WO2008019270A2

WO2008019270A2 - Smart power saving power supply

Info

Publication number: WO2008019270A2
Application number: PCT/US2007/074968
Authority: WO
Inventors: Don R. Johnson
Original assignee: Everhart, Mark, R.
Priority date: 2006-08-04
Filing date: 2007-08-01
Publication date: 2008-02-14
Also published as: WO2008019270A3

Abstract

Disclosed herein is a method of monitoring the output power of a power supply and electrically disconnecting the power supply from a power source when no power is drawn from the output side. Also disclosed is a power supply having a primary side connected to an AC power source and an output side that connected to a power consuming device. The power supply is adapted to monitor the output side to determine whether a power is being supplied to the power consuming device and if not, the power supply is adapted to disconnect the primary side from the AC power source to conserve power. The power supply may further be adapted to continually monitor the output side of the power supply and reconnect the primary side to the AC power source when a device begins to draw power from the output side.

Description

SMART POWER SAVING POWER SUPPLY

by

Mark R. Everhart and Don Richard Johnson

CROSS REFERENCE TO RELATED APPLICATION

[oooi] This application claims the benefit of U.S. Provisional Application Ser. No. 60/835,640, entitled, "Smart Power Saving Power Supply," by Mark R. Everhart and Don Richard Johnson, filed August 4, 2006, hereby incorporated by reference in its entirety herein.

BACKGROUND OF THE INVENTION Field of the Invention

[ooo2] The present invention relates generally to a power supply having a primary side connected to an AC power source and an output side that may be connected to a power consuming device. The power supply is adapted to monitor the output side to determine whether a power consuming device is connected and consuming power, and if not, the power supply is adapted to disconnect the primary side from the AC power source, thus conserving power. The power supply may further be adapted to monitor the output side of the power supply and reconnect the primary side to the AC power source when a power consuming device begins to draw power from the power supply.

Description of the Related Art

[ooo3] In today's high tech world, millions of electronic devices are operated in conjunction with a power supply. The power supply converts normal high voltage AC power (typically 100 to 240 VAC) to low voltage DC power to run the device and/or charge batteries used to provide the necessary power to operate the device. The power supply may include a transformer or other electronics to convert the AC power to the appropriate low voltage power to run a specific electronic device. The electronic device could be any of a number of electronic devices, such as a personal digital assistant ("PDA") or a digital camera for example, as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. [ooo4] Although today's power supplies have been designed to be efficient and minimize power consumption, present power supplies generally continue to consume source power while connected to a power source. Even when the electronic device is turned off or is not connected to the power supply, the transformer or other voltage converter electronic connected to the primary side of the power supply continues to consume power from the power source. As this power is not consumed by the electronic device, this power is simply wasted. The consumption of unused power may also produce undesired heat to the circuitry of the power supply, which may affect the overall life of the power supply. The life of the power supply may be extended if the power supply only consumed power when a power drawing electronic device was connected to the output side.

[ooo5] In light of the foregoing, it would be desirable to provide a power supply that does not consume power when a connected electronic device is not drawing power from the output side of the power supply. It would also be desirable to provide a power supply that does not consume power when an electronic device is not connected to the output side of the power supply. It would be further desirable to provide a power supply that disconnects the primary side from a power source when no power is being drawn from the output side of the power supply. It would be desirable to provide means for monitoring the output side of a power supply, such as a monitoring circuit, that may be connected to a typical power supply and disconnects or reconnects the input side of the power supply with a power source based on the activity of the output side.

[ooo6] The present invention is directed to overcoming, or at least reducing the effects of, one or more of the issues set forth above. SUMMARY OF THE INVENTION

[ooo7] The object of the present disclosure is to provide a power supply having a primary side connected to an output side, the primary side may be connected to a power source and a device may be connected to the output side, wherein the primary side includes means for converting power from the power source to be consumed by the device. The power supply further includes means for monitoring the output side and means for disconnecting the primary side from the power source when a power consuming device is not connected to the output side or when a device is connected, but is not consuming power. The power supply may further include means for reconnecting the primary side to the power source when a power consuming device is connected to the output side and the device consumes power.

[0008] In one embodiment a method for conserving the amount of power used by a power supply is disclosed. The method comprises connecting a power supply to a power source, the power supply comprising a primary side connected to the power source, an output side, and a circuit electrically connected to both the primary side and the power source, wherein the circuit is adapted to disconnect and reconnect the primary side with the power source and to monitor the power consumed from the output side. The method further comprises converting the power from the power source to a low voltage power and connecting a power consuming device to the output side, wherein the low voltage power may be provided to the device from the output side of the power supply. The method further comprises monitoring the power provided to the device from the output side of the power supply with the circuit. The method further comprises disconnecting the primary side from the power source when power is not being provided from the output side to the device. The method may further comprise reconnecting the primary side to the power source when power is provided from the output side to the device. [ooo9] In another embodiment, power supply is disclosed that includes a primary side, the primary side being connectable to a power source, an output side operatively connected to the primary side, wherein an electronic device may be connected to the output side, and means for converting power from the power source into power that may be consumed by the electronic device. The means for converting the power may be electrically connected to the primary side or alternatively may comprise the primary side of the power supply. The means for converting power may include transformers or electronics adapted for the conversion of voltage as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure.

[ooio] The power supply may further include means for monitoring the output side of the power supply to determine whether the electronic device is consuming any power from the output side of the power supply. The means for monitoring the output side of the power supply may be able to determine when the electronic device is not consuming any power, such as when the electronic device is disconnected, turned off, or in sleep mode. The power supply further includes means for disconnecting the primary side of the power supply from the power source. The means for monitoring as well as the means for disconnecting the primary side of the power supply from the power source may be a circuit connected to the positive output side of the power supply. The actual configuration of the circuit may be varied to both monitor the output side as well as disconnect the primary side of the power supply as would be recognized by one of ordinary skill in the art having the benefit of this disclosure.

[ooii] In one embodiment, the circuit may include a triac and a triac driver. The triac driver may be used detect current flow through the positive side of the power supply to determine whether the electronic device is consuming any power. Upon detection of no current flow, the triac driver deactivates or "turns off the triac, thus preventing current to flow from the power source to the primary side of the power supply. The circuit may include a capacitor to supply voltage to the output side if an electronic device is connected when the primary side is disconnected from the power supply as discussed below. Alternatively, when the triac driver detects current flow through the positive output side of the power supply, it activates or "turns on" the triac, thus allowing current to flow from the power source to the primary side of the power supply.

[ooi2] The circuit may further include a capacitor connected between the positive and negative leads of the output side of the power supply. The capacitor may be charged to the output voltage delivered to the electronic device during the normal operation of the power supply. When the electronic device ceases to consume power and the triac has been "turned off disconnecting the primary side of the power supply from the power source, the capacitor has been charged to a voltage equal to the normal output voltage. When the electronic device resumes the consumption of power, such as being reconnected to the output side, being turned back on, or coming out of sleep mode, the capacitor will discharge the normal output voltage through the electronic device. The discharge of the capacitor provides a current flow through the positive output side of the power supply, which will be detected by the triac driver. Upon detection of current flow, the triac driver activates or "turns on" the triac, thus connecting the primary side of the power supply to the power source.

[ooi3] The circuit may include a pair of diodes or, alternatively, a zener diode to ensure the proper voltage drop across the triac driver when there is current flow through positive output side of the power supply to the electronic device. Additionally, a diode may be located between the primary side of the power supply and the capacitor to prevent the discharge of the capacitor when the primary side has been disconnected from the power source. [ooi4] The power supply may include means for bypassing the means for disconnecting the primary side of the power supply from the power source. The means for bypassing may include a momentary contact switch that directly connects the primary side of the power supply to the power source. The bypass means may allow current flow through the power supply when the power supply and electronic device are initially connected to the power source. The bypass means provides for the reset of the means for disconnecting the primary side from the power source. This may be necessary if the electronic device has been disconnected from the power supply for an extended period of time or that the charge on the capacitor has been depleted.

BRIEF DESCRIPTION OF THE DRAWINGS

[ooi5] Figure 1 illustrates an exemplary circuit that may be connected to a power supply to monitor the power consumed on the output side of the power supply and disconnected the primary side of the power supply from the power source when no power is being consumed.

[ooi6] Figure 2 is a flow chart of a method of conserving the amount of power consumed by a power supply.

[ooi7] While the invention is susceptible to various modifications and alternative forms, the specific embodiment shown by way of example in the drawing will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. Specifically, the invention of the present disclosure is the method of monitoring the output of a power supply and connecting or disconnecting the power supply from a power source when the no power is being consumed from the output of the power supply.

DETAILED DESCRIPTION [ooi8] Illustrative embodiments of the invention are described below as they might be employed in the use of a power supply that monitors the output side of the power supply and as a result disconnects or reconnects the primary side of the power supply to a power source accordingly. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[ooi9] Further aspects and advantages of the various embodiments of the invention will become apparent from consideration of the following description and drawings.

[0020] Figure 1 shows a schematic diagram of a power supply incorporating certain teachings of the present disclosure. The schematic diagram shows a circuit 5 that electrically connects a typical AC-in / DC-out power supply 20 to an AC high voltage power source 10. The power supply 20 converts the high voltage AC power from the power supply 10 to a low voltage DC power that may be consumed by a power consuming device (not shown) connected to the output side 100 of the power supply 20.

[002i] The connecting circuit 5 includes a triac 40, a triac driver 50, a resistor 60, and a bypass switch 30. The bypass switch may be one of a various types of switches, such as a push- to-make switch or a momentary contact switch, as would be recognized by one of ordinary skill in the art having the benefit of this disclosure. The triac driver 50 may be used to "turn on" or "turn off" the triac 40 of the connecting circuit 5. The triac driver 50 is connected to both the high voltage connecting circuit 5 and the low voltage output side of the power supply 20. The triac driver 50 includes a diode 51 optically connected to a triac 52. The diode 51 of the triac driver 50 is connected to the low voltage output side of the power supply 20 and is used to monitor whether power is consumed by a device connected to the output side of the power supply. The triac 52 of the triac driver 50 is connected to the circuit 5 that connects the AC power source 10 to the power supply 20. The diode 51 is optically connected to the triac 52 to isolate the low voltage DC output side from the high voltage AC side.

[0022] When there is no current flowing through the diode 51, the triac 52 of the triac driver 50 is turned off, which also turns of the triac 40 in the connecting circuit 5. With the triac 40 turned off, the power supply 20 is electrically disconnected from the AC power source 10, thus it is no long consuming any power. There will be no current flowing through the diode 51 when a power consuming device is not connected to the output side 100 or if the power consuming device is connected by is turned off or in a standby mode.

[0023] Capacitor 90 will be charged to the output voltage of the output side 100 while the power supply 20 is connected to the power source 10. Capacitor 90 provides the proper voltage to the output side 100 when a power consuming device is connected while triac 40 is off disconnecting the power supply 20 from the power source 10. The discharge of the capacitor 90 provides current flow through diode 51 turning on the triac 51 in the triac driver 50 and the triac 40 reconnecting the power supply 20 to the power source 10. A diode 95 may be used to prevent the discharge of the capacitor 90 prior to connecting or turning on a power consuming device to the output side 100. The reconnection of the power supply 20 will provide the proper charge on the capacitor 90 as well as provide voltage to the output side 100. [0024] The connection circuit 5 may include a switch 30 that may be closed momentarily to directly connect the power supply 20 to the power source 10 bypassing the triac 40 and the triac driver 50. It may be necessary to close switch 30 when initially connecting the power supply 20 to the power source 10 as the capacitor 90 will not initially have a charge. The bypass switch 30 may also be used in the event a power consuming device has not been connected for an extended period of time and the capacitor 90 has lost its charge. The output side of the power supply 20 may include diodes 80, 85 and a resistor 70 to ensure the proper voltage drop for the power consuming device. Alternatively, a zener diode could be used in place of the two diodes 80, 85 as would be appreciated by one of ordinary skill in the art. Figure 1 shows one embodiment of a circuit that may be used in connection with a typical power supply to monitor and disconnect the power supply from a power source when no power is consumed from the output side of the power supply. The power supply itself could be adapted to include a circuit to monitor and disconnect the power supply to conserve energy when no power is consumed from a connected device. The above described circuit is an exemplary configuration of a power supply to achieve the disclosed invention. One of ordinary skill in the art having the benefit of this disclosure would appreciate numerous configurations may be applicable to provide a power supply adapted to monitor power consumption by a connected device and to electrically connect or disconnect the power supply from a power source based on the power consumption of the connected device.

[0025] Figure 2 shows a flow chart of a method of conserving the amount of power consumed by a power supply incorporating certain teachings of the present disclosure. The method includes connecting a power supply to a power source. The power supply may be comprised of a primary side connected to the power source, an output side, and a circuit electrically connected to both the primary side and the power source. The circuit may be adapted to disconnect and reconnect the primary side with the power source and also be adapted to monitor the power consumed from the output side of the power supply.

[0026] The method includes connecting a power consuming device to the output side of power supply. If this is the initial connection of the power consuming device a momentary contact bypass switch may be closed to bypass the connecting circuit and directly connect the primary side of the power supply to the power source. The method further includes converting power from the power source to a low voltage power that may be used by the power consuming device.

[0027] The method of Figure 2 further includes monitoring the power provided to the power consuming device. The circuit electrically connected to both the primary side and the power source may be used to monitor the power provided to the power consuming device. If the power consuming device is consuming power, the method provides for continuing to monitor the power delivered to the power consuming device. If no power is being consumed by the power consuming device, the method of Figure 2 includes disconnecting the primary side of the power supply from the power source. The method further includes monitoring the power supplied to the device and if power is consumed by the power consuming device the method includes reconnecting the primary side of the power supply to the power source and converting power from the power source to a low voltage power that may be used by the power consuming device. As disclosed above, a capacitor charged to the operation voltage may supply power to the power consuming device while the primary side of the power supply is disconnected from the power source. [0028] Although various embodiments have been shown and described, the invention isimited and will be understood to include all such modifications and variations as wouldrent to one skilled in the art.

Claims

WHAT IS CLAIMED IS:

1. A power supply comprising: a primary side that includes a transformer, the primary side being electrically connectable to a power source; an output side operatively connected to the primary side, wherein a device may be connected to the output side; the transformer converting power from the power source to be consumed by the device; and a circuit connected to both the primary side and the output side, the circuit adapted to monitor the output side to determine the power consumption of the device and to disconnect or connect the primary side to the power source, wherein the circuit disconnects the primary side from the power source when no power is being consumed and connects the primary side to the power source when power is consumed.

2. A power supply comprising: a primary side, the primary side being connectable to a power source; an output side operatively connected to the primary side, wherein a device may be connected to the output side; means for converting power from the power source into power that may be consumed by the device, wherein the means for converting power is electrically connected to the primary side; means for monitoring the output side to determine whether the device is consuming power; and means for electrically disconnecting or electrically connected the primary side with the power source based on the means for monitoring the output side.

3. A method of conserving the amount of power consumed by a power supply comprising the steps of: connecting a power supply to a power source, the power supply comprising a primary side connected to the power source, an output side, and a circuit electrically connected to both the primary side and the power source, wherein the circuit is adapted to disconnect and reconnect the primary side with the power source and to monitor the power consumed from the output side of the power supply; converting power from the power source to a low voltage power; connecting a power consuming device to the output side, wherein the low voltage power may be provided to the power consuming device from the output side of the power supply; monitoring the power provided to the power consuming device with the circuit electrically connected to both the primary side and the power source; disconnecting the primary side of the power supply from the power source when no power is provided to the power consuming device from the output side; and reconnecting the primary side of the power supply to the power source when power is provided to the power consuming device from the output side.