Power supply device and power supply method

Abstract

To provide a power supply device and a power supply method.SOLUTION: The power supply device 101 includes a supply terminal VI connected to the power generation device, a power storage terminal to which power based on power from the supply terminal is input and which is connected to the power storage device, a load terminal VOUT to which power based on power from the supply terminal is input and which is connected to the load, a first capacitor that stores power based on power from the supply terminal, a second capacitor that stores power based on power from the supply terminal, and a third capacitor that is provided between the power storage terminal and a node between the supply terminal and the first capacitor. A first power supply circuit unit that switches whether or not to supply power to the power storage device based on the amount of power stored in the first capacitor, a second power supply circuit unit that is provided between the second capacitor and the load terminal and switches whether or not to supply power to the load based on the amount of power stored in the second capacitor, and a current control unit that is provided between the first capacitor and the second capacitor and adjusts the amount of current supplied to the second capacitor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply device and a power supply method. [Background Art]

[0002] Patent Document 1 describes that "the power storage device 550 stores surplus power that is not consumed by the load 15 and the capacitor 500 among the supply power Pddc output by the overcharge prevention circuit 200." (paragraph 0014). [Prior Art Literature] [Patent Literature] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2015-171265 [Summary of Invention]

[0003] According to a first aspect of the present invention, a power supply device is provided. The power supply device includes: a supply terminal connected to a power generator; a power storage terminal to which power based on the power from the supply terminal is input and which is connected to a power storage device; a load terminal to which power based on the power from the supply terminal is input and which is connected to a load; a first capacitor that stores power based on the power from the supply terminal; a second capacitor that stores power based on the power from the supply terminal; a first power supply circuit unit provided between a node between the supply terminal and the first capacitor and the power storage terminal, and configured to switch whether to supply power to the power storage device based on the stored power amount of the first capacitor; a second power supply circuit unit provided between the second capacitor and the load terminal, and configured to switch whether to supply power to the load based on the stored power amount of the second capacitor; and a current control unit configured to adjust an amount of supply current to the second capacitor, wherein the current control unit is provided between the first capacitor and the second capacitor.

[0004] In the above power supply device, the first power supply circuit unit may include a hysteresis comparator.

[0005] In any of the above-described power supply devices, the first power supply circuit may supply power from the supply terminal to the power storage terminal when the potential of the first node connected to one end of the first capacitor becomes equal to or greater than a predetermined power storage start threshold, and may stop supplying power from the supply terminal to the power storage terminal when it becomes equal to or less than a power storage end threshold which is lower than the power storage start threshold.

[0006] In any of the above-described power supply devices, the second power supply circuit section may include a hysteresis comparator.

[0007] In any of the above-described power supply devices, the second power supply circuit may supply power from the supply terminal to the load terminal when the potential of the second node connected to one end of the second capacitor becomes equal to or greater than a predetermined power supply start threshold, and may stop supplying power from the supply terminal when it becomes equal to or less than a power supply end threshold which is lower than the power supply start threshold.

[0008] In any of the above-described power supply devices, the power supply start threshold may be smaller than the energy storage end threshold used by the first power supply circuit to compare with the potential of the first node connected to one end of the first capacitor in order to determine when to stop supplying power from the supply terminal to the energy storage terminal.

[0009] In any of the above-described power supply devices, the current control unit may have a first electrical resistance element connected between one end of the first capacitor and one end of the second capacitor.

[0010] In any of the above-described power supply devices, the magnitude of the resistance value of the first electrical resistance element may be 0 ohms or more and several megaohms or less.

[0011] In any of the above-described power supply devices, the current control unit may include a first switch connected to one end of the first capacitor, a first electrical resistance element connected between one end of the first capacitor and one end of the second capacitor, and a first timer circuit for controlling the on / off state of the first switch.

[0012] In any of the above-described power supply devices, the first timer circuit may include a second resistive element, a second switch connected between one end of the second resistive element and one end of the first capacitor, a third capacitor connected to the other end of the second resistive element, and a first voltage monitoring unit that controls the on / off status of the first switch and the second switch based on the potential of a third node provided between the other end of the second resistive element and the third capacitor.

[0013] In any of the above-described power supply devices, the first voltage monitoring unit may switch the first switch and the second switch from on to off when the potential of the third node exceeds a predetermined upper threshold, and when the second switch is off, the power stored in the third capacitor is discharged by self-consumption current, thereby switching the first switch and the second switch from off to on when the potential of the third node falls below a lower threshold that is lower than the upper threshold.

[0014] In any of the above-described power supply devices, the current control unit may include a switched-capacitor circuit including a group of switches and a capacitor connected to one end of the first capacitor, and a second timer circuit for controlling the on / off state of the group of switches.

[0015] In any of the above power supply devices, the switched-capacitor circuit may include a fourth capacitor, a third switch connected between one end of the fourth capacitor and one end of the first capacitor, and a fourth switch connected between the third switch and the load terminal, which is controlled to be on or off in a complementary manner to the third switch. In any of the above power supply devices, the second timer circuit may include a second resistive element, a second switch connected between one end of the second resistive element and one end of the first capacitor, a third capacitor connected to the other end of the second resistive element, and a second voltage monitoring unit that controls the on / off status of the second switch, the third switch, and the fourth switch based on the potential of a third node provided between the other end of the second resistive element and the third capacitor.

[0016] In any of the above-described power supply devices, the current control unit may have a variable resistor unit for controlling the amount of supplied current.

[0017] In any of the above-described power supply devices, the current control unit may have a resistance adjustment unit that adjusts the magnitude of the resistance of the variable resistor based on the amount of energy stored in the energy storage device.

[0018] Any of the above power supply devices may include a second load terminal to which power based on the power from the supply terminal is input and which is connected to a second load. Any of the above power supply devices may include a fifth capacitor for storing power based on the power from the supply terminal. Any of the above power supply devices may include a third power supply circuit that switches whether or not to supply power to the second load based on the amount of charge stored in the fifth capacitor. Any of the above power supply devices may include a second current control unit for adjusting the amount of current supplied to the fifth capacitor. In any of the above power supply devices, the second current control unit may be provided between the first capacitor and the fifth capacitor.

[0019] In any of the above-described power supply devices, the current control unit may have a first electrical resistance element connected between one end of the first capacitor and the second capacitor. In any of the above-described power supply devices, the second current control unit may have a third electrical resistance element connected between one end of the first capacitor and the fifth capacitor. In any of the above-described power supply devices, the current control unit and the second current control unit may adjust the resistance ratio of the first electrical resistance element and the third electrical resistance element based on the amount of charge stored in the energy storage device.

[0020] Any of the above power supply devices may include a fourth power supply circuit that switches whether or not to consume power using a discharge resistor in order to suppress the power supplied to the power storage device, based on the amount of energy stored in the first capacitor.

[0021] In any of the above-described power supply devices, the fourth power supply circuit may consume power through a discharge resistor to lower the voltage of the first node connected to one end of the first capacitor when the potential of the first node exceeds a predetermined second upper threshold, and may stop consuming power through the discharge resistor when the potential falls below a second lower threshold that is lower than the second upper threshold.

[0022] A second embodiment of the present invention provides a power supply method. The power supply method includes switching whether or not to supply power from a power generation device to a power storage device based on the amount of charge stored in a first capacitor that stores power based on power from a power generation device; switching whether or not to supply power from a power generation device to a load based on the amount of charge stored in a second capacitor that stores power based on power from a power generation device; and adjusting the amount of current supplied to the second capacitor by a current control unit provided between the first capacitor and the second capacitor.

[0023] It should be noted that the above summary of the invention does not enumerate all of its features. Furthermore, subcombinations of these features may also constitute an invention. [Brief explanation of the drawing]

[0024] [Figure 1] 1 illustrates an outline of the configuration of a power supply apparatus 101 according to the first embodiment. [Figure 2] illustrates an example of a specific configuration of the power supply apparatus 101 according to the first embodiment. [Figure 3] illustrates an example of a specific configuration of a hysteresis comparator 310 in the power supply apparatus 101 of the first embodiment. [Figure 4] illustrates the magnitude relationship of operation threshold voltages in the power supply apparatus 101 of the first embodiment. [Figure 5] is a flow diagram illustrating an example of an operation of a first power supply circuit unit 301 in the power supply apparatus 101 of the first embodiment. [Figure 6] is a flow diagram illustrating an example of an operation of a second power supply circuit unit 302 in the power supply apparatus 101 of the first embodiment. [Figure 7] is a timing chart illustrating an example of an operation of the power supply apparatus 101 according to the first embodiment. [Figure 8] illustrates an example of a specific configuration of a current control unit 402 in a power supply apparatus 102 of the second embodiment. [Figure 9] illustrates the magnitude relationship of operation threshold voltages in the power supply apparatus 102 of the second embodiment. [Figure 10] is a flow diagram illustrating an example of an operation of a current control unit 402 in the power supply apparatus 102 of the second embodiment. [Figure 11] is a timing chart illustrating an example of an operation of a current control unit 402 in the power supply apparatus 102 of the second embodiment. [Figure 12] illustrates an example of a specific configuration of a current control unit 403 in a power supply apparatus 103 of the third embodiment. [Figure 13] is a flow diagram illustrating an example of an operation of a current control unit 403 in the power supply apparatus 103 of the third embodiment. [Figure 14] illustrates an outline of the configuration of a power supply apparatus 104 according to the fourth embodiment. [Figure 15]A specific modification of the configuration of the current control unit 404 in the power supply device 104 of the fourth embodiment is shown. [Figure 16] The configuration of the power supply device 105 according to the fifth embodiment is shown. [Figure 17] This shows the relative magnitudes of the operating threshold voltages in the power supply device 105 of the fifth embodiment. [Figure 18] This is a flowchart showing an example of the operation of the third power supply circuit section 303 in the power supply device 105 of the fifth embodiment. [Figure 19] This is a timing chart showing an example of the operation of the power supply device 105 according to the fifth embodiment. [Figure 20] The configuration of the power supply device 106 according to the sixth embodiment is shown. [Figure 21] An example of the specific configuration of the fourth power supply circuit section 304 in the power supply device 106 of the sixth embodiment is shown. [Figure 22] This shows the relative magnitudes of the operating threshold voltages in the power supply device 106 of the sixth embodiment. [Figure 23] This is a flowchart showing an example of the operation of the fourth power supply circuit section 304 in the power supply device 106 of the sixth embodiment. [Figure 24] This is a timing chart showing an example of the operation of the power supply device 106 according to the sixth embodiment. [Modes for carrying out the invention]

[0025] The present invention will be described below through embodiments of the invention, but these embodiments are not intended to limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0026] Figure 1 shows an overview of the configuration of the power supply device 101 according to the first embodiment. The power supply device 101 outputs output power Pout to the load 15 according to the input power Pin generated by the power generator 10. The power supply device 101 may output output power Pout to the load 15 if the output power Pout rises above the power required for the operation of the load 15.

[0027] The power supply device 101 comprises a first capacitor 501, a second capacitor 502, an energy storage device 550, a first power supply circuit section 301, a second power supply circuit section 302, and a current control unit 401, and is connected to the power generator 10 and the load 15. The power supply device 101 does not necessarily have to include the energy storage device 550 itself; that is, the energy storage device 550 may be located outside the power supply device 101. Also, the power supply device 101 may include the power generator 10 and the load 15 itself.

[0028] The power supply device 101 further includes a supply terminal VI, a load terminal VOUT, and a power storage terminal VS. The supply terminal VI is connected to the power generator 10. Input power Pin is input to the supply terminal VI from the power generator 10. The load terminal VOUT is connected to the load 15. Power based on the power from the supply terminal VI is input to the load terminal VOUT. The load terminal VOUT outputs output power Pout to the load 15. The power storage terminal VS is connected to the power storage device 550. Power based on the power from the supply terminal VI is input to the power storage terminal VS. The power generator 10, load 15, first capacitor 501, second capacitor 502, and power storage device 550 can be connected to the supply terminal VI, load terminal VOUT, and power storage terminal VS, respectively.

[0029] The power generation device 10 is, for example, an ambient energy generator that generates electricity based on photoelectric conversion of outdoor or indoor light, or on thermoelectric conversion elements such as Peltier. The power generation device 10 outputs the generated input power Pin to the supply terminal VI of the power supply device 101. The power generation device 10 may be a general silicon-type solar cell or a dye-sensitized solar cell. Furthermore, the power generation device 10 may be a power generation device with a small input power Pin, consisting of a single solar cell or the like. The input power Pin increases or decreases in response to changes in ambient light.

[0030] Load 15 can be, for example, an MCU (Micro Controller Unit), a sensor, or a BLE (Bluetooth® Low Energy) device. Load 15 operates using the output power Pout from the power supply device 101.

[0031] The first capacitor terminal VO1 of the first capacitor 501 and the second capacitor terminal VO2 of the second capacitor 502 are connected to the supply terminal VI, the load terminal VOUT, and the energy storage terminal VS, respectively. The first capacitor 501 and the second capacitor 502 store power based on the power from the supply terminal VI. The first capacitor 501 temporarily stores the input power Pin from the supply terminal VI until the input power Pin is equal to or greater than the power required to charge the energy storage device 550. The second capacitor 502 temporarily stores the input power Pin from the supply terminal VI until the input power Pin is equal to or greater than the power required to operate the load 15. The capacitances of the first capacitor 501 and the second capacitor 502 are smaller than the capacitance of the energy storage device 550.

[0032] The energy storage device 550 is, for example, a large-capacity capacitor or a secondary battery. The energy storage device 550 stores at least a portion of the input power Pin generated by the power generator 10. When the power generation of the power generator 10 decreases, the energy storage device 550 can supply the stored power to the load 15 as a voltage compensation capacitor.

[0033] The first power supply circuit 301 is provided between the node between the supply terminal VI and the first capacitor 501 and the energy storage terminal VS. The first power supply circuit 301 switches whether or not to supply power to the energy storage device 550 based on the amount of energy stored in the first capacitor 501. More specifically, the first power supply circuit 301 monitors the voltage vc1 at the first capacitor terminal VO1 and switches whether or not to connect the supply terminal VI and the energy storage terminal VS according to the magnitude of the voltage vc1.

[0034] The second power supply circuit 302 is provided between the second capacitor 502 and the load terminal VOUT. The second power supply circuit 302 switches whether or not to supply power to the load 15 based on the amount of charge stored in the second capacitor 502. More specifically, the second power supply circuit 302 monitors the voltage vc2 at the second capacitor terminal VO2 and switches whether or not to connect the supply terminal VI or the charge storage terminal VS to the load terminal VOUT according to the magnitude of the voltage vc2.

[0035] The current control unit 401 adjusts the amount of current supplied to the second capacitor 502. The current control unit 401 is located between the first capacitor 501, which is located on the supply terminal VI side, and the second capacitor 502, which is located on the load terminal VOUT side. The current control unit 401 can also be defined as controlling the amount of charge stored in the second capacitor 502, which is located on the load terminal VOUT side.

[0036] The power supply device 101, having the above configuration, enables the storage of energy in the energy storage device 550 even when the power generated by the power generator 10 is less than the power consumed by the load 15. Furthermore, the power supply device 101 allows the ratio of power supply to the load 15 to charging the energy storage device 550 to be changed. In addition, even if power generation by the power generator 10 ceases, the power supply device 101 enables power supply from the energy storage device 550 to the load 15 if there is power stored in the energy storage device 550.

[0037] Figure 2 shows an example of the specific configuration of the power supply device 101 according to the first embodiment. In the power supply device 101 according to the first embodiment, the first power supply circuit section 301 has a hysteresis comparator 310 and a switch F1. Similarly, the second power supply circuit section 302 has a hysteresis comparator 320 and a switch F2.

[0038] Hysteresis comparators 310 and 320 each have a power supply terminal VDD, an output terminal VOU, and a reference terminal VSS, respectively. Hysteresis comparators 310 and 320 output high or low from the output terminal VOU depending on the voltage input to the power supply terminal VDD. The reference terminal VSS is connected to ground.

[0039] Switch F1 of the first power supply circuit 301 is controlled by a hysteresis comparator 310 to switch whether or not to connect the energy storage terminal VS to the supply terminal VI and the load terminal VOUT. One end of switch F1 is connected to the energy storage terminal VS, and the other end is connected to the supply terminal VI, the first capacitor terminal VO1, the second capacitor terminal VO2, and switch F2.

[0040] In this example, the control terminal of switch F1 is connected to the output terminal VOU of the hysteresis comparator 310.

[0041] The hysteresis comparator 310 controls switch F1 to output input power Pin to the energy storage device 550 when the first capacitor 501 is sufficiently charged and the input power Pin from the supply terminal VI reaches the power required to charge the energy storage device 550. The hysteresis comparator 310 also controls switch F1 to prevent the output power Pout output to the load 15 from decreasing. The hysteresis comparator 310 controls the on / off state of switch F1 based on the voltage vc1 at the first capacitor terminal VO1. As will be described in detail later with reference to Figure 3, the hysteresis comparator 310 outputs a low if the voltage vc1 at the first capacitor terminal VO1 is less than a predetermined threshold voltage generated within the hysteresis comparator 310, and outputs a high if it is above the predetermined threshold voltage.

[0042] Switch F2 of the second power supply circuit 302 is controlled by a hysteresis comparator 320 to switch whether or not to connect the load terminal VOUT to the supply terminal VI and the energy storage terminal VS. One end of switch F2 is connected to the load terminal VOUT, and the other end is connected to the supply terminal VI, the first capacitor terminal VO1, the second capacitor terminal VO2, and switch F1.

[0043] In this example, the control terminal of switch F2 is connected to the output terminal VOU of the hysteresis comparator 320.

[0044] The hysteresis comparator 320 controls switch F2 to output output power Pout to load 15 when the second capacitor 502 is sufficiently charged and the input power Pin from supply terminal VI reaches the power required for the operation of load 15. The hysteresis comparator 320 controls the on / off state of switch F2 based on the voltage vc2 at the second capacitor terminal VO2. Similar to the hysteresis comparator 310, the hysteresis comparator 320 outputs low to turn off switch F2 if the voltage vc2 at the second capacitor terminal VO2 is less than a predetermined threshold voltage generated within the hysteresis comparator 320, and outputs high to turn on switch F2 if it is greater than or equal to the predetermined threshold voltage.

[0045] In this specification, each power switch, such as switch F1 and switch F2, uses a semiconductor switch, and may be any type, such as Nch type or Pch type, and the insertion position may differ depending on the type. In the following figures, for the sake of clarity, power switches may be shown as boxes labeled SW or as simple on / off switches.

[0046] In the power supply device 101 according to the first embodiment, the current control unit 401 has a first electrical resistance element 411. The first electrical resistance element 411 is connected between one end of the first capacitor 501 and one end of the second capacitor 502. The magnitude of the resistance value of the first electrical resistance element 411 is, for example, 0 ohms or more and several megaohms or less. As an example, if the capacitances of the first capacitor 501 and the second capacitor 502 are 47 uF each, the magnitude of the resistance value of the first electrical resistance element 411 may be 510 kΩ.

[0047] Figure 3 shows an example of a specific configuration of the hysteresis comparator 310 in the power supply device 101 of the first embodiment. In Figure 3, the configuration of the hysteresis comparator 310 is described in detail, while a detailed description of the configuration of the hysteresis comparator 320, which has a configuration corresponding to that of the hysteresis comparator 310, is omitted. Note that, unlike the hysteresis comparator 310, the input voltage of the hysteresis comparator 320 is vc2 instead of vc1.

[0048] The hysteresis comparator 310 is a CMOS inverter comparator type switching circuit. CMOS inverter comparator type switching circuits operate with low power consumption. The hysteresis comparator 310 comprises a reference voltage generation unit 20, an inverter 30, a voltage selection unit 40, a comparator 50, a power supply terminal VDD, an output terminal VOU, and a reference terminal VSS.

[0049] The hysteresis comparator 310 operates in a hysteresis manner and outputs a signal from the output terminal VOU corresponding to the input voltage vc1 input to the power supply terminal VDD. The hysteresis comparator 310 controls whether to output a high or low signal from the output terminal VOU depending on whether the input voltage vc1 exceeds a predetermined operating threshold voltage. The operating threshold voltage has two different values: an upper operating threshold voltage and a lower operating threshold voltage. The hysteresis comparator 310 achieves hysteresis operation by changing the value of the operating threshold voltage to the upper operating threshold voltage and the lower operating threshold voltage.

[0050] The reference voltage generation unit 20 generates a predetermined reference voltage corresponding to the operating threshold voltage (target voltage). In this example, the reference voltage generation unit 20 comprises an upper reference voltage generation unit 25 and a lower reference voltage generation unit 26, both having non-volatile memory elements. The reference voltage generation unit 20 adjusts the reference voltages generated by the upper reference voltage generation unit 25 and the lower reference voltage generation unit 26 by adjusting the non-volatile memory elements. The use of non-volatile memory elements is just one example and is not limited to this system.

[0051] The upper reference voltage generation unit 25 generates a predetermined upper reference voltage VrefH corresponding to the upper operating threshold voltage and outputs it to the voltage selection unit 40. The lower reference voltage generation unit 26 generates a predetermined lower reference voltage VrefL corresponding to the lower operating threshold voltage and outputs it to the voltage selection unit 40. The lower reference voltage VrefL may be smaller than the upper reference voltage VrefH.

[0052] The voltage selection unit 40 includes switches SWH and SWL and a NOT circuit. The upper reference voltage VrefH output by the upper reference voltage generation unit 25 is input to switch SWH. On the other hand, the lower reference voltage VrefL output by the lower reference voltage generation unit 26 is input to switch SWL. Switches SWH and SWL output the input reference voltages to the positive input terminal of the comparator 50.

[0053] The voltage selection unit 40 selects either the upper reference voltage VrefH or the lower reference voltage VrefL and outputs it to the comparator 50. Specifically, the voltage selection unit 40 selects the lower reference voltage VrefL when the input voltage vc1 exceeds the threshold voltage determined by the upper reference voltage VrefH. Also, the voltage selection unit 40 selects the upper reference voltage VrefH when the input voltage vc1 falls below the threshold voltage determined by the lower reference voltage VrefL. As a result, the hysteresis comparator 310 operates hysterically at a voltage between the upper operating threshold voltage and the lower operating threshold voltage.

[0054] Furthermore, switch SWH is turned on and off in response to the signal obtained by inverting the output of comparator 50 using a NOT gate. On the other hand, switch SWL is turned on and off in response to the signal output by comparator 50. In this example, switches SWH and SWL are controlled so that their on / off states are inversely reversed. For example, when the output of comparator 50 is high, SWH is turned off and SWL is turned on. Conversely, when the output of comparator 50 is low, SWH is turned on and SWL is turned off.

[0055] The output of the comparator 50 transitions depending on whether the input voltage vc1 exceeds the operating threshold voltage. In this example, when the input voltage vc1 is below the operating threshold voltage, the output of the comparator 50 becomes a reference potential such as ground potential. When the input voltage vc1 exceeds the operating threshold voltage, the output of the comparator 50 becomes a voltage approximately equal to the voltage input to the power supply terminal VDD. The comparator 50 determines whether the voltage input to the power supply terminal VDD exceeds the operating threshold voltage based on whether the output has inverted. In this specification, the change in the output of the comparator 50 from the reference potential to the voltage input to the power supply terminal VDD, and the change from the voltage input to the power supply terminal VDD to the reference potential, are referred to as the output of the comparator 50 "inverting".

[0056] The inverter 30 switches on and off in accordance with the output signal of the comparator 50. The inverter 30 is located between the power supply terminal VDD and the output terminal VOU. In the hysteresis comparator 310, the inverter 30 outputs the input voltage vc1 from the output terminal VOU when the input voltage vc1 exceeds the operating threshold voltage. On the other hand, the inverter 30 blocks the output of the input voltage vc1 from the output terminal VOU when the input voltage vc1 is below the operating threshold voltage.

[0057] More specifically, the inverter 30 inverts the output of the comparator 50 and outputs it to the output terminal VOU. The inverter 30 comprises a single-stage CMOS inverter circuit consisting of a PMOS transistor and an NMOS transistor, with a parasitic diode connected in parallel to each transistor. The positive power supply terminal of the CMOS inverter circuit of the inverter 30 is connected to the power supply terminal VDD, and the negative power supply terminal is connected to ground. The parasitic diode of the inverter 30 is positioned to block the current flowing from the power supply terminal VDD when the transistors of the inverter 30 are turned off.

[0058] For example, when comparator 50 outputs high, hysteresis comparator 310 outputs the signal input to the reference terminal VSS. The signal input to the reference terminal VSS may be the ground voltage. Also, when comparator 50 outputs low, hysteresis comparator 310 outputs the signal input to the power supply terminal VDD. In other words, hysteresis comparator 310 outputs a signal that is the opposite of the signal output by comparator 50, with high and low values ​​being reversed.

[0059] The configuration of the hysteresis comparator 310 in this example can also be applied to other hysteresis comparators such as the hysteresis comparator 320. In that case, the operating threshold voltage is set individually for each.

[0060] Figure 4 shows the relative magnitudes of the operating threshold voltages in the power supply device 101 of the first embodiment. The operating threshold voltages include a power storage start threshold VDETH1, which is the voltage threshold for starting power storage in the power storage device 550; a power storage end threshold VDETL1, which is the voltage threshold for ending power storage in the power storage device 550; a power supply start threshold VDETH2, which is the voltage threshold for starting power supply to the load 15; and a power supply end threshold VDETL2, which is the voltage threshold for ending power supply to the load 15.

[0061] The energy storage start threshold VDETH1 can also be defined as the rising threshold of the hysteresis comparator 310, and the energy storage end threshold VDETL1 can also be defined as the falling threshold of the hysteresis comparator 310. Similarly, the power supply start threshold VDETH2 can also be defined as the rising threshold of the hysteresis comparator 320, and the power supply end threshold VDETL2 can also be defined as the falling threshold of the hysteresis comparator 320. Each rising threshold corresponds to the upper reference voltage VrefH explained using Figure 3, and each falling threshold corresponds to the lower reference voltage VrefL explained using Figure 3, and the same applies in the following explanation.

[0062] Each operating threshold voltage decreases in the following order: power storage start threshold VDETH1, power storage end threshold VDETL1, power supply start threshold VDETH2, and power supply end threshold VDETL2. In Figure 4, power storage of the power storage device 550 begins when the voltage vc1 at the first capacitor terminal VO1 exceeds the power storage start threshold VDETH1, and power storage of the power storage device 550 ends when the voltage vc1 at the first capacitor terminal VO1 falls below the power storage end threshold VDETL1. Similarly, power supply to the load 15 begins when the voltage vc2 at the second capacitor terminal VO2 exceeds the power supply start threshold VDETH2, and power supply to the load 15 ends when the voltage vc2 at the second capacitor terminal VO2 falls below the power supply end threshold VDETL2.

[0063] Figure 5 is a flowchart showing an example of the operation of the first power supply circuit 301 in the power supply device 101 of the first embodiment. In this embodiment, the first power supply circuit 301 supplies power from the supply terminal VI to the power storage terminal VS when the potential of the first node N1 connected to one end of the first capacitor 501 becomes equal to or greater than a predetermined power storage start threshold VDETH1, and stops supplying power from the supply terminal VI to the power storage terminal VS when it becomes equal to or less than a power storage end threshold VDETL1 which is lower than the power storage start threshold VDETH1. An example of the first node N1 described above is shown in Figure 2.

[0064] More specifically, the first power supply circuit 301 waits until the voltage vc1 at the first capacitor terminal VO1 becomes greater than VDETH1 (step S300: NO), and when it becomes greater than VDETH1 (step S300: YES), it switches switch F1 ON (conductive) (step S310). In response to switch F1 being switched ON, in addition to the input power Pin input to input terminal VI, the power stored in the first capacitor 501 is also used to charge the energy storage device 550. As a result, the voltage vc1 at the first capacitor terminal VO1 begins to decrease.

[0065] The first power supply circuit 301 waits until the voltage vc1 at the first capacitor terminal VO1 becomes less than VDETL1 (step S320: NO), and when it becomes less than VDETL1 (step S320: YES), it switches switch F1 to OFF (non-conductive) (step S330) and returns to step S300.

[0066] Figure 6 is a flowchart showing an example of the operation of the second power supply circuit 302 in the power supply device 101 of the first embodiment. In this embodiment, the second power supply circuit 302 supplies power from the supply terminal VI to the load terminal VOUT when the potential of the second node N2 connected to one end of the second capacitor 502 becomes equal to or greater than a predetermined power supply start threshold VDETH2, and stops supplying power from the supply terminal VI when it becomes equal to or less than a power supply end threshold VDETL2 which is lower than the power supply start threshold VDETH2. An example of the second node N2 described above is shown in Figure 2. As shown in Figure 4, the power supply start threshold VDETH2 is smaller than the energy storage end threshold VDETH2 which the first power supply circuit 301 uses to compare with the potential of the first node N1 connected to one end of the first capacitor 501 in order to decide whether to stop supplying power from the supply terminal VI to the energy storage terminal VS.

[0067] More specifically, the second power supply circuit 302 waits until the voltage vc2 at the second capacitor terminal VO2 becomes greater than VDETH2 (step S400: NO), and when it becomes greater than VDETH2 (step S400: YES), it switches switch F2 ON (conducting) (step S410). In response to switch F2 being switched ON, in addition to the input power Pin input to input terminal VI, the power stored in the second capacitor 502 is also used to supply power to the load 15. As a result, the voltage vc2 at the second capacitor terminal VO2 begins to decrease.

[0068] The second power supply circuit 302 waits until the voltage vc2 at the second capacitor terminal VO2 becomes less than VDETL2 (step S420: NO), and when it becomes less than VDETL2 (step S420: YES), it switches switch F2 to OFF (non-conductive) (step S430) and returns to step S400.

[0069] Figure 7 is a timing chart showing an example of the operation of the power supply device 101 according to the first embodiment. In the graph of Figure 7, the horizontal axis represents time T, and the vertical axis represents voltage V. In the graph of Figure 7, the four operating threshold voltages VDETH1, VDETL1, VDETH2, and VDETL2 mentioned above are shown as straight dashed lines. Also in the graph of Figure 7, times t1 to t5 are shown as straight dashed lines.

[0070] Referring to Figure 7, after the first capacitor 501 begins to store energy, at time t1, the voltage vc1 at the first capacitor terminal VO1 becomes greater than VDETH1, charging of the energy storage device 550 begins, and the voltage vbat of the energy storage device 550 begins to rise. Subsequently, the voltage vc1 at the first capacitor terminal VO1 decreases, and at time t2, it becomes less than VDETL1, and charging of the energy storage device 550 temporarily ends. As a result, the voltage vbat of the energy storage device 550 stops rising. Note that between times t1 and t2, the voltage vc1 of the first capacitor 501 decreases because charging of the first capacitor 501 from the generator 10 continues, but charging of the energy storage device 550 is also taking place.

[0071] Subsequently, the voltage vc1 at the first capacitor terminal VO1 rises again, and at time t3, it becomes greater than VDETH1, so charging of the energy storage device 550 begins again, and the voltage vbat of the energy storage device 550 begins to rise. Then, between time t3 and t5, it operates in the same way as between time t1 and t3.

[0072] Thus, charging of the energy storage device 550 is intermittently stopped until time t5. After time t5, the voltage value obtained by adding the voltage drop caused by the current flowing through the internal resistor of the energy storage device 550 to the voltage at the energy storage terminal VS of the energy storage device 550, i.e., the voltage of the energy storage device 550 vbat, reaches the voltage vc1 of the first capacitor 501. As a result, the voltage vc1 at the first capacitor terminal VO1 no longer falls below VDETL1, and charging of the energy storage device 550 continues. In this way, the power supply device 101 according to this embodiment charges the energy storage device 550 regardless of the amount of energy stored in the energy storage device 550.

[0073] Referring to Figure 7, after the second capacitor 502 begins to store energy, the voltage vc2 at the second capacitor terminal VO2 becomes greater than VDETH2, power supply to the load 15 begins, and the voltage vc2 at the second capacitor terminal VO2 begins to decrease. Subsequently, the voltage vc2 at the second capacitor terminal VO2 decreases to less than VDETL2, and power supply to the load 15 is temporarily terminated. This operation is then repeated. As shown in Figure 7, the voltage vc2 at the second capacitor terminal VO2 rises with a gentler slope than the voltage vc1 at the first capacitor terminal VO1. Note that while power is being supplied to the load 15, the voltage vc2 at the second capacitor terminal VO2 decreases because power is being supplied to the load 15, even though charging of the second capacitor 502 from the generator 10 continues.

[0074] As shown in Figure 7, it is understood that charging the second capacitor 502 and supplying power to the load 15 are performed independently of charging the first capacitor 501 and charging the energy storage device 550. This is because the current control unit 401, which is provided between the first capacitor 501 and the second capacitor 502, has a first electrical resistance element 411, as in this embodiment, so that even if the voltage vc2 at the second capacitor terminal VO2 is consumed by supplying power to the load 15, the power stored in the first capacitor 501 does not decrease easily.

[0075] Furthermore, when the voltage vc2 at the second capacitor terminal VO2 becomes greater than VDETH2, and the second power supply circuit 302 switches switch F2 ON (conductive) to begin supplying power to the load 15, a portion of the power stored in the first capacitor 501 may also be used to supply power to the load 15. Therefore, in Figure 7, the rise in vc1 momentarily stops at that point.

[0076] In the power supply device 101 according to the first embodiment described above, the power generation device 10 may be used to charge the second capacitor 502 or supply power to the load 15 during periods when the power generation device 10 is not generating power, or when the power stored in the energy storage device 550 is greater than the input power Pin from the power generation device 10.

[0077] As a comparative example with the power supply device 101 according to this embodiment, we assume a device that does not include the current control unit 401 and the second capacitor 502 in the power supply device 101. In the comparative example device, two power supply circuits with different operating voltage thresholds both monitor the voltage vc at the capacitor terminal VO, and switch the switches of each power supply circuit according to vc to adjust the amount of power supplied to the energy storage device and the load.

[0078] Of the two power supply circuits, the power supply circuit for supplying power to the load starts supplying power to the load when the vc exceeds the load power supply start threshold. On the other hand, the power supply circuit for storing energy in the energy storage device cannot start storing energy in the energy storage device 550 until the vc exceeds the energy storage start threshold for the energy storage device 550. The energy storage start threshold is set higher than the power supply start threshold.

[0079] Therefore, in the comparative example device, after power supply to the load is started, the vc can only exceed the energy storage start threshold and use the surplus power for storage if the amount of power generated by the power generation device is greater than the power consumed by the load, resulting in surplus power. In other words, in the comparative example device, if the amount of power generated by the power generation device is less than the power consumed by the load and no surplus power is generated, the vc will not exceed the energy storage start threshold, and energy storage in the energy storage device may not start at all.

[0080] In contrast, according to the power supply device 101 of this embodiment, which has the configuration described with reference to Figures 1 to 7, the first power supply circuit 301 switches whether or not to supply power from the power generation device 10 to the energy storage device 550 based on the amount of charge stored in the first capacitor 501, which stores power from the power generation device 10. Furthermore, according to the power supply device 101, the second power supply circuit 302 switches whether or not to supply power from the power generation device 10 to the load 15 based on the amount of charge stored in the second capacitor 502, which stores power from the power generation device 10. Furthermore, according to the power supply device 101, the amount of current supplied to the load 15 is adjusted by a current control unit 401 provided between the first capacitor 501 and the second capacitor 502.

[0081] With a power supply device 101 having such a configuration, even when the power generated by the power generator 10 is less than the power consumed by the load 15, it is possible to store energy in the energy storage device 550. Furthermore, with the power supply device 101, it is possible to change the ratio of power supply to the load 15 and charging of the energy storage device 550 by controlling the amount of current from the supply terminal VI to the second capacitor 502 by the current control unit 401, and by adjusting the respective capacities of the first capacitor 501 and the second capacitor 502. In addition, even if power generation by the power generator 10 stops, the power supply device 101 can supply power from the energy storage device 550 to the load 15 if there is power stored in the energy storage device 550.

[0082] Figure 8 shows an example of the specific configuration of the current control unit 402 in the power supply device 102 of the second embodiment. The power supply device 102 of the second embodiment differs from the power supply device 101 of the first embodiment in that it has a current control unit 402 instead of a current control unit 401. Since the other configurations are the same, the same reference numerals are used for the other configurations and redundant explanations are omitted. In addition, in the figures of the following embodiments, for the sake of clarity, the configurations that were shown in detail using Figures 1 to 7 and the corresponding configurations are omitted again in detail.

[0083] The current control unit 402 comprises a first switch 421, a first electrical resistance element 411, and a first timer circuit unit 422. The first switch 421 is connected to one end of the first capacitor 501. The first electrical resistance element 411 is connected between one end of the first capacitor 501 and the second capacitor 502.

[0084] The first timer circuit 422 is a circuit for controlling the on / off state of the first switch 421. The first timer circuit 422 includes a second electrical resistance element 426, a second switch 427, a third capacitor 428, and a first voltage monitoring unit 429. The second switch 427 is connected between one end of the second electrical resistance element 426 and one end of the first capacitor 501. The third capacitor 428 is connected to the other end of the second electrical resistance element 426. The third capacitor 428 may have a capacitance of 10% or less compared to the capacitances of the first capacitor 501 and the second capacitor 502.

[0085] The first voltage monitoring unit 429 controls the on / off state of the first switch 421 and the second switch 427 based on the potential vc3 of the third node N3, which is located between the other end of the second electrical resistance element 426 and the third capacitor 428. The first voltage monitoring unit 429 includes a configuration similar to that of a hysteresis comparator 310, etc.

[0086] The first voltage monitoring unit 429 switches the first switch 421 and the second switch 427 from on to off when the potential vc3 of the third node N3 becomes equal to or greater than a predetermined upper threshold VDETH3. With the second switch 427 off, the first voltage monitoring unit 429 discharges the power stored in the third capacitor 428 using its self-consumption current, and switches the first switch 421 and the second switch 427 from off to on when the potential vc3 of the third node N3 becomes equal to or less than the lower threshold VDETL3, which is lower than the upper threshold VDETH3. The discharge current by the first voltage monitoring unit 429 can also be defined as the operating current of the first voltage monitoring unit 429.

[0087] Figure 9 shows the relative magnitudes of the operating threshold voltages in the power supply device 102 of the second embodiment. The power supply device 102 having the above configuration has a current control unit 402 that performs time-division current supply from the first capacitor 501 to the second capacitor 502. By performing the above operation, the current control unit 402 charges the second capacitor 502 with an average current.

[0088] The operating threshold voltage shown in Figure 9 includes, in addition to the operating threshold voltage shown in Figure 4, the upper limit threshold VDETH3 and the lower limit threshold VDETL3 of the first voltage monitoring unit 429. The upper limit threshold VDETH3 can also be defined as the rising threshold of the first voltage monitoring unit 429, and the lower limit threshold VDETL3 can also be defined as the falling threshold of the first voltage monitoring unit 429.

[0089] The operating threshold voltages decrease in the following order: charge start threshold VDETH1, charge end threshold VDETL1, power supply start threshold VDETH2, power supply end threshold VDETL2, upper limit threshold VDETH3, and lower limit threshold VDETL3. In Figure 9, in addition to the operations described using Figure 4, the connection between the first capacitor 501 and the second capacitor 502 is broken when the potential vc3 at the third node N3 exceeds VDETH3, and the connection between the first capacitor 501 and the second capacitor 502 is restored when the potential vc3 at the third node N3 falls below VDETL3.

[0090] Figure 10 is a flowchart showing an example of the operation of the current control unit 402 in the power supply device 102 of the second embodiment. When the third capacitor 428 is empty, the first switch 421 and the second switch 427 start in the ON (conducting) state (step S500-0), and the current control unit 402 waits until the potential vc3 of the third node N3 becomes greater than VDETH3 (step S500: NO), and when it becomes greater than VDETH3 (step S500: YES), it switches the first switch 421 and the second switch 427 to OFF (non-conducting) (step S510). In response to the first switch 421 and the second switch 427 being switched to OFF, the connection between the first capacitor 501 and the second capacitor 502 and the third capacitor 428 is interrupted.

[0091] The current control unit 402 waits until the potential vc3 of the third node N3 becomes less than VDETL3 (step S520: NO), and when it becomes less than VDETL3 (step S520: YES), it switches the first switch 421 and the second switch 427 to ON (conductive) (step S530), and returns to step S500.

[0092] Figure 11 is a timing chart showing an example of the operation of the current control unit 402 in the power supply device 102 of the second embodiment. In the graph of Figure 11, the horizontal axis represents time T, and the vertical axis represents voltage V. In the graph of Figure 11, the two operating threshold voltages VDETH3 and VDETL3 mentioned above are shown as straight dashed lines. Also in the graph of Figure 11, the six points in time at which the first switch 421 and the second switch 427 are switched on and off are also shown as straight dashed lines.

[0093] As described above, the power supply device 102 according to the second embodiment has the same effects as the power supply device 101 according to the first embodiment. Furthermore, the current control unit 402 of the power supply device 102 according to the second embodiment can reduce resistance and thus reduce losses, although the number of components increases compared to the current control unit 401 of the power supply device 101 according to the first embodiment.

[0094] Figure 12 shows an example of the specific configuration of the current control unit 403 in the power supply device 103 of the third embodiment. The power supply device 103 of the third embodiment differs from the power supply device 102 of the second embodiment in that it has a current control unit 403 instead of a current control unit 402. Since the other configurations are the same, redundant explanations of the other configurations are omitted using the same reference numerals.

[0095] The current control unit 403 includes a switched-capacitor circuit 431 which includes a group of switches and a capacitor connected to one end of the first capacitor 501, and a second timer circuit unit 432 for controlling the on / off state of the group of switches.

[0096] The switched-capacitor circuit 431 includes a fourth capacitor 433, a third switch 434, and a fourth switch 435. The third switch 434 is connected between one end of the fourth capacitor 433 and one end of the first capacitor 501. The fourth switch 435 is connected between the third switch 434 and the load terminal VOUT, and its on / off control is complementary to that of the third switch 434.

[0097] The second timer circuit 432 differs from the first timer circuit 422 of the second embodiment in that it includes a second voltage monitoring unit 439 instead of a first voltage monitoring unit 429. Since the other configurations are the same, redundant explanations of the other configurations are omitted using the same reference numbers.

[0098] The second voltage monitoring unit 439 controls the on / off state of the second switch 427, the third switch 434, and the fourth switch 435 based on the potential vc3 of the third node N3, which is located between the other end of the second electrical resistance element 426 and the third capacitor 428. The second voltage monitoring unit 439 includes a configuration similar to that of the first voltage monitoring unit 429, such as a hysteresis comparator 310.

[0099] The second voltage monitoring unit 439 switches the second switch 427 and the third switch 434 from on to off and the fourth switch 435 from off to on when the potential vc3 of the third node N3 becomes equal to or greater than a predetermined upper threshold VDETH3. With the second switch 427 off, the second voltage monitoring unit 439 discharges the power stored in the third capacitor 428 using its self-consumption current, and when the potential vc3 of the third node N3 becomes less than or equal to a lower threshold VDETL3, which is lower than the upper threshold VDETH3, it switches the second switch 427 and the third switch 434 from off to on and the fourth switch 435 from on to off. The discharge current by the second voltage monitoring unit 439 can also be defined as the operating current of the second voltage monitoring unit 439. In this embodiment, the upper threshold VDETH3 and lower threshold VDETL3 may be the same as, or different from, the upper threshold VDETH3 and lower threshold VDETL3 in the second embodiment described above.

[0100] Figure 13 is a flowchart showing an example of the operation of the current control unit 403 in the power supply device 103 of the third embodiment. When the third capacitor 428 is empty, the first switch 421 and the second switch 427 start in the ON (conducting) state (step S600-0), and the current control unit 403 waits until the potential vc3 of the third node N3 becomes greater than VDETH3 (step S600: NO), and when it becomes greater than VDETH3 (step S600: YES), it switches the second switch 427 and the third switch 434 from ON (conducting) to OFF (non-conducting) and switches the fourth switch 435 from OFF (non-conducting) to ON (conducting) (step S610). In response to the switching of the second switch 427 and the third switch 434 to OFF, the connection between the first capacitor 501 and the third capacitor 428 and the fourth capacitor 433 is interrupted. On the other hand, when the fourth switch 435 is switched ON, the connection is made between the fourth capacitor 433 and the second capacitor 502.

[0101] The current control unit 402 waits until the potential vc3 of the third node N3 becomes less than VDETL3 (step S620: NO), and when it becomes less than VDETL3 (step S620: YES), it switches the second switch 427 and the third switch 434 from OFF (non-conductive) to ON (conductive) and switches the fourth switch 435 from ON (conductive) to OFF (non-conductive) (step S630), and returns to step S600. In step S630, in response to the second switch 427 and the third switch 434 being switched ON, the connection between the first capacitor 501 and the third capacitor 428 and the fourth capacitor 433 is made. On the other hand, in response to the fourth switch 435 being switched OFF, the connection between the fourth capacitor 433 and the second capacitor 502 is broken.

[0102] As described above, the power supply device 103 according to the third embodiment has the same effects as the power supply device 101 according to the first embodiment. Furthermore, the current control unit 403 of the power supply device 103 according to the third embodiment can always separate the first capacitor 501 and the second capacitor 502 compared to the current control unit 401 of the power supply device 101 according to the first embodiment, and the charging of the second capacitor 502 and the supply of power to the load 15 can be performed completely independently of the charging of the first capacitor 501 and the charging of the energy storage device 550.

[0103] Figure 14 shows an overview of the configuration of the power supply device 104 according to the fourth embodiment. The power supply device 104 of the fourth embodiment differs from the power supply device 101 of the first embodiment in that it has a current control unit 404 instead of a current control unit 401. Since the other configurations are the same, redundant explanations of the other configurations are omitted using the same reference numerals.

[0104] The current control unit 404 has a variable resistor unit 441 for controlling the amount of current supplied to the load 15. In this example, the variable resistor unit 441 includes a variable resistor element 442. The current control unit 404 further has a resistance adjustment unit 446 that adjusts the magnitude of the resistance of the variable resistor unit 441 based on the amount of charge stored in the energy storage device 505. The resistance adjustment unit 446 includes a configuration similar to that of a hysteresis comparator 310, etc. In this example, the resistance adjustment unit 446 adjusts the magnitude of the electrical resistance of the variable resistor element 442 based on the amount of charge stored in the energy storage device 550.

[0105] Figure 15 shows a modified example of the specific configuration of the current control unit 404 in the power supply device 104 of the fourth embodiment. In this example, the variable resistor unit 441 in the current control unit 404 includes a main electrical resistance element 443, a sub-electrical resistance element 444, and a switch 445, instead of the variable resistor element 442 in the example of Figure 14. In this example, the resistance adjustment unit 446 switches the switch 445 from off to on so that current is bypassed to the sub-electrical resistance element 444, which has a smaller electrical resistance than the main electrical resistance element 443, or switches the switch 445 from on to off so that no current flows to the sub-electrical resistance element 444, based on the amount of charge stored in the energy storage device 550.

[0106] As described above, the power supply device 104 according to the fourth embodiment has the same effects as the power supply device 101 according to the first embodiment. Furthermore, the current control unit 404 of the power supply device 104 according to the fourth embodiment can adjust the amount of current supplied to the load 15 according to the charging status of the energy storage device 550. The power supply device 104 can monitor the voltage vc1 of the first capacitor terminal VO1 and switch the current resistance in the variable resistor unit 441 according to the status of the voltage vbat of the energy storage device 550. For example, the power supply device 104 may be controlled to increase the amount of current supplied to the load 15 when the amount of power generated by the power generator 10 is large and the amount of energy stored in the energy storage device 550 is sufficient, and may be controlled to decrease the amount of current supplied to the load 15 when the amount of power generated by the power generator 10 is small and the amount of energy stored in the energy storage device 550 is insufficient.

[0107] The power supply device 104 can also adjust the startup interval and charging current to match the startup interval required for the load 15 and the charging current to the energy storage device 550, or it can change the startup interval of the load 15 according to the voltage vbat of the energy storage device 550. For example, if the startup interval required for the load 15 is relatively long, charging of the energy storage device 550 can be prioritized to prepare for the case when power generation by the generator 10 does not occur. For example, if it is desired that the load 15 will operate immediately even when the energy storage device 550 is empty, the energy storage capacity of the energy storage device 550 can be reduced to prioritize starting the load 15 quickly.

[0108] Figure 16 shows an overview of the configuration of the power supply device 105 according to the fifth embodiment. The power supply device 105 of the fifth embodiment differs from the power supply device 101 of the first embodiment in that it is equipped with a current control unit 450 instead of a current control unit 401, and additionally includes a second load 16, a second load terminal VOUT, a fifth capacitor 503, a third power supply circuit section 303, and a second current control unit 460. Since the other configurations are the same, redundant explanations of the other configurations will be omitted using the same reference numbers.

[0109] The second load terminal VOUT receives power based on the power from the supply terminal VI and is connected to the second load 16. The second load 16 may be an MCU or the like, similar to load 15. The power consumption, startup interval, etc., of the second load 16 and load 15 may be the same or different.

[0110] The fifth capacitor 503 stores power based on the power from the supply terminal VI. In this embodiment, the first capacitor terminal VO1 of the first capacitor 501, the second capacitor terminal VO2 of the second capacitor 502, and the third capacitor terminal VO3 of the fifth capacitor 503 are connected to the supply terminal VI, the load terminal VOUT, the second load terminal VOUT, and the power storage terminal VS, respectively. The fifth capacitor 503 temporarily stores the input power Pin from the supply terminal VI until the input power Pin becomes equal to or greater than the power required for the operation of the second load 16. The capacitance of the fifth capacitor 503 is smaller than the capacitance of the power storage device 550.

[0111] The third power supply circuit 303 switches whether or not to supply power to the second load 16 based on the amount of charge stored in the fifth capacitor 503. More specifically, the third power supply circuit 303 monitors the voltage vc3 at the third capacitor terminal VO3 and switches whether or not to connect the supply terminal VI or the charge storage terminal VS to the second load terminal VOUT depending on the magnitude of the voltage vc3. The third power supply circuit 303 may have a configuration similar to that of the first power supply circuit 301, etc.

[0112] The second current control unit 460 adjusts the amount of current supplied to the fifth capacitor 503. The second current control unit 460 is located between the first capacitor 501, which is located on the side of the supply terminal VI, and the fifth capacitor 503, which is located on the side of the second load terminal VOUT. The second current control unit 460 can also be defined as controlling the amount of charge stored in the fifth capacitor 503, which is located on the side of the second load terminal VOUT.

[0113] In this embodiment, the current control unit 450 has a first electrical resistance element 451 connected between one end of the first capacitor 501 and the second capacitor 502, and the second current control unit 460 similarly has a third electrical resistance element 461 connected between one end of the first capacitor 501 and the fifth capacitor 503. In this example, both the first electrical resistance element 451 and the third electrical resistance element 461 are variable resistance elements. The current control unit 450 further has a resistance adjustment unit 452 that adjusts the magnitude of the resistance of the first electrical resistance element 451 based on the amount of charge stored in the energy storage device 505, and the second current control unit 460 similarly has a resistance adjustment unit 462 that adjusts the magnitude of the resistance of the third electrical resistance element 461 based on the amount of charge stored in the energy storage device 505. The resistance adjustment unit 452 and the resistance adjustment unit 462 include a configuration similar to that of a hysteresis comparator 310, etc.

[0114] Figure 17 shows the relative magnitudes of the operating threshold voltages in the power supply device 105 of the fifth embodiment. In addition to the operating threshold voltages shown in Figure 4, the operating threshold voltages shown in Figure 17 include a power supply start threshold VDETH3, which is the voltage threshold for starting power supply to the second load 16, and a power supply end threshold VDETL3, which is the voltage threshold for ending power supply to the second load 16.

[0115] The power supply start threshold VDETH3 can also be defined as the rising threshold of the hysteresis comparator included in the third power supply circuit 303, and the power supply end threshold VDETL3 can also be defined as the falling threshold of the hysteresis comparator. Note that the power supply start threshold VDETH3 and power supply end threshold VDETL3 in this embodiment are different from the upper limit threshold VDETH3 and lower limit threshold VDETL3 in the second and third embodiments described above. As described above, the capacitance of the third capacitor 428 in the second and third embodiments is 10% or less compared to the capacitances of the first capacitor 501 and the second capacitor 502, and is also 10% or less compared to the capacitance of the fifth capacitor 503.

[0116] Each operating threshold voltage decreases in the following order: power storage start threshold VDETH1, power storage end threshold VDETL1, power supply start threshold VDETH2, power supply start threshold VDETH3, power supply end threshold VDETL2, and power supply end threshold VDETL3. In Figure 17, in addition to the operations described using Figure 4, power supply to the second load 16 starts when the voltage vc3 at the fifth capacitor terminal VO3 exceeds the power supply start threshold VDETH3, and power supply to the second load 16 ends when the voltage vc3 at the fifth capacitor terminal VO3 falls below the power supply end threshold VDETL3.

[0117] Figure 18 is a flowchart showing an example of the operation of the third power supply circuit 303 in the power supply device 105 of the fifth embodiment. In this embodiment, the third power supply circuit 303 supplies power from the supply terminal VI to the second load terminal VOUT when the potential of the node connected to one end of the fifth capacitor 503 becomes equal to or greater than a predetermined power supply start threshold VDETH3, and stops supplying power from the supply terminal VI when it becomes equal to or less than a power supply end threshold VDETL3, which is lower than the power supply start threshold VDETH3.

[0118] More specifically, the third power supply circuit 303 waits until the voltage vc3 at the fifth capacitor terminal VO3 becomes greater than VDETH3 (step S700: NO), and when it becomes greater than VDETH3 (step S700: YES), it switches the switch F3 included in the third power supply circuit 303 to ON (conductive) (step S710). In response to the switch F3 being switched ON, in addition to the input power Pin input to the input terminal VI, the power stored in the fifth capacitor 503 is also used to supply power to the second load 16. As a result, the voltage vc3 at the fifth capacitor terminal VO3 begins to decrease.

[0119] The third power supply circuit 303 waits until the voltage vc3 at the third capacitor terminal VO3 becomes less than VDETL3 (step S720: NO), and when it becomes less than VDETL3 (step S720: YES), it switches switch F3 to OFF (non-conductive) (step S730) and returns to step S700.

[0120] Figure 19 is a timing chart showing an example of the operation of the power supply device 105 according to the fifth embodiment. In the graph of Figure 19, the horizontal axis represents time T, and the vertical axis represents voltage V. In the graph of Figure 19, the six operating threshold voltages VDETH1, VDETL1, VDETH2, VDETH3, VDETL2, and VDETL3 are shown as straight dashed lines. Also in the graph of Figure 19, times t1 to t5 are shown as straight dashed lines.

[0121] In the timing chart of Figure 19, the changes in the voltage vc1 at the first capacitor terminal VO1, the voltage vc2 at the second capacitor terminal VO2, and the voltage vbat at the energy storage terminal VS are the same as those shown in the timing chart of Figure 7. Referring to Figure 19, after the fifth capacitor 503 starts to store energy, the voltage vc3 at the fifth capacitor terminal VO3 becomes greater than VDETH3, power supply to the second load 16 begins, and the voltage vc3 at the fifth capacitor terminal VO3 begins to decrease. Subsequently, the voltage vc3 at the fifth capacitor terminal VO3 decreases to less than VDETL3, and power supply to the second load 16 is temporarily terminated. This operation is then repeated.

[0122] As shown in Figure 19, the voltage vc3 at the fifth capacitor terminal VO3 rises with a gentler slope than the voltage vc1 at the first capacitor terminal VO1, similar to the voltage vc2 at the second capacitor terminal VO2. Note that the voltage vc3 at the fifth capacitor terminal VO3 decreases while power is being supplied to the second load 16, because although charging of the fifth capacitor 503 from the generator 10 continues, power is being supplied to the second load 16.

[0123] As shown in Figure 19, it is understood that the charging of the second capacitor 502 and the supply of power to the load 15, the charging of the fifth capacitor 503 and the supply of power to the second load 16, and the charging of the first capacitor 501 and the charging of the energy storage device 550 are carried out independently of each other. This is because the current control unit 450 provided between the first capacitor 501 and the second capacitor 502, and the second current control unit 460 provided between the first capacitor 501 and the fifth capacitor 503, for example, have a first electrical resistance element 451 and a third electrical resistance element 461, as in this embodiment, so that even if the voltage vc2 at the second capacitor terminal VO2 is consumed by supplying power to the load 15, or the voltage vc3 at the fifth capacitor terminal VO3 is consumed by supplying power to the second load 16, the power stored in the first capacitor 501 does not decrease easily.

[0124] In the power supply device 105 having the above configuration, the current control unit 450 and the second current control unit 460 may further adjust the resistance ratio of the first electrical resistance element 451 and the third electrical resistance element 461 based on the amount of energy stored in the energy storage device 550. If the resistance ratio is not adjusted in this way, the current control unit 450 and the second current control unit 460 may have electrical resistance elements with predetermined resistance values ​​instead of variable resistance elements.

[0125] As described above, the power supply device 105 according to the fifth embodiment has the same effects as the power supply device 101 according to the first embodiment. Furthermore, with the power supply device 105 according to the fifth embodiment, even if any multiple loads are added, the same effects can be obtained by configuring it in the same way as the configuration described in this embodiment.

[0126] Furthermore, according to the power supply device 105 of the fifth embodiment, the ratio of the amount of power generated by the power generator 10 distributed to each load can be adjusted by adjusting the resistance ratio of the electrical resistance elements in each current control unit based on the amount of power stored in the energy storage device 550. In addition, according to the power supply device 105 of the fifth embodiment, each load can be operated at different starting intervals by changing the operating voltage threshold in each current circuit section provided on the side of each load, and the power required by each load, which has different power consumption, can be supplied to each load.

[0127] Figure 20 shows an overview of the configuration of the power supply device 106 according to the sixth embodiment. The power supply device 106 of the sixth embodiment differs from the power supply device 101 of the first embodiment in that it additionally includes a fourth power supply circuit section 304. Since the other configurations are the same, redundant explanations of the other configurations are omitted using the same reference numerals.

[0128] The fourth power supply circuit 304 switches whether or not to consume power through a discharge resistor in order to suppress the power supplied to the energy storage device 550, based on the amount of charge stored in the first capacitor 501. Specifically, the fourth power supply circuit 304 switches whether or not to pass a portion of the supply current from the supply terminal VI to an overcharge prevention shunt resistor, based on the amount of charge stored in the first capacitor 501. More specifically, the fourth power supply circuit 304 monitors the voltage vc1 at the first capacitor terminal VO1 and switches whether or not to connect the supply terminal VI to the overcharge prevention shunt resistor according to the magnitude of the voltage vc1.

[0129] Figure 21 shows an example of the specific configuration of the fourth power supply circuit 304 in the power supply device 106 of the sixth embodiment. The fourth power supply circuit 304 has a configuration similar to the hysteresis comparator 310 shown in Figure 3 and is a CMOS inverter comparator type switching circuit. Specifically, the fourth power supply circuit 304 differs from the hysteresis comparator 310 shown in Figure 3 in that it has a PMOS transistor 34 instead of an inverter 30 and does not have a reference terminal VSS. The other configurations of the fourth power supply circuit 304 are the same as the corresponding configurations of the hysteresis comparator 310 shown in Figure 3, so the same reference numbers are used and redundant explanations are omitted.

[0130] The fourth power supply circuit 304 operates in a hysteresis manner, outputting the supply current input from the power supply terminal VDD from the output terminal VOU and flowing it through the shunt resistor. The fourth power supply circuit 304 controls whether or not to supply current from the output terminal VOU to the shunt resistor depending on whether or not the input voltage vc1 exceeds a predetermined operating threshold voltage.

[0131] The PMOS transistor 34 switches on and off in accordance with the output signal of the comparator 50. The PMOS transistor 34 is located between the power supply terminal VDD and the output terminal VOU. In the fourth power supply circuit section 304, when the input voltage vc1 exceeds the operating threshold voltage, the PMOS transistor 34 outputs the supply current input from the power supply terminal VDD through the output terminal VOU. On the other hand, when the input voltage vc1 is below the operating threshold voltage, the PMOS transistor 34 blocks the output of the supply current input from the power supply terminal VDD through the output terminal VOU.

[0132] Figure 22 shows the relative magnitudes of the operating threshold voltages in the power supply device 106 of the sixth embodiment. The operating threshold voltages shown in Figure 22 include, in addition to the operating threshold voltages shown in Figure 4, a second upper limit threshold VDETH4, which is the voltage threshold at which the fourth power supply circuit 304 begins to consume power through the discharge resistor in order to protect the energy storage device 550 from overcharging, and a second lower limit threshold VDETL4, which is the voltage threshold at which the fourth power supply circuit 304 stops consuming power through the discharge resistor. The second upper limit threshold VDETH4 can also be defined as the rising threshold of the fourth power supply circuit 304, and the second lower limit threshold VDETL4 can also be defined as the falling threshold of the fourth power supply circuit 304.

[0133] Each operating threshold voltage decreases in the following order: second upper threshold VDETH4, second lower threshold VDETL4, power storage start threshold VDETH1, power storage end threshold VDETL1, power supply start threshold VDETH2, and power supply end threshold VDETL2. In Figure 22, in addition to the operations described using Figure 4, the fourth power supply circuit 304 starts consuming power through the discharge resistor when the potential vc1 of the first node N1 exceeds VDETH4, and the fourth power supply circuit 304 stops consuming power through the discharge resistor when the potential vc1 of the first node N1 falls below VDETL4.

[0134] Figure 23 is a flowchart showing an example of the operation of the fourth power supply circuit 304 in the power supply device 106 of the sixth embodiment. In this embodiment, the fourth power supply circuit 304 consumes power through a discharge resistor to lower the voltage of the first node N1 connected to one end of the first capacitor 501 when the potential of the first node N1 exceeds a predetermined second upper threshold VDETH4, and stops consuming power through the discharge resistor when it falls below a second lower threshold VDETL4, which is lower than the second upper threshold VDETH4. An example of the first node N1 described above is shown in Figure 20.

[0135] More specifically, the fourth power supply circuit 304 waits until the voltage vc1 at the first capacitor terminal VO1 becomes greater than VDETH4 (step S800: NO), and when it becomes greater than VDETH4 (step S800: YES), it starts consuming power through the discharge resistor (step S810). That is, in addition to the input power Pin input to the input terminal VI, the power stored in the first capacitor 501 and the power stored in the energy storage device 550 also begin to be consumed through the discharge resistor. As a result, the voltage vc1 at the first capacitor terminal VO1 and the voltage vbat at the energy storage terminal VS begin to decrease.

[0136] The fourth power supply circuit section 304 waits until the voltage vc1 at the first capacitor terminal VO1 becomes less than VDETL4 (step S820: NO), and when it becomes less than VDETL4 (step S820: YES), it stops power consumption by the discharge resistor (step S830) and returns to step S800.

[0137] Figure 24 is a timing chart showing an example of the operation of the power supply device 106 according to the sixth embodiment. In the graph of Figure 23, the horizontal axis represents time T, and the vertical axis represents voltage V. In the graph of Figure 23, the six operating threshold voltages VDETH4, VDETL4, VDETH1, VDETL1, VDETH2, and VDETL2 mentioned above are shown as straight dashed lines. In the graph of Figure 24, times t1 to t5 are also shown as straight dashed lines.

[0138] In the timing chart of Figure 24, the changes in the voltage vc1 at the first capacitor terminal VO1, the voltage vc2 at the second capacitor terminal VO2, and the voltage vbat at the energy storage terminal VS are the same as those shown in the timing chart of Figure 7 until the voltage vc1 at the first capacitor terminal VO1 exceeds VDETH4. Referring to Figure 24, at that point, the fourth power supply circuit 304 begins to consume power through the discharge resistor, and the voltage vc1 at the first capacitor terminal VO1 and the voltage vbat at the energy storage terminal VS begin to decrease. Subsequently, the voltage vc1 at the first capacitor terminal VO1 decreases to less than VDETL4, and the fourth power supply circuit 304 temporarily stops consuming power through the discharge resistor. This operation is then repeated.

[0139] As described above, the power supply device 106 according to the sixth embodiment has the same effects as the power supply device 101 according to the first embodiment. Furthermore, as described above, the power supply device 106 according to the sixth embodiment can prevent overcharging of the energy storage device 550.

[0140] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0141] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, it does not mean that it is essential to perform the operations in that order. [Explanation of Symbols]

[0142] 10 Power generation equipment 15 load 101 Power supply equipment VI supply terminal VS storage terminal VOUT load terminal 501 First Capacitor 502 Second Capacitor VO1 First capacitor terminal VO2 2nd capacitor terminal 301 1st power supply circuit section 310 Hysteresis comparator 20 Reference voltage generation unit 25 Upper reference voltage generation unit 26 Lower reference voltage generation unit 30 Inverters 40 Voltage Selection Section 50 Comparators F1 Switch F1 302 2nd power supply circuit section 320 Hysteresis Comparator F2 switch 401 Current Control Unit 411 First electrical resistance element 550 Energy storage device N1 First Node N2 Second Node 102 Power supply equipment 402 Current Control Unit 421 Switch 1 411 First electrical resistance element 422 First Timer Circuit Section 426 Second electrical resistance element 427 Second switch 428 Third Capacitor 429 First Voltage Monitoring Unit 103 Power supply equipment 403 Current Control Unit 431 Switched Capacitor Circuit 432 Second Timer Circuit Section 433 Fourth Capacitor 434 Third switch 435 Fourth switch 439 Second Voltage Monitoring Unit 104 Power supply equipment 404 Current Control Unit 441 Variable Resistor Section 442 Variable Resistor Element 446 Resistance adjustment section 443 Main electrical resistance element 444 Sub-electrical resistance element 445 Switch 105 Power supply equipment 16 2nd load VOUT 2nd load terminal 503 Fifth Capacitor VO3 Fifth capacitor terminal 303 Third power supply circuit section 450 Current Control Unit 451 First electrical resistance element 452 Resistance adjustment section 460 Second Current Control Unit 461 Third electrical resistance element 462 Resistance adjustment section 106 Power supply equipment 304 4th power supply circuit section 34 PMOS transistors

Claims

1. A supply terminal connected to the power generation device, Power based on the power from the aforementioned supply terminal is input to the energy storage terminal, which is connected to the energy storage device. Power based on the power from the aforementioned supply terminal is input to the load terminal, which is connected to the load, A first capacitor that stores power based on the power from the aforementioned supply terminal, A second capacitor that stores power based on the power from the aforementioned supply terminal, A first power supply circuit unit is provided between the node between the supply terminal and the first capacitor and the energy storage terminal, and switches whether or not to supply power to the energy storage device based on the amount of energy stored in the first capacitor. A second power supply circuit is provided between the second capacitor and the load terminal, and switches whether or not to supply power to the load from at least the second capacitor based on the amount of charge stored in the second capacitor. A current control unit that adjusts the amount of current supplied to the second capacitor and Equipped with, The current control unit is provided between the first capacitor and the second capacitor. Power supply device.

2. The first power supply circuit section includes a hysteresis comparator. The power supply device according to claim 1.

3. The first power supply circuit unit supplies power from the supply terminal to the power storage terminal when the potential of the first node connected to one end of the first capacitor exceeds a predetermined power storage start threshold, and stops supplying power from the supply terminal to the power storage terminal when it falls below a power storage end threshold that is lower than the power storage start threshold. The power supply device according to claim 2.

4. The second power supply circuit section includes a hysteresis comparator. The power supply device according to claim 1.

5. The second power supply circuit unit supplies power from the supply terminal to the load terminal from at least the second capacitor when the potential of the second node connected to one end of the second capacitor exceeds a predetermined power supply start threshold, and stops supplying power from the supply terminal when it falls below a power supply end threshold that is lower than the power supply start threshold. The power supply device according to claim 4.

6. The power supply start threshold is smaller than the power storage end threshold used by the first power supply circuit to compare with the potential of the first node connected to one end of the first capacitor in order to determine when to stop supplying power from the supply terminal to the power storage terminal. The power supply device according to claim 5.

7. The current control unit has a first electrical resistance element connected between one end of the first capacitor and one end of the second capacitor. The power supply device according to claim 1.

8. The magnitude of the resistance value of the first electrical resistance element is greater than 0 ohms and less than or equal to several megaohms. The power supply device according to claim 7.

9. The current control unit includes a first switch connected to one end of the first capacitor, a first electrical resistance element connected between one end of the first capacitor and one end of the second capacitor, and a first timer circuit for controlling the on / off state of the first switch. The power supply device according to claim 1.

10. The first timer circuit section is, The second electrical resistance element, A second switch is connected between one end of the second electrical resistance element and one end of the first capacitor, A third capacitor connected to the other end of the second electrical resistance element, A first voltage monitoring unit controls the on / off state of the first switch and the second switch based on the potential of a third node provided between the other end of the second electrical resistance element and the third capacitor. including, The power supply device according to claim 9.

11. The first voltage monitoring unit is, When the potential of the third node exceeds a predetermined upper threshold, the first switch and the second switch are switched from on to off. With the second switch in the off state, the power stored in the third capacitor is discharged by the self-consumption current, and when the potential of the third node falls below a lower threshold that is lower than the upper threshold, the first switch and the second switch are switched from off to on. The power supply device according to claim 10.

12. The current control unit includes a switched-capacitor circuit including a group of switches and a capacitor connected to one end of the first capacitor, and a second timer circuit for controlling the on / off state of the group of switches. The power supply device according to claim 1.

13. The aforementioned switched-capacitor circuit is, The fourth capacitor, A third switch is connected between one end of the fourth capacitor and one end of the first capacitor, A fourth switch is connected between the third switch and the load terminal and its on / off control is complementary to that of the third switch. Includes, The second timer circuit section is, The second electrical resistance element, A second switch is connected between one end of the second electrical resistance element and one end of the first capacitor, A third capacitor connected to the other end of the second electrical resistance element, A second voltage monitoring unit controls the on / off state of the second switch, the third switch, and the fourth switch based on the potential of a third node provided between the other end of the second electrical resistance element and the third capacitor. including, The power supply device according to claim 12.

14. The current control unit has a variable resistor unit for controlling the amount of supplied current. The power supply device according to claim 1.

15. The current control unit has a resistance adjustment unit that adjusts the magnitude of the resistance of the variable resistor based on the amount of energy stored in the energy storage device. The power supply device according to claim 14.

16. Power based on the power from the aforementioned supply terminal is input to a second load terminal, which is connected to a second load, A fifth capacitor that stores power based on the power from the aforementioned supply terminal, A third power supply circuit unit that switches whether or not to supply power to the second load from at least the fifth capacitor based on the amount of charge stored in the fifth capacitor, A second current control unit that adjusts the amount of current supplied to the fifth capacitor, Equipped with, The second current control unit is provided between the first capacitor and the fifth capacitor, The power supply device according to claim 1.

17. The current control unit has a first electrical resistance element connected between one end of the first capacitor and the second capacitor. The second current control unit has a third electrical resistance element connected between one end of the first capacitor and the fifth capacitor. The current control unit and the second current control unit adjust the resistance ratio of the first electrical resistance element and the third electrical resistance element based on the amount of charge stored in the energy storage device. The power supply device according to claim 16.

18. The system includes a fourth power supply circuit that, based on the amount of charge stored in the first capacitor, switches whether or not to allow power to be consumed by a discharge resistor in order to suppress the power supplied to the energy storage device. The power supply device according to claim 1.

19. The fourth power supply circuit unit consumes power through a discharge resistor to lower the voltage of the first node when the potential of the first node connected to one end of the first capacitor exceeds a predetermined second upper threshold, and stops consuming power through the discharge resistor when it falls below a second lower threshold that is lower than the second upper threshold. The power supply device according to claim 18.

20. Based on the amount of charge stored in the first capacitor, which stores power based on the power generated by the power generation device, the system switches whether or not to supply power from the power generation device to the power storage device. Based on the amount of charge stored in the second capacitor, which stores power based on the power from the aforementioned power generation device, the system switches whether or not to supply power from the power generation device to the load from at least the second capacitor, A current control unit provided between the first capacitor and the second capacitor adjusts the amount of current supplied to the second capacitor. A power supply method comprising the following features.

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