JP2011239567A - Charging battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging battery that can prevent a current from being consumed wastefully and an input side capacitor from being damaged because of a charge voltage exceeding a withstand voltage thereof.SOLUTION: The charging battery comprises: a capacitor C1; a resistance Rg1; a depression type FET3 of which a drain is connected to a positive electrode of the capacitor C1, a source is connected to a positive-electrode output terminal of the charging battery and a positive electrode of a capacitor C2, and a gate is connected to the source via the resistance Rg1; a capacitor C2 of which a positive electrode is connected to the source of the FET3 and the positive-electrode output terminal of the charging battery, and a negative electrode is connected to a negative-electrode output terminal of the charging battery; and a diode D1 of which an anode is connected to the gate of the FET3, and a cathode is connected to the negative-electrode output terminal of the charging battery.

Description

  The present invention relates to a rechargeable battery using a capacitor.

  In order to extend the life of the battery to be used as much as possible, an electronic device that operates with an AA battery or a button battery uses a low-power consumption component such as a CMOS-IC or a liquid crystal display to reduce the power supply voltage from 1.2V to 2V. The current consumption is a very small value of several μA to several tens of μA. However, in the case of a battery, since the output resistance is extremely small, a large current flows when the load is short-circuited, and there is a risk of causing an accident. In order to prevent this, it is conceivable to supply power to such an electronic device using a capacitor instead of a battery. Recently, small and large-capacity electric double layer capacitors have appeared, and as long as the breakdown voltage is not exceeded, there is no chemical change, so repeated charge and discharge characteristics are superior to batteries, and there is a method of power supply using such capacitors. Proposed.

  However, even if the capacity is large, the small type has a capacitance of the Farad (F) order, which is much smaller than the equivalent capacitance of the battery. For example, the capacity of an AA nickel metal hydride battery is generally about 2 Ah, and assuming that the full charge voltage is 1.4 V and the discharge end voltage is 0.9 V, the discharge charge amount when 2 A is continuously discharged for 1 hour is Since Qeffect = 1 × 3600 = 3600 (c) and the voltage drop due to this discharge is 0.5V, the equivalent capacitance is 3600 / 0.5 = 7200 (F), which is the same size It is thought that it has an effective capacity more than 1000 times that of the capacitor.

  Therefore, when a capacitor is used, it is necessary to use charging means periodically or continuously. This means that if such a charging means is present, a maintenance-free power source that does not require battery replacement or the like can be realized. For this reason, clean and maintenance-free power supply can be expected by using as a charging means a power generation means that uses natural energy such as sunlight, wind, and waves, or energy that was previously discarded, such as vibration and waste heat. .

  The configuration shown in FIG. 7 can be considered as a method for realizing the above power source. When the power generation means as described above is used, the generated voltage is generally intermittent or fluctuates. On the other hand, the output voltage is the same voltage as the battery (for example, nominal 1.5V) because it is an alternative means of the battery. Need to keep on). Accordingly, once the irregular voltage from the power generation means is accumulated by the capacitor C1, the fluctuation component is reduced, and the voltage is converted into a predetermined output voltage by the regulator and output. The output capacitor C2 is for absorbing steep load fluctuations. In general, the regulator IC is provided with an overcurrent protection function, so that even if the output is short-circuited, a large current continues to flow and is not destroyed.

  In order to extend the discharge time, it is desirable to increase the charge stored in the capacitor C1 as much as possible. Therefore, it is preferable that the capacity and the withstand voltage of C1 are larger. However, since the size of the capacitor is determined by the CV product, if the withstand voltage is increased if the size is the same, the capacitance decreases. When the power generation means as described above is used, the input voltage (charge voltage) fluctuates greatly. Therefore, if the withstand voltage of the capacitor is selected in accordance with the maximum value, the capacitance becomes small. On the contrary, if a capacitor having a large capacitance is selected, the withstand voltage is lowered, so that the withstand voltage is exceeded when a large charge voltage is applied.

  FIG. 8 shows a circuit in which a constant voltage diode ZD and a resistor Rs are added to protect the capacitor C1 from overvoltage. As a result, the voltage applied to the capacitor C1 is limited to the voltage of the constant voltage diode ZD. However, in the circuits of FIGS. 7 and 8, the regulator used itself consumes some current. Even a low current consumption type regulator made of CMOS usually has a current consumption of about several μA, and this current is consumed even without connecting a load. Therefore, the load current of about several tens of μA is targeted as described above. Therefore, the current consumption of the regulator cannot be ignored. If an overvoltage protection circuit is provided as shown in FIG. 8, the leakage current of the constant voltage diode ZD cannot be ignored.

JP 2000-350443 A JP-A-11-98710

  The present invention has been made to solve the above-described conventional problems, and one object is to provide a rechargeable battery that can prevent wasteful current consumption and prevent overcurrent.

  Another object of the present invention is to provide a rechargeable battery that prevents wasteful current consumption and prevents the charging voltage of the capacitor on the input side from exceeding the withstand voltage and being damaged.

  A rechargeable battery according to a preferred embodiment of the present invention is a rechargeable battery that charges a capacitor with an output voltage in accordance with a voltage supplied from a charging means, the first capacitor being charged by the charging means, a first resistor, The drain is connected to the positive electrode of the first capacitor, the source is connected to the positive output terminal of the rechargeable battery and the positive electrode of the second capacitor, and the gate is connected to the source via the first resistor. 1 depletion type FET, a positive electrode is connected to a source of the first depletion type FET and a positive output terminal of the rechargeable battery, a negative electrode is connected to a negative output terminal of the rechargeable battery, and the source of the first depletion type FET The second capacitor that is charged by the current from the battery and generates the output voltage of the rechargeable battery, and one end of the first depletion type F It is connected to the gate T, then and a first voltage-current non-linear element and the other end is connected to the negative output terminal of the rechargeable battery.

  In this case, it is possible to provide a rechargeable battery that can prevent wasteful current consumption and prevent overcurrent.

  In a preferred embodiment, values or characteristics of the first resistor and the first voltage-current nonlinear element are set such that a charging voltage when the second capacitor is fully charged is substantially equal to a nominal voltage of the battery. Yes.

  In a preferred embodiment, the second resistor and the drain are connected to the positive output terminal of the charging means, the source is connected to the drain of the first depletion type FET and the positive electrode of the first capacitor, and the gate is the first resistor. The second depletion type FET connected to the source of the second depletion type FET via two resistors, one end connected to the gate of the second depletion type FET and one end of the second resistor, and the other end A second voltage-current nonlinear element connected to the source of the first depletion type FET and the positive electrode of the first capacitor;

  In this case, useless current consumption can be prevented, and the charging voltage of the capacitor on the input side can be prevented from exceeding the withstand voltage and being damaged.

  In a preferred embodiment, the value or characteristic of the second resistor and the second voltage-current nonlinear element is set so that the maximum value of the charging voltage of the first capacitor does not exceed the withstand voltage of the first capacitor. ing.

  A rechargeable battery according to another preferred embodiment of the present invention is a rechargeable battery that charges a capacitor with an output voltage in accordance with a voltage supplied from a charging means, the first capacitor being charged by the charging means, and an input terminal Is connected to the positive electrode of the first capacitor, the output terminal is connected to the positive electrode output terminal of the charging battery and the positive electrode of the second capacitor, and the third terminal is connected to the negative electrode output terminal of the charging battery. The regulator, the positive electrode is connected to the output terminal of the three-terminal regulator and the positive output terminal of the charging battery, the negative electrode is connected to the negative output terminal of the charging battery, and is charged by the current from the three-terminal regulator, The second capacitor that generates the output voltage of the rechargeable battery, the second resistor, and the drain are connected to the positive output terminal of the charging means, and the source is the front The second depletion type FET, which is connected to the input terminal of the three-terminal regulator and the positive electrode of the first capacitor, and whose gate is connected to the source of the second depletion type FET via the second resistor, and one end of the second depletion type FET A second voltage-current nonlinear element connected to the gate of the second depletion type FET and one end of the second resistor, and having the other end connected to the output terminal of the three-terminal regulator and the positive electrode of the second capacitor. Prepare.

  In this case, useless current consumption can be prevented, and the charging voltage of the capacitor on the input side can be prevented from exceeding the withstand voltage and being damaged.

  ADVANTAGE OF THE INVENTION According to this invention, the rechargeable battery which can prevent consumption of useless electric current and can prevent overcurrent can be provided.

  Alternatively, according to the present invention, it is possible to provide a rechargeable battery that prevents consumption of useless current and prevents the charging voltage of the capacitor on the input side from exceeding the withstand voltage and being damaged.

1 is a circuit diagram showing a rechargeable battery 1 according to a preferred embodiment of the present invention. It is a figure which shows the characteristic of FET3 and the diode D1 at the time of no load. It is a figure which shows the characteristic of FET3 when the load current IL flows, and the diode D1. It is a circuit diagram which shows the rechargeable battery 11 by another preferable embodiment of this invention. It is a circuit diagram which shows the rechargeable battery 21 by another preferable embodiment of this invention. 2 is an external view showing rechargeable batteries 1, 11, and 21. FIG. It is a circuit diagram which shows the conventional rechargeable battery. It is a circuit diagram which shows the conventional rechargeable battery.

  Hereinafter, a rechargeable battery according to preferred embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to these embodiments.

  FIG. 1 is a circuit diagram illustrating a capacitor (also referred to as a capacitor; hereinafter the same) rechargeable battery (hereinafter referred to as a rechargeable battery) 1 according to the present embodiment. The rechargeable battery 1 includes a charging unit 2, capacitors C1 and C2, a depletion type FET 3, a resistor Rg1, and a diode (voltage / current nonlinear element) D1.

  The charging unit 2 generates a power supply voltage for charging by an arbitrary power generation method such as natural energy such as sunlight, wind, and waves, vibration, waste heat, etc., and supplies the generated voltage to the capacitor C1. .

  The capacitor C1 has a positive electrode connected to a connection point between the positive electrode output terminal of the charging unit 2 and the drain of the FET 3, and a negative electrode connected to a connection point between the negative electrode output terminal of the charging unit 2 and the negative electrode output terminal of the rechargeable battery 1. Yes. The capacitor C1 is supplied with a current based on the voltage supplied from the charging unit 2, and charges the voltage by accumulating electric charge. The voltage charged in the capacitor C1 is supplied to the drain of the FET3.

  The FET 3 is a depletion type as described above, and the drain current Id can flow from the drain to the source even when the gate-source voltage is 0V. The FET 3 has a drain connected to the positive electrode of the capacitor C1, a source connected to a connection point between the positive output terminal of the rechargeable battery 1, one end of the resistor Rg1, and a positive electrode of the capacitor C2, and a gate connected to the anode of the diode D1 and the resistor Rg1. It is connected to the connection point with the other end. The negative electrode of the capacitor C2 and the cathode of the diode D2 are connected to the negative output terminal of the rechargeable battery 1, respectively.

  The values (characteristics) of the resistor Rg1 and the diode D1 are set so that the charging voltage when the capacitor C2 is fully charged is substantially equal to the nominal voltage (for example, 1.5 V) of the battery.

  The operation of the rechargeable battery 1 will be described. Current is supplied to the capacitor C1 by the voltage supplied from the charging means 2, and the capacitor C1 is charged. In the FET 3, current is supplied to the drain based on the charging voltage of the capacitor C1, and a drain current Id (current flowing from the drain to the source) flows. The drain current Id is supplied to the capacitor C2 and charges the capacitor C2. The charging voltage (both ends voltage) of the capacitor C2 is the output voltage Vo of the rechargeable battery 1.

  Here, when a current flows from the charging voltage (output voltage Vo) of the capacitor C2 to the diode D1 (anode to cathode) via the resistor Rgl, the voltage at the connection point between the diode D1 and the resistor Rg1 becomes the gate of the FET3. To be supplied. Accordingly, the FET 3 is reverse-biased by the resistor Rg1, and the drain current Id of the FET 3 is controlled by the voltage at the connection point between the diode D1 and the resistor Rg1.

  Hereinafter, the operation of the FET 3 will be mainly described with reference to the characteristic diagram. 2A shows the drain current Id of the FET 3 when there is no load (that is, when the load is not connected to the positive electrode output terminal and the negative electrode output terminal of the rechargeable battery 1 and the load current IL does not flow), and the FET 3 It is a figure which shows the relationship with the gate-source voltage VGS of. The gate-source voltage when the drain current Id1 flows is VGS1, and the drain current when the gate-source voltage is 0 V is Idss (that is, the maximum value of the drain current Id). FIG. 2B is a diagram showing the relationship between the voltage VF across the diode D1 and the current IF flowing through the diode D1 when there is no load. The voltage across the diode D1 when the drain current Id1 flows is VF1.

Since no load current IL flows when there is no load, the drain current Id1 of the FET 3 is only the current flowing through the diode D1 via the resistor Rgl. Therefore, the output voltage Vo of the rechargeable battery 1 and the drain current Id1 of the FET 3 are expressed by the following equations.

  Here, Vp is the pinch-off voltage of the FET 3 (the gate-source voltage at which the drain current Id becomes 0 as shown in FIG. 2A), Is is the saturation current of the diode D1, k is the Boltzmann constant, and q is the charge of the electrons. The quantity, T, is absolute temperature. Vo that satisfies the above equation is the output voltage at this time.

On the other hand, FIG. 3A shows the drain current Id of the FET 3 when the load is connected between the positive output terminal and the negative output terminal of the rechargeable battery 1 and the load current IL flows, and the gate-source of the FET 3. It is a figure which shows the relationship with the inter-voltage VGS. FIG. 3B is a diagram showing the relationship between the voltage VF across the diode D1 and the current IF flowing through the diode D1 when the load current IL flows. The current ΔId flowing through the diode D1 via the output voltage Vo, the drain current Id2, and the resistor Rg1 of the rechargeable battery 1 is expressed by the following equation.

  The drain current Id2 of the FET 3 is obtained by adding ΔId to the load current IL. Vo that satisfies the above equation is the output voltage at this time. 2 and 3, since Id1> ΔId, VF1> VF2, | Vgs1 |> | Vgs2 |, and the sum of the voltage change of the diode D1 and the gate-source voltage change of the FET1 is the load. This is a voltage drop when the current IL flows. As Idss is larger and | Vp | is smaller, the slope of the characteristic diagram becomes steeper, the change in VF and VGS becomes smaller, and the voltage drop at the time of load can be reduced.

  Here, it will be described that the rechargeable battery 1 has a voltage limiting function of the output voltage Vo. If the output voltage Vo is to be increased, the output voltage Vo is the sum of the voltage VF across the diode D1 and the voltage across the resistor Rg1, and the voltage across the diode D1 does not rise above a predetermined value, so the resistor Rg1 Will increase the voltage at both ends. Therefore, the current flowing through the resistor Rg1 is increased, and the drain current Id is increased. In order to increase the drain current Id, it is necessary to lower the absolute value of the gate-source voltage VGS of the FET 3 (approach it to 0 V) as shown in FIGS. 2 (a) and 3 (a). As a result, the output voltage Vo also decreases, and the output voltage Vo does not increase above a certain voltage. Therefore, the rechargeable battery 1 has a voltage limiting function for the output voltage Vo.

  Next, it will be described that the rechargeable battery 1 has an overcurrent prevention function. If the load current IL is to be increased, the drain current Id needs to be increased. Therefore, as shown in FIG. 3A, the absolute value of the gate-source voltage VGS of the FET 3 needs to be reduced (close to 0V). There is. However, since the absolute value of VGS decreases only to 0V, the drain current Id can be increased only to Idss. Therefore, it turns out that the rechargeable battery 1 has an overcurrent prevention function. Therefore, even when the load is short-circuited, an overcurrent greater than Idss does not flow, and the FET 3 is not damaged.

  Moreover, according to the rechargeable battery 1, the current consumed in the rechargeable battery 1 can be made sufficiently smaller than 1 μA by setting the resistance value of the resistor Rg1 to a large value. As described above, according to the rechargeable battery 1, wasteful current consumption can be prevented and overcurrent can be prevented.

  FIG. 4 is a circuit diagram showing a charging device 11 according to another embodiment. In addition to the configuration of the rechargeable battery 1 shown in FIG. 1, the rechargeable battery 11 includes a depletion type FET (hereinafter referred to as FET) 4, diodes D2 to D4 (voltage / current nonlinear element), and a resistor Rg2. Although it does not specifically limit, the charging means 2 has the electric power generation means 2a which generates an alternating voltage, and the bridge | rectifier rectifier circuit (diodes D101-D104) for rectifying an alternating voltage. When the power generation means 2a generates a DC voltage, it is sufficient to provide only one backflow preventing diode instead of the bridge rectifier circuit.

  The FET 4 has a drain connected to the positive output terminal of the charging means 2 (the cathodes of the diodes D101 and D102), a source connected to the connection point between the drain of the FET 3, the positive electrode of the capacitor C1, and one end of the resistor Rg2, and the gate The other end of the resistor Rg2 and the anode of the diode D4 are connected. The diodes D2 to D4 are connected in series between the gate of the FET 4 and the source of the FET 3. That is, the diode D4 has an anode connected to the gate of the FET 4 and the other end of the resistor Rg2, and a cathode connected to the anode of the diode D3. The cathode of the diode D3 is connected to the anode of the diode D2. The cathode of the diode D2 is connected to the connection point between the source of the FET 3 and the positive electrode of the capacitor C2.

  The values (characteristics) of the resistor Rg2 and the diodes D2 to D4 are set so that the drain current Id of the FET 4 can be controlled so that the maximum value of the charging voltage of the capacitor C1 does not exceed the withstand voltage of the capacitor C1. Therefore, depending on the case, the diodes D2 to D4 may be one diode or two diodes.

  The operation of the rechargeable battery 11 will be described. Due to the voltage supplied from the charging means 2, a current flows from the drain of the FET 4 to the capacitor C1 via the source, and charges the capacitor C1. A current due to the charging voltage of the capacitor C1 flows from the drain of the FET 3 to the capacitor C2 via the source, and charges the capacitor C2. The charging voltage of the capacitor C2 becomes the output voltage Vo of the rechargeable battery 11, and the current due to the output voltage Vo flows to the diode D1 through the resistor Rg1, and the voltage of the diode D1 is supplied to the gate of the FET 3, and the drain current of the FET 3 Id is controlled. The above operation is basically the same as that of the rechargeable battery 1 of FIG.

  Further, due to the voltage supplied from the charging means 2, a current flows from the drain of the FET 4 to the capacitor C2 via the source, the resistor Rg2, the diodes D4, D3, and D2, and charges the capacitor C2. By this operation, a voltage obtained by adding the voltages across the diodes D2, D3 and D4 to the output voltage Vo of the rechargeable battery 11 is supplied to the gate of the FET 4. Accordingly, the drain current Id of the FET 4 is controlled according to the voltage obtained by adding the voltages across the diodes D2, D3, and D4 to the output voltage Vo. Therefore, the maximum voltage charged in the capacitor C1 is limited according to the output voltage Vo. That is, referring to FIGS. 2A and 3A, when the output voltage Vo increases, the gate-source voltage of the FET 4 increases (the absolute value increases), so that the drain current Id decreases and the capacitor The charging voltage of C1 is limited.

  That is, in the rechargeable battery 11, as shown in FIG. 8, the maximum value of the voltage charged in the capacitor C1 is not limited by providing a resistor and a Zener diode in front of the capacitor C1, but the output voltage Vo of the rechargeable battery 11 is not limited. The maximum charging voltage charged in the capacitor C1 is limited by limiting the amount of current flowing into the capacitor C1 by a voltage obtained by adding a predetermined voltage to the capacitor C1. As described above, since the current flowing through the resistor Rg2 and the diodes D4, D3, and D2 becomes the current flowing through the capacitor C2 and the load current, there is an advantage that the current is not wasted.

  According to the rechargeable battery 11, any power generation means can be used as the charging means as long as the maximum power generation voltage of the power generation means 2a is equal to or lower than the withstand voltage of the FET 4. The withstand voltage of the electric double layer capacitor is generally about 2.5V to 5.5V, while the withstand voltage of the FET is 30V to 50V.

  As an example, FET3 and FET4 are 2SK372 (Vp≈0.5V selection), C1 is 5.5V, 0.66F (0.22F × 3), C2 is 5.5V, 0.22F, D1 to D4 are red LEDs, Rg1 = 5.6MΩ, When the circuit was actually made with Rg2 = 3.6 MΩ, Vo = 1.7 V when no load was applied, and Vo = 1.4 V when 1 mA load was obtained, an output voltage substantially corresponding to a manganese battery was obtained. The maximum voltage applied to the capacitor C1 is limited to about 5 V, and the current consumption in the circuit can be suppressed to 0.1 μA or less.

In the circuit of FIG. 4, the unit of capacitance of the capacitors C1 and C2 is Farad (F), the voltage of the capacitor C1 at full charge is Vcharge (V), and the minimum power supply voltage at which the device as the load operates is Vend ( Assuming V), the effective charge amount Qeffect (C) that can be used from this circuit is expressed by the following equation when the gate bias current is ignored.

Accordingly, the discharge duration (life) Tlife (sec) at the time of load current IL (A) is calculated as follows.

In the above constant, if C1 = 0.66F, C2 = 0.22F, Vcharge = 5V, Vo = 1.5V, Vend = 1.2V,
Qeffect = 2.574C
It is. Therefore, when the load current IL is 1 mA,
Tlife = 2574sec = 42.9min
Similarly, if IL = 0.1 mA,
Tlife = 25740sec = 429min = 7.15h
And if IL = 10μA,
Tlife = 257400sec = 4290min = 71.5h ≒ 2.98days
The result is obtained.

  FIG. 5 is a circuit diagram showing a rechargeable battery 21 according to still another preferred embodiment of the present invention. Compared to the rechargeable battery 11 of FIG. 4, the rechargeable battery 21 is obtained by replacing the FET 3, the resistor Rg <b> 1, and the diode D <b> 1 with a three-terminal regulator 22.

  The three-terminal regulator 22 has an input terminal connected to the positive electrode of the capacitor C1, an output terminal connected to the positive electrode output terminal of the charging battery 21 and the positive electrode of the capacitor C2, and a ground terminal (third terminal) connected to the negative electrode of the charging battery 21. Connected to the output terminal. The three-terminal regulator 22 generates a constant voltage from the voltage supplied via the FET 4, supplies a current based on the constant voltage to the capacitor C2, and charges the capacitor C2. The capacitor C2 has a positive electrode connected to the output terminal of the three-terminal regulator 22 and the positive electrode output terminal of the rechargeable battery, a negative electrode connected to the negative electrode output terminal of the rechargeable battery, and is charged by the current from the three-terminal regulator 22, 21 output voltages are generated.

  The FET 4 has a drain connected to the positive output of the charging means 2, a source connected to the input terminal of the three-terminal regulator 22, and a gate connected through the resistor Rg 2 to the source of the FET 4, the positive electrode of the capacitor C 1, and the input of the three-terminal regulator 22. It is connected to the connection point with the terminal.

  According to the rechargeable battery 21, as in the rechargeable battery 11, a voltage obtained by adding the voltages across the diodes D2, D3, and D4 to the output voltage Vo is supplied to the gate of the FET 4, and the drain current Id of the FET 4 is controlled. As a result, the maximum value of the voltage charged in the capacitor C1 can be limited according to the voltage obtained by adding the voltages across the diodes D2, D3, and D4 to the output voltage Vo. Therefore, it is possible to prevent useless current consumption and to limit the maximum voltage charged in the capacitor C1 to less than the withstand voltage.

  FIG. 6 shows an example of an external view of the rechargeable batteries 1, 11, and 21. The circuit of the rechargeable batteries 1, 11, and 21 is housed in a case that can be inserted into a battery holder as an alternative to the battery, and external charging It is characterized by a shape in which a charging input connector is provided so that charging is possible by means.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment.

  The present invention can be suitably employed as a rechargeable battery for electronic devices.

DESCRIPTION OF SYMBOLS 1 Rechargeable battery 2 Charging means 3 Depletion type FET
4 Depletion type FET
11 Rechargeable battery 21 Rechargeable battery 22 Three-terminal regulator

Claims (5)

A rechargeable battery that charges an output voltage to a capacitor according to a voltage supplied from a charging means,
A first capacitor charged by the charging means;
A first resistor;
The drain is connected to the positive electrode of the first capacitor, the source is connected to the positive electrode output terminal of the rechargeable battery and the positive electrode of the second capacitor, and the gate is connected to the source via the first resistor. A depletion type FET,
The positive electrode is connected to the source of the first depletion type FET and the positive output terminal of the rechargeable battery, the negative electrode is connected to the negative output terminal of the rechargeable battery, and is charged by the current from the source of the first depletion type FET. The second capacitor for generating the output voltage of the rechargeable battery;
A charging battery comprising: a first voltage-current nonlinear element having one end connected to the gate of the first depletion type FET and the other end connected to a negative output terminal of the charging battery.   The value or characteristic of said 1st resistance and said 1st voltage current nonlinear element is set so that the charging voltage at the time of a full charge of said 2nd capacitor may become substantially equal to the nominal voltage of a battery. The rechargeable battery described. A second resistor;
The drain is connected to the positive output terminal of the charging means, the source is connected to the drain of the first depletion type FET and the positive electrode of the first capacitor, and the gate is connected to the second depletion type FET via the second resistor. The second depletion type FET connected to the source;
A second voltage current having one end connected to the gate of the second depletion type FET and one end of the second resistor, and the other end connected to the source of the first depletion type FET and the positive electrode of the first capacitor. The rechargeable battery according to claim 1, further comprising a non-linear element.   4. The value or characteristic of the second resistor and the second voltage-current nonlinear element is set so that the maximum value of the charging voltage of the first capacitor does not exceed the withstand voltage of the first capacitor. The rechargeable battery described in 1. A rechargeable battery that charges an output voltage to a capacitor according to a voltage supplied from a charging means,
A first capacitor charged by the charging means;
The input terminal is connected to the positive electrode of the first capacitor, the output terminal is connected to the positive electrode output terminal of the charging battery and the positive electrode of the second capacitor, and the third terminal is connected to the negative electrode output terminal of the charging battery. A three-terminal regulator;
The positive electrode is connected to the output terminal of the three-terminal regulator and the positive electrode output terminal of the charging battery, the negative electrode is connected to the negative electrode output terminal of the charging battery, and is charged by the current from the three-terminal regulator. The second capacitor for generating an output voltage;
A second resistor;
The drain is connected to the positive output terminal of the charging means, the source is connected to the input terminal of the three-terminal regulator and the positive electrode of the first capacitor, and the gate is the source of the second depletion type FET via the second resistor. The second depletion type FET connected to
A second voltage-current nonlinearity in which one end is connected to the gate of the second depletion type FET and one end of the second resistor, and the other end is connected to the output terminal of the three-terminal regulator and the positive electrode of the second capacitor. A rechargeable battery comprising the element.

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