Wireless charging can feel a bit like magic—without plugging anything in, your device can recharge cord-free. But how does this technology work? It’s all based on some pretty simple physics, combined with some international cooperation.
Understanding Induction and Induction-Based Charging
Wireless charging is a type of induction-based charging. Induction is a process that allows electricity to be transferred without direct contact between two objects. Instead of plugging a cable into your phone to charge it, induction uses invisible magnetic fields to transfer energy from a charging pad to your device. It's similar to how some electric toothbrushes charge when placed on their stands without any physical connection—in fact, the Philips Sonicare toothbrush was one of the first commercialized applications of induction charging technology.
How Induction Works
To understand induction, let's start with a basic concept: magnets. When you bring two magnets close together, they can either attract or repel each other because of their magnetic fields. Induction takes advantage of this magnetic field concept.
Imagine a wire wound into a coil, like a spring or a spiral. When electricity flows through this coil, it creates a magnetic field around it. This is the essence of induction. Now, if you bring another coil close to this magnetic field, the magnetic field can create an electric current in the second coil. This means that energy is transferred from the first coil (the charger) to the second coil (your device) without them actually touching.
Induction-Based Charging
Induction-based charging uses this principle to power devices like smartphones, tablets, and even electric vehicles. Here's a simple breakdown of how it works:
- Charging Pad or Surface: This contains the first coil (transmitting coil). When you plug the charging pad into an outlet, electricity flows through the coil, creating a magnetic field.
- Device Coil: Your device, like a smartphone, has a second coil (receiving coil) inside it. When you place your device on the charging surface, the receiving coil gets close to the transmitting coil's magnetic field.
- Energy Transfer: The magnetic field from the charging pad induces an electric current in the device's coil. This electric current is then converted into power, which charges your device's battery.
This method of charging is convenient because it eliminates the need for cords and connectors. You simply place your device on the charging surface, and the energy transfer happens through the air via the magnetic field. This technology, known as magnetic induction, is the basis for the Qi (pronounced “chee”) standard used in many wireless chargers today.
The Evolution of Wireless Charging
The foundation of wireless power dates back to the late 1800s, rooted in the groundbreaking work of Nikola Tesla. Tesla filed a patent for what is known as the Tesla coil in 1891 (and further refined in 1914), which laid the groundwork for wireless power technology. However, it wasn't until the 1990s that significant advancements were made in the field, particularly with the method known as magnetic induction, which underpins the Qi standard.
Commercial Applications
In the early 2000s, the first commercial applications of wireless power emerged, particularly in electric toothbrushes. Philips was a pioneer in this area, introducing a product that utilized wireless charging.
Adoption of the Qi Standard
By 2008, extensive research and development by various companies and universities led to the formation of the Wireless Power Consortium (WPC). This collaborative effort aimed to create a universal standard for magnetic induction-based wireless power, resulting in the Qi standard. The first Qi standard devices began rolling out around 2012, and by 2013, Samsung's adoption of the Qi standard solidified its position as the global benchmark for wireless charging.
Summary
- Nikola Tesla's work laid the foundation for wireless power in the late 19th century.
- Early 2000s saw the first commercial use in electric toothbrushes.
- The Wireless Power Consortium (WPC) formed in 2008, leading to the Qi standard.
- Samsung's adoption in 2013 cemented Qi as the global standard.
The Role of the Wireless Power Consortium (WPC)
The WPC played a crucial role in establishing the Qi standard, which has become the global benchmark for wireless charging.
Calling something a “standard” is more than just a title—it means that an industry has accepted certain guidelines for using this technology in order to best serve consumers and continue innovation across brands. It also means that consumers can be assured that the items they buy will be compatible with various other accessories for years to come. Examples of common technology standards include Wi-Fi, Bluetooth, HDMI, USB, and more.
Major Contributions
Why are technological standards so important? Here’s a few advantages to establishing standards such as the Qi standard:
- Standard Essential Patents: Companies that participate in a standard license their patents on “fair, reasonable, and nondiscriminatory” terms.
- Industry Collaboration: Unified research and development efforts create a universal standard, ensuring that different devices can work together.
- Forwards and Backwards Compatibility: Under technological standards, devices are designed to be forwards and backwards compatible. If you buy a brand new phone, it will work with your existing Wi-Fi, just like your new Bluetooth headphones will work with your older phone. The same is true for the Qi standard of wireless charging.
- Supply Chain and Economies of Scale: With an entire industry agreeing on a technology standard, manufacturers can create products for a lower price point.
Considerations for Qi Wireless Charging
Wireless charging offers a wide range of benefits for users, but also has some natural limitations.
Convenience
With charging surfaces like FreePower, you can set your phone on the surface and it immediately starts charging. That’s pretty simple and convenient! Wireless charging also eliminates the need to carry a cord with you everywhere you go, let alone multiple types of cords.
Speed
Wireless charging is not as fast as charging with a cord. If you need fast power, your best bet is to plug-in. However if you’re looking to charge your phone for an extended period (like at night or during a meeting), or you just want to top off your charge while having lunch, wireless charging is the perfect solution.
Safety
Wireless chargers and devices are “smart”—they can communicate with each other to ensure that charging happens safely. Your phone sends a message to the charger indicating how much power to send through in order to charge as fast as possible. As the phone heats up as a result of the charge, it can tell the charger to send less power to manage battery temperatures. Wireless chargers also employ foreign object detection to ensure that power is not sent to something that is not intended to receive it.
The Future of Qi Wireless Charging
As wireless charging technology continues to evolve, the Qi standard remains a cornerstone due to its reliability and widespread adoption.
Continued Advancements
Ongoing research aims to improve the efficiency and speed of wireless charging. Innovations like the FreePower charging surface have made wireless charging even more convenient by allowing for free placement anywhere within the charging halo, as well as allowing for multiple devices to be charged at once.
As our world becomes more and more digital, the need for charging batteries grows. Anything that uses energy could technically be powered wirelessly, from your laptop to kitchen appliances to your car.
Wireless Charging is Here to Stay
The Qi standard has revolutionized wireless charging by providing a reliable, efficient, and universally accepted method for powering devices. Understanding how Qi wireless charging works highlights the intricate interplay of technology and safety standards that make this convenient method of powering devices possible. As technology advances, Qi wireless charging is poised to become even more integral to our everyday lives, offering unparalleled convenience and efficiency.
