Energy supply circuit without power converter and electronic device using same

• US 10,379,568 B2
• Filed: 10/21/2014
• Issued: 08/13/2019
• Est. Priority Date: 10/21/2013
• Status: Active Grant

• Current Assignee: Seoul National University R&DB Foundation (Seoul National University)
• Original Assignee: Seoul National University R&DB Foundation (Seoul National University)
• Inventors: Chang, Nae-Hyuck, Yang, Jin-Young, Rim, Chai-Yeol, Kyung, Chong-Min
• Primary Examiner(s): Cole, Brandon S
• Application Number:
  US15/030,777
• Publication Number:
  US 20160246320A1
• Time in Patent Office: 1,757 Days
• Field of Search: 307139-147
• CPC Class Codes: G01G 23/36 Indicating the weight by electrical means, e.g. using photoelectric cells
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• CPC Class Codes: G05F 5/00 Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

The present invention relates to an energy supply circuit for instantly supplying power without a power converter and an electronic device which operates only when energy is supplied from an energy source using the same. An energy supply circuit without a power converter according to the present invention comprises: an energy extraction unit 10 for generating power from an energy source; and output unit 20 for supplying power to an external electronic circuit; a switch unit 30 interposed between the energy extraction unit and the output unit 20 to connect an output end of the energy extraction unit 10 to the output unit 20 when switched on; and a maximum power point tracking control unit 40 for generating an open/closed signal for opening or closing the switch unit 30 according to the voltage and current of the energy extraction unit 10. The present invention has a technical feature wherein a turn-on point of the open/closed signal comes at a time when the output end voltage of the energy extraction unit 10 is Vh, and a turn-off point comes at a time when the output end voltage of the energy extraction unit 10 is Vl. Accordingly, the present invention has a simple configuration, low manufacturing costs, has no energy loss due to the power conversion, and has no reduction in life due to charging and discharging of an energy storage device.

Claims

1. An energy supply circuit, comprising:

an energy source configured to generate a power;

an outputter configured to supply the power to an electronic circuit;

a switch configured to control connection between the energy source and the outputter; and

a controller configured to;

generate a turn on signal for turning on the switch when a voltage of the energy source is higher than Vh which corresponds to a maximum power point (MPP) of a maximum irradiance,

generate a turn off signal for turning off the switch when the voltage of the energy source is lower than Vl which corresponds to a MPP of a minimum irradiance, and

generate a sleep signal or a wake up signal that controls a power mode of the electronic circuit, and

wherein the Vh is sufficiently close to the Vl for supplying the constant voltage to drive the electronic circuit.

2. The energy supply circuit of claim 1, wherein the energy source comprises photoelectric element.

3. The energy supply circuit of claim 1, wherein the controller is configured to generate the wake up signal after generating the turn on signal, and generate the sleep signal before generating the turn off signal.

4. The energy supply circuit of claim 1, further comprising a bulk capacitor connected to each end of the energy source in parallel and a decoupling capacitor connected to each end of the outputter in parallel.

5. The electronic device of claim 4, wherein a duty cycle Ddpm of the on signal is expressed as equations below, Vpv being an output of the energy source, Ipv being an output current of the energy source, Cbulk being a capacitance of the bulk capacitor, Cdecoup being a capacitance of the decoupling capacitor, Vmid being an output voltage of the energy source at a time at which charge sharing between the bulk capacitor and the decoupling capacitor occurs when the switch is turned-on, Pon being an energy consumed by the electronic circuit, and Psw being an energy consumed when the switch is switched

6. An electronic device, comprising:

an energy supply circuit; and

an electronic circuit supplied a power from the energy supply circuit,

wherein the energy supply circuit comprises an energy source configured to generate the power, an outputter configured to supply the power to the electronic circuit, a switch configured to control connection between the energy source and the outputter and a controller configured to generate a turn on signal for turning on the switch when a voltage of the energy source is higher than Vh which corresponds to a maximum power point (MPP) of a maximum irradiance, generate a turn off signal for turning off the switch when the voltage of the energy source is lower than Vl which corresponds to a MPP of a minimum irradiance, and generate a sleep signal or a wake up signal that controls a power mode of the electronic circuit, and wherein the Vh is sufficiently close to the Vl for supplying the constant voltage to drive the electronic circuit.

7. The electronic device of claim 6, wherein the electronic circuit comprises a non-volatile microprocessor.

8. The electronic device of claim 6, wherein the electronic circuit comprises an ultraviolet sensor configured to sense ultraviolet light, a processor configured to accumulate ultraviolet light amounts based on an output of the ultraviolet sensor, remember a state of a current operation when the sleep signal is received, and restore the remembered state when the wake up signal is received, and a display configured to display an ultraviolet index based on the accumulated ultraviolet light amounts.

9. The electronic device of claim 6, wherein the electronic circuit comprises an ultraviolet sensor configured to sense ultraviolet light, and a display configured to display an ultraviolet index based on an output of the ultraviolet sensor.

10. The electronic device of claim 8, further comprising a patch configured to allow the electronic device to be attached to an object.