Three major standards of wireless charging technology: PLA, Qi, and a4wp

Although most people are not unfamiliar with the wireless charging technology, after the release of the Nokia Lumia 920, wireless charging functions have received widespread attention. As one of the main selling points, wireless charging makes Lumia 920 different from mainstream mobile phone products, with distinctive personality.However, Nokia was not the first manufacturer to use wireless charging technology on mobile phones. A year ago, Philips launched a mobile phone with the Qi wireless charging standard, but it did not attract consumer attention.

In fact, the current wireless charging technology is not yet mature, not only the development of technology is slow, standards have not yet been unified.Currently, there are three mainstream wireless charging standards:Power matters Alliance (PMA) Standard,Qi Standard,Alliance for wireless power (a4wp)Standard. Below we will briefly introduce these three standards.

Power matters Alliance Standard

The power matters Alliance standard was initiated by Duracell powermat, which is a joint venture between P & G and the wireless charging technology company powermat and has excellent comprehensive strength. In addition, powermat is also a support member of the Alliance for wireless power (a4wp) standard.

CurrentlyAt&t, Google, and Starbucks joined the PMA Alliance). The PMA alliance is committed to building wireless power supply standards for mobile phones and electronic devices that comply with IEEE standards and have a leading position in the wireless charging field.

At present, Duracell powermat has launchedWICC charging cardThe power matters Alliance standard is used. WICC is a ring larger than the SD card. It is embedded with components such as coils and electrodes used for Electromagnetic Inductive non-contact charging. The card thickness is thin and can be used only when it is inserted next to an existing smartphone battery, with this card, many portable terminals can easily support non-contact charging.

 
WICC charging card

In addition, Starbucks plans to launch a Duracell powermat wireless charging pilot in 17 stores in the Boston region, which will provide strong support for PMA's U.S. foothold. "Starbucks will place wireless charging devices on some desktops to see how customers respond," said Adam Brotman, Chief Digital Officer of Starbucks ." If the customer does not have a charging shell that matches the iPhone or galaxy, Starbucks will be given a small portion of the free space during the pilot period, and some of the cabinets will also be lent out.

Qi Standard

Qi is the world's first organization to promote wireless charging technology standardization --Wireless Power Consortium (WPC)The "wireless charging" standard has two features: convenience and versatility. First, all products of different brands can be charged with a Qi wireless charger if they have a Qi logo. Second, it overcomesThe technical bottleneck of wireless charging "versatility"In the near future, mobile phones, cameras, computers, and other products can all be charged with Qi wireless chargers, providing the possibility for large-scale wireless charging applications.

Currently, the mainstream wireless charging technologies in the market mainly adopt three methods:Electromagnetic Induction, radio waves, and resonance, AndQi uses the most popularElectromagnetic Induction Technology. In terms of technical application, Chinese companies have already stood at the forefront of the wireless charging industry. It is reported that at present, Qi's application products in China are mainly mobile phones. This is the first stage and will be applied to different categories or higher-power digital products in the future. Up to now, the Alliance has grown to 74 members, including Philips, HTC, Nokia, Samsung, Sony Ericsson, and Best Buy.

Small Qi wireless power chip launched by Texas Instruments

Typical products of the Qi standard include Nokia Lumia 920, Nokia Lumia 820, and Google Nexus 4. When using these mobile phones, you don't need to install any accessories. You can simply put them on any charger that supports the Qi standard to start charging, at present, there are already a large number of different types of wireless chargers available for brands such as power and powermate on the market.

Nokia Lumia 920

A4wp Standard

A4wp is short for the alliance for wireless power standard. It was created by Qualcomm, Samsung, and powermat. The Alliance also includes ever win industrial es, gill industrial es, peiker acustic, SK Telecom, and other Members, the goal is to set up technical standards and industry dialogs for wireless charging devices for electronic products, including portable electronic products and electric vehicles.

The wireless charging alliance willThe "electromagnetic resonance wireless charging" technology is introduced in particular, which is different from Qi's "electromagnetic induction technology ".The two technologies have their own merits.The former may have low transmission efficiency, but it can achieve wireless charging at a relatively long distance. The latter requires close contactFor example, if you place your mobile phone on a base, you can use inductive charging without wiring, but the charging efficiency is high.

The a4wp standard Alliance hopes to make wireless charging more popular and allow users to perform wireless charging anywhere. Or, a4wp wants to make wireless charging cheaper and add charging interfaces without increasing the volume of mobile phones, tablets, or laptops, which means more and more manufacturers will choose wireless chargers by default.

Industry insiders believe that the wireless charging alliance established by Qualcomm, Samsung, and powermat has expanded its scope of products, including electric vehicles and other more extensive electronic products.

Due to the late composition of the Alliance, this standard is rarely used. Samsung once said that the Galaxy s iii smartphone accessories contain a wireless charger, but the time to market is not determined, it is assumed that the wireless charger will comply with a4wp standards. However, because a4wp and Qi have different technical principles, the charger for Galaxy s iii and Lumia 920 cannot be used in general, and users have to prepare two chargers to charge different products.