JP3575256B2 - Chopper circuits, chopper-type charging circuits, electronic devices and watches - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a chopper circuit, a chopper-type charging circuit, and an electronic device and a wristwatch using the same, which are suitable for reducing current consumption required for control during charging.
[0002]
[Prior art]
As a charging circuit for charging an AC voltage generated by a generator to a capacitor or a battery, a bridge-type charging circuit is known. FIG. 4 is a circuit diagram of a conventional charging circuit. In this charging circuit, the comparators COM1 and COM2 compare the voltage of the output terminals A and B of the generator AG with the voltage of the power supply Vdd, and compare the voltage of the output terminals A and B of the generator AG with the voltage of the ground GND. Comparators COM3 and COM4 and a large-capacity capacitor C for storing a charging current are provided. The outputs of the comparators COM1 to COM4 control ON / OFF of the P-channel FETs P1, P2, N1, and N2.
[0003]
Here, when the voltage of the output terminal A falls below the voltage of 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 P-channel FET P2 is turned on by the comparator COM2, 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, so that a current flows along a path opposite to the arrow and the inconvenience such as a reduction in charging efficiency does not occur. Has become.
[0004]
Thus, in a conventional charging circuit, a field effect transistor and a comparator are combined to form a unidirectional unit that allows current to flow in one direction under certain conditions, thereby increasing charging efficiency. I have.
By the way, in a charging circuit using a one-way unit, ON / OFF of each field effect transistor is controlled by a comparator. Therefore, when examining the charging efficiency of the charging circuit, it is necessary to consider the current consumption of the comparator. The comparator can be constituted by a differential amplifier using a field-effect transistor, and its operation speed depends on the speed of the field-effect transistor. In general, the operating speed of a field-effect transistor increases as the current consumption increases. Therefore, the higher the comparator speed, the higher the current consumption.
[0005]
In the conventional charging circuit, the comparator COM2 charges the capacitor C with as much electric charge as possible, so that when the voltage at the output terminal B of the generator AG exceeds the voltage of the power supply Vdd, the P-channel FET P2 needs to be turned on immediately. There is. Therefore, it is necessary to use a high-speed comparator COM2.
On the other hand, the comparator COM3 that controls the N-channel FET N1 may turn on the N-channel FET N1 before the comparator COM2 turns on the P-channel FET P2. Here, since the electromotive voltage generated between the output terminals A and B of the generator AG fluctuates in a sinusoidal manner, after the voltage of the output terminal A falls below the voltage of the ground GND, the voltage of the output terminal B is changed to the voltage of the power supply Vdd. There is some time before the voltage is exceeded. Therefore, a comparator having a low response speed can be used as the comparator COM3.
[0006]
[Problems to be solved by the invention]
Incidentally, a chopper type booster circuit is known as a technique for obtaining a voltage higher than the electromotive voltage generated between the output terminals A and B of the generator AG, in which it is necessary to switch the electromotive voltage at a high frequency. is there. When the above-described charging circuit is configured by a chopper type, the waveform of the electromotive voltage changes in a spike shape. Therefore, it is necessary to increase the speed of the comparators COM3 and COM4 for comparing with the voltage of the ground GND. Therefore, when the conventional charging circuit is applied to a chopper-type charging circuit, there is a problem that the current consumption of the comparators COM3 and COM4 cannot be reduced, and the charging efficiency decreases.
[0007]
The present invention has been made in view of the above circumstances, and has as its object to increase charging efficiency with a simple configuration in a chopper-type charging circuit using a unidirectional unit. Another object is to apply the chopper type charging circuit to an electronic device or a wristwatch.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, in the invention according to claim 1, first switch means provided between one output terminal of the AC generator and the first line, and Second switch means provided between the other output terminal and the first line, third switch means provided between the one output terminal and the second line, and the other output terminal A fourth switch means provided between a terminal and the second line, wherein the electromotive force generated by the AC generator is converted into a chopper voltage synchronized with a clock signal, and A chopper circuit generated between the second line and a voltage of the one output terminal and a voltage of the first line, and outputs a signal of a comparison result obtained by the comparison. The first switch First comparing means for controlling ON and OFF of the switching means, comparing the voltage of the other output terminal with the voltage of the first line, and outputting a signal of a comparison result obtained by the comparison. A chopper operation synchronized with the clock signal by detecting the voltage at one and the other output terminals of the AC generator and the second comparing means for controlling ON and OFF of the second switch means. When the third switch means and the fourth switch means are controlled as described above, and a signal for turning on the first switch means is output from the first comparing means, the signal is used by using the signal. When the fourth switch is turned on and a signal for turning on the second switch is output from the second comparator, the signal is used to turn on the third switch. Control means for controlling, wherein the first comparing means outputs a signal for turning on the first switch means when the voltage of the one output terminal exceeds the voltage of the first line. The second comparing means outputs a signal for turning on the second switch means when the voltage of the other output terminal exceeds the voltage of the first line. .
[0009]
Further, in the invention according to claim 2, the control unit compares the voltage of the other output terminal with a predetermined first voltage, and determines that the voltage of the other output terminal is equal to the first voltage. Comparing the voltage at the one output terminal with a predetermined second voltage, and comparing the voltage at the one output terminal with the second voltage. And a fourth comparing means for detecting that the voltage of the other output terminal has exceeded the first voltage by the third comparing means. The third switch means is controlled so as to perform a chopper operation synchronized with a signal, and when it is detected by the fourth comparison means that the voltage of the one output terminal exceeds the second voltage. Performs a chopper operation synchronized with the clock signal Controlling the fourth switch means as described above, and when a signal for turning on the first switch means is output from the first comparison means, the fourth switch means is turned on using the signal; When a signal for turning on the second switch means is output from the second comparison means, control is performed using the signal to turn on the third switch means.
[0010]
Further, in the invention according to claim 3, the control means includes a step of detecting that a voltage of the other output terminal exceeds the first voltage by the third comparing means. Alternatively, the third switching means is turned on during a period in which the second switching means is turned on by the second comparing means, and in other periods, the third switching means is turned on based on the clock signal. ON / OFF control, and a period in which the fourth comparison means detects that the voltage of the one output terminal exceeds the second voltage, or Turning on the fourth switch means during a period when the switch means is turned on, and controlling on and off of the fourth switch means based on the clock signal during other periods; The third comparing means has a slower response speed or lower current consumption than the first comparing means and the second comparing means, and the fourth comparing means has the first comparing means and the second comparing means. The response speed is lower than that of the second comparing means, or the current consumption is smaller.
[0011]
Further, in the invention according to claim 4, the first line is a power supply line, and the second line is ground.
In the invention according to claim 5, the first line is a ground and the second line is a power supply line.
[0012]
In the invention according to claim 6, a chopper-type charging circuit using the chopper circuit is connected to the power supply line and the ground of the chopper circuit, and boosts the chopper voltage. And a booster circuit for storing the boosted voltage.
According to a seventh aspect of the present invention, there is provided an electronic device including the chopper-type charging circuit, wherein the electronic device operates by power supplied from the chopper-type charging circuit.
Further, according to the invention as set forth in claim 8, 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 circuit outputs the clock signal from the clock circuit to the chopper. It is characterized in that it is supplied to a charging system.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
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 the embodiment
FIG. 1 is a circuit diagram of a chopper-type charging circuit used in a wristwatch according to the present embodiment.
In the figure, output terminals AG1 and AG2 of AC generator AG are connected to ground GND via resistors R1 and R2. Therefore, when the AC generator AG is in the non-power generation state, the output terminals AG1 and AG2 are pulled down. The values of the resistors R1 and R2 are set to approximately 200 KΩ, which is much larger than the on-resistance of each FET.
Next, the unidirectional unit 1 includes a P-channel FET P1 and a comparator COM1. The positive input terminal of the comparator COM1 is connected to the power supply Vdd, and its negative input terminal is connected to the output terminal AG1 of the AC generator AG. 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, when the voltage of the power supply Vdd falls below the voltage of the output terminal AG1, the signal φP1 becomes high level and the P-channel FET P1 is turned off. Therefore, unidirectional unit 1 supplies a current from output terminal AG1 to power supply Vdd only when the voltage at output terminal AG1 exceeds the voltage at power supply Vdd.
[0014]
The one-way unit 2 is connected to the output terminal AG2 of the AC generator AG, and has the same configuration as the one-way unit 1 described above. In this case, the unidirectional unit 2 supplies a current from the output terminal AG2 to the power supply Vdd only when the voltage of the output terminal AG2 exceeds the voltage of the power supply Vdd.
[0015]
Here, in consideration of charging efficiency, it is desirable that the P-channel FET P1 be turned on immediately when the voltage of the output terminal AG1 of the AC generator AG exceeds the voltage of the power supply Vdd. Therefore, the current consumption of the comparator COM1 is relatively large, so that the comparator COM1 can cope with high-speed operation. Similarly, since the current consumption of the comparator COM2 is set to a relatively large value, high-speed operation can be supported.
[0016]
By the way, in a small and lightweight device such as a wristwatch, if the AC generator AG is to be built in, the size of the output coil constituting the AC generator AG is small because the AC generator AG becomes very small. Has certain limits. 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 to stably operate 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-like chopper voltage, which is boosted by the booster 5 to a desired voltage. Voltage. It should be noted that the booster 5 may have a well-known configuration such as a so-called voltage doubler circuit. For example, it may be configured by combining a capacitor and a one-way unit.
[0017]
Next, the unidirectional unit 4 includes an N-channel FET N2, an OR circuit OR2, and a comparator COM4. The negative input terminal of the comparator COM4 is connected to the output terminal AG1 of the AC generator AG, and the positive input terminal thereof 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. 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 goes low. By the way, although a very small leakage current flows through each FET, as described above, since the output terminals AG1 and AG2 are connected to the ground GND by the resistors R1 and R2, when the AC generator AG is in a non-power generation state, The voltages at the output terminals AG1 and AG2 are pulled down to the ground GND. Therefore, by applying the reference voltage Vref1 to the ground GND, the polarity of power generation can be reliably detected.
[0018]
The OR circuit OR2 is supplied with a signal CN2, a signal obtained by inverting the signal φP1 by the inverting circuit IN1, and a high-speed clock signal CLK generated by the clock device 7 described later. The OR circuit OR2 calculates these ORs and supplies them as a signal φN2 to the gate of the N-channel FET N2.
Therefore, the N-channel FET N2 turns on when any of these signals goes to a high level, and turns off when all of these signals go to a low level. The one-way unit 3 has the same configuration as the one-way unit 4.
[0019]
According to such a configuration, when the signal φP1 is at the low level, that is, when the P-channel FET P1 is turned on, the signal φN2 is immediately turned to the high level, and the N-channel FET N2 can be turned on. Therefore, even if the operation speed of the comparator COM4 is low, the N-channel FET N2 can be reliably turned on, and the current i can be charged in the path indicated by the arrow (2) in the figure. Therefore, a comparator having a slow response speed can be used for the comparators COM3 and COM4.
[0020]
Here, FIG. 2 is a perspective view showing the configuration of the AC generator AG and its peripheral mechanism. As shown in the drawing, the AC generator AG includes a rotor 14 and a stator 15. When the rotor 14 in the form of a bipolar magnetized disk rotates, an electromotive force is generated in an output coil 16 of the stator 15, and an AC output is generated. Can be taken out. In the figure, reference numeral 13 denotes a rotating weight that makes a turning motion in the wristwatch main body case, and 11 denotes a wheel train mechanism that transmits the rotating motion of the rotating 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.
[0021]
The alternating current output from the AC generator AG is rectified by the chopper type charging circuit 100 according to the present embodiment, and 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 master clock signal or a signal obtained by dividing the master clock signal is supplied to the above-described chopper type charging circuit 100 as the clock signal CLK. Therefore, the circuit for generating the clock signal CLK can be shared by the chopper-type charging circuit 7 and the timepiece device 100. As a result, the circuit configuration can be simplified, and the current consumption of the entire wristwatch can be reduced.
[0022]
2. Operation of the embodiment
Next, the operation of the present embodiment will be described with reference to the drawings.
FIG. 3 is a timing chart of the chopper-type charging circuit 100 according to the present embodiment. In this example, it is assumed that the voltage of the output terminal AG1 of the AC generator AG is higher than the voltage of the output terminal AG2.
[0023]
Assuming that the clock signal CLK is as shown in FIG. 3A, while the clock signal CLK is at the high level, the output signal φN2 of the OR circuit OR2 and the output signal φN1 of the OR circuit OR1 are always at the high level. Therefore, the N-channel FET N1 and the N-channel FET N1 are turned on. In this case, since the output terminal AG1 and the output terminal AG2 are grounded to the ground GND, their voltages are lower than the voltage of the power supply Vdd. Therefore, the P-channel FET P1 and the P-channel FET P2 are turned off, and a closed circuit indicated by an arrow (1) in the figure is formed.
[0024]
In this closed circuit, current flows through the path of the alternator AG → the output terminal AG1 → the N-channel FET N1 → the ground GND → the N-channel FET N2 → the output terminal AG2 → the alternator AG. The voltage of AG2 becomes the same potential. In this case, a certain amount of current is consumed by the internal resistance component of the output coil 16, but the value is small, and most of the electromotive current of the AC generator AG is stored in the output coil 16.
[0025]
On the other hand, when the clock signal CLK goes low, the N-channel FET N1 turns off, and the voltage of the output terminal AG1 rises sharply as shown in FIG. Here, the comparator COM4 generates the signal CN2 by comparing the voltage of the output terminal AG1 with the reference voltage Vref1, but since the comparator COM4 has a low response speed in order to reduce current consumption, Even if the voltage at the output terminal AG1 exceeds the reference voltage Vref1, the signal CN2 does not immediately switch from the low level to the high level. For example, assuming that the delay time of the comparator COM4 is td1, the signal CN2 is as shown in FIG.
[0026]
If the OR circuit OR2 is generated only from the signal CN2 and the clock signal CLK, the N-channel FET N2 cannot be turned on during the delay time td1. Therefore, during the period, the current i cannot be charged along the path indicated by the arrow (2) shown in FIG. 1, and a charge loss occurs.
However, the signal φP1 (see FIG. 3F) obtained by the high-speed comparator COM1 is supplied to the OR circuit OR2 of the present embodiment via the inverting circuit IN1 (FIG. 3D). ), The delay of the comparator COM4 can be compensated. As a result, the signal φN2 becomes as shown in FIG. 3E, and the N-channel FET N2 can be turned on while the signal CN2 is at the high level.
[0027]
That is, the inverting circuit IN1, the comparator COM4, and the OR circuit OR2 operate during the period when the clock signal CLK is at the high level, during the period when the voltage of the output terminal AG1 exceeds the predetermined reference voltage Vref, or when the comparator COM1 turns on the P-channel FET P1. During this period, the N-channel FET N2 is turned on, and functions as control means for controlling the N-channel FET N2 to be turned off in other periods.
[0028]
Further, when the voltage of the output terminal AG1 exceeds the power supply Vdd, the comparator COM1 generates the signal φP1 shown in FIG. 3F and turns on the P-channel FET P1, so that the comparator COM1 is charged along the path indicated by the arrow (2). The current i is as shown in FIG.
[0029]
As described above, in the present embodiment, the gates of the N-channel FETs N1 and N2 are controlled in synchronization with the output signals φP1 and φP2 of the comparators COM1 and COM2 responding at high speed. The accompanying charge loss can be reduced. Further, by using the comparators COM3 and COM4 having slow response speeds, it is possible to reduce the current consumption accompanying the control. As a result, a chopper-type charging circuit 100 having high charging efficiency can be provided. 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 to the wristwatch, such as the chopper-type charging circuit 100 described above. As a result, the watch can be charged efficiently even if the user is wearing the watch for a short time, so that the watch will stop and use even if the user has not used the watch for a long time. The situation where the user does not know the time when he or she wants can be greatly reduced.
[0030]
3. Modified example
The present invention is not limited to the above-described embodiment, and for example, various modifications described below are possible.
(1) In the above-described embodiment, a wristwatch is described as an example of the electronic device using the chopper-type charging circuit 100. However, the present invention is not limited to this. For example, a portable blood pressure monitor, The present invention can be applied to a mobile phone, a pager, a pedometer, and the like. In short, any electronic device that consumes power may be applied. In such an electronic device, the electronic circuit and the mechanical system built therein can be continuously operated without a battery, so that the electronic device can be used at any time, and a troublesome battery can be used. No need for replacement. Further, there is no problem associated with the disposal of the battery.
[0031]
Note that the battery may also be used as the above-described chopper-type charging circuit 100. In this case, when the electronic device has not been carried around for a long time, the electronic device can be operated immediately by the power from the battery, Thereafter, when the user carries the electronic device, the electronic device can be operated by the generated power.
[0032]
(2) In the above-described embodiment, the P-channel FETs P1 and P2 and the N-channel FETs N1 and N2 are illustrated as examples of the switch means. Instead, an NPN-type bipolar transistor may be used. 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 control.
[0033]
(3) In the above-described embodiment, the comparators COM1 to COM4, the OR circuits OR1 and OR2, and the inverting circuits IN1 and IN2 are configured using FETs, and the entire chopper-type charging circuit 100 is built in a one-chip IC. It may be.
[0034]
(4) In the above embodiment, the chopper operation is performed by switching the N-channel FETs N1 and N2 on the ground GND side in synchronization with the clock signal CLK1, but the comparators COM1 to COM4, the logic circuit, and the like are turned upside down. With such a configuration, the P-channel FETs P1 and P2 on the power supply Vdd side may be switched. 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. 1 are connected to the power supply Vdd, and the reference voltages Vref1 and Vref2 are applied to the power supply Vdd. That is, each reference voltage (potential difference) is applied to the line to which the FET for switching is connected. Further, a line having a constant potential may be used instead of the ground GND. The present invention can also be applied to a case where a full-wave rectifier circuit using a unidirectional unit as shown in FIG. In this case, by detecting the terminal voltage of the AC generator, the N-channel FETs N1 and N2 are controlled so as to perform the chopper operation in synchronization with the clock signal, and when the P-channel FET P1 is turned on, the N-channel FET is turned on. The FET N2 is turned on, and when the P-channel FET P2 is turned on, control may be performed so as to turn on the N-channel FET N1. The point is that when performing the chopper operation between the two lines, the voltages of the output terminals AG1 and AG2 of the AC generator AG are compared with the two threshold values, and the chopper operation is performed according to the comparison result. However, the present invention can be applied.
[0035]
(5) In the above embodiment, the reference voltage Vref1 and the reference voltage Vref2 are given by differentiating the threshold values of the field effect transistors of the differential pair constituting the comparators COM3 and COM4. The difference between the threshold values may be set in consideration of the relationship with the noise level. However, when a small AC generator AG is used like a wristwatch, for example, when a difference of several mV to several hundred mV occurs. , The output of the comparator may be made active. In this case, the reference voltage Vref1 and the reference voltage Vref2 are set to substantially equal values.
[0036]
【The invention's effect】
As described above, according to the present invention, the current consumption of the third and fourth control means can be set smaller than the current consumption of the first and second control means. Can be increased.
Further, in the chopper-type charging circuit, the voltage generated by the AC generator can be converted to a high voltage and stored.
Also, in an electronic device using a chopper-type charging circuit, for example, an electronic circuit and a mechanical system built therein can be continuously operated without a battery, so that troublesome battery replacement is unnecessary. it can.
In a wristwatch using a chopper-type charging circuit, a clock signal is generated by a clock circuit, so that a circuit configuration for generating a clock signal in the chopper-type charging circuit 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 an embodiment.
FIG. 2 is a perspective view showing a configuration of an AC generator according to the embodiment and a peripheral mechanism thereof.
FIG. 3 is a timing chart of the chopper-type charging circuit of the embodiment.
FIG. 4 is a circuit diagram of a conventional charging circuit.
[Explanation of symbols]
1-4: One-way unit
5. Booster section (boosting means)
COM1 to COM4... Comparator (first to fourth comparing means)
P1, P2... P-channel FET (first and second switch means)
N1, N2... N-channel FET (third and fourth switch means)
IN1, IN2... Inverting circuits (fourth and third comparing means)
OR1, OR2... OR circuit (third and fourth comparing means)

Claims (8)

First switch means provided between one output terminal of the alternator and the first line; and second switch means provided between the other output terminal of the alternator and the first line. Switch means, third switch means provided between the one output terminal and the second line, and fourth switch means provided between the other output terminal and the second line. A chopper circuit that converts an electromotive force generated by the AC generator into a chopper voltage synchronized with a clock signal and generates the chopper voltage between the first line and the second line,
A first control unit that compares the voltage of the one output terminal with the voltage of the first line and outputs a signal of a comparison result obtained by the comparison, thereby controlling on and off of the first switch unit Means of comparison,
Comparing the voltage of the other output terminal with the voltage of the first line, and outputting a signal of a comparison result obtained by the comparison, thereby controlling on and off of the second switch means; Means of comparison,
By detecting the voltage of one and the other output terminals of the AC generator, controlling the third switch means and the fourth switch means to perform a chopper operation in synchronization with the clock signal, When a signal for turning on the first switch means is output from the first comparison means, the fourth switch means is turned on using the signal, and the second comparison means outputs the second switch signal. Control means for controlling to turn on the third switch means using the signal when a signal for turning on the switch means is output,
The first comparing means outputs a signal for turning on the first switch means when the voltage of the one output terminal exceeds the voltage of the first line;
Wherein the second comparing means outputs a signal for turning on the second switching means when the voltage of the other output terminal exceeds the voltage of the first line. . The control means,
Third comparing means for comparing the voltage of the other output terminal with a predetermined first voltage and detecting that the voltage of the other output terminal exceeds the first voltage;
Fourth comparing means for comparing the voltage of the one output terminal with a predetermined second voltage, and detecting that the voltage of the one output terminal exceeds the second voltage;
When the third comparison means detects that the voltage of the other output terminal exceeds the first voltage, the third switch means is configured to perform a chopper operation in synchronization with the clock signal. Control and
When the fourth comparing means detects that the voltage of the one output terminal exceeds the second voltage, the fourth switching means performs a chopper operation in synchronization with the clock signal. Control and
When a signal for turning on the first switch is output from the first comparing means, the fourth switch is turned on using the signal,
When a signal for turning on said second switch means is output from said second comparing means, control is performed using said signal to turn on said third switch means. 2. The chopper circuit according to 1. The control unit is configured to detect the period when the voltage of the other output terminal exceeds the first voltage by the third comparing unit or the second switch by the second comparing unit. Turning on the third switch means during a period when the means is turned on, and controlling on and off of the third switch means based on the clock signal during other periods;
The period in which the voltage of the one output terminal exceeds the second voltage is detected by the fourth comparing means, or the first switching means is turned on by the first comparing means. Turning on the fourth switch means during a certain period, controlling on and off of the fourth switch means based on the clock signal during other periods,
The third comparing means has a lower response speed or a smaller current consumption than the first comparing means and the second comparing means,
3. The chopper circuit according to claim 2, wherein the fourth comparison unit has a lower response speed or a smaller current consumption than the first comparison unit and the second comparison unit. 4. 4. The chopper circuit according to claim 1, wherein the first line is a power supply line, and the second line is a ground. 4. The chopper circuit according to claim 1, wherein the first line is a ground, and the second line is a power supply line. 5. A chopper circuit according to claim 2 or 3,
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; An electronic device comprising the chopper-type charging circuit according to claim 6 and being operated by electric power supplied from the chopper-type charging circuit. A chopper-type charging circuit according to claim 6,
A clock circuit that is supplied with power from the chopper-type charging circuit and measures time.
A wristwatch, wherein the clock circuit supplies the clock signal to the chopper-type charging circuit.

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