hello everybody, I am currently working on a lighting project where I have decided to use wirless charging, although the coils are going to be directly connected to the power outlet.
There will be, of course, a giving coil and a receiver coil. However, the project includes magnets between the lamp and the supporting piece so my question is which type of magnets are best and does the magnet have to be on the same wavelenght as the coils? (im not an expert so idk if wavelenght is the right word but I hope you get what the question is)

thankss

 

coils are going to be directly connected to the power outlet

I would be re-thinking this. There are reasons why wireless charging is done at ~100 kHz instead of 50 or 60 Hz.

does the magnet have to be on the same wavelength as the coils?

Assuming you mean permanent magnets, there is no wavelength associated with them.

 

I would be re-thinking this. There are reasons why wireless charging is done at ~100 kHz instead of 50 or 60 Hz.
The problem is that the light i am designing would be for art galleries and having something with batteries that run out and have to be charged is not ideal, so either i change the whole concept or I connect the coils to the power directly. anyways I really dont know much, what would the problem be with directly connecting them?

Assuming you mean permanent magnets, there is no wavelength associated with them.

okay, thanks!

 

Wireless Charging is not a beginner project !!! It can be very complex.
You will also get much faster Charging with a wired charger connection.
A Permanent-Magnet will not provide any useful improvement in a Wireless-Charging setup.
An open-ended Transformer-Core may improve the Charging Current by
concentrating the Magnetic-Field towards the center of the receiving coil.
Using a 60hz Frequency will lower the efficiency of power transfer substantially.
.
.
.

 

Efficient wireless power transfer depends on coil design, higher frequencies, proper alignment, and safety measures to contain the magnetic field.

 

hello everybody, I am currently working on a lighting project where I have decided to use wirless charging, although the coils are going to be directly connected to the power outlet.
There will be, of course, a giving coil and a receiver coil. However, the project includes magnets between the lamp and the supporting piece so my question is which type of magnets are best and does the magnet have to be on the same wavelenght as the coils? (im not an expert so idk if wavelenght is the right word but I hope you get what the question is)

thankss

Hi,

As others have pointed out, it's probably not a good idea to go right into the power outlet, unless maybe you also step down the voltage first to something like 12vac using a transformer with the right isolation class rating.

The main idea is that you have one inductor which we can all the primary, and another inductor which we can call the secondary. The primary will transmit to the secondary.
The primary inductor has to handle the entire voltage applied to it, which means it has to have enough inductance to limit current to the level it can handle without overheating. It would have to have a magnetically active core material too which would lower the required number of turns and help to couple the magnetic field to the secondary. If the two core pieces (primary and secondary) can touch, you can get a VERY good transfer of energy, better than most wireless chargers do today. This is even at 60Hz. The two exposed core surfaces should be smooth and connect each other with some force to keep them together.
This is actually the way early wireless chargers worked, and the mechanical part of the design was made so that the two core surfaces touched when the toothbrush was placed into the holder. They may not do it this way anymore though with the advent of higher frequency wireless charges, but this way is more efficient although it is harder to implement in most devices like cell phones.
To compare this to some ordinary wall warts, it is very similar the only difference is the wall wart will have the two core parts joined permanently with only a very small gap which provides for some leakage inductance, and the wires in the two coils are actually physically separated also to meet the isolation specs.

It would be interesting to see this type on a cell phone, but there would be problems because the core surface would have to be exposed on the back of the phone. I don't think many phone manufacturers would go for that and would probably take up too much room. Electric toothbrushes have a very different form factor.

 

Hi,

As others have pointed out, it's probably not a good idea to go right into the power outlet, unless maybe you also step down the voltage first to something like 12vac using a transformer with the right isolation class rating.

The main idea is that you have one inductor which we can all the primary, and another inductor which we can call the secondary. The primary will transmit to the secondary.
The primary inductor has to handle the entire voltage applied to it, which means it has to have enough inductance to limit current to the level it can handle without overheating. It would have to have a magnetically active core material too which would lower the required number of turns and help to couple the magnetic field to the secondary. If the two core pieces (primary and secondary) can touch, you can get a VERY good transfer of energy, better than most wireless chargers do today. This is even at 60Hz. The two exposed core surfaces should be smooth and connect each other with some force to keep them together.
This is actually the way early wireless chargers worked, and the mechanical part of the design was made so that the two core surfaces touched when the toothbrush was placed into the holder. They may not do it this way anymore though with the advent of higher frequency wireless charges, but this way is more efficient although it is harder to implement in most devices like cell phones.
To compare this to some ordinary wall warts, it is very similar the only difference is the wall wart will have the two core parts joined permanently with only a very small gap which provides for some leakage inductance, and the wires in the two coils are actually physically separated also to meet the isolation specs.

It would be interesting to see this type on a cell phone, but there would be problems because the core surface would have to be exposed on the back of the phone. I don't think many phone manufacturers would go for that and would probably take up too much room. Electric toothbrushes have a very different form factor.

thank you so much, this is very useful