JP2012145388A - Power supply device and electronic watch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device and an electronic watch capable of operating a high-load function part without exerting an adverse effect to the operation of a low-load function part.SOLUTION: The electronic watch includes: a low-load secondary battery B1; power generation means 11; a high-load secondary battery B2 capable of supply power larger than that of the low-load secondary battery B1; voltage detection means 12, 13 for measuring output voltages of the respective secondary batteries B1, B2; first switching means SW1 for connecting the low-load secondary battery B1 to the high-load secondary battery B2; second switching means SW2 for supplying power by the high-load secondary battery B2; and control means 104 for controlling the first and second switching means SW1, SW2. When an output voltage of the low-load secondary battery B1 is less than a low-load lower limit voltage and an output voltage of the high-load secondary battery B2 is a high-load set voltage and more, the control means 104 turns off the first switching means SW1, and when the output voltage of the high-load secondary battery B2 is less than a load lower limit voltage, turns off the second switching means SW2.

Description

  The present invention relates to a power supply circuit capable of supplying power to a plurality of loads having different sizes, and an electronic timepiece including the power supply circuit and an additional function.

  Conventionally, as a secondary battery used for a portable electronic device with low power consumption such as an electronic wristwatch, there is a button-type lithium ion battery. By combining a small button-type lithium ion battery and a power generation function such as a solar battery, it is possible to reduce the size of the portable electronic device while enabling continuous use for a long time.

  Some electronic wrist watches have an additional function that consumes more electric power than a clock operation, such as an illumination function for illuminating a dial. Conventionally, such an electronic wristwatch has a problem that even the clock operation stops as a result of excessive lighting. Therefore, for example, in Patent Document 1, two batteries are arranged in parallel via a backflow prevention diode, and the operation of the additional function is performed by only one battery, and the other battery that performs the clock operation is excessive. A technique is disclosed in which when one battery is discharged, power can be supplied from the one battery to the timepiece function and the operation is stably performed.

  In addition, as a technique related to the invention of the present application, Patent Document 2 discloses that in a portable device in which two electric double layer capacitors are connected in parallel to a battery, when the output voltage of the battery decreases, two electric double layer capacitors A technology is disclosed in which the devices are connected in series so that they can be connected and can operate in a short time in an emergency.

  As another technique related to the invention of the present application, in Patent Document 3, in a portable device including a main battery and a large-capacity capacitor for backup, the output voltage of the main battery is set when charging the large-capacity capacitor. A technique for controlling charging timing and period while detecting is disclosed.

JP-A-53-53376 JP 2000-69691 A JP 2007-28744 A

  However, in recent years, mobile devices have become more multifunctional and sophisticated, and electronic wristwatches have an additional function that requires a current that is several orders of magnitude larger than the current required for clock operation, such as the GPS function. There is a case. In such a case, in the conventional power supply configuration, even if the power is used for a short time, if a large amount of power is output by the operation of the additional function, the output voltage from the power supply decreases and the clock operation is stably performed. There is a problem that it becomes impossible.

  An object of the present invention is to provide a power supply device capable of executing a function having a large load without adversely affecting the operation of a function unit having a small load, and an electronic timepiece having the power supply device and an additional function. There is.

In order to achieve the above object, the invention described in claim 1
A low-load secondary battery capable of supplying power at a predetermined voltage;
Power generation means for supplying power to the low-load secondary battery;
A high-load secondary battery capable of supplying power at a higher power than the low-load secondary battery;
Voltage detection means for measuring the output voltage of the secondary battery for low load and the output voltage of the secondary battery for high load;
First switching means for switching on / off of power supply from the low-load secondary battery to the high-load secondary battery;
Second switching means for switching on / off of power supply by the high-load secondary battery;
Control means for controlling the first switching means and the second switching means based on the measurement result by the voltage detection means;
With
The control means includes
When the voltage detection means detects that the output voltage of the low load secondary battery is lower than a predetermined low load lower limit voltage, and the output voltage of the high load secondary battery is predetermined. When it is detected that the voltage is higher than the set high load voltage, the first switching means is turned off,
When the voltage detecting means detects that the output voltage of the high load secondary battery is less than the predetermined high load lower limit voltage below the high load set voltage, the second switching means is turned off. It is a power supply device characterized by these.

  According to the present invention, a power supply device and an electronic timepiece including the power supply device include a power generation unit, a low-load secondary battery, a high-load secondary battery, and a voltage detection unit. When supplying power to the secondary battery and the voltage of the secondary battery for low load is lower than the lower limit voltage or the voltage of the secondary battery for high load is higher than the set voltage, the secondary battery for low load Switch off the power supply from the battery to the high-load secondary battery, and switch off the power supply from the high-load secondary battery when the voltage of the high-load secondary battery is lower than the lower limit voltage Since the process for controlling the means is performed by the control means, it is possible to execute a function having a large load without adversely affecting the operation of the function unit having a small load.

It is a block diagram which shows the structure of the electronic timepiece provided with the power supply part which is embodiment of the power supply device of this invention. It is a figure which shows the circuit structure of a power supply part. It is a circuit diagram which shows the specific example 1 of a voltage converter circuit. It is the figure which showed the switch switching procedure and voltage change in the specific example 1 of a voltage converter circuit. It is a circuit diagram which shows the specific example 2 of a voltage converter circuit. It is the figure which showed the switch switching procedure and voltage change in the specific example 2 of a voltage converter circuit. It is a figure which shows the specific example of the voltage change in a secondary battery. It is a graph which shows the on-off control pattern of the switch in a power supply part. It is a flowchart which shows the switch control procedure of the power supply part by CPU of a timepiece control part.

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

  FIG. 1 is a block diagram showing a configuration of an electronic timepiece including a power supply unit according to an embodiment of the power supply device of the present invention.

  The electronic timepiece 100 includes an oscillation circuit 101, a frequency dividing circuit 102, a time measuring circuit 103 (time measuring means), an LSI (Large Scale Integration) as a control means 104, and a drive section 105 (drive means). A wheel train mechanism 106, a pointer 107, an operation unit 108, an additional function unit 109, a power supply unit 110 (power supply device), and the like.

  The oscillation circuit 101 is a circuit that oscillates a clock signal having a predetermined frequency, and is, for example, a crystal oscillation circuit. The frequency dividing circuit 102 is a circuit that divides a signal having a predetermined frequency input from the oscillation circuit 101 and converts the signal to a signal having a frequency used by the time measuring circuit 103 or the LSI 104. The time measuring circuit 103 counts time based on the signal input from the frequency dividing circuit 102 and outputs time data to the LSI 104.

  The drive unit 105 includes a stepping motor and operates the stepping motor based on a pointer drive control signal input from the LSI 104. The train wheel mechanism 106 includes a plurality of gears that rotate the pointer by a predetermined angle based on the operation of the drive unit 105. The hand 107 includes an hour hand, a minute hand, and a second hand for displaying the time, and is configured to be able to rotate. The pointer 107 may include other function hands, or may not include the second hand. The drive unit 105 and the train wheel mechanism 106 may be provided independently for different hands, or only the second hand is rotated by the independent drive unit 105 and the train wheel mechanism 106. Also good.

  For example, the operation unit 108 converts an alarm setting or an execution command of an additional function to the additional function unit 109 into an input signal based on a user operation with a button provided on a side surface of the electronic timepiece 100, and transmits the input signal to the LSI 104. .

  The LSI (clock control unit) 104 includes a central processing unit (CPU) that controls various arithmetic processes and clock functions, a random access memory (RAM) that provides a working memory space for the CPU, various execution programs, A ROM (Read Only Memory) for storing initial data is provided. The LSI 104 continuously receives power from the power supply unit 110, and outputs a pointer drive control signal at a timing for operating the pointer to the drive unit 105 based on a time signal input from the timer circuit 103. The LSI (clock control unit) 104 controls the switching operation of the switches included in the power supply unit 110 based on output voltage information input from the power supply unit 110. The switch switching control processing of the power supply unit 110 by the LSI 104 will be described in detail later.

  The additional function unit 109 performs operation processing of additional functions other than the clock operation when power is supplied from the power supply unit 110. This operation process is, for example, an operation process of an illumination function for illuminating a dial face or a positioning function using GPS (Global Positioning System). The additional function unit 109 may include a separate CPU and RAM independently of the LSI 104. In addition, when it is necessary for the clock function operation by the LSI 104 and the operation of the additional function unit 109, it is assumed that a digital display unit such as a liquid crystal display unit is provided, based on the control signal from the LSI 104 and / or the additional function unit 109. Information may be displayed.

  The power supply unit 110 stores generated power and supplies power to the LSI 104 and the additional function unit 109, respectively.

  FIG. 2 is a circuit diagram illustrating a power supply circuit of the power supply unit 110.

  The power supply unit 110 includes a solar cell 11 as power generation means, a backflow prevention diode D1, two secondary batteries B1 and B2 (low load secondary battery, high load secondary battery), and voltage detection means. BLD (Battery Level Detector) 12, 13, two switches SW 1, SW 2 (first switching means, second switching means), and two voltage converters 14, 15 (boosting means, step-down means), and LSI 104 In addition, power is supplied to the additional function unit 109.

  The solar cell 11 generates power by receiving sunlight and light from illumination and converting incident light into electricity. The solar cell 11 is connected to the LSI 104, the secondary battery B1, and the switch SW1 via a backflow prevention diode D1. The backflow prevention diode D <b> 1 is a diode for preventing a current from flowing back to the solar cell 11. Therefore, when the output voltage (electromotive force) of the solar cell 11 is higher than the output voltage VB1 of the secondary battery B1, power is supplied from the solar cell 11 to the secondary battery B1.

  The secondary batteries B1 and B2 store or discharge electric power using a chemical reaction. The secondary battery B1 continuously supplies the power supplied from the solar cell 11 to the LSI 104. This secondary battery B1 has a predetermined voltage VB1 (for example, 2.3 V) necessary for the operation of the stepping motor in the driving unit 105, the timekeeping operation, and the overall control of the clock function, and a low current (about several μA). A battery capable of continuously outputting electric power, for example, a button-type lithium ion battery having a diameter of 9.5 mm. Further, the secondary battery B1 is connected to the secondary battery B2 via the switch SW1 and the voltage conversion unit 14. The power supplied from the secondary battery B1 while the switch SW1 is on is voltage-converted by the voltage converter 14 and supplied to the secondary battery B2.

  The secondary battery B2 stores the power supplied from the secondary battery B1 while the switch SW1 is on. The secondary battery B2 is connected to the additional function unit 109 via the switch SW2 and the voltage conversion unit 15, and supplies power to the additional function unit 109 while the switch SW2 is on. The secondary battery B2 can execute the operation of the additional function unit 109 having a large load for a short time (for example, several tens of minutes), and is, for example, a sheet battery (paper battery) including a solid electrolyte. As the solid electrolyte, lithium cobaltate is preferably used. For example, the sheet-like battery is applied and arranged on the back cover of an electronic timepiece. The nominal voltage when charging such a sheet battery is, for example, 4.1V.

  The BLD 12 is provided in parallel with the secondary battery B1. The BLD 12 compares the output voltage VB1 of the secondary battery B1 with a predetermined set voltage, and continuously outputs a signal representing the comparison result to the LSI 104. In the power supply unit 110 of the present embodiment, a lower limit setting voltage V1L higher than an operation lower limit voltage necessary for stably operating the LSI 104, and a charge setting voltage indicating a voltage level not exceeding the full charge voltage of the secondary battery B1. Two set voltages V1H are provided, and compared with the output voltage VB1, respectively, and a comparison result is output. For this voltage comparison, for example, a comparator is used. It should be noted that the output signal may be a single signal of three levels by combining two comparison results. It is also possible to transmit voltage value data itself to the LSI 104 instead of the comparison result. A capacitor C1 is connected in parallel to the secondary battery B1 (see FIGS. 3 and 5). This capacitor C1 is a power storage means used for backup of the secondary battery B1, and is intended to prevent the secondary battery B1 from being overloaded when the output from the secondary battery B1 increases rapidly. is there.

  The BLD 13 is provided in parallel with the secondary battery B2. The BLD 13 compares the output voltage VB2 of the secondary battery B2 with a predetermined set voltage, and continuously outputs a signal representing the comparison result to the LSI 104. In the power supply unit 110 of the present embodiment, two set voltages of a lower limit set voltage V2L that is a voltage level required in the operation of the additional function unit 109 and a charge set voltage V2H that does not exceed the full charge voltage of the secondary battery B2. Are compared with the output voltage VB2, and the comparison results are output. The operation request voltage level indicated by the former lower limit setting voltage V2L is, for example, a process until the GPS receiver is operated to receive radio waves from GPS satellites and the calculation process for obtaining the current position based on the received data is completed. This is a level at which a necessary voltage can be continuously supplied during a predetermined number of executions. For this voltage comparison, for example, a comparator is used. It should be noted that the output signal may be a single signal of three levels by combining two comparison results.

  The voltage conversion unit 14 has an input side connected to the secondary battery B1 via the switch SW1, and an output side connected to the secondary battery B2. The voltage conversion unit 14 increases the voltage VB1 input from the secondary battery B1 during the period in which the switch SW1 is on (for example, 4.6 V) and outputs the voltage VB1 to the secondary battery B2. The boosting method will be described in detail later.

  The voltage conversion unit 15 steps down the power output from the secondary battery B2 to the operating voltage of the additional function unit 109 (for example, 2.5 V) while the switch SW2 is on and supplies the power to the additional function unit 109. The voltage conversion unit 15 is, for example, a DC-DC converter using a switching element. A filter for removing noise generated from the DC-DC converter is provided in the voltage conversion unit 15 or in each part of the power supply unit 110 as necessary.

  Next, the circuit configuration of the voltage conversion unit 14 will be described.

  The voltage converter 14 uses a charge pump circuit.

  FIG. 3 is a diagram for explaining a circuit configuration of a specific example 1 of the voltage conversion unit 14.

  A specific example 1 of the voltage conversion unit 14 includes capacitors C1 and C2 and switches SW3 to SW6. The resistors R3 to R6 are internal resistors (switch resistors) of the switches SW3 to SW6, respectively, and are about 10Ω, for example. The switches SW <b> 3 to SW <b> 6 are each switched and controlled by a switch control signal sent from the LSI 104. The states of the switches SW3 to SW6 shown in FIG. 3 are all states when a low level signal is input as a switch control signal. When the switch SW1 is turned on in this state, power is supplied from the secondary battery B1 to the capacitor C2 via the resistor R3, the switch SW3, the switch SW6, and the resistor R6. The other end of the capacitor C2 is grounded via a resistor R5, a switch SW5, a resistor R4, and a switch SW4. The capacitance of the capacitor C2 is, for example, 1 μF, which is sufficiently smaller than the electric capacities of the secondary batteries B1 and B2.

  FIG. 4 is a diagram illustrating a switching procedure of switch control signals sent to the switches SW3 to SW6 and changes in voltages output from the secondary batteries B1 and B2.

  First, when the switch SW1 is turned on while the switch control signals input to the switches SW3 to SW6 are all at a low level, the secondary battery B1 stores the capacitor C2 (period (a) in FIG. 4). . The voltage applied to the capacitor C2 gradually approaches the output voltage VB1 of the secondary battery B1 as time elapses based on the time constant determined by the capacitance of the capacitor C2 and the resistance values of the resistors R3 to R6. After the power is stored in the capacitor C2 based on this time constant, when the switch control signal input to the switches SW3 and SW4 is sequentially switched to the high level, the capacitor C2 is first disconnected from the secondary battery B1. And then disconnected from ground. Then, a high level signal is sent to the switch SW5 so that the capacitor C2 is connected in series with the secondary battery B1, and the potential on the positive side of the capacitor C2 is between the voltage of the capacitor C2 and the output voltage VB1 of the secondary battery B1. The sum rises (period (b) in FIG. 4).

  When the switch control signal input to the switch SW6 is switched from the low level to the high level, the secondary battery B1 and the capacitor C2 connected in series and the secondary battery B2 are connected in parallel, and the capacitor C2 Current flows based on the potential difference between the positive electrode side potential of the battery and the output voltage VB2 of the secondary battery B2, and power is supplied to the secondary battery B2. At the moment when the switch SW6 is switched, the potential on the positive side of the secondary battery B2 rises to the potential on the positive side of the capacitor C2, but the current flowing between the capacitor C2 and the secondary battery B2 causes the positive side of the capacitor C2. And the potential on the positive electrode side of the secondary battery B2 are equal. Here, the equalized potential is slightly higher than the output voltage of the secondary battery B2 before the secondary battery B1, the capacitor C2, and the secondary battery B2 are connected in parallel (FIG. 4). Period (c)).

  After the potential difference disappears between the positive electrode side of the capacitor C2 and the positive electrode side of the secondary battery B2, the switch SW3 is switched in the reverse order when the secondary battery B1, the capacitor C2, and the secondary battery B2 are connected in parallel. The switch control signal input to .about.SW6 is switched from the high level to the low level. That is, first, the switch control signal input to the switch SW6 is switched from the high level to the low level, and the positive side of the capacitor C2 and the positive side of the secondary battery B2 are disconnected. Subsequently, when the switch control signal input to the switch SW5 is switched to the low level, the series connection between the capacitor C2 and the secondary battery B1 is disconnected. Next, when the switch control signals input to the switches SW4 and SW3 are sequentially switched to the low level, the capacitor C2 and the secondary battery B1 are connected in parallel after the capacitor C2 is grounded (period in FIG. 4). (D)). By this switching, power is supplied again from the secondary battery B1 to the capacitor C2 whose voltage has been reduced by supplying power to the secondary battery B2. At this time, the output voltage of the secondary battery B1 temporarily decreases due to the potential difference between the positive electrode side of the secondary battery B1 and the positive electrode side of the capacitor C2 and the current flowing to the capacitor C2 due to this potential difference. As the capacitor C2 is charged, the output voltage VB1 of the secondary battery B1 is recovered. Here, when the secondary battery B1 is not charged from the solar cell 11, the output voltage VB1 of the secondary battery B1 after recovery is slightly lower than before the parallel connection with the capacitor C2. (Period (e) in FIG. 4).

  Note that the intervals at which the switches SW3 to SW6 are switched in the periods (b) and (d) of FIG. 4 are set as appropriate, and can be performed substantially simultaneously, for example, as long as the order is not changed.

  By repeating the connection switching operation between the capacitor C2 and the secondary batteries B1 and B2 while the switch SW1 is turned on (periods (f) to (i) in FIG. 4), Power is gradually supplied from the secondary battery B1 to the secondary battery B2 via the capacitor C2, and the voltage VB1 of the secondary battery B1 decreases and the voltage VB2 of the secondary battery B2 increases.

  FIG. 5 is a diagram for explaining a circuit configuration of a second specific example of the voltage conversion unit. FIG. 6 is a diagram showing a switching procedure of switch control signals sent to the switches SW3 to SW5 and a change in voltage output from the secondary batteries B1 and B2 in the specific example 2 of the voltage conversion unit. It is.

  As shown in FIG. 5, the voltage conversion unit 14 includes three switches SW3 to SW5 and two capacitors C2 and C3. The three resistors R3 to R5 are switch resistors of the switches SW3 to SW5, respectively, and further include a resistor R2. The capacitor C1 is backup power storage means for preventing the secondary battery B1 from being overloaded. The states of the switches SW <b> 3 to SW <b> 5 shown in FIG. 5 indicate the states when a low level signal is input from the LSI 104.

  The switches SW3 to SW5 in the charge pump circuit of the voltage converter 14 operate as shown in FIG. That is, when the switch control signal input to the switches SW3 to SW5 is at a low level and the switch SW1 is turned on, the capacitors C2 and C3 are connected to the secondary battery B1 via the switches SW4 and SW5. Capacitors C2 and C3 are charged by being connected in parallel. The other end of the capacitor C2 is grounded via the switch SW3, and the other end of the capacitor C3 is grounded via the resistor R2 (period (a) in FIG. 6).

  Next, switching operations of the switches SW3 to SW5 are sequentially performed while the capacitors C2 and C3 are charged. First, the switch control signal input to the switch SW3 is switched to a high level, whereby the capacitor C2 is disconnected from the ground and enters a floating state. Subsequently, the capacitor C2 is connected to the secondary battery B2 by switching the switch control signal input to the switch SW4 to the high level (period (b) in FIG. 6).

  Finally, by switching the switch control signal input to the switch SW5 to the high level, the capacitor C3 and the capacitor C2 are connected in series, and the potential on the positive side of the capacitor C2 is applied to the voltage applied to the capacitor C2 and the capacitor C3. The voltage rises to the added value. For example, when the output voltage VB1 of the secondary battery B1 and the voltage applied to the capacitors C2 and C3 are equal, the potential on the positive side of the capacitor C2 when the capacitors C2 and C3 are connected in series is the output voltage of the secondary battery B1. The value is twice that of VB1. And electric power is supplied to the secondary battery B2 from the capacitors C2 and C3 connected in series. At this time, the positive electrode side potential of the secondary battery B2 rises at the moment when the capacitor C2 and the capacitor C3 are connected in series, but the capacitance of the capacitor C2, the resistance value of the switch resistor R4, and the secondary battery B2 The potential difference between the positive electrode side of the capacitor C2 and the positive electrode side of the secondary battery B2 will eventually be caused by the current flowing in the direction from the capacitors C2 and C3 to the secondary battery B2 based on the time constant determined by the internal resistance of the capacitor C2. It becomes zero. At this time, the output voltage VB2 of the secondary battery B2 is slightly increased according to the amount of power supplied from the capacitor C2 as compared with the voltage before being connected to the capacitor C2 (period (c) in FIG. 6). ).

  After the potential on the positive electrode side of the capacitor C2 and the potential on the positive electrode side of the secondary battery B2 are substantially equal, the switches SW3 to SW5 are configured so that the capacitors C2 and C3 connected in series and the secondary battery B2 are connected in parallel. It can be switched in the reverse order of connection. And the capacitors C2 and C3 are returned to the state connected in parallel with the secondary battery B1 (period (d) of FIG. 6).

  In the period (d) of FIG. 6, the switch control signals input to the switches SW5 and SW4 are sequentially switched to the low level, and the capacitors C2 and C3 are connected to the secondary battery B1 at the timing of the secondary battery B1. The output voltage VB1 decreases for a moment when current flows from the secondary battery B1 to the capacitors C2 and C3. Thereafter, the potential difference between the secondary battery B1 and the capacitors C2 and C3 converges to zero. Then, the switch control signal input to the switch SW3 is switched to the low level, and the capacitor C2 is grounded. At this time, the output voltage VB1 of the secondary battery B1 is switched to the low level when the power is not supplied from the solar cell 11 to the secondary battery B1, and the secondary battery B1 is connected to the capacitor C3. It is slightly lower than the previous output voltage.

  While the switch SW1 is turned on, the output voltage VB2 of the secondary battery B2 gradually increases by repeating the switching operation of the capacitors C2 and C3 and the secondary batteries B1 and B2. The output voltage VB1 of the secondary battery B1 gradually decreases (periods (f) to (i) in FIG. 6).

  In the switch switching operation (periods (b) and (d) in FIG. 6) in the specific example 2 of the voltage conversion unit 14, the interval of each switching operation is changed within a range where the switching order is not switched. be able to.

  Next, the setting of the charging period of the secondary battery B2 and the operable period of the additional function unit 109 will be described.

  FIG. 7 is a schematic diagram showing a voltage change of the secondary battery B1 during the charging period of the secondary battery B2.

  Whether or not the secondary battery B2 can be charged and whether or not the additional function unit 109 can be operated are set by the LSI 104 operating the switches SW1 and SW2 based on the output signals of the BLDs 12 and 13.

  When the power supply from the solar cell 11 to the secondary battery B1 is slower than the power supply from the secondary battery B1 to the secondary battery B2, or when no power is supplied from the solar cell 11 to the secondary battery B1. As shown in FIG. 7, when the charging operation from the secondary battery B1 to the secondary battery B2 through the voltage converter 14 is repeated while the switch SW1 is on, the output voltage VB1 of the secondary battery B1 is The voltage gradually decreases while repeating the short voltage drop shown in FIGS. 4 (e) and 6 (d). When the output voltage VB1 of the secondary battery B1 becomes less than the lower limit set voltage V1L, the signal indicating the voltage comparison result output from the BLD 12 connected in parallel to the secondary battery B1 to the LSI 104 changes. The LSI 104 stops the charging operation of the secondary battery B2 by the secondary battery B1 by turning off the switch SW1 based on the input signal from the BLD 12. When the secondary battery B1 is charged by the solar cell 11 and the output voltage VB1 gradually recovers, first, the output voltage VB1 of the secondary battery B1 becomes equal to or higher than the lower limit setting voltage V1L, and finally the charging setting voltage of the secondary battery B1. V1H or higher. The LSI 104 restarts the charging operation of the secondary battery B2 by turning on the switch SW1 again based on a signal from the BLD 12 indicating that the output voltage VB1 of the secondary battery B1 is equal to or higher than the charge setting voltage V1H. Alternatively, the timing for resuming the charging operation of the secondary battery B2 may be set to the set voltage V1M that is lower than the charge set voltage V1H and equal to or higher than the lower limit set voltage V1L, not the comparison with the charge set voltage V1H.

  Similarly, when the additional function unit 109 operates with the switch SW2 turned on based on the switch control signal input from the LSI 104, power is supplied from the secondary battery B2 to the additional function unit 109, and the secondary battery The output voltage VB2 of B2 gradually decreases. When the BLD 13 detects that the output voltage VB2 has dropped below the lower limit setting voltage V2L, the LSI 104 sends a switch control signal for turning off the switch SW2 based on a signal input from the BLD 13 to the LSI 104. . Then, the operation of the additional function unit 109 is prohibited by turning off the switch SW2. At this time, if the output voltage VB1 of the secondary battery B1 is in a state from the time when the voltage equal to or higher than the charge setting voltage V1H is measured until the voltage lower than the lower limit setting voltage V1L is measured, the LSI 104 switches the switch SW1. To turn on the secondary battery B2. Then, the output voltage VB2 of the secondary battery B2 gradually increases. When the output voltage VB2 of the secondary battery B2 becomes equal to or higher than the lower limit set voltage V2L and finally recovers to the charge set voltage V2H or higher of the secondary battery B2, the output voltage VB2 of the secondary battery B2 is equal to or higher than the charge set voltage V2H. A signal from the BLD 13 is input to the LSI 104. Then, the LSI 104 outputs a switch control signal for turning on the switch SW2 again based on this input signal. As a result, the operation of the additional function unit 109 is permitted. At this time, the setting voltage for turning on the switch SW2 may be not the charging setting voltage V2H but a setting voltage V2M lower than the charging setting voltage V2H and equal to or higher than the lower limit setting voltage V2L.

  FIG. 8 shows on / off switching states of the switches SW1 and SW2 based on the output voltages VB1 and VB2 of the secondary batteries B1 and B2 detected by the BLDs 12 and 13, and whether or not the secondary battery B2 can be charged and the additional function unit 109. 6 is a table summarizing whether or not these operations are possible.

  First, as to whether or not the additional function operation is possible, the switch SW2 is turned off during the period from when the output voltage VB2 of the secondary battery B2 becomes less than the lower limit set voltage V2L to when it becomes the charge set voltage V2H or more. Operation is not allowed. During a period from when the output voltage VB2 of the secondary battery B2 becomes equal to or higher than the charge setting voltage V2H to when it becomes lower than the lower limit setting voltage V2L, the switch SW2 is turned on and the additional function operation is permitted. When the output voltage VB2 of the secondary battery B2 is equal to or higher than the charge setting voltage V2H and the output voltage VB1 of the secondary battery B1 is less than the lower limit setting voltage V1L, the additional function operation is not permitted. Also good. Further, whether or not the additional function can be operated may be set by the user based on an operation input signal from the operation unit 108. Further, even when the additional function operation is permitted, the switch SW2 may not be turned on except during a period in which the additional function unit 109 operates based on an operation input signal from the operation unit 108.

  On the other hand, regarding whether or not the charging operation of the secondary battery B2 is possible, the switch SW1 is turned off during the period from when the output voltage VB1 of the secondary battery B1 becomes less than the lower limit setting voltage V1L to when it becomes the charging setting voltage V1H or more. Thus, charging of the secondary battery B2 by the secondary battery B1 is prohibited. In the period from when the output voltage VB1 of the secondary battery B1 becomes equal to or higher than the charge setting voltage V1H until it becomes lower than the lower limit setting voltage V1L, switching of the switch is further determined by the output voltage VB2 of the secondary battery B2. That is, during the period from when the output voltage VB2 of the secondary battery B2 is less than the lower limit set voltage V2L to when the output voltage V2H becomes equal to or higher than the charge set voltage V2H, the switch SW1 is turned on and the secondary battery B1 is charged by the secondary battery B1. The Further, the switch SW1 is turned off and the secondary battery B2 is not charged during the period from when the output voltage VB2 of the secondary battery B2 is equal to or higher than the charge setting voltage V2H to below the lower limit setting voltage V2L.

  FIG. 9 is a flowchart showing switching control processing of the switches SW1 and SW2 by the CPU of the LSI 104.

  This switch switching control processing by the CPU of the LSI 104 is automatically started when the power is turned on, and is continuously executed while the LSI 104 continues to operate.

  When the switch switching control process is started, the CPU first determines whether or not the output voltage VB2 of the secondary battery B2 is less than the lower limit set voltage V2L based on the input signal from the BLD 13 (step S21). If it is determined that the output voltage VB2 of the secondary battery B2 is less than the lower limit setting voltage V2L, the process proceeds to step S23, and the CPU sends a low level switch control signal to the switch SW2 to turn off the switch SW2. To do. Then, the CPU sets the additional function operation prohibited state (step S24). This state setting is executed by providing a flag and storing it in the RAM of the LSI 104, for example. Thereafter, the processing of the CPU proceeds to step S31.

  On the other hand, when it is determined that the output voltage VB2 of the secondary battery B2 is equal to or higher than the lower limit set voltage V2L, the processing of the CPU proceeds to step S22, and then the CPU outputs the output voltage of the secondary battery B2. It is determined whether or not VB2 is equal to or higher than the charge setting voltage V2H. When it is determined that the output voltage VB2 of the secondary battery B2 is equal to or higher than the charge setting voltage V2H, the CPU sends a low level switch control signal to the switch SW1 to turn off the switch SW1 (step S25). Then, the additional function is set in an operable state (step S26). Then, the CPU sends a high level switch control signal to the switch SW2 to turn on the switch SW2 (step S27). Then, the processing of the CPU proceeds to step S31.

  If it is determined in step S22 that the output voltage VB2 of the secondary battery B2 is less than the charge setting voltage V2H, the processing of the CPU proceeds directly to step S31.

  When the processing of the CPU proceeds to step S31, the CPU determines whether or not the output voltage VB1 of the secondary battery B1 is less than the lower limit setting voltage V1L. When it is determined that the output voltage VB1 of the secondary battery B1 is less than the lower limit set voltage V1L, the CPU sends a low level switch control signal to the switch SW1 to turn off the switch SW1 (step S33), The secondary battery B2 is set in a charging prohibited state (step S34). Then, the processing of the CPU returns to step S21.

  On the other hand, when it is determined that the output voltage VB1 of the secondary battery B1 is not less than the lower limit set voltage V1L, the CPU subsequently determines whether or not the output voltage VB1 of the secondary battery B1 is equal to or higher than the charge set voltage V1H. Is determined (step S32). When it is determined that the output voltage VB1 of the secondary battery B1 is equal to or higher than the charge setting voltage V1H, the CPU sets the secondary battery B2 in a chargeable state (step S35), and then proceeds to the process of step S36. Transition. If it is determined that the output voltage VB1 of the secondary battery B1 is not equal to or higher than the charge setting voltage V1H, the processing of the CPU proceeds to step S36 as it is.

  In step S36, the CPU determines whether or not the secondary battery B2 is in a chargeable state and is in an additional function operation prohibited state. If it is determined that the secondary battery B2 can be charged and the additional function operation is prohibited, the CPU sends a high-level switch control signal to the switch SW1 to turn on the switch SW1 (step S1). S37). Then, the processing of the CPU returns to step S21. If it is determined that the secondary battery B2 is not in a chargeable state or is not in an additional function operation prohibited state, the CPU processing returns directly to step S21.

As described above, according to the power supply unit 110 as the embodiment of the power supply device of the present invention,
The secondary battery B1, the solar cell 11 that supplies power to the secondary battery B1, the secondary battery B2 that can supply power at a higher power than the secondary battery B1, and the output voltages of the secondary batteries B1 and B2, respectively. The measurement results of the BLDs 12 and 13 to be measured, the switch SW1 for switching on / off the power supply from the secondary battery B1 to the secondary battery B2, the switch SW2 for switching on / off of the power supply by the secondary battery B2, and the BLDs 12 and 13 And the LSI 104 that controls switching of the switches SW1 and SW2, and the LSI 104 detects that the output voltage of the secondary battery B1 is less than the lower limit setting voltage V1L by the BLD 12, and the secondary by the BLD 13. When it is detected that the output voltage of the battery B2 is equal to or higher than the charge setting voltage V2H, the switch SW1 is turned off. A configuration in which power supply to the secondary battery B2 is prohibited, and when the BLD 13 detects that the output voltage of the secondary battery B2 is less than the lower limit setting voltage V2L, the switch SW2 is turned off to prohibit power supply Therefore, even when a large amount of power is output from the secondary battery B2 to the functional unit having a large load, the output from the secondary battery B1 can be stably continued. In addition, since the secondary battery B2 is charged only during a period when the secondary battery B1 is sufficiently charged, the output power of the secondary battery B1 is ensured.

  Further, when the output voltage VB2 of the secondary battery B2 is less than the voltage V2L at which the minimum operation unit in the additional function unit can be executed, the power supply from the secondary battery B2 is prohibited. The operation during the operable period can be performed reliably.

  In addition, when the output voltage VB1 of the secondary battery B1 measured by the BLD 12 becomes less than the lower limit setting voltage V1L, the LSI 104 turns off the switch SW1 until the output voltage VB1 becomes equal to or higher than the charging setting voltage V1H. Thus, since the secondary battery B2 is not charged, the output voltage VB1 of the secondary battery B1 can be quickly recovered from the lower limit setting voltage V1L.

  Further, when the output voltage VB2 of the secondary battery B2 measured by the BLD 13 becomes less than the lower limit set voltage V2L, the LSI 104 turns off the switch SW2 until the output voltage VB2 becomes equal to or higher than the charge set voltage V2H. As a result, the power supply by the secondary battery B2 is not performed, so that the output voltage of the secondary battery B2 can be quickly recovered, and after the output voltage VB2 of the secondary battery B2 has sufficiently recovered, The additional function can be reliably executed by the electric power supplied from the battery B2.

  Further, by using a sheet-like thin film battery (paper battery) as the secondary battery B2, it is possible to cope with an additional function that is executed for a short time without increasing the volume occupied by the power supply unit 110. Further, an additional function with a large load can be executed without increasing the size of a portable device such as the electronic timepiece 100 on which the power supply unit 110 is mounted.

  In addition, since the voltage converter 14 that boosts the output voltage VB1 of the secondary battery B1 by the charge pump circuit is provided, boosting can be performed with a small and simple circuit configuration. In addition, since the amount of electricity stored in the capacitors C2 and C3 at the same voltage is small compared to the electric capacity of the secondary batteries B1 and B2, a little load is not applied to the secondary batteries B1 and B2 due to inrush current or the like. The secondary battery B2 can be charged one by one.

  Further, the voltage converter 14 boosts the output voltage VB1 supplied from the secondary battery B1, and the voltage converter 15 reduces the output voltage VB2 supplied from the secondary battery B2, so that the secondary battery B1 is used. A lithium-ion battery having a 2.3V output voltage used in a conventional analog electronic watch is used, and a thin-film lithium battery having a 4.1V output voltage with good load characteristics is used as the secondary battery B2. Thus, it is possible to execute an additional function with a large load without greatly changing the internal configuration and structure of the conventional analog electronic timepiece.

  Further, by mounting the power supply unit 110 as described above on the analog electronic timepiece 100, a load such as a GPS positioning function can be performed while stably and continuously performing the timepiece operation without increasing the size of the electronic timepiece 100. Large additional functions can be executed.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, in the said embodiment, although electric power was supplied to secondary battery B1 by solar power generation using a solar cell, it is not restricted to this. For example, other power generation means such as power generation by vibration may be used.

  In the power supply unit 110 of the above embodiment, when the secondary battery B2 is charged by the secondary battery B1, the voltage conversion unit 14 boosts the voltage and by the voltage conversion unit 15 when power is supplied from the secondary battery B2. In the case where the secondary battery B2 having the output voltage suitable for the output voltage is available, the voltage conversion unit 15 is not necessary. The voltage conversion unit 14 may be used for step-down. When the output voltage VB1 of the secondary battery B1, the output voltage VB2 of the secondary battery B2, and the input voltage of the additional function unit 109 are all equal, the voltage conversion unit 14 does not need to perform voltage conversion. In this case, the voltage conversion unit 14 may not be included, and the secondary battery B2 may be charged little by little using two switches and a capacitor.

  In the above embodiment, the switch of the power supply unit 110 is controlled using the LSI 104 for clock operation, but an independent control unit used for the power supply unit 110 may be provided.

  In the above-described embodiment, the power supply unit 110 mounted on the analog pointer-type electronic timepiece 100 has been described as an example. For example, an electronic compass or an electronic altimeter provided with a similar pointer driving mechanism may be used, or a digital electronic timepiece or pedometer may be used.

Moreover, although the GPS positioning function was mentioned as an example as a function of the additional function part 109, it is not restricted to this. It can be used for other wireless communication transmission / reception functions, and various arithmetic functions can be executed.
In addition, details such as specific configurations and numerical values shown in the above embodiment can be changed as appropriate without departing from the spirit of the present invention.

  As described above, several embodiments of the present invention have been described. However, the power supply apparatus and the electronic timepiece of the present invention are included in the invention described in the claims and the equivalent scope thereof. Hereinafter, the invention described in the scope of claims of the present application will be appended.

The first invention is
A low-load secondary battery capable of supplying power at a predetermined voltage;
Power generation means for supplying power to the low-load secondary battery;
A high-load secondary battery capable of supplying power at a higher power than the low-load secondary battery;
Voltage detection means for measuring the output voltage of the secondary battery for low load and the output voltage of the secondary battery for high load;
First switching means for switching on / off of power supply from the low-load secondary battery to the high-load secondary battery;
Second switching means for switching on / off of power supply by the high-load secondary battery;
Control means for controlling the first switching means and the second switching means based on the measurement result by the voltage detection means;
With
The control means includes
When the voltage detection means detects that the output voltage of the low load secondary battery is lower than a predetermined low load lower limit voltage, and the output voltage of the high load secondary battery is predetermined. When it is detected that the voltage is higher than the set high load voltage, the first switching means is turned off,
When the voltage detecting means detects that the output voltage of the high load secondary battery is less than the predetermined high load lower limit voltage below the high load set voltage, the second switching means is turned off. It is a power supply device characterized by these.

A second invention is the power supply device of the first invention, wherein
The control means includes
When the voltage detection means detects that the output voltage of the low-load secondary battery is less than the low-load lower limit voltage, the output voltage is a low load that is predetermined above the low-load lower-limit voltage. The first switching means is turned off until a value equal to or higher than a set voltage is obtained.

A third invention is the power supply device of the first invention or the second invention.
The control means includes
When it is detected by the voltage detecting means that the output voltage of the secondary battery for high load is less than the high load lower limit voltage, the output voltage is until the output voltage becomes a value equal to or higher than the high load set voltage. The second switching means is turned off.

4th invention is a power supply device in any one of 1st-3rd invention,
As the high-load secondary battery, a sheet-like one is used.

A fifth invention is the power supply device according to any one of the first to fourth inventions,
There is provided boosting means for boosting the output voltage of the low load secondary battery by a charge pump circuit.

A sixth invention is the power supply device of the fifth invention, wherein
A step-down means for stepping down the output voltage of the high-load secondary battery is provided.

The seventh invention
Any one of the power supply devices of the first to sixth inventions;
A time counting means for counting time;
A plurality of pivotable pointers;
Driving means for driving the plurality of hands;
An additional function unit that performs a predetermined operation with the power supplied from the high-load secondary battery;
With
The control means operates with electric power supplied from the low-load secondary battery, and operates the driving means based on time data counted by the time measuring means.

11 Solar cells 12, 13 BLD
14, 15 Voltage conversion unit 100 Electronic timepiece 101 Oscillation circuit 102 Frequency division circuit 103 Timekeeping circuit 104 LSI (timepiece control unit)
105 Drive unit 106 Train wheel mechanism 107 Pointer 108 Operation unit 109 Additional function unit 110 Power supply unit B1, B2 Secondary batteries C1, C2, C3 Capacitor D1 Backflow prevention diodes R2-R6 Resistors SW1-SW6 Switches V1H, V2H Charge setting voltage V1L , V2L lower limit setting voltage

Claims (7)

A low-load secondary battery capable of supplying power at a predetermined voltage;
Power generation means for supplying power to the low-load secondary battery;
A high-load secondary battery capable of supplying power at a higher power than the low-load secondary battery;
Voltage detection means for measuring the output voltage of the secondary battery for low load and the output voltage of the secondary battery for high load;
First switching means for switching on / off of power supply from the low-load secondary battery to the high-load secondary battery;
Second switching means for switching on / off of power supply by the high-load secondary battery;
Control means for controlling the first switching means and the second switching means based on the measurement result by the voltage detection means;
With
The control means includes
When the voltage detection means detects that the output voltage of the low load secondary battery is lower than a predetermined low load lower limit voltage, and the output voltage of the high load secondary battery is predetermined. When it is detected that the voltage is higher than the set high load voltage, the first switching means is turned off,
When the voltage detecting means detects that the output voltage of the high load secondary battery is less than the predetermined high load lower limit voltage below the high load set voltage, the second switching means is turned off. A power supply device characterized by that. The control means includes
When the voltage detection means detects that the output voltage of the low-load secondary battery is less than the low-load lower limit voltage, the output voltage is a low load that is predetermined above the low-load lower-limit voltage. The power supply apparatus according to claim 1, wherein the first switching unit is turned off until a value equal to or higher than a set voltage. The control means includes
When it is detected by the voltage detecting means that the output voltage of the secondary battery for high load is less than the high load lower limit voltage, the output voltage is until the output voltage becomes a value equal to or higher than the high load set voltage. The power supply apparatus according to claim 1, wherein the second switching unit is turned off. The power supply device according to any one of claims 1 to 3, wherein a sheet-like battery is used as the high-load secondary battery. The power supply device according to any one of claims 1 to 4, further comprising boosting means for boosting an output voltage of the low-load secondary battery by a charge pump circuit. The power supply apparatus according to claim 5, further comprising step-down means for stepping down the output voltage of the high-load secondary battery. The power supply device according to any one of claims 1 to 6,
A time counting means for counting time;
A plurality of pivotable pointers;
Driving means for driving the plurality of hands;
An additional function unit that performs a predetermined operation with the power supplied from the high-load secondary battery;
With
The electronic timepiece is characterized in that the control means is operated by electric power supplied from the low-load secondary battery and operates the driving means based on time data counted by the time measuring means.

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