Inductive charging
The portable equipment can be placed near a charging station or inductive pad without needing to be precisely aligned or make electrical contact with a dock or plug.
[2] In California in the 1980s, a bus was produced, which was powered by inductive charging, and similar work was being done in France and Germany and Europe around this time.
Using a generic brand wireless charging pad and mis-aligning the phone produced consumption up to 25.62 Wh, or an 80% increase.
The analysis noted that while this is not likely to be noticeable to individuals, it has negative implications for greater adoption of smartphone wireless charging.
[15] Newer approaches reduce transfer losses through the use of ultra thin coils, higher frequencies, and optimized drive electronics.
This results in more efficient and compact chargers and receivers, facilitating their integration into mobile devices or batteries with minimal changes required.
[16][17] These technologies provide charging times comparable to wired approaches, and they are rapidly finding their way into mobile devices.
An increase in high-power inductive charging devices has led to researchers looking into the safety factor of the electromagnetic fields (EMF) put off by larger inductor coils.
With the recent interest in the expansion of high power inductive charging with electric cars, an increase in health and safety concerns has arisen.
[clarification needed] This much exposure of electromagnetic waves to the skin of a human could prove harmful if not met within the right conditions.
[19][clarification needed] There are two main standards that ensure compatibility between chargers and small electronic devices: Qi and PMA.
Many manufacturers of smartphones have started adding this technology into their devices, the majority adopting the Qi wireless charging standard.
Major manufacturers such as Apple and Samsung produce many models of their phones in high volume with Qi capabilities.
These are geared for consumers who wish to have smaller chargers that would be located in common areas and blend in with the current décor of their home.
[36] Inductive charging is not considered a mature dynamic charging technology as it delivers the least power of the three electric road technologies, its receivers lose 20%-25% of the supplied power when installed on trucks, and its health effects have yet to be documented, according to a French government working group on electric roads.
Foreign objects pose a fire or burn risk if metals or organisms are between the ground pad and the receiver when the system is active.
[23] The German Ministry of Economy, BMWK tested infrastructure by Electreon in 2023 with a bus equipped with inductive coils that receive power from a 200-meter strip of transmitters under the road surface.
The first commercialized DWPT system, Online Electric Vehicle (OLEV), was developed as early as 2009 by researchers at the Korea Advanced Institute of Science and Technology (KAIST).
[42]: 57 In the 2020s, companies and organizations such as Vedecom,[43] Purdue University, ENRX (formerly IPT),[44] Electreon, and Magment developing dynamic inductive coil charging technologies.
[50] The major advantage of the inductive approach for vehicle charging is that there is no possibility of electric shock, as there are no exposed conductors, although interlocks, special connectors and RCDs (ground fault interruptors, or GFIs) can make conductive coupling nearly as safe.
January 2015, eight electric buses were introduced to Milton Keynes, England, which uses inductive charging in the road with proov/ipt technology at either end of the journey to prolong overnight charges.,[58] Later bus routes in Bristol, London and Madrid followed.
[59] Vehicles that could take advantage of this type of wireless charging lane to extend the range of their onboard batteries are already on the road.
Without a commercial way to monetize this technology, many cities have already turned down plans to include these lanes in their public works spending packages.
Researchers have been able to print wireless power transmitting antenna on flexible materials that could be placed under the skin of patients.
[60] While these flexible polymers are safer than ridged sets of diodes they can be more susceptible to tearing during either placement or removal due to the fragile nature of the antenna that is printed on the plastic material.
