PPB October 2019

Can a wireless charger overcharge the device? It is perfectly safe to leave the smartphone on the wireless charger for prolonged periods. Wireless chargers use what is known as trickle charging: if the device battery gets below 100 percent while still on the wireless charger, a small amount of current will start to trickle, ensuring that the device is kept charged. Single-coil and dual-coil chargers? It only takes a single-coil to charge your phone, but some wireless chargers offer a dual-coil option. This does not increase the charging speed but gives you the ability to position the phone in landscape or portrait orientations and still get a charge. Having dual-coils is truly important when you are dealing with wireless charging stands because without the second coil the transmitting and receiving coils for the alternate orientation will not line up and be in range for the transmission to happen. Dual- coil devices solve this problem. What is Qi? The key to knowing whether you’re getting a quality wireless charger is understanding Qi (pronounced “chee”). Qi is the established wireless charging standard. It’s owned by a group called The Wireless Power Consortium and it’s backed by pretty much every major mobile device manufacturer: Apple, Google, HTC, Huawei, Sony, Nokia, Motorola and more. Its aim is to deliver safe, easy-to-use wireless charging, as well as compatibility with all devices that bear the Qi logo. 5/7.5/10W Oh My? Wireless chargers have various power outputs. The minimum is a 5W. Many wireless- enabled charging devices support 5W, 7.5W and 10W wireless charging. If a device is 7.5W/10W, it’s considered fast-charging. Wireless chargers that support 7.5W/10W are preferred to the 5W chargers as they charge devices much more quickly. 5W chargers are usually standard with smartphones even if they support fast charging. Quality wireless chargers come standard with smartchips that regulate the amount of power that is delivered to the device. For instance, if the device is 5W and the charger is rated up to 10W, the wireless charger will recognize that the device only needs 5W of power and will deliver just what is required. Popular devices that are Qi-enabled include: 7.5W-Enabled Devices • iPhone XS • iPhone XS Max • iPhone XR • iPhone X • iPhone 8 Plus • iPhone 8 10W-Enabled Devices • Samsung Galaxy S8 • Samsung Galaxy Note8 • Sony • LG • Other What’s the difference between Qi-Certified and Qi-Standard? Both Qi-Certified and Qi-Standard devices have been manufactured to meet or exceed Qi specifications, resulting in the highest-quality product. The difference between the two is that Qi-Certified wireless chargers have been tested by a third party, whereas Qi-Standard devices have been tested by the manufacturer. Are wireless chargers safe? Yes. It is safe to be in close proximity of wireless chargers and charging devices for extended periods. Chargers that are not in use emit a harmless signal that looks for a wireless charging receiver, like the one in your smartphone. The signal emitted does not extend past the maximum distance specified on the wireless charger (3mm to 10mm). Provided that the wireless charger meets safety regulations set by organizations like the FCC in the United States and CE in Europe, they emit less radiation than a phone connected to a mobile network. Also, to ensure the wireless charger is safe to use anywhere, including hospitals, the wireless charging frequency needs to be strictly controlled at the manufacturing and QC stages. The 110-205khz frequency means that the wireless charges will not affect the normal operation of surrounding wireless devices. That means no interference with devices such as hearing aids or pacemakers, or with any devices that use infrared (IR) technology like thermometers, so they are safe to use in any health-care application. Will the charger get hot? All charging devices create heat as they charge, and the heat that comes off the charger represents a loss of energy. The most efficient chargers go through extensive testing to minimize the energy wasted through as heat. The best wireless chargers also have built-in safety protocols that will temporarily shut down to protect the charging device if excessive heat is detected. Techno l ogy Pr oduc t s 48 | OCTOBER 2019 | GROW