Power supplies and chargers

A new role in energy efficiency

By Philippa Martin-King

Small economies in energy can be obtained through improved standby control. One area where small is starting to play a new role in energy efficiency is that of power supplies. 

Wireless Power Consortium Qi logo The Qi in the logo of the Wireless Power Consortium means "vital energy" in Asian philosophy - an intangible flow of power. Behind the philosophy that wireless is beautiful because electric power can be transported without wires or connectors is their quest for international interoperability

Clunky power supplies are a thing of the past, believes US Company Green Plug. Its digital GPP (Green Power Processor) tunes the power supply dynamically according to the extant operating conditions. The chip can control multiple outlets and communicates between devices and the power adapter.

The company’s GLP (Green Load Processor) is a hardware and software protocol stack that provides smart power control. Embedded as a chip on devices it communicates with the GPP informing it of changing power needs, such as higher or lower voltage, or telling it to shut off entirely when conditions permit. Other smart devices include a smart quad port power adaptor that delivers power to multiple devices dynamically tuning the power supply according to need.

Charging wirelessly

Another solution which removes the need for multiple adapters, thereby saving space while reducing manufacturing costs consists of a multiple device wireless charger.

One wireless charging model is Powermat’s PowerPlate Wireless Induction Charger. It consists of a pad which is connected to the wall socket. To charge a mobile phone or other accessory, you simply place it on the mat in a special Powercube charging device and the batteries hold their power as if they’d been charged up using their own specific charger. Another system using wireless induction is Duracell’s myGrid Wireless USB Charger which acts like a portable power pack. Devices placed on the mat simply charge up as if they were plugged into the wall.

At CES, the ElectroHub universal wireless charging station promised to charge up to six electronic devices simultaneously, simply by placing them on the device which is flat and tablet-like.

Devices to be charged are made compatible simply by swapping their own standard AA or AAA batteries for a specially designed ElectroHub battery. It does away with the need for a specific customized casing for converting and charging batteries.

Standardization of the magnetic induction technology on which it is based looks set to continue development. Until now, because devices couldn’t be charged directly without first being placed in protective casing containing the induction hardware, induction charging mats were really only useful for small items. Now the technology looks set to continue development. Tremendous economies of scale can be achieved by not having to manufacture separate power adapters for each consumer product.

The technology forms the basis of the interface definition launched by the Wireless Power Consortium. This is a cooperative group of over 70 companies set up to produce an international standard for globally compatible wireless charging stations. Headsets, cameras, remote controls, and all mobile electronics carrying the logo will work with all Qi compatible charging stations.

This Qi 1.0 interface definition certifies interoperability between low-power mobile devices such as mobile phones and enables up to 5W to be transmitted wirelessly between device and charger. Parts 2 and 3 of the definition (performance requirements and compliance testing) are only provided to members of the Consortium. The Consortium is also said to be working on standards for medium-power devices such as netbooks and laptops.

Managing power

Another product on show at CES was the Fulton Innovation’s eCoupled wireless charging technology. Fulton has played a significant role in developing the Qi global low-power standard for wireless power and is now going one step further. Their charging device which incorporates a storage capacitor in its charging stand can be used for high-powered devices such as an electric vehicle. Once the device on the stand is fully charged, it switches off the mains power. The charger then goes into ultra-low power mode which prevents no-load power consumption, ie energy being used unnecessarily because the charger has simply been left plugged into the mains power.

Power management is one of the key issues that needs to be addressed, believe Harrington and Nordman. So features like standby management, cutting power flow to a charged device and super low-power draw are what are required. It’s not difficult to design for new devices, and not particularly costly to implement. It’s harder to contend with the energy vampire of existing products and retrofitting devices to make them more efficient and manageable. 

Gallery
eCoupled car Electric vehicle wireless charging at CES
greenload processor The Green Load Processor can reduce energy consumption by "choosing" to shut down a device when conditions permit
Wireless Power Consortium Qi logo The Qi in the logo of the Wireless Power Consortium means "vital energy" in Asian philosophy - an intangible flow of power. Behind the philosophy that wireless is beautiful because electric power can be transported without wires or connectors is their quest for international interoperability