There are different wireless chargers for different devices; the user must determine which to use. How about if the machine itself decided?

The charger's brain would query the device, learn its identity and battery parameters along with what percentage of charge it currently had, and ramp the charging parameters up/down to fit the device.

"Ahh, you are an Android S5 (iPhone, iPad, Chromebook, etc) with the standard battery that is down to 35%. I shall charge you with 1 (2, 3, 99, etc) amps of wireless magic. Here we go."
-- whatrock, Dec 14 2015

Switcheroo Power Supply Switcheroo_20Power_20Supply
As mentioned in an annotation. [Vernon, Dec 14 2015]

Wireless chargers necessarily use induction, not horribly unlike how an ordinary transformer uses induction. Therefore a key fact relates to the "number of turns" in each of two induction-linked coils. Inside a transformer, the ratio of the two numbers-of-turns in the two different coils determines the degree to which voltage and amperage are adjusted (the output of the transformer is usually different from the input). If the turn-ratio is 2:1 then the voltage can be doubled or halved (and vice-versa for the amperage), depending on if it is the input coil or the output coil that has twice as many turns.

For this Idea to work, the wireless charger coil needs to have an adjustable number of turns. The query would want to ask how many turns are in the device that would be charged, as well as what voltage was expected. Only then would the charger be able to determine how many turns of its charging-coil to activate. (For notions regarding one way to activate varying numbers of circuits --and each coil-turn could be considered one circuit-- see an Idea I posted several years ago, "Switcheroo Power Supply".)

Note that what you wrote about amperage is not going to be easy to implement. Normally when voltage is adjusted upward by a transformer, available amperage goes down. Amperage can go up when the voltage goes down, but there is a limit, because if the voltage is too low, internal resistances of circuits can basically prevent current (amps) from flowing hardly at all.
-- Vernon, Dec 14 2015


Welcome to the HB, [whatrock]!
-- MaxwellBuchanan, Dec 14 2015


There is some pushback against communication between the charger and chargee, for security reasons. "USB condoms" are available to prevent the loading of viruses on your phone by malicious public chargers. This would need some kind of way to prevent the transmission of malware from charger to chargee. It could be as simple as a very limited protocol that only allows a single message specifying charge rate.
-- notexactly, Dec 15 2015



random, halfbakery