JPH11206031A - Power feeding method of chopper circuit, the chopper circuit, chopper-type charging circuit, electronic equipment and wrist watch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce current to be consumed for the control of a chopper-type charging circuit. SOLUTION: When it is detected by a power generation detecting section 10 that an AC power generator AG is in the power generating condition, unidirectional units 3, 4 are fed. Thereafter, when voltages of the output terminal AG1, AG2 exceed reference voltages Vref1, Vref2, the unidirectional units 1, 2 are fed. When the voltages of the output terminals AG1, AG2 exceed the voltage of power supply Vdd, a charging current is supplied to a voltage boosting section 30, via the power supply Vdd and a spike-form electromotive voltage is boosted and is then accumulated. Therefore, since power feeding to the unidirectional units 1 to 4 can be controlled depending on the electromotive voltage condition, current dissipation can be saved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply method for a chopper circuit suitable for reducing current consumption during standby.
The present invention relates to a chopper circuit, a chopper-type charging circuit, and an electronic device and a wristwatch using the same.

[0002]

2. Description of the Related Art A bridge-type charging circuit is known as a charging circuit for charging a capacitor or a battery with an AC voltage generated by a generator. FIG. 7 is a circuit diagram of a conventional charging circuit. In this charging circuit, the comparators COM1 and COM2 compare the voltages of the output terminals A and B of the generator AG with the voltage of the power supply Vdd, and compare the voltages of the output terminals A and B of the generator AG with the voltage of the ground GND. Comparator COM
3, COM4, and a large-capacity capacitor C for storing a charging current are provided. And each comparator COM1
~ P4 FETs P1, P2, N
1, ON / OFF of N2 is controlled.

[0003] Here, the voltage of the output terminal A is equal to the ground GND.
, The N-channel FET N1 is turned on by the comparator COM3, and the output terminal A is grounded. When the voltage of the output terminal B exceeds the voltage of the power supply Vdd, the comparator COM2 sets the P-channel FET
P2 is turned on, and the electric charge is charged in the capacitor C along the path indicated by the arrow. In this case, as long as the voltage of the output terminal B does not exceed the voltage of the power supply Vdd, the P-channel FET P2 does not turn on. Has become.

As described above, in the conventional charging circuit,
Combining field effect transistors and comparators,
A unidirectional unit that allows current to flow in one direction under certain conditions is configured, thereby increasing charging efficiency.

[0005]

In a charging circuit using a one-way unit, since the on / off of each field effect transistor is controlled by a comparator, it is necessary to always operate the comparator. . Therefore, there is a problem that the comparator consumes current during a period in which the generator AG does not generate power or a period in which the electromotive voltage is too small to charge even if power is generated, and the charging efficiency is reduced.

The present invention has been made in view of the above circumstances, and has as its object to improve charging efficiency with a simple configuration in a chopper-type charging circuit using a one-way unit. Another object is to apply the chopper type charging circuit to an electronic device or a wristwatch.

[0007]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, the first switch is compared with the voltage between its output terminals by comparing the first switch with the voltage between its output terminals. The first control means for controlling the on / off of the switch means, the second switch means, and the voltage of the output terminal of the AC generator are compared with a reference voltage to detect whether or not the charging condition is satisfied. A second control means for controlling on / off of the second switch means based on a result of the detection, wherein a power supply method of a chopper circuit for converting an electromotive voltage of the AC generator into a chopper voltage is provided. By monitoring the voltage at the output terminal of the generator, the power generation state of the AC generator is detected, and when the power generation state is detected, power is supplied to the second control means, and the second control is started. Charged by means When it is detected that satisfies the condition, characterized in that it starts to supply power to the first control means. In the invention according to claim 2, when power supply to the second control means is started, power supply to the first and second control means is continued for a predetermined time. I do.

[0008] Further, in the invention according to claim 3,
First switch means, first control means for controlling on / off of the first switch means by comparing a voltage between its output terminals, second switch means, and an output of the alternator; A second control unit for detecting whether the charging condition is satisfied by comparing the voltage of the terminal with a reference voltage, and controlling on / off of the second switch unit based on the detection result; In a chopper circuit that converts an electromotive voltage of the AC generator into a chopper voltage, a power generation detecting unit that detects a power generation state of the AC generator by monitoring a voltage of an output terminal of the AC generator; When the power generation state is detected by the means, the second
And a power supply control means for starting power supply to the first control means when it is detected by the second control means that the charging condition is satisfied. And Further, in the invention according to claim 4, when the power supply control unit starts supplying power to the second control unit, the power supply control unit continues supplying power to the first and second control units for a predetermined time. It is characterized by the following.

Further, in the invention according to claim 5,
First and second switch means respectively provided between the first line and both output terminals of the alternator, and respective first and second switch means provided between the second line and both output terminals of the alternator. The third and fourth switch means compares the voltage of the first line with both output terminal voltages of the AC generator to control the on / off of the first and second switch means. First and second comparing means, and comparing a potential difference between both output terminals of the AC generator and the second line with a reference potential difference to turn on / off the third and fourth switch means. In a power supply method for a chopper circuit including third and fourth comparing means for controlling, a potential difference between each output terminal of the AC generator and the second line is compared with a potential difference smaller than the reference potential difference. This allows the alternator to Determines whether the state, when the AC generator is determined to be in the power generation state, and starts to supply power to the third and fourth comparing means, after this, the third
And when the fourth comparing means detects that one of the output terminals of the AC generator has exceeded the reference voltage, power supply to the first and second comparing means is started. It is characterized by the following.

[0010] In the invention according to claim 6,
The electromotive force generated by the AC generator is converted into a chopper voltage synchronized with the clock signal, and the first line and the second
In the chopper circuit generated between the second line and the second line, by detecting whether or not the potential difference between one or the other output terminal of the AC generator and the second line exceeds a first reference potential difference Power generation detection means for detecting the power generation state of the AC generator, first comparison means for comparing the voltage of the first line and the voltage of the one output terminal,
The output terminal is provided between the one output terminal and the first line, and is turned on and off based on a comparison result of the first comparison means.
A first switch means that is controlled to be off, a second comparison means for comparing the voltage of the first line with the voltage of the other output terminal, and the other output terminal and the first line; And a second switch means, which is turned on and off based on a comparison result of the second comparison means, and a potential difference between the other output terminal and the second line. Third comparing means for comparing the reference potential difference with the second reference potential difference;
Fourth comparison means for comparing a potential difference between the one output terminal and the second line with a third reference potential difference, provided between the one output terminal and the second line;
When the third comparison means detects that the potential difference of the other output terminal exceeds the second reference potential difference, it is turned on, and the fourth comparison means reduces the potential difference of the one output terminal. A third switch for turning on and off based on the clock signal when it is detected that the potential exceeds the third reference potential difference, and a third switch between the other output terminal and the second line; And turned on when the fourth comparing means detects that the potential difference of the one output terminal exceeds the third reference potential difference, and the third comparing means turns on the other output terminal. And a fourth switch for controlling on / off based on the clock signal when it is detected that the potential difference between the terminals exceeds the second reference potential difference. When power is constantly supplied and power generation is detected by the power generation detection unit, power supply to the third comparison unit and the fourth comparison unit is started, and the output is output by the third or fourth comparison unit. When it is detected that the potential difference between the terminals exceeds the second or third reference voltage, power supply to the first comparing means and the second comparing means is started.

Further, in the invention according to claim 7,
The first line is a power supply line, and the second line is a ground. Further, in the invention according to claim 8, the first line is a ground, and the second line is a power supply line.

[0012] In the invention according to claim 9,
In the chopper circuit, the current consumption of the third and fourth comparison means is lower than the current consumption of the first and second comparison means, and the current consumption of the power generation detection means is reduced by the third and fourth comparison means. It is characterized in that it is set lower than the current consumption of the means. Further, in the invention according to claim 10, the chopper circuit, a booster circuit connected to the power supply line and the ground of the chopper circuit, boosts the chopper voltage and stores the boosted voltage. Characterized in that it is a chopper-type charging circuit provided with:

[0013] The invention according to claim 11 is characterized in that the chopper-type charging circuit is built-in, and the electronic device is operated by electric power supplied from the chopper-type charging circuit. . Claim 1
In the invention described in 2, the chopper-type charging circuit, and a clock circuit that is supplied with power from the chopper-type charging circuit and measures time, the clock signal is sent from the clock circuit to the chopper-type charging circuit. It is a watch to be supplied.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wristwatch to which a chopper type charging circuit is applied will be described as an embodiment of the present invention. 1. Configuration of Embodiment FIG. 1 is a circuit diagram of a chopper-type charging circuit used in a wristwatch according to the present embodiment. Chopper type charging circuit 10
0 denotes a power generation detection unit 10 for detecting the presence or absence of a power generation state of the AC generator AG, a chopper circuit 20 for converting an electromotive voltage of the AC generator AG into a pulse-like chopper voltage, and a chopper voltage obtained by the chopper circuit 20. And a booster 30 that stores the boosted voltage.

First, the configuration of the main part of the chopper circuit will be described. The unidirectional unit 1 includes a P-channel FET P1,
It comprises a comparator COM1 and switches S1 and S2. The positive input terminal of the comparator COM1 is connected to the power supply Vdd, and its negative input terminal is the output terminal AG1 of the AC generator AG.
It is connected to the. Therefore, when the voltage of the power supply Vdd exceeds the voltage of the output terminal AG1, the signal φP1 becomes low level and the P-channel FET P1 is turned on. On the other hand, the power supply Vd
When the voltage of d becomes lower than the voltage of the output terminal AG1, the signal φP1
Becomes high level, and the P-channel FET P1 is turned off. Therefore, the unidirectional unit 1 is connected to the output terminal AG
A current is supplied from the output terminal AG1 to the power supply Vdd only when the voltage of the power supply Vdd exceeds the voltage of the power supply Vdd.

Next, the one-way unit 2 has the same configuration as the one-way unit 1 described above, and the output terminal A
The current is supplied from the output terminal AG2 to the power supply Vdd only when the voltage of G2 exceeds the voltage of the power supply Vdd.

Here, in consideration of the charging efficiency, it is desirable to turn on the P-channel FETs P1 and P2 as soon as the voltage of the output terminals AG1 and AG2 of the AC generator AG exceeds the voltage of the power supply Vdd. Therefore, the comparators COM1, COM1,
The current consumption of COM2 is relatively large, so that it can cope with high-speed operation. However, during the period when the AC generator AG is not generating power or during the period when the electromotive voltage is small even if the power is generated, charging is not possible even if the voltage is boosted, so that there is no need to operate the comparators COM1 and COM2. Therefore, in the present embodiment, the switches S1 and S2 are provided inside the one-way unit 1, and the switches S1 and
3 and S4 are provided and controlled by the signal φS to reduce the current consumption of the comparators COM1 and COM2.

Here, the switch S1 is a P-channel FE
The switch S2 is provided between the negative power supply terminal of the comparator COM1 and the ground GND between the gate of TP1 and the power supply Vdd. The switches S1 and S2 are configured such that the switch S1 is turned on and the switch S2 is turned off when the signal φS goes high, and the switch S1 is turned off and the switch S2 is turned on when the signal φS goes low. Therefore, when the signal φS is made low, the comparator C
Power is supplied to OM1, and ON / OFF of the P-channel FET P1 is controlled according to the comparison result. On the other hand, the signal φ
When S goes high, power supply to the comparator COM1 is cut off and the P-channel FET P1 is turned off. That is, the unidirectional unit 1 is controlled by the signal φS.
Can be controlled, and when not operated, the current consumption of the comparator COM1 can be reduced.

The switch S3 of the one-way unit 2
Corresponds to the switch S1 of the one-way unit 1, and the switch S4 of the one-way unit 2 corresponds to the switch S2 of the one-way unit 1. In this case, if the signal φS is at a low level, the power is supplied to the comparator COM2, and the P-channel F
ON / OFF of ETP1 is controlled. On the other hand, if the signal φS is at the high level, the power supply to the comparator COM2 is cut off, and the P-channel FET P2 is turned off. Therefore, the operation of the one-way unit 2 is controlled by the signal φS similarly to the one-way unit 1, and when not operated, the current consumption of the comparator COM2 can be reduced.

By the way, if a small and lightweight device such as a wristwatch incorporates the AC generator AG, the AC generator AG becomes very small, so that the output coil constituting the AC generator AG is formed. There is a certain limit on the size of. Since the electromotive voltage of the AC generator AG is proportional to the number of windings of the output coil, it is difficult to generate a high voltage by such an AC generator AG. For this reason, even if the electromotive voltage of the AC generator AG is rectified, it is not possible to obtain a voltage sufficient for stably operating the components built in the wristwatch. Therefore, in the present embodiment, the unidirectional units 3 and 4 are chopper-operated to convert the electromotive voltage of the AC generator AG into a spike-shaped chopper voltage, which is stepped up by the step-up unit 30 to obtain a desired voltage. Voltage.
It should be noted that the booster 30 may have a known configuration such as a so-called voltage doubler circuit, and may be configured by combining a capacitor and a unidirectional unit, for example.

Next, the one-way unit 4 includes an N-channel FET N2, an OR circuit OR2, a comparator COM4, and switches S7 and S8. Comparator COM4
Is connected to the output terminal AG1 of the AC generator AG, and its negative input terminal is supplied with the reference voltage Vref1. The reference voltage Vref1 is set to a voltage slightly higher than the voltage of the ground GND. The relationship between the reference voltage Vref1 and the reference voltage Vref used for detecting the state of power generation by the power generation detection unit 10 will be described later.

In this case, when the voltage at the output terminal AG1 exceeds the reference voltage Vref1, the signal CN2 goes high, and when the voltage at the output terminal AG1 falls below the reference voltage Vref1, the signal CN2
Becomes low level. The OR circuit OR2 has the signal CN2
And a clock signal CLK1, where the logical sum of both signals is calculated. The operation result is supplied to the gate of the N-channel FET N2 as a signal φN2. Therefore, the N-channel FET N2 receives the signal CN2 or the clock signal CLK1.
If one of them goes high, it turns on, and if both signals go low, it turns off. The one-way unit 3 is configured similarly to the one-way unit 4.

Here, assuming that the AC generator AG is in a power generating state and the voltage of the output terminal AG1 is higher than the voltage of the output terminal AG2, the output terminal AG2 is connected to the N-channel FET.
While grounded by N2, N-channel FET N1 repeatedly turns on and off in synchronization with clock signal CLK1. As a result, the voltage of the output terminal AG1 fluctuates in a pulse shape. When this voltage exceeds the power supply Vdd, the charging current flows through the path of the alternator AG → P-channel FET P1 → power supply Vdd → boost unit 30 and the boost unit The voltage boosted at 30 is stored.

In the unidirectional unit 4, a switch S is provided between the gate of the N-channel FET N2 and the ground GND.
7 is provided, and a switch S8 is provided between the negative power supply terminal of the comparator COM4 and the ground GND.
When the signal φSL goes high, the switches S7 and S8 turn on the switch S7 and turn off the switch S8.
When the signal φSL becomes low level, the switch S7 is turned off,
The switch S8 is configured to be turned on. Therefore, when the signal φSL is set to low level, the comparator
Power is supplied to COM4, and the comparison operation is performed. On the other hand, when the signal φSL is made high, the comparator COM4
To the N-channel FET N2
Is turned off. Therefore, whether or not the one-way unit 4 is operated can be controlled by the signal φSL, and when not operated, the current consumption of the comparator COM4 can be reduced.

The switch S5 of the one-way unit 3
Corresponds to the switch S7 of the one-way unit 4, and the switch S6 of the one-way unit 3 corresponds to the switch S8 of the one-way unit 4. Here, if the signal φSL is at a low level, power is supplied to the comparator COM3, and according to the comparison result, the N-channel FE
ON / OFF of TN1 is controlled. On the other hand, if the signal φSL is at the high level, the power supply to the comparator COM3 is cut off, and the N-channel FET N1 is turned off.
Therefore, whether or not to operate unidirectional unit 3 can be controlled by signal φSL, and when not operated, current consumption of comparator COM3 can be reduced.

Next, the power generation detecting unit 10 for generating the signal φSL
Will be described. The power generation detection unit 10 includes an AC generator AG
Is compared with a predetermined threshold value, and when the threshold value is exceeded, it is determined that the AC generator AG is in the power generation state. For example, the AC generator AG is configured by a circuit shown in FIG. Is done.

In the figure, a positive input terminal of a comparator COM5 grounded via a resistor R1 is connected to an output terminal AG1, and a negative input terminal thereof is supplied with a reference voltage Vref. On the other hand, the positive input terminal of the comparator COM6, which is grounded via the resistor R2, is connected to the output terminal AG2, and its negative input terminal is supplied with the reference voltage Vref. The values of the resistors R1 and R2 are set to approximately 200 KΩ. In addition, the reference voltage Vref
So that it can detect whether or not
It is set to slightly exceed the voltage of GND.

Therefore, when one of the output signals of the comparators COM5 and COM6 becomes high level, it is possible to detect that the power is being generated. For this reason, the OR circuit 11 calculates the logical sum of the two signals, detects whether or not the AC generator AG is in the power generation state, and generates the signal φAG.

A signal .phi.S generated by a latch circuit 6, which will be described later, is supplied to one input terminal of the NOR circuit 13 via an inverting circuit 12, and the other input terminal is supplied to the other input terminal.
An output signal φAG of the OR circuit 11 is supplied, and the NOR circuit 13 generates a signal φSL based on these signals. The operation of the unidirectional units 3 and 4 is controlled by the signal φSL. Here, the signal φSL is generated in consideration of not only the output signal of the OR circuit 11 but also the signal φS because the operation speeds of the power generation detection unit 10 and the comparators COM3 and COM4 are set to be low, so that the power generation state is set. This is because charging cannot be performed in a case where the existing AC generator AG temporarily stops generating power and then immediately starts generating power. This will be described later.

Next, the NOR circuit NOR1 shown in FIG.
Based on N1 and the signal φN2, it is detected whether or not the voltages of the output terminals AG1 and AG2 have exceeded the reference voltages Vref1 and Vref2. Here, the reference voltages Vref1, Vref2 of the unidirectional units 3, 4
Is set to a value larger than the reference voltage Vref of the power generation detection unit 10. FIG. 3 shows the reference voltage Vref1 and the relationship between the reference voltage Vref and the voltage of the output terminal AG1. In the figure, if the voltage of the output terminal AG1 changes like Va, the voltage of the output terminal AG1 exceeds the reference voltage Vref at time ta, so that the signal φSL becomes low level and power is supplied to the comparator COM4. Thereafter, when the voltage Va of the output terminal AG1 rises and exceeds the reference voltage Vref1 at time tc, the output signal of the comparator COM4 becomes high level, and the voltage of the output terminal AG1 exceeds the reference voltage Vref1 by the NOR circuit NOR1. Is detected. On the other hand, assuming that the voltage of the output terminal AG1 changes like Vb, the voltage of the output terminal AG1 exceeds the reference voltage Vref at time tb, so that the power is supplied to the comparator COM4 but does not exceed the reference voltage Vref1. The output signal φN of the NOR circuit NOR1 does not go low.

Next, the NOR circuit NOR2 shown in FIG.
Negative OR of N and the clock signal CLK1 is calculated, and the output signal is supplied to the OR circuits OR1 and OR2. Therefore, while the signal φN is at the high level, the clock signal is not supplied to the unidirectional units 3 and 4, and the chopper operation is not performed. In this sense, the NOR circuit NOR2 functions as clock inhibiting means.

Next, when the set terminal S goes low, the latch means 6 sets the output signal to low level,
When the reset terminal R goes low, the output signal is set high. For example, an inverted SR flip-flop can be used. In this example, since the signal φN is supplied to the set terminal S, when the signal φN goes low, that is, when the voltages of the output terminals AG1 and AG2 exceed the reference voltages Vref1 and Vref2, the latch means 6 Latched, the signal φS goes low. As described above, the unidirectional units 1 and 2 are powered and operated when the signal φS goes low, so that when the voltage of the output terminals AG1 and AG2 exceeds the reference voltages Vref1 and Vref2, the unidirectional units 1 and 2 become unidirectional. Sex units 1 and 2 can be operated.

That is, when the voltages of the output terminals AG1 and AG2 exceed the reference voltage Vref, the comparators COM3 and COM4 are operated. It is working.

The reason why the power supply is controlled by providing the two-stage threshold value in this way is as follows. As in this example, the purpose of the chopper-type charging circuit is to boost a small electromotive voltage.The reference voltage is a voltage slightly higher than the voltage of the ground GND, and the power generation state of the AC generator AG is detected. It is necessary to control the power supply of the unidirectional unit based on the result. However, if the reference voltage is set to a small value, the output terminals AG1, AG1,
If an electromotive voltage is induced between AG2 or a small electromotive voltage that cannot be charged even if the user of the wristwatch slightly raises his or her arm to raise the voltage, the voltage of output terminals AG1 and AG2 is changed to power supply Vdd. Therefore, the charging current cannot be obtained after all. In such a case, if the current is consumed by supplying power to the comparators COM1 and COM2 which are fast but consume a large amount of current, the charging efficiency is reduced. Therefore, in the present embodiment, the electromotive voltage of the AC generator AG is monitored using the reference voltage Vref and the reference voltages Vref1 and Vref2, and power is supplied to the unidirectional units 1 to 4 as necessary. It controls to reduce current consumption.

As described above, the power supply to each of the unidirectional units 1 to 4 is controlled, so that the comparator COM1
The current consumption of ~ COM6 is set as follows. COM1, COM2> COM3, COM4> COM5, COM6 The reason why the current consumption of the comparators COM5, COM6 is set to be the smallest is that they are provided inside the power generation detection unit 10 and constantly generate the electromotive voltage of the AC generator AG. It is necessary to monitor. Further, the reason why the current consumption of the comparators COM1 and COM2 is set to be the largest is that it is detected that the voltages of the output terminals AG1 and AG2, which are the conditions for charging, exceed the power supply Vdd. Further, the reason why the current consumption of the comparators COM3 and COM4 is set smaller than that of the comparators COM1 and COM2 is that the comparators COM3 and COM4 detect the precondition for charging that the output terminals AG1 and AG2 start rising. Comparator CO
Although the operating speed may be lower than that of M1 and COM2, it is necessary to operate the unidirectional units 3 and 4 before the output terminals AG1 and AG2 exceed the power supply Vdd. This is because it is necessary to have

By setting the current consumption in this way, power can be supplied in order from the one with the smallest current consumption to the one with the largest current consumption, so that the current consumption can be further reduced and the charging efficiency can be improved. Specifically, the total current consumption of the comparators COM1 to COM4 is about 500 nA, whereas the current consumption of the comparators COM5 and COM6 is about 10 nA. Therefore, the current consumption during standby can be reduced to about 1/50 of that during normal operation.

By the way, the operating speed of the comparator becomes slower as the current consumption becomes smaller. Therefore, when the current consumption is set as described above, even if the AC generator AG changes from the power generation state to the non-power generation state, the operation is immediately stopped. Power generation status cannot be detected. Then, when the AC generator AG further changes from the non-power generation state to the power generation state, the state change is detected after the delay time of the comparators COM5 and COM6 has elapsed.

Therefore, if the AC generator AG repeats the power generation state and the non-power generation state in a short cycle, the electromotive voltage of the AC generator AG exceeds the voltage of the power supply Vdd in the power generation state, and the charging condition is satisfied. However, there is an inconvenience that charging can be performed only in part of the period.

Therefore, in the present embodiment, after the comparators COM3 and COM4 detect that the voltages at the output terminals AG1 and AG2 have fallen below the reference voltages Vref1 and Vref2, a fixed time period is required for each one-way operation. The power supply to the units 1 to 4 is continuously performed, and the power supply is stopped after a predetermined time has elapsed.

More specifically, the output signal φN of the NOR circuit NOR1
Changes from low level to high level,
The voltages of the output terminals AG1 and AG2 are equal to the reference voltages Vref1 and Vref2.
Is detected, the signal φN is output to the NOR circuit NOR.
2. The signal φR is supplied to the reset terminal R of the timer counter 5 via NOR3.

Here, the timer counter 5 counts the clock signal CLK and outputs a ripple carry signal which becomes a low level when the count value reaches a predetermined value as a signal φR1, and counts when its reset terminal R becomes a low level. It is configured to reset the value to zero.

Therefore, when the signal φN changes from the low level to the high level, the signal φR changes from the low level to the high level, the reset is released, and the timer count 5 starts time measurement. When the signal φN is at a high level, that is, the non-power generation state continues for a predetermined time and the count value reaches a predetermined value, the signal φR1
Becomes low level, and the latch means 6 is reset. As described above, when the latch means 6 is reset, the output signal φS is set to the high level. Therefore, the signal φS is set to the high level for the first time, and the power supply to the comparators COM1 and COM2 is stopped. When the signal φS is supplied to the power generation detection unit 10, the signal φS is output as the signal φSL via the inverting circuit 12 and the NOR circuit 13, and thereby the comparator φ
Power supply to COM3 and COM4 is stopped.

On the other hand, during measurement by the timer counter 5,
The voltages of the output terminals AG1 and AG2 are equal to the reference voltages Vref1 and Vref2.
, The signal φN goes low, the timer counter 5 is reset again, the latch means 6 is not reset, and the signal φS is maintained at low level. That is, the time measurement by the timer counter 5 is performed retriggerably, and only when the non-power generation state continues for a predetermined time,
The power supply to the comparators COM1 to COM4 is stopped.

Next, the configuration of the AC generator AG and its peripheral mechanism will be described. FIG. 4 is a perspective view showing the configuration of the AC generator AG and its peripheral mechanism. As shown, the alternator A
G has a rotor 14 and a stator 15. When the bipolar rotor 14 rotates, an electromotive force is generated in the output coil 16 of the stator 15, so that an AC output can be taken out. In the figure, 13
Is a rotating weight that makes a turning motion in the watch body case,
Reference numeral 11 denotes a train wheel mechanism for transmitting the rotational movement of the rotary weight 13 to the generator AG. The oscillating weight 13 rotates according to the swing of the arm of the person wearing the wristwatch, and accordingly, an electromotive force can be obtained from the AC generator AG.

The AC output from the AC generator AG is rectified by the chopper type charging circuit 100 according to the present embodiment.
It is supplied to the processing device 9. The processing device 9 drives the timepiece device 7 with the electric power discharged from the chopper-type charging circuit 100. The timepiece device 7 includes a crystal oscillator, a counter circuit, and the like. The master clock signal generated by the crystal oscillator is frequency-divided by the counter circuit, and time is measured based on the frequency division result. In this example, the chopper type charging circuit 100 is used as a master clock signal or a signal obtained by dividing the master clock signal as a clock signal CLK.
To supply. Therefore, the circuit for generating the clock signal CLK can be shared by the chopper type charging circuit 100 and the timepiece device 7. As a result, the circuit configuration can be simplified and the current consumption of the entire wristwatch can be reduced.

2. Next, the operation of the present embodiment will be described with reference to the drawings. 2-1: Power supply start operation First, an operation from a state in which the AC generator AG is in a non-power generation state and power is not supplied to the unidirectional units 1 to 4 until power supply is started will be described. FIG. 5 is a timing chart of the chopper-type charging circuit 100 according to the present embodiment.

Now, at time t1, if the user moves the wrist wearing the wristwatch, the AC generator AG starts generating power. In this case, the voltage of the output terminal AG1 is
If it changes as shown in (a), the voltage of the output terminal AG1 exceeds the reference voltage Vref at time t2. Then, the power generation detection unit 10 detects that the voltage of the output terminal AG1 has exceeded the reference voltage Vref, and changes the signal φAG from low level to high level. However, since the comparators COM5 and COM6 used for detection have low current consumption and low response speed, the change in the signal φAG is accompanied by a delay. Here, assuming that the delay time is td, the signal φAG is
As shown in (b), it goes high at time t3 (= t1 + td).

The signal φAG is inverted by the NOR circuit 13 and output to the switches S5 and S6 of the one-way unit 3 and the switches S7 and S8 of the one-way unit 4 as a signal φSL shown in FIG. You. This allows
As shown in FIGS. 5D and 5E, at time t3, switches S5 and S7 are turned off and switches S6 and S8 are turned on, so that power is supplied to unidirectional units 3 and 4, and time t3 From the reference voltages Vref1, Vref2 and the output terminal AG
The comparison of the voltages of AG1 and AG2 is started. Therefore, when the voltages of the output terminals AG1 and AG2 are less than the reference voltage Vref, power is not supplied to the comparators COM3 and COM4, so that current consumption can be reduced.

Thereafter, the voltage of the output terminal AG1 rises,
As shown in FIG. 5A, at time t4, the reference voltage Vref
When it exceeds 1, the signal φN2 changes from low level to high level (see FIG. 5 (f)). The signal φN2 is the NOR circuit NO
The signal is inverted by R1 and supplied to the NOR circuit NOR2 as a signal φN shown in FIG. The NOR circuit NOR2 is shown in FIG.
The logical OR of the clock signal CLK and the signal φN shown in (i) is calculated, and the calculation result is expressed by the clock signal shown in FIG.
It is output to the unidirectional units 3 and 4 as CLK1. Here, while the signal φN is at the high level, the clock signal CLK1
Becomes low level, so that the unidirectional units 3 and 4 do not perform the chopper operation. That is, the output terminals AG1, A
When the voltage of G2 exceeds the reference voltages Vref1 and Vref2, the chopper operation starts.

The signal φN is supplied to the set terminal S of the latch means 6. The latch means 6 has a set terminal S
Goes to a high level, the output terminal is set to a low level, so that the signal φS is at time t as shown in FIG.
At 4, it goes low. The signal φS is supplied to switches S1 and S2 of unidirectional unit 1 and switches S3 and S4 of unidirectional unit 2. As a result, as shown in FIGS. 5 (l) and (m), at time t4, the switches S1 and S3 are turned off and the switches S2 and S4 are turned on, so that power is supplied to the unidirectional units 1 and 2. From time t4, the voltage of the power supply Vdd and the output terminals AG1, A
The comparison of the voltage of G2 is started.

On the other hand, as shown in FIG. 5A, the voltage of the output terminal AG1 exceeds the reference voltage Vref at time t7,
Assuming that the voltage falls below the reference voltage Vref1 at time t8 without exceeding the reference voltage Vref1, the one-way unit 3,
4 is supplied with power, but the unidirectional units 1 and 2 are not supplied with power. Therefore, the output terminals AG1, AG
2 is less than the reference voltages Vref1 and Vref2,
Since power is not supplied to the comparators COM1 and COM2, current is not consumed during a period in which charging is not possible due to a small electromotive voltage. As a result, current consumption can be reduced and charging efficiency can be increased.

2-2: Power Supply Stopping Operation Next, the operation from the state where the AC generator AG is in the power generation state and the power is supplied to the unidirectional units 1 to 4 until the power supply is stopped will be described.

The electromotive force of the AC generator AG gradually decreases,
As shown in FIG. 5A, at time t5, the output terminal A
When the voltage of G1 falls below the reference voltage Vref1, the comparator C
OM4 detects that the voltage of the output terminal AG1 has fallen below the reference voltage Vref1. As a result, signal φN attains a high level at time t5. Then, the signal φR goes high as shown in FIG.
Starts the time measurement. In this example, since the voltage of the output terminal AG1 does not exceed the reference voltage Vref1 after time t5, as shown in FIG.
At time t6 when the timer set time TM has elapsed from 5, the output signal φR1 of the timer counter 5 goes low.

Here, since the latch means 6 is reset by the signal φR1, the signal φS changes from low level to high level at time t6. The switches S1 to S4 are controlled by the signal φS, and at time t6,
Switches S1 and S3 are turned on, and switches S2 and S4 are turned off. Thereby, the power supply to the unidirectional units 1 and 2 is stopped. When the signal φS is supplied to the power generation detection unit 10, the signal φS is supplied to the unidirectional units 3 and 4 as the signal φSL via the inverting circuit 12 and the NOR circuit 13. Therefore, when signal φS goes high at time t6, signal φSL also goes high, and power supply to unidirectional units 3 and 4 is stopped.

Therefore, when the power supply is stopped, the output terminal AG
1 and AG2 on condition that the voltages of the reference voltages Vref1 and Vref2 continue to be lower than a predetermined time. Accordingly, even if the comparators COM5 and COM6 used in the power generation detection unit 10 have low current consumption and low response speed,
It is possible to reliably detect the non-power generation state and control the power supply to be stopped.

2-3: Overall Operation Next, the overall operation of the power supply in the chopper type charging circuit of this embodiment will be described. FIG. 6 is a state transition diagram of the comparators COM1 to COM4. First, when the non-power generation state of the AC generator AG continues, the power supply to the comparators COM1 to COM4 is in the state A in which the power supply is stopped. In state A,
When the voltage at the output terminal AG1 is lower than the reference voltage Vref and the voltage at the output terminal AG2 is lower than the reference voltage Vref, the state A is maintained (path K1).

Next, in the state A, the voltage of the output terminal AG1 becomes higher than the reference voltage Vref, or
When the voltage of G2 becomes equal to or higher than the reference voltage Vref, a transition is made from state A to state B (path K2). In this case, the power supply to the comparators COM1 and COM2 is stopped, but the power supply to the comparators COM3 and COM4 is started. Therefore, in the state B, the voltages of the output terminals AG1 and AG2 are compared with the voltages of the reference voltages Vref1 and Vref2.

Next, in the state B, the voltage of the output terminal AG1 is lower than the reference voltage Vref, and
2 is lower than the reference voltage Vref,
The state transitions from state B to state A (path K3). Therefore, when the electromotive voltage of the AC generator AG is too small to be charged, the power supply to the comparators COM3 and COM4 is stopped, so that the current consumption can be reduced.

Next, in the state B, when the voltage of the output terminal AG1 becomes higher than the reference voltage Vref1 or the voltage of the output terminal AG2 becomes higher than the reference voltage Vref2, the state B
To state C (path 4). In this case, power is supplied to the comparators COM1 to COM4, and preparation for supplying a charging current to the power supply Vdd is completed. Here, the output terminals AG1, A
When the voltage of G2 exceeds the voltage of the power supply Vdd, charging is performed.

Next, in state C, the voltage of the output terminal AG1 falls below the reference voltage Vref1 and the output terminal AG2
If the time during which the voltage falls below the reference voltage Vref2 continues for the timer set time TM or more, the state changes from state C to state A (path K5), and the power supply to the comparators COM1 to COM4 is stopped. Thus, even if the comparators COM5 and COM6 used in the power generation detection unit 10 have low current consumption and low response speed, it is possible to reliably detect the non-power generation state and control the power supply to stop. it can.

3. Conclusion As described above, according to the present embodiment, the power generation state of the AC generator AG is detected using the reference voltage Vref, and power is supplied to the comparators COM3 and COM4 only when the power generation state is detected. The current consumed by the comparators COM3 and COM4 can be reduced. In addition, the comparator COM
3. Output terminals AG1, A of AC generator AG by COM4
Since the power is supplied to the comparators COM1 and COM2 only when it is detected that the voltage of G2 has exceeded the reference voltages Vref1 and Vref2, the current consumed by the comparators COM1 and COM2 can be reduced. Moreover, since the current consumption of each comparator is set in the order of “COM1, COM2> COM3, COM4> COM5, COM6”, power is supplied in ascending order of current consumption, so that current consumption can be further reduced.

When the power supply is stopped, the condition is that the voltages at the output terminals AG1 and AG2 are lower than the reference voltages Vref1 and Vref2. Can be stopped. On the other hand, if the current consumption of the comparator is reduced, the response speed is slowed down.
In this example, the timer counter 5 measures the time during which the voltages at the output terminals AG1 and AG2 continuously fall below the reference voltages Vref1 and Vref2. When this time reaches a predetermined time, it is regarded as a non-power generation state. Since the power supply is stopped, the above-described problem does not occur. Therefore, even if a comparator with low current consumption is used, the non-power generation state can be reliably detected and the power supply can be stopped, so that the current consumption can be significantly reduced. Further, once the power supply to the comparators COM1 and COM2 is started, the power supply to the comparators COM1 to COM4 is continuously performed at least until the timer set time TM set in the timer counter 5 elapses. Charging can be performed with good responsiveness to voltage.

As described above, according to the present embodiment, the current consumption of the control system is greatly reduced, so that the chopper-type charging circuit 100 having high charging efficiency can be provided. Further, in a wristwatch that is required to be light and small, the AC generator AG provided therein must be small. Therefore, the electromotive voltage generated in the AC generator AG is small, and the rectification efficiency is not good. Therefore, it is extremely useful to apply a device with good charging efficiency, such as the above-described chopper-type charging circuit 100, to a wristwatch. In particular, in the above-described chopper-type charging circuit 100, during a period in which the user does not wear the wristwatch on the wrist, power is supplied to only the comparators COM5 and COM6 that consume the least amount of current to monitor the state of power generation. Therefore, the current consumed during that time is very small. Therefore, even when the user has not used the wristwatch for a long period of time, it is possible to greatly reduce a situation in which the watch stops and the time is not known when the user wants to use the wristwatch.

4. Modifications The present invention is not limited to the above-described embodiment, and for example, various modifications described below are possible. (1) In the embodiment described above, a wristwatch was described as an example of the electronic device using the chopper-type charging circuit 100. However, the present invention is not limited to this, and for example, a portable blood pressure monitor, Mobile phones, pagers,
It can be applied to pedometers and the like. In short, any electronic device that consumes power may be applied. In such an electronic device, since the electronic circuit and the mechanical system built therein can be continuously operated without a battery, the electronic device can be used at any time,
Moreover, troublesome battery replacement can be eliminated. Furthermore,
There is no problem associated with battery disposal.

The battery may also be used as the above-mentioned chopper type charging circuit 100. In this case, when the electronic device has not been carried for a long time, the electronic device is immediately operated by the power from the battery. After that, when the user carries the electronic device, the electronic device can be operated by the generated power.

(2) In the above-described embodiment, P-channel FETs P1, P2, N
Although the channel FETs N1 and N2 are illustrated, the P-channel F
A PNP transistor may be used instead of ETP1 and P2, and an NPN bipolar transistor may be used instead of N-channel FETs N1 and N2. However, in these bipolar transistors, the saturation voltage between the emitter and the collector is usually about 0.3 V. Therefore, when the electromotive voltage of the AC generator AG is small, as in the above-described embodiment, It is desirable to use an FET for the power supply.

(3) In the above-described embodiment, the comparators COM1 to COM4 and the respective logic circuits may be configured using FETs, and the entire chopper-type charging circuit 100 may be built in a one-chip IC.

(4) In the above embodiment, the N-channel FETs N1 and N2 on the ground GND side are connected to the clock signal C
The chopper operation was performed by switching in synchronization with LK1, but the comparators COM1 to COM4 and the logic circuit were configured to be inverted upside down, and the P-channel FETs P1 and P2 on the power supply Vdd side were configured to be switched. You may. In this case, since the relationship between the power supply Vdd and the ground GND is reversed, the resistors R1 and R2 shown in FIG. 2 are connected to the power supply Vdd,
Reference voltage Vref is applied to power supply Vdd. Further, the reference voltages Vref1 and Vref2 are given to the power supply Vdd. That is, each reference voltage is applied to the line to which the switching FET is connected. Further, a line having a constant potential may be used instead of the ground GND. In short, when the chopper operation is performed between the two lines, the voltages of the output terminals AG1 and AG2 of the AC generator AG are compared with two threshold values, and the comparator is supplied with power according to the comparison result to reduce current consumption. Any one may be used.

(5) In the above embodiment, a chopper circuit for performing full-wave rectification has been described as an example. However, the present invention is not limited to this, and a chopper circuit used for half-wave rectification, Needless to say, the present invention can be applied to a chopper circuit used in performing voltage doubler rectification by combining one unidirectional unit and a capacitor. For example, when the present invention is applied to half-wave rectification, one of the above-described unidirectional units 1 and 2 may be deleted. In short, a means for detecting the power generation state and a means for detecting the charging condition are provided, and when the power generation state of the AC generator is detected, power supply is started to the means for detecting the charging condition, and the charging condition is determined by the means. If it is found that
Any chopper circuit may be used as long as it starts feeding power to all components.

(6) In the above-described embodiment, the power generation detecting section 10 has the output terminals AG1 and A of the AC generator AG.
Although the voltage of G2 was constantly monitored, the present invention is not limited to this, and each output terminal AG1, AG1,
The voltage of AG2 may be monitored. Further, the timer setting time TM is appropriately set, and each output terminal AG1, A
The power generation state may be monitored based on one of the voltages of G2. For example, the timer setting time T
When M is set to 30 ms and the generated power is compared between the case where the power generation state is monitored based on the voltage of one output terminal and the case where the power generation state is monitored based on both output terminals, the two powers substantially match. Therefore, by appropriately setting the timer set time TM, it is possible to detect the power generation state based on the voltage of one output terminal. In this case, one of the comparators COM5 and COM6 can be reduced, so that the current consumption during standby can be further reduced. Specifically, the current consumption during standby can be reduced to approximately 5.5 nA, so that the current consumption can be reduced to about 1/100 of that during normal operation. Also, in a conventional rectifier circuit using a Schottky diode, a leakage current of about 20 nA per element causes a reduction in current consumption as compared with this.

(7) The chopper circuit according to the above-described embodiment may be applied to an electronically controlled mechanical timepiece having a mainspring type generator. FIG. 8 is a perspective view showing the mechanical structure of the electronically controlled mechanical timepiece. In this watch, the mainspring 1
Reference numeral 10 is connected to a crown (not shown), and mechanical energy is accumulated in the mainspring 110 by winding the crown. A speed increasing gear train 120 is provided between the mainspring 110 and the rotor 131 of the generator 130. The speed increasing wheel train 120 includes a second wheel & pinion 121, a third wheel & pinion 122, and a second hand 12 to which a minute hand 124 is fixed.
5 is fixed to a fourth wheel 123 and the like. The speed-up wheel train 120 causes the mainspring 11 to rotate.
The motion of 0 is transmitted to the rotor 131 of the generator 130 to generate power. Here, the generator 130
Also acts as an electromagnetic brake, and rotates a pointer fixed to the speed increasing wheel train 120 at a constant speed. In this sense, the generator 130 also functions as a governor.

FIG. 9 is a block diagram showing an electrical configuration of the electronically controlled mechanical timepiece. In the figure, the chopper circuit 200 includes a generator 130 and a rectifier circuit 140. The electromotive voltage of the generator 130 is determined by the rectifier circuit 1
The current is rectified by 40 and the capacitor 150 is charged. The capacitor 150 supplies power to the chopper circuit 200, the speed control circuit 170, and the oscillation circuit 160. The oscillation circuit 160 generates the clock signal CLK using the crystal oscillator 161. In the speed control circuit 170, when the detection circuit 102 detects the power generation frequency of the generator 130, the control circuit 103
The rectifier circuit 140 is controlled so that the electromagnetic brake is adjusted so that the rotation cycle of the rotor 131 matches the cycle of the clock signal CLK and the rotation speed of the rotor 131 is constant.
In this case, the rectifier circuit 140 is controlled by a control signal generated based on the clock signal CLK.

Here, the rotation of the generator 130 is controlled by turning on and off both ends of the coil of the generator 130 with short-circuitable switches and choppering. This switch corresponds to, for example, the N-channel FETs N1 and N2 in the above-described embodiment. When the switch is turned on by this chopper ring, a short brake is applied to the generator 130, and electric energy is accumulated in the coil of the generator 130. On the other hand, when the switch is turned off,
The generator 130 operates, the electric energy stored in the coil is released, and an electromotive voltage is generated. At this time, the electric voltage at the time when the switch is turned off is added to the electromotive voltage, so that the value can be increased. For this reason, when the generator 130 is controlled by choppering, the decrease in the generated power during braking can be compensated for by the increase in the electromotive voltage at the time of switch-off, and the braking torque can be increased while maintaining the generated power at or above a certain level. An electronically controlled mechanical timepiece with a long time can be constructed. In such an electronically controlled mechanical timepiece, the power supply method and power supply stop method of the chopper circuit described in the above embodiment may be applied. In this case, the charging efficiency can be further improved, and an electronically controlled mechanical timepiece having a longer duration can be provided.

[0074]

As described above, according to the present invention, power can be supplied to necessary components according to the power generation state of the AC generator, so that the current consumption of the chopper circuit can be reduced. , Charging efficiency can be improved. Further, in the chopper type charging circuit, the voltage generated by the AC generator can be converted to a high voltage and stored. Further, in an electronic device using a chopper-type charging circuit, for example, even without a battery, it is possible to continuously operate an electronic circuit and a mechanical system built therein,
The troublesome battery replacement can be eliminated. In a wristwatch using a chopper-type charging circuit, a clock signal is generated by a clock circuit.
A circuit configuration for generating a clock signal can be omitted.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a chopper-type charging circuit used in a wristwatch according to the present embodiment.

FIG. 2 is a circuit diagram of a power generation detection unit according to the embodiment.

FIG. 3 illustrates a reference voltage Vref1 and a relationship between the reference voltage Vref and a voltage of an output terminal AG1 according to the first embodiment.

FIG. 4 is a perspective view showing a configuration of an AC generator and a peripheral mechanism according to the embodiment.

FIG. 5 is a timing chart of the chopper-type charging circuit of the embodiment.

FIG. 6 shows comparators COM1 to COM4 according to the embodiment.
3 is a state transition diagram of FIG.

FIG. 7 is a circuit diagram of a conventional charging circuit.

FIG. 8 is a perspective view showing a mechanical structure of an electronically controlled mechanical timepiece according to a modification.

FIG. 9 is a block diagram showing an electrical configuration of an electronically controlled mechanical timepiece according to a modification.

[Explanation of symbols]

1-4 unidirectional unit 5 step-up unit (step-up circuit) 10 power generation detection unit (power generation detection means) COM1-COM4 comparators (first-fourth comparison means) P1, P2 P-channel FET (first N1, N2 ... N-channel FETs (third and fourth switch means) AG ... AC generators AG1, AG2 ... output terminals (one and the other output terminals)

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02P 9/00 H02P 9/00 Z

Claims (12)

[Claims] 1. A first control means for controlling on / off of the first switch means by comparing a voltage between output terminals of the first switch means, a second switch means, A second control for detecting whether or not a charging condition is satisfied by comparing a voltage of an output terminal of the alternator with a reference voltage, and controlling on / off of the second switch means based on a result of the detection; And a power supply method for a chopper circuit that converts an electromotive voltage of the AC generator into a chopper voltage, wherein a power generation state of the AC generator is detected by monitoring a voltage of an output terminal of the AC generator. When the power generation state is detected, power supply to the second control means is started. When the second control means detects that the charging condition is satisfied, power is supplied to the first control means. Start A power supply method for a chopper circuit, comprising: 2. The chopper circuit according to claim 1, wherein when power supply to said second control means is started, power supply to said first and second control means is continued for a predetermined time. Power supply method. 3. A first control means for controlling ON / OFF of the first switch means by comparing a voltage between the first switch means and an output terminal thereof, a second switch means, A second control for detecting whether or not a charging condition is satisfied by comparing a voltage of an output terminal of the alternator with a reference voltage, and controlling on / off of the second switch means based on a result of the detection; A chopper circuit for converting an electromotive voltage of the AC generator into a chopper voltage, wherein a power generation detecting means for detecting a power generation state of the AC generator by monitoring a voltage of an output terminal of the AC generator. When a power generation state is detected by the power generation detection means, power supply to the second control means is started, and when the second control means detects that the charging condition is satisfied, Chopper circuit, characterized in that a power supply control means for starting the power supply to the control means. 4. The power supply control means according to claim 3, wherein, when power supply to said second control means is started, power supply to said first and second control means is continued for a predetermined time. The described chopper circuit. 5. A method according to claim 1, wherein said first and second switch means are respectively provided between said first line and both output terminals of said alternator, and said second line is connected to both output terminals of said alternator. Third and fourth switch means provided between the first and second switch means, respectively, comparing the voltage of the first line with the output terminal voltages of the alternator to turn on the first and second switch means. First and second comparing means for controlling off;
Third and fourth comparing means for controlling on / off of the third and fourth switch means by comparing a potential difference between both output terminals of the AC generator and the second line with a reference potential difference. Wherein the potential difference between each output terminal of the alternator and the second line is compared with a potential difference smaller than the reference potential difference so that the alternator is in a power generation state. And if it is determined that the alternator is in the power generating state, the power supply to the third and fourth comparing means is started, and thereafter, the third and fourth comparison When the means detects that one terminal voltage among the output terminals of the alternator has exceeded the reference voltage, power supply to the first and second comparison means is started. How to feed the chopper circuit . 6. A chopper circuit for converting an electromotive force generated by an AC generator into a chopper voltage synchronized with a clock signal and generating the chopper voltage between a first line and a second line, wherein the AC generator One or the other output terminal and the second
Power generation detecting means for detecting the power generation state of the AC generator by detecting whether or not the potential difference between the first line and the second line exceeds a first reference potential difference; and the voltage of the first line and the one output. A first comparing means for comparing the voltage of the first terminal with the output voltage of the first comparing means;
First switch means that is controlled to be off; second comparison means for comparing the voltage of the first line with the voltage of the other output terminal; and the other output terminal and the first line. A second switch means provided between the second output means and the second output means, the second switch means being turned on and off based on a comparison result of the second comparison means; and a potential difference between the other output terminal and the second line. A third comparing means for comparing the potential difference between the one output terminal and the second line with a third reference potential difference; a third comparing means for comparing the potential difference between the one output terminal and the second line with a third reference potential difference; Provided between the terminal and the second line, and turned on when the third comparison means detects that the potential difference of the other output terminal exceeds the second reference potential difference, The fourth comparing means allows the one output terminal Third switch means for controlling on / off based on the clock signal when the potential difference exceeds the third reference potential difference; the other output terminal and the second line And when the fourth comparing means detects that the potential difference of the one output terminal exceeds the third reference potential difference, it is turned on, and the third comparing means sets And a fourth switch means that is turned on and off based on the clock signal when it is detected that the potential difference of the other output terminal exceeds the second reference potential difference. Always supplies power, and when a power generation state is detected by the power generation detection means, power supply to the third comparison means and the fourth comparison means is started, and the power is supplied to the third or fourth comparison means. When the potential difference of the force pin may exceed the second or third reference voltage is detected, the chopper circuit, characterized in that to start supplying power to said first comparing means and said second comparing means. 7. The first line is a power supply line,
The chopper circuit according to claim 6, wherein the second line is a ground. 8. The chopper circuit according to claim 6, wherein said first line is a ground, and said second line is a power supply line. 9. In the chopper circuit, the current consumption of the third and fourth comparing means is lower than the current consumption of the first and second comparing means, and the current consumption of the power generation detecting means is the third current. 7. The chopper circuit according to claim 6, wherein the current consumption is set lower than the current consumption of the fourth comparing means. 10. A chopper type comprising a chopper circuit according to claim 6, and a booster circuit connected to the power supply line and the ground of the chopper circuit, the booster circuit boosting the chopper voltage and storing the boosted voltage. Charging circuit. 11. An electronic apparatus comprising the chopper-type charging circuit according to claim 10 and being operated by electric power supplied from the chopper-type charging circuit. 12. A chopper-type charging circuit according to claim 11, further comprising: a clock circuit that is supplied with power from the chopper-type charging circuit and measures time, and supplies the clock signal from the clock circuit to the chopper-type charging circuit. A wristwatch characterized by the following.