), the voltage drop estimated count value is incremented by 3 ing. Furthermore, it indicates that the voltage drop estimated count value is incremented by one every two seconds (every time the third operation is completed) in the tracking operation period T2 after the capture is successful.

  More specifically, first, the counter 39 sets the estimated voltage drop count value to zero. Then, the reception operation is started, and when one second has elapsed from the start of the acquisition operation in the acquisition operation period T1, the count is incremented by one. As a result, the voltage drop estimated count value becomes one. Furthermore, when 2 seconds pass after that, 3 counts up. The voltage drop estimated count value at this point is four. Then, the recapture is started in response to the capture failure. Count up 3 when 2 seconds have passed for the recapture execution time. As a result, the voltage drop estimated count value becomes 7. In the example of FIG. 10, when re-acquisition is performed for just 2 seconds, acquisition is successful and tracking operation is started. Then, every 2 seconds after the start of the tracking operation, one count up is performed. In the example of FIG. 10, it indicates that the satellite signal has been successfully received four seconds after the start of the tracking operation.

  In FIG. 11, in the capturing operation period T1, after 1 second has passed from immediately after the start of the capturing operation (after the completion of the first operation), the estimated voltage drop count value is incremented by one and after 2 seconds have elapsed In the following example, the voltage drop estimated count value is incremented by three, and after capturing is successful, the voltage drop estimated count value is incremented by 1 every 2 seconds (every time the third operation is completed) in the tracking operation period T2. Is shown. And, after the upper limit time of the tracking operation has passed, reception of satellite signals has not been completed, and when satellite tracking can not be continued (in this example, 4 seconds), an example of starting the reception operation again is shown. .

  More specifically, first, the counter 39 sets the estimated voltage drop count value to zero. Then, the reception operation is started, and when one second has elapsed from the start of the acquisition operation in the acquisition operation period T1, the count is incremented by one. As a result, the voltage drop estimated count value becomes one. Furthermore, when 2 seconds pass after that, it counts up 3 counts. The voltage drop estimated count value at this point is four. In this example, when the capture operation is performed for exactly 2 seconds, the capture is successful and the tracking operation is started. Then, it increments by one every two seconds after the start of the tracking operation. Even if the upper limit time 4 seconds has passed, reception of the satellite signal has not been completed, and if the satellite tracking can not be continued, the reception operation is started again. The reception operation is started again, and is incremented by one when one second has elapsed from the start of the acquisition operation in the acquisition operation period T1. Furthermore, it counts up 3 when 2 seconds have passed. The voltage drop estimated count value at this point is 10. Then, after capturing is successful, the tracking operation is started.

  Furthermore, the second embodiment will be described with reference to the flowchart of FIG. FIG. 12 is a flow chart showing control of the microcontroller in the second embodiment. The control shown in the figure is executed when the periodic satellite signal reception timing arrives or the satellite signal reception instruction is given by the operation unit 60.

  First, the microcontroller 31 acquires voltage data from the voltage sensor of the secondary battery 42, and acquires temperature data from the temperature sensor 37 (S201). Then, with reference to the upper limit count table, the upper limit count value Vth is acquired based on the acquired voltage data and temperature data (S202). At this time, when the acquired upper limit count value Vth is “0” (YES in S203), the prohibition flag is read, and the reception circuit 20 is not caused to execute the reception operation. That is, the reception prohibition process is performed (S204). At this time, it is preferable that a pointer such as the second hand 52 c indicates the character “NG” which is the reception state display 61. Alternatively, apart from "NG", a mark representing "prohibited" is provided on the dial 53 as the reception status display 61, and the pointer instructs the mark representing this "prohibited", whereby the user is prohibited from receiving operation. It may be configured to notify that effect. When the acquired upper limit count value is other than “0” (NO in S203), the microcontroller 31 turns on the switch SW2, and the reception circuit 20 starts the reception operation.

  If it is determined that the reception operation is to be started, the microcontroller 31 starts counting the time of the timer (S205), and sets the voltage drop estimated count value of the counter 39 to 0 (S206). Thereafter, the capture operation is started (S207), and with the start of the capture operation, the estimated voltage drop count value is incremented by 1 (S208). Then, if the capture is successful before the upper limit time of the capture operation has elapsed (YES in S209), the tracking operation is started (S210). On the other hand, if the upper limit time of the capture operation has passed before the capture is successful (YES in S211), the estimated voltage drop count value is less than the upper limit count value Vth (YES in S212), and the timer time count is accumulated. If the upper limit time (for example, 80 seconds) of the execution time of the reception operation has not passed (NO in S213), the capture operation is started again (S207). On the other hand, when the total of the voltage drop estimated count value is equal to or more than the upper limit count value Vth (NO in S212), or when the time count of the timer has exceeded the upper limit time of the reception operation execution time (YES in S213) The reception operation is stopped and reception failure processing is performed (S214). In addition, every time the designated time of the capture operation elapses (YES in S230) before counting the success of the capture and before the upper limit time of the capture operation elapses, a value corresponding to the elapse of the designated time is counted. Up (S231). The designated time here is two seconds after one second has elapsed from the start of the capturing operation described with reference to FIGS. 10 and 11. Moreover, it is good to set "3" with the value corresponding to progress of designated time.

  In addition, when the acquisition of the satellite signal is successful before the tracking operation is started and the upper limit time of the tracking operation has elapsed (YES in S215), reception success processing is performed (S216). On the other hand, if the tracking fails (S217: NO) or the upper limit time of the tracking operation passes (S218: YES), the above-mentioned S212 to S213 are performed before the acquisition of the satellite signal succeeds, and the capturing operation is performed again. (S207) or stop the reception operation, and perform reception failure processing (S214). Further, each time the designated time of the tracking operation has passed (S219), a value corresponding to the lapse of the designated time is counted up (S220). The designated time referred to here is the time every two seconds from the start of the tracking operation described with reference to FIGS. Also, it is preferable that the value corresponding to the passage of the designated time be “1”. That is, it is preferable to increment by one every two seconds after the start of the tracking operation, and even when the upper limit time of the tracking operation has not elapsed, the upper limit time of the execution time of the reception operation has elapsed ( If the voltage drop estimated count value is equal to or greater than the upper limit count value Vh (YES in S221), reception failure processing is performed (S214). If the upper limit time of the execution time of the reception operation has not elapsed (NO at S221) and the total of the voltage drop estimated count values is not larger than the upper limit count value Vh (NO at S222) It is determined whether acquisition has succeeded (S215).

  In addition, even if the voltage drop estimated count value is equal to or more than the upper limit at the time of S222, the tracking operation may be continued until the tracking is successful in order to increase the accuracy of the reception success as much as possible. Good. This is because the voltage drop amount due to the tracking operation is relatively small, and there is little possibility that the system will be down even if the tracking operation is performed subsequently.

  In the second embodiment and the modification thereof described above, more precise battery management can be performed as compared with the first embodiment. As a result, it is possible to prevent the occurrence of a system down due to an excessive drop in the voltage supplied to the microcontroller 31, and to improve the accuracy of the reception success.

  In addition, about count-up by the capture operation in the second embodiment, the capture operation is performed once as in the first embodiment without counting up the voltage drop estimated count value every time the designated time of the capture operation passes. It may be performed only when it is performed. That is, S230 and S231 in the flowchart of FIG. 12 may be omitted. This is because the voltage drop due to the capture operation is the largest immediately after the start of the capture operation, and the voltage drop due to the operation after the start immediately after the start is small, so there is little influence even if ignored. In addition, when counting up only when the capture operation is performed once, for example, the count-up value may be larger than the value shown in FIG. In that case, for example, it is preferable to set the count-up value when the capture operation is performed once to "3" or "4".

  The upper limit count value shown in FIG. 9 and the method of counting up described with reference to FIGS. 10 and 11 are merely examples, and the present invention is not limited to this. For example, during the capture operation period T1, the count-up value is gradually increased, such as incrementing one count after the first one second, incrementing one after the lapse of one second, and incrementing two more after one second. The configuration may be Alternatively, the configuration may be such that the count-up value is gradually lowered. In addition, during the capture operation period T1, 1 is incremented after the first one second, then is incremented by 2 after 2 seconds, and is further incremented by 3 after 3 seconds, etc. The configuration may be such that the interval of up is changed. In addition, in the tracking operation period T2, instead of being incremented by one every two seconds, counting by two may be performed every four seconds. Further, in the tracking operation period T2, the count up may not be performed as in the first embodiment.

  Furthermore, the upper limit count value may be fixed regardless of the voltage and temperature of the secondary battery 42, and the count-up value of the estimated voltage drop count value may be determined based on the voltage and temperature of the secondary battery 42. . For example, if the temperature is high, the estimated voltage drop count value is incremented by 1 in the first second of the capture operation period T1, and if the temperature is low, the voltage is estimated in the first 1 second of the capture operation period T1. The configuration may be such that the estimated descent count value is incremented by two. In that case, it is preferable to store in the ROM 34 a table storing candidates for count-up values to be accumulated for each predetermined operation content in association with the combination of the voltage and temperature of the secondary battery 42 respectively.

  In the first embodiment and the second embodiment, an example is shown in which the upper limit count value is set in association with the combination of the voltage and temperature of the secondary battery 42 in order to perform more precise battery management. The present invention is not limited to this, and the upper limit count value may be set in association with either the voltage of the secondary battery 42 or the temperature of the secondary battery 42. Furthermore, the upper limit count value may be set without associating the voltage of the secondary battery 42 with the temperature. For example, regardless of the voltage or temperature of the secondary battery 42, the upper limit count value may always be set to "4".

  In the first embodiment and the second embodiment, although the case of performing the reception operation for time measurement has been described, the present invention is not limited to this and is also applicable to the case of performing the reception operation for positioning. it can. In order to obtain time information in the reception operation for time measurement, it is sufficient to receive only a part of the satellite signal from one satellite, but in order to obtain highly accurate position information in the reception operation for positioning. The need to receive satellite signals from multiple satellites also increases the size of the satellite signals that must be received. For this reason, reception operation for positioning takes longer time to receive satellite signals than reception operation for time measurement. Generally, it takes about 1 to 8 seconds for capturing operation in positioning reception operation, and about 30 to 45 seconds for tracking operation. That is, in the reception operation for positioning, it takes about 31 to 53 seconds per one operation.

  Therefore, the amount of voltage drop per one operation is larger in the reception operation for positioning than in the reception operation for time measurement. Therefore, when performing the receiving operation for positioning, it is better to make the upper limit count value smaller than when performing the receiving operation for time measurement. Specifically, when performing the reception operation for positioning in the first embodiment, the upper limit count value may be acquired using the upper limit count table shown in FIG. In this case, for example, two tables of the upper limit count table (FIG. 5) in the case of performing the reception operation for time measurement (FIG. 5) and the upper limit count table (FIG. 13) in the case of performing the reception operation for positioning are stored in the ROM 34. It is preferable to store them, and the microcontroller 31 may use those tables according to the purpose of reception. In this case, the upper limit count table in which the ROM 34 sets the upper limit count value when performing reception operation for time measurement to an integral multiple (for example, six times) of the upper limit count value when performing reception operation for positioning You may memorize. As a result, even when storing a plurality of upper limit count tables, it is possible to reduce the data capacity stored in the ROM 34. However, any one upper limit count table may be stored in the ROM 34, and battery management corresponding to only one of the reception operations may be performed.

  Similarly, in the second embodiment, when performing the reception operation for positioning, it is preferable to obtain the upper limit count value using the upper limit count table shown in FIG. In this case, for example, two tables of the upper limit count table (FIG. 9) in the case of performing the reception operation for time measurement (FIG. 9) and the upper limit count table (FIG. 14) in the case of performing the reception operation for positioning are stored in the ROM 34. It is preferable to store them and the microcontroller 31 may use those tables according to the purpose of reception. However, any one upper limit count table may be stored in the ROM 34, and battery management corresponding to only one of the reception operations may be performed.

  In the above embodiment, although an example of receiving a satellite signal from GPS has been described, the present invention is not limited to this. For example, it is possible to use a Quasi-Zenith Satellite System (QZSS) or a Global Navigation Satellite System (GLONASS). Satellite signals may be received. As a result, even when the GPS is in a position behind a building, the satellite signal reception success rate is improved by making it possible to receive other satellites. Also, when acquisition fails, in the case of reacquisition, the type of satellite may be switched in order to improve the reception success rate.

  In addition, even if the reacquisition is performed, the receiving operation may be terminated immediately if none of the satellites can acquire. As a result, unnecessary reception operation can be suppressed under a situation where the possibility of receiving satellite signals is extremely low.

  Also, cold start and hot start may be used separately when performing the capture operation. Cold start is to start satellite acquisition from a state where there is no satellite information, and hot start is to utilize satellite information (almanac data and ephemeris data) acquired at the time of previous reception. It is a technology that can shorten the acquisition time. For example, a hot start may be performed in the first acquisition, and a cold start may be performed if satellites can not be acquired within a predetermined time.

  Reference Signs List 1 satellite radio-controlled wristwatch, 10 antennas, 20 receiving circuits, 21 high frequency circuits, 22 decoding circuits, 22a correlator, 22b tracking circuits, 23, 23a, 23b DCDC converters, 30 control circuits, 31 microcontrollers, 32 operating units, 33 RAM , 34 ROM, 35 motor drive circuit, 36 oscillation circuit, 37 temperature sensor, 38 vibrator, 39 counter, 40 power supply unit, 41 solar battery, 42 secondary battery, 50 drive mechanism, 51 time display unit, 52 hands, 52a hour hand, 52b minute hand, 52c second hand, 53 dial, 60 operation unit, 61 reception status display.

Claims (12)

With built-in battery,
A receiving circuit which receives a power supply from the internal battery and executes a receiving operation of receiving an external signal;
Every time a predetermined operation content of the receiving operation is executed, the voltage drop estimated count value is integrated by a predetermined value determined in advance according to the operation content, and the voltage drop estimated count value is the upper limit count value. A control circuit for stopping the reception operation when the above occurs;
Radio clock with. The receiving operation includes an acquiring operation for acquiring the signal,
The control circuit integrates the estimated voltage drop count value by a predetermined value determined in advance according to the capturing operation every time the capturing operation is performed.
The radio controlled watch according to claim 1. The receiving operation includes an acquiring operation for acquiring the signal,
The control circuit integrates the voltage drop estimated count value by a predetermined value determined in advance according to the predetermined operation content of the capture operation each time the predetermined operation content of the capture operation is executed.
The radio controlled watch according to claim 1. The receiving operation further includes a tracking operation which is executed after the capturing operation and tracks the signal.
The control circuit integrates the voltage drop estimated count value by a predetermined value determined in advance according to the predetermined operation content of the tracking operation every time the predetermined operation content of the tracking operation is executed.
The radio controlled watch according to claim 3. The predetermined operation content is determined corresponding to a predetermined period of the execution period of the reception operation.
The radio controlled watch according to any one of claims 1 to 4. And a voltage sensor for outputting voltage data of the built-in battery at the start of the reception operation,
The upper limit count value is determined based on the voltage data.
The radio controlled watch according to any one of claims 1 to 5. It further comprises a temperature sensor for outputting temperature data of the internal battery at the start of the reception operation,
The upper limit count value is determined based on the temperature data.
The radio controlled watch according to claim 6. A memory for storing a plurality of candidates for the upper limit count value in association with the combination of the temperature data and the voltage data, respectively;
The radio controlled watch according to claim 7. The memory includes a plurality of candidates for the upper limit count value when performing the reception operation for time measurement, and a plurality of candidates for the upper limit count value when performing the reception operation for positioning. Storing each in association with a combination of the temperature data and the voltage data,
The radio controlled watch according to claim 8. The range of the temperature data associated with each of the plurality of candidates for the upper limit count value is narrower as the range relates to lower temperatures.
The radio controlled watch according to claim 8 or 9. A voltage sensor for outputting voltage data of the internal battery at the start of the reception operation;
A temperature sensor for outputting temperature data of the internal battery at the start of the reception operation;
And a memory for storing a plurality of candidates of the predetermined predetermined value in association with the combination of the temperature data and the voltage data.
The radio controlled watch according to any one of claims 1 to 5. When the execution time of the reception operation exceeds the upper limit time, the control circuit stops the reception operation regardless of whether the voltage drop estimated count value becomes equal to or more than the upper limit count value.
The radio controlled watch according to any one of claims 1 to 11.

Images