# Looking for tips with a wireless charger summer project

• coljnr9
In summary, the author is looking for help with a wireless phone charger, and asks for advice on what he should do.
coljnr9
Hey everyone! I've gotten some really good help over in the math section of physicsforums, and I was hoping to get some more of the same here in engineering.
I've just finished my sophomore year in school, and I'm about to apply for the EE program at the university in spring.

Anyway, I thought it would be a great summer to build something I have been kicking around for a while, a wireless phone charger! I'm planning for it to be fairly crude, and to cannibalize some circuity from stuff I have laying around, but the basic idea is that I will push AC current through a solenoid, use that changing magnetic field to induce a current in a second loop, and then have that loop connected to the guts of a usb wall charger that I have. The idea is that the induced current will be AC, and hopefully the wall charger will clean that up, convert it to DC, and give me something that the phone can use.

My questions are:
1) Is this even reasonable? I have a quarter of E&M under by belt, but absolutely no EE classes, is there something I am missing completely?
2) I need help taking power from a wall outlet and configuring it so I can connect it to my primary solenoid. I don't know a thing about AC current, and I don't want to get myself killed (too badly), or start fires. What should the wiring between the wall and the primary solenoid look like?
- I would assume that I would at least need a resistor, so that I can limit the current through my wire to a reasonable level (~2 amps? I'm thinking of using something around 18 gauge wire). Does $$I=V/R$$ with V being 120 Volts mean I could use something around 60 ohms of resistance?
3) Should I give up and just get a breadboard?

Thanks for any help!
coljnr9

If I were you I would not even consider any project involving mains electricity until you are seriously competent and qualified. You need to get battery circuits to work properly first - for the understanding bit- and then learn the 'regs' on a proper course. You can get low voltage 'lab' DC power supplies for not much money.
Anything stuck directly into the mains should be of an approved design and manufacture.
I think I can safely say that PF would not support this project idea.

Fair enough, thank you. If I get one of these DC supplies, is there some component I can put in the circuit so that the current through the primary solenoid varies?

If you want to make yourself a sort of transformer then you could do what they do with toothbrush chargers. They are definitely 'wireless' and need a very small gap between the primary and secondary circuit.
If you look into 'wireless power' you will find that they usually use AC at a higher frequency than the 50 / 60 Hz because the components are smaller and the coupling can be made better.

If you want to do this project, then you will need to do a fair bit of homework as it's not trivial. That's why it's still very much in its infancy.

Well, I guess that's actually good news, because I was trying to find a project that would teach me some new stuff over the summer.

Thanks for the heads up. I suppose I'm off to Google for a while.

## 1. What is a wireless charger and how does it work?

A wireless charger is a device that uses electromagnetic induction to transfer energy from the charger to a compatible device without the need for a physical connection. The charger contains a coil that generates an alternating magnetic field, which induces a current in the receiver coil of the device, charging the battery.

## 2. What are some tips for choosing the right wireless charger for my project?

When choosing a wireless charger for your project, there are a few key factors to consider. First, make sure the charger is compatible with the devices you want to charge. Secondly, consider the charging speed and efficiency of the charger. Lastly, look for additional features such as overcharge protection and compatibility with different charging positions.

## 3. Are there any safety concerns when using a wireless charger for my project?

Yes, there are a few safety concerns to keep in mind when using a wireless charger. It is important to use a charger that is certified by a reputable organization, such as Qi or UL, to ensure it meets safety standards. Additionally, avoid using metal objects near the charger and do not leave the charger plugged in when not in use.

## 4. Can I use a wireless charger with any device?

No, not all devices are compatible with wireless chargers. Most newer smartphones and some other devices, such as smartwatches, are equipped with wireless charging capabilities. However, older devices and those without built-in wireless charging capabilities will not work with a wireless charger.

## 5. Are there any DIY wireless charger projects I can try this summer?

Yes, there are many DIY wireless charger projects that you can try this summer. Some popular options include using old or broken smartphones to create a wireless charging pad, building a solar-powered wireless charger, or even making a wireless charger out of household items such as a pencil and a coil of wire. Just be sure to follow safety precautions and do thorough research before attempting any DIY project.

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