Here's another attempt I made on wireless power:


I borrowed ideas from http://4hv.org/e107_plugins/forum/forum_viewtopic.php?74096 but due to limited stock on hand, I had to use what I can.

I used 6VDC for power in the form of 4 AA batteries. when testing L3 (transmitter inductor) by connecting voltmeter from one end of the inductor to ground, I get 11.6V output which is about double of the measured battery voltage.

So then I placed my mini receiver circuit made on a pcb that consists of a 100uH inductor connected across the analog inputs of a DF005M rectifier. then its outputs are connected to a capacitor in parallel with a jumper that represents the remote power source.

In my test I literally have the insulating materials of each inductor directly touching each other. when I measured the voltage at the pins, all I get is zero volts. How do I make the number greater than zero? Ideally, I'd like to have at least 3 or 4V so that I'm heading in the right direction.

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    \$\begingroup\$ Show a model of your impedances and attenuation. \$\endgroup\$ – Tony Stewart EE75 Oct 3 '17 at 5:15

There's a VERY clear difference between your setup and this one:

enter image description here

  • the antenna coils have a large diameter

  • everything is soldered so series resistances are much lower

  • especially note how the transmitter coil and the 6 red capacitors are soldered together in such a way that the Quality factor is is high as possible meaning low losses.

You are assuming that the proximity of the coils is enough but it is not. The axial inductor you seem to be using as an antenna has an extremely small coil diameter. So it simply cannot couple to the receiver coil as well as you want it to.

Wireless power transfer as in the photo relies on coupled inductors so basically it is a through-the-air transformer. The magnetic coupling needs to be very good in order to pick up any energy.

  • \$\begingroup\$ So basically everything else is right and the only concern then is to replace my tiny inductors with large copper rings? \$\endgroup\$ – user152879 Oct 3 '17 at 6:05
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    \$\begingroup\$ I'm not going to say that what you have is correct. I mentioned the most obvious differences. I count 6 red capacitors in the photo, you do not have them. In the photo a light bulb is used at the receiver, you don't have that. There will be many more differences which cannot be seen from these photos. To sum up, the working setup shows that the person who made it knows what they're doing. You tried to do the same but missed the essential details needed to actually make the setup work. Having the same schematic is only 1% of the whole thing. \$\endgroup\$ – Bimpelrekkie Oct 3 '17 at 6:16

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