Wireless Power Transfer - Future Wireless Charging

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wirelesspowertransmitter.jpg
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Well, that is really nothing what's worth to mention since there are millions of already done projects like this one on youtube and other channels.

However, I am still working on my desktop robot and want to charge the battery during runtime without having to plug the robot into a charging unit. 

Wireless charging is the magic word and it's quite common theses days so I could just buy the whole thing. I won't do that since I am happy when I can play with components which seems to be from an ancient time, transistors. 

That circuit I found on youtube in Ludic Science's channel is perhaps the most easy one with the less components. You will just need one common transistor (a 2N2222 will do the trick), a LED, some magnet wire and a single AA battery.

I tried to do that before but failed. The magig is the resonance which enables the power transfer. The two coils have to be in resonance to make it work. 

This is the circuit (borrowed screenshot from Ludic's video)

wirelesspowertransmitter.jpg

This is the transmitter coil. Make 12 windings then take a wire loop and do another 12 windings so that you end up with 3 wires, the middel one is twisted together.The circuit is straight forward, so I am not going to explain much more here. The receiver coil is 24 windings and each end of the wire is just connected to a LED.

The only thing I changed on that circuit was to add a 1k base resistor since the 2222 got quite hot. 

I left it running over night and will see how the battery looks tomorrow morning. Depending on the result I will try to put a 10k or larger base resistor in place, trying to save more battery power by the same output.

UPDATE #1: The 10k resistor did not light up the LED bright enough so I kept the 1k in place. 

Update #2: The current with one red LED is around 5mA. If I have time I will figure out and test a circuit to charge a battery.

Update #3: Correction, the receiver coil is 24 windings, NOT 12. Also I forgot tom mention that by 5mA output the primary circuit is drawing 84mA.

https://www.youtube.com/watch?v=_aVeT5GBp6g
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Very Cool

Looks like the Inventor in you is coming out. Great idea, remember Tesla and what he tried to do using Electro Magents… Looks very similiar except scaled down quite a bit. I am interested in seeing how well it can charge a battery. This would work great as a charging station for a robot so that the robot would not have to come in direct contact with the contacts of the charging unit but be within a proximity of the unit.

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If you end up becoming a

If you end up becoming a wizard of electromagnetism, just make sure to make Tesla’s death ray. ;D

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Guys, thanks for the flowers

Guys, thanks for the flowers but that’s not my invention since I just re-build (another term for copying) it from that Russian guy.

Anyway, yes i build that with further improvements in mind, keyword wireless charging of swarm robots. Right now I am just keeping it on my desk and wait until the battery is drained. So far it lights up the LED since yesterday.

Today I tried a 10k base resistor but that’s too much, the LED is barely lit up. I did not have time to measeure currents yet, that will be a task for next week.

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Nice project Lumi.

I collected this one so that I can follow your progress!

I do have one question for you though…In your post you mentioned that the transmitter coil is a 24 turn center tapped coil and that the receiver coil is 12 turns. Maybe that was just a type-o, but if not, doesn’t that in effect create a step-down transformer with an output from the receive coil that is half the voltage of the transmit coil? I think that the receive coil should also be 24 turns for a theoretical 1:1 transfer.

Maybe this has something to do with your diminished voltage to the diode? Just food for thought my friend.

Don

 

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Thanks but I only copied it

Thanks but I only copied it :slight_smile:

However, I just wrote Update #3 to correct my typo. The receiver coil is 24 windings and NOT 12. I have no clue about the numbers in that circuit but I will try to figure it out when I have time.

The trick with wireless power transfer is the resonance.

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Thanks for posting Lumi!

Thanks for posting Lumi! Something that I can learn from, and probably integrate into some robots (most likely miniature ones).

 I guess Lumi and viswesh should join forces to create the ultimate wireless power system. :smiley:

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Indeed, I would like that.

Indeed, I would like that. For now I do not have time and perhaps not much for the rest of the year but there will be some hours where I can work on that.