Inductive Charging: Bad News for Cable Makers
If you live in California or a few other states that have traffic signals that are switched by vehicles, you already know about induction. You also know about it if you use an electric toothbrush. Transmitting electricity by induction has been around a long time and the phenomena is well understood by electrical engineers. If you want to read about how it works, click here. Basically, there parts consist of a transmitting coil and a receiving coil. In the presence of a magnetic field, current travels between the coils wirelessly.
Today, there are two major efforts afoot with regard to inductive charging. One primarily concerned with cellphones and the other for electric cars. The technology for cellphone charging is based an established standard called Qi (pronounced “chee”) adopted by the Wireless Power Consortium (WPC), and industry standards group. Although there are some inductive charging systems available for cars, there is no industry standard. However, the Society of Automotive engineers (SAE) expects to have one by 2014.
The differences between charging a cellphone and charging a car are vast. All you need for a practical cellphone system is a couple of watts transmitted over a very short distance – inches. A practical system for a car requires kilowatts transmitted over as much as several feet.
The systems available for phones now consist of a pad (transmitting coil) that is wired to a power source and a “case” that encircles the phone (the receiving coil). Placing the phone in the case on the pad charges the phone. In the future, phones will be manufactured with the receiving coil built-in, so the case won’t be needed. If the phone supports Qi, then one Qi pad that will suffice for any Qi-enabled device. The charger from battery company, Energizer, is a good example of the current state of the art.
Personally, I find it difficult to get excited about inductive charging of cell phones. With the current state-of-the-art, it takes 2-4 times longer to charge a phone than with a car or wall charger. That time differential will surely improve, but still it’s not very compelling. The most interesting system I’ve seen is one from Oregon Scientific that puts the pad into a clock. If you need a clock, and many people do, then why not have an inductive pad too?
The car charger is much more interesting to me. It will be possible (and technically feasible) to put transmission pads under roadways, say at stoplit intersections. While you are waiting for the light to change, your car’s batteries could be charging, and your credit card could automatically be debited for the cost! In addition, there is some significant economic muscle behind inductive charging. The Korean, Japanese, and German auto companies are pushing the technology, not to mention Chrysler, Ford, GM and even Tesla!. It is going to happen. Pick a car manufacturers name, couple it with “inductive charging” and Google or Bing the words. You’ll be flooded with hits.
In summary, inductive charging technology, something that has been around for decades is going to be a very big deal!~