Energy harvesting load control switch

• US 9,166,405 B2
• Filed: 09/24/2012
• Issued: 10/20/2015
• Est. Priority Date: 09/24/2012
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Cooper Technologies Company (Eaton Corporation PLC.)
• Inventors: Brandt, Nathan Allen, Lucas, Richard William, Johnson, Justin Bruce, Jonasson, Brent Thomas
• Primary Examiner(s): DUNN, DARRIN D
• Application Number:
  US13/625,397
• Publication Number:
  US 20140088776A1
• Time in Patent Office: 1,121 Days
• Field of Search: 700/286, 700/291, 700/295, 700/297
• US Class Current: 1/1
• CPC Class Codes: H01H 47/22 for supplying energising current for relay coil
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/22 The renewable source being solar energy
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 2310/54 according to a pre-established time schedule
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin
• CPC Class Codes: Y04S 20/14 Protecting elements, switches, relays or circuit breakers

Abstract

A method, device, and system for controlling power delivered to a power-consuming device. The device can harvest power from a conductor carrying a high voltage using a power harvesting device. The device can include a power storage device to power a hardware processor and a communication component when there is no voltage flowing through the conductor. The device can determine when a control event is to occur. At such time, the device terminates control power delivered to the power-consuming device and continues to withhold the control power until the control event expires. When the control event has ended, the device allows control power to flow to the power-consuming device. The device uses a timer and the communication component to send and receives signals associated with a control event to a user. The device can also operate in a limited mode to conserve power when the device is not in use.

Claims

1. A method for controlling power delivered to a power-consuming device, the method comprising:

receiving, from a current transformer, a low voltage energy signal harvested from a high voltage energy signal generated by an energy source;

conditioning, using a power storage device conditioner of a load control switch, the low voltage energy signal to generate a trickle charge;

charging a power storage device of the load control switch using the trickle charge generated by the power storage device conditioner;

applying power from the power storage device to a plurality of components of the load control switch, wherein the plurality of components of the load control switch comprises a timer, a hardware processor, and a communication component;

determining, using the communication component, the hardware processor, and the timer, a start time of a control event;

terminating, using a relay at the start time of the control event, the power delivered to the power-consuming device, wherein the relay is energized using the power applied to the hardware processor of the load control switch by the power storage device of the load control switch; and

delivering, using the relay at an end time of the control event, the power to the power-consuming device,

wherein when the current transformer initiates generating the low voltage energy signal or when the hardware processor stops operating in a limited mode, the communication component searches for a signal associated with the control event for a delay period of time while a relay contact of the relay is held in an open position for the delay period of time.

2. The method of claim 1, further comprising:

boosting the low voltage energy signal to generate a boosted signal;

delivering the boosted signal to a coil of the relay up until the start time of the control event and at the end time of the control event,

wherein delivering the boosted signal to the coil closes the relay contact.

3. The method of claim 1, further comprising:

operating the communication component and the hardware processor in a limited mode prior to receiving the low voltage energy signal harvested from the energy source.

4. The method of claim 1, wherein the hardware processor determines the start time and the end time based on a current time provided by the timer.

5. The method of claim 1, wherein the high voltage signal flows through a conductor, wherein the high voltage signal is at least 110 volts alternating current.

6. The method of claim 5, wherein the high voltage signal is also transformed into a control signal by a transformer and delivered to one end of the relay contact by a thermostat.

7. The method of claim 6, wherein the control signal delivered from the transformer to the thermostat is approximately 24 volts alternating current.

8. The method of claim 7, wherein the thermostat sends the control signal to the relay contact when an ambient temperature exceeds a high temperature threshold.

9. The method of claim 1, wherein the power-consuming device is an air conditioning unit.

10. A load control switch, comprising:

a current transformer that is configured to harvest a low voltage energy signal from a high voltage signal generated by an energy source;

a housing comprising;

a power storage device conditioner electrically coupled to the current transformer, wherein the power storage device conditioner receives the low voltage energy signal and generates a trickle charge;

a power storage device electrically coupled to the power storage device conditioner, wherein the power storage device receives the trickle charge to store power;

a timer electrically coupled to the power storage device, wherein the timer operates using the power stored by the power storage device;

memory for storing a plurality of instructions;

a hardware processor electrically coupled to the power storage device and the timer, and communicably coupled to the memory, wherein the hardware processor executes the plurality of instructions stored in the memory, wherein the hardware processor operates using the power stored by the power storage device;

a communication component communicably coupled to the hardware processor, wherein the communication component receives a signal for a control event; and

a relay electrically coupled to the hardware processor, wherein the relay comprises a relay contact, wherein the relay contact has an open state and a closed state, wherein the open state is enabled during the control event, and wherein the closed state is enabled outside of the control event,

wherein the relay contact is configured to couple to an energy-consuming device, and

wherein when the current transformer initiates generating the low voltage energy signal or when the hardware processor stops operating in a limited mode, the communication component searches for a signal associated with the control event for a delay period of time while the relay contact is held in an open position for the delay period of time.

11. The load control switch of claim 10, wherein the housing further comprises:

a boost converter electrically coupled to the current transformer and the hardware processor, wherein the boost converter generates a voltage to energize a coil of the relay outside of the control event.

12. The load control switch of claim 11, wherein the voltage is approximately 50% greater than the low voltage energy signal received by the boost converter from the current transformer.

13. The load control switch of claim 11, wherein the boost converter is further electrically coupled to the communication component.

14. The load control switch of claim 10, wherein the power storage device is a 1.1 amp-hour power storage device.

15. The load control switch of claim 10, wherein the timer, the hardware processor, and the communication component operate in the limited mode when an amount of time since receiving the low voltage energy signal from the current transformer exceeds a threshold time.

16. The load control switch of claim 15, wherein the limited mode comprises at least one selected from a group consisting of checking for a signal associated with a control event on a periodic basis and otherwise being idle, and being idle until receiving a signal associated with a control event.

17. The load control switch of claim 10, wherein the current transformer comprises a clamp and at least one lead, wherein the clamp is positioned around a conductor carrying the high voltage signal, and wherein the power storage device is electrically coupled to at least one lead of the current transformer.

18. The load control switch of claim 10, wherein the communication component uses radio frequency radio to communicate with a user.

19. A system, comprising:

a power-consuming device;

a transformer that processes a high voltage signal carried on a conductor from a primary power source;

a thermostat electrically coupled to the transformer, wherein the thermostat has an enabled state and a disabled state, wherein the enabled state allows power from the primary power supply to pass therethrough, and wherein the disabled state prevents the power from the primary power supply to pass therethrough; and

a load control switch electrically coupled to the thermostat and the power-consuming device, wherein the load control switch comprises;

a current transformer that generates a low voltage signal from a high voltage signal, wherein the high voltage signal is generated by an energy source;

a power storage device conditioner coupled to the current transformer, wherein the power storage device conditioner receives the low voltage energy signal and generates a trickle charge;

a power storage device electrically coupled to the power storage device conditioner, wherein the power storage device receives the trickle charge to store power;

a timer electrically coupled to the power storage device, wherein the timer operates using the power stored by the power storage device;

memory for storing a plurality of instructions;

a hardware processor electrically coupled to the power storage device and the timer, and communicably coupled to the memory, wherein the hardware processor executes the plurality of instructions stored in the memory, wherein the hardware processor operates using the power stored by the power storage device;

a communication component communicably coupled to the hardware processor, wherein the communication component receives a signal for a control event; and

a relay electrically coupled to the hardware processor, the thermostat, and the power-consuming device, wherein the relay comprises a relay contact, wherein the relay contact has an open state and a closed state, wherein the open state is enabled during the control event, and wherein the closed state is enabled outside of the control event,

wherein the relay contact, when in the closed state, delivers the voltage signal processed by the transformer to the power-consuming device, and

wherein when the current transformer initiates generating the low voltage energy signal or when the hardware processor stops operating in a limited mode, the communication component searches for a signal associated with the control event for a delay period of time while the relay contact is held in an open position for the delay period of time.