How Does Wireless Charging Work—And Is It Safe?

iStock
iStock

by James Hunt

In 1899, the inventor Nikola Tesla began performing the first successful experiments on wireless power transfer. His initial success led him to believe that one day power would be transmitted around the planet without the need for cables. It took over 100 years, but his dream of wire-free power transmission was eventually realized—though perhaps not by the methods he envisioned.

When creating phones and tablets, manufacturers are faced with the challenge of giving the device a long battery life, keeping it lightweight, and making charging as painless as possible. Wireless power, which makes recharging your phone as easy as putting it down, could be the solution to that last part. But how does it actually work? And, perhaps more importantly, how safe is it?

Modern wireless power draws on the same principle that Tesla investigated over a century ago: induction. Electromagnetic induction—using an electromagnetic field to transfer power between two objects—forms the basis of all modern wireless charging, as well as things like contactless payment, cooktops, and wireless speakers.

In a practical sense, the way induction works is simple: First, you feed power to a base unit or charging station that contains a “transmitter” coil. An electromagnetic field forms around the transmitter and when a second “receiver” coil comes near enough, the receiver coil interacts with the magnetic field to create an electric current. By putting the second coil inside another device, you can wirelessly transfer power from the base to the device.

Most induction chargers only operate over a short distance, however, and while physical contact between a device and its base unit isn't necessary for induction to work, the fields generated lose so much power as the devices get farther away that it's usually the only way to get the two coils close enough.

As for safety, there's really nothing to worry about. The average induction charger creates a field no more dangerous than radio waves, and it isn't strong enough to have any effect on the human body. If anything, plugging in and unplugging a cable is more dangerous because there's a minute chance it could fray and shock you. By contrast, induction hardware can be safely encased in thick plastic and still work. This is why electric toothbrushes have long used induction to charge: The units can remain sealed and waterproof.

Sounds great, right? So why don't we use wireless charging all the time? For starters, it’s slow going. While wireless charging has improved dramatically over the past few years, wired charging is still generally faster. Also, the process creates a lot of waste heat, so much so that some Samsung charging pads have fans to keep everything cool.

The big issue is practicality, though. You can easily use your phone while it's plugged into a charger, but it's tricky to hold your phone up to your ear while it's resting on a wireless base station.

But things are changing.

Returning to Tesla's original experiments, an effect called Resonant Inductive Coupling allowed the inventor to safely transmit power over several meters. Perhaps the most popular wireless charging standard, Qi, has recently been updated to allow a version of this to be implemented in compatible devices. The result is that the charging range has increased to four centimeters.

It might not sound like much, but it's a start. In the future, wall-sized charge stations might be able to transmit power to multiple devices in multiple rooms as you move about your house. It may have taken over a century to get to this point, but we're closer than ever to wireless power transfer becoming commonplace. It's what Tesla would've wanted.

Scotland Could Become the First Country to Provide Universal Period Products to Citizens

emapoket, iStock via Getty Images
emapoket, iStock via Getty Images

Fears over where to find—and how to afford—sanitary products before their next menstrual cycle may no longer be an issue for people in Scotland. Earlier today, as the BBC reports, Members of Scottish Parliament passed the first part of a bill that would make items like pads and tampons free to the public.

The Period Products Bill was first put forth in 2017 to address period poverty, which affects people who are unable to afford essential menstrual hygiene products. Pads, tampons, and some reusable menstrual items are currently available to students in primary schools and universities in the country. The Scottish government has also expanded the program to include additional public places and sports clubs, but this new bill goes even further. If passed, Scotland would become the first country to provide free period products to citizens on a universal scale.

Ministers in the Scottish Parliament were initially concerned about the bill's £24 million ($31 million) annual price tag, but earlier this month, members of all parties in the government came out in support of the legislation. Though the bill passed through the first stage of parliament today, February 25, the BBC wrote that "The government is expected to put forward a raft of amendments to address their 'significant' concerns about the legislation," including the aforementioned cost.

Period poverty is an issue that's felt around the world. In America, many lawmakers are fighting to end the "tampon tax": a sales tax that's added to sanitary products and waived from other hygiene products deemed essential in many states, like dandruff shampoo.

[h/t BBC]

10 Simple Tricks for Charging Your Smartphone Faster

Makidotvn, iStock via Getty Images
Makidotvn, iStock via Getty Images

Smartphones always seem to reach low power at the least convenient moments possible. If you've ever urged your device to charge faster in the minutes before a phone interview or when you're about to board a plane, you can relate. While the easiest way to avoid this scenario is to plug in your device before the battery dips into the danger zone, if you've already reached this point, there are simple ways to speed up the charging process.

Some hacks for charging a phone faster involve steps you can take in anticipation of the next time you're surviving on minimum energy. Certain gadgets, like special chargers and battery packs, will power-up your device more efficiently than others. For moments when your phone is dying and all you have is your regular charging cable, adjusting your phone's settings to minimize the power it consumes also works in a pinch.

You can find some specific ways to charge your phone quickly below: 

  1. Plug it into a wall outlet instead of a USB port.
  1. Use a portable battery pack.
  1. Buy a special "fast" phone charger.
  1. Switch to low power mode.
  1. Switch to airplane mode.
  1. Let your phone drain completely on its own once a month to the extend the battery life.
  1. Close any background apps.
  1. Stop automatic app updates.
  1. Don't check your phone while it's charging
  1. Keep your phone out of the heat.

For more tricks for making your phone usage more efficient, check out these tips for typing faster.

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