Wireless Charging

[Sterer]

TL;DR

5V DC to 5V AC, 5W

I need a circuit that converts 5V DC to 5V AC and can supply 5W for a wireless charging coil. I am finding incredibly little information online
Edit: It also needs to run at 275kHz, so a standard relaxation oscillator to my knowledge would not work

 

[berkeman]

Welcome to PF.

How are you physically going to place the charging coil and the target device? How close will they be?

Also, keep in mind that the 3rd harmonic of your charging frequency is in the AM radio band, which is regulated by the FCC in the US (and there are similar regulations around the world). If you cause interference with your charging device, you could be subject to some penalties.

What is the application?

 

[AlexB23]

TL;DR: 5V DC to 5V AC, 5W

I need a circuit that converts 5V DC to 5V AC and can supply 5W for a wireless charging coil. I am finding incredibly little information online
Edit: It also needs to run at 275kHz, so a standard relaxation oscillator to my knowledge would not work

What is your use case for this charger? It may not be good for phones

 

[Sterer]

It is for charging a battery connected to a custom external board. It does not need to be too efficient but should deliver some amount of power

 

[berkeman]

but should deliver some amount of power

Over what distance? Can the charging coil be placed in direct external contact with the battery case? Or better yet, can it be designed so the battery power receiver part fits inside the charging coil, kind of like some electric toothbrushes are recharged?

https://www.google.com/url?sa=t&sou...cKEwjQloWF2oSTAxUAAAAAHQAAAAAQCA&opi=89978449

 

[Sterer]

Nothing should be visible externally, but there is a possibility to have the charging coil inside the receiving coil. They will be over a cm apart though.

 

[Averagesupernova]

Also, keep in mind that the 3rd harmonic of your charging frequency is in the AM radio band...

As is the 2nd, 4th, and 5th. Typically the 3rd and 5th are higher in amplitude than the even harmonics. I believe I have this right. Feel free to correct me as I would put more faith in your knowledge of RF than pretty much anyone I know these days.
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At any rate, this is a challenging project for a beginner. Anyone who phrases the original post in the way that it was I would have to assume is in fact a beginner.