White Paper - Green

An Overview of the iGo Green® Technology Intellectual Property Portfolio Eliminating Vampire Power from the Primary Side

What is Vampire Power?

Vampire Power is electricity drawn from the wall by electronic devices even when they are turned off. The biggest culprits of Vampire Power include chargers that are plugged in and running 24 hours a day, regardless of whether the devices they charge require power or not.

The Environmental Protection Agency (EPA) estimates that Vampire Power accounts for more than 100 billion kilowatt hours of electricity consumed in the United States annually, resulting in over $10 billion in wasted electricity costs.

iGo Green Technology Overview

Short of unplugging all your devices and chargers every day, there has been no reliable way to reduce Vampire Power. To address this problem, iGo developed and patented a method of automatically shutting off the charger or outlet when power was not needed and turning it back on when power was required again. With this technology, iGo introduced the world’s first green laptop charger and a family of surge protectors that all automatically reduce Vampire Power by up to 85%.

iGo Green Technology includes the following patents, with others still pending:

• United States Patent No. 7,770,039

• United States Patent No. 7,779,278

• United States Patent No. 7,795,759

• United States Patent No. 7,795,760

• United States Patent No. 7,800,252

iGo Green Technical Details

iGo Green Technology is a novel approach to virtually eliminating Vampire Power. A power adapter or power strip includes a primary side (input) for receiving power from a main power supply and a secondary side (output) for providing operating and/or charging power, derived from the primary side, to an electronic device connected to the secondary side. iGo’s patented technology is based on an ultra-low idle power supply that monitors the behavior of the primary circuit and disengages the power supply if an idle state or no load condition exists. As a result, power consumption is reduced to 1/10th to 1/1000th or less of active power and Vampire Power is reduced by at least 85%. A standby switch is used to transition the power supply from the ultra-low idle power mode to an active mode or a normal idle mode when power is required by an electronic device.

iGo’s approach to addressing Vampire Power has two unique characteristics:

• It utilizes primary side circuit controls in power adapters, rather than secondary side controls (11 different companies hold patents on technologies that utilize secondary side circuit controls, creating a minefield of patent issues with that approach)

• It provides for the shutting down of individual outlets in power strips, rather than shutting down all outlets at once like conventional “green” power strips that utilize the “master-slave” model

Due to these characteristics, iGo believes that its unique approach to reducing Vampire Power has significant cost and design advantages.

Advantages of Controlling Vampire Power from the Primary Side:

1. Any primary side PWM controller and/or PFC controller can be used – no special “green” replacement controller needed. Allows existing non-green designs to be updated to improve standby power specifications.

2. Power measurement and control circuit only needed on primary side – no added secondary side components.

3. Lower parts count for primary side control (9) compared to known secondary method (19).

4. No added optocoupler or pulse transformer needed.

5. No additional secondary side energy storage required.

6. Simple power shutoff to PWM and/or PFC controller chips; the power supply behaves as though it was simply unplugged from the AC line.

7. During green mode, output voltage drops cleanly to 0 volts – just like a power-off.

8. Output voltage rises cleanly on shift to full power mode – just like a power-on.

9. Power supply does not need to be periodically restarted to recharge secondary side energy store.

Disadvantages of Controlling Vampire Power from the Secondary Side:

1. Requires control and power measurement circuits on primary and secondary sides.

2. Secondary side status must be fed back across isolation barrier through additional optocoupler or pulse transformer, resulting in increased cost and larger board space usage.

3. Measurement/control circuits on secondary side require power source to communicate back to primary – resulting in extra capacitance or battery/super cap that increase costs and space requirements.

4. Power supply must be periodically restarted to recharge secondary side energy store.

5. If battery used for secondary side energy store, then battery life, charging, replacement and temperature must be considered.

6. Output voltage may pulse or periodically decay causing connected device Power-on-Reset, under voltage, or battery charging circuits to become confused.

7. Maximum power savings may require special “green” controller on primary side.

8. Typical secondary side output circuits (LED, voltage reference, etc.) remain powered when primary side is in standby. This may require extra disconnects for these circuits on the secondary side to preserve the energy store on secondary side.

9. Parts count for secondary side control method at 19 extra components vs. 9 for primary side.

10. Seeks to regulate an output voltage that is not being used (disconnected from device).

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