4

A friend of mine recently shared this video on his timeline about turning a cellphone charger into a wireless charger.

enter image description here

I am certain that this video is wrong, but I don't know how to eloquently convince him of it; he is also not an engineer, but he is open minded enough that a good equation could convince him. However, I don't know how to relate the distance between wireless devices to the transfer of energy.

Was this video faked?

migrated from electronics.stackexchange.com Oct 20 '16 at 19:20

This question came from our site for electronics and electrical engineering professionals, students, and enthusiasts.

  • It is classified as entertainment on youtube. Does that sound like it is intended to be real? – matt_black Oct 23 '16 at 10:41
  • @matt_black My question was changed when it was transferred from Electronics.SE. I know that it is not real and in my original question I was asking for an equation to prove it. – Klik Oct 24 '16 at 0:21
9

Any basic introduction to how wireless charging works and what it requires should make it immediately apparent that none of those elements are present. For example, here's a writeup on Qi with the obvious problems bolded:

Under the Qi specification, "low power" for inductive transfers denotes power deliveries below 5 W. Systems that fall within the scope of this standard are those that use inductive coupling between two planar coils to transfer power from the power transmitter to the power receiver. The distance between the two coils is typically 5 mm. It is possible to extend that range to at least 40 mm. Regulation of the output voltage is provided by a digital control loop where the power receiver communicates with the power transmitter and requests more or less power. Communication is unidirectional from the power receiver to the power transmitter via backscatter modulation. In backscatter modulation, the power-receiver coil is loaded, changing the current draw at the power transmitter. These current changes are monitored and demodulated into the information required for the two devices to work together.] Qi

Also, there is simply nothing to generate a signal that is capable of being sent wirelessly. There is nothing to aim this signal at the phone. And, most importantly, there is nothing to shut this signal down if the power is absorbed by something other than the phone, so this would be a serious fire hazard if it worked.

  • 7
    And the switch on the power cord is off. – T. Sar Oct 20 '16 at 19:47
  • 2
    @ThalesPereira Actually, I hunted that particular surge protector down on amazon.in, and apparently (according to an answer to one of the customer questions) the first outlet which the plug is plugged into is controlled only by the main switch on the far left, while the remaining three are each controlled respectively by the switches directly to the left of them. – iamnotmaynard Oct 20 '16 at 22:53
  • You can see a slight skip in the video aswell, between him pushing the switch, and the cellphone showing the battery loading screen – Lyrion Oct 21 '16 at 11:32

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .