Hi, I'm working on a wireless power transfer project through electromagnetic inductance, currently i got everything to work properly, led light on the receiving side ligh up since i matched up the frequency to the transferred side.

The question i have is on the receiving side (air coil) right now i have 1" x 75 winding using 28 gauge wire. Is there a way I can increase inductance by adding a soft core iron in the middle and decrease the amount of winding? or even reduce the size of the coil to just .5"? Please let me know if i need to provide additional info. Thank you so much for any input regarding adding soft iron core to increase inductance and efficiency on the receiving side..

Thanks. T

 

Seems odd. You built a device that uses inductance. Which means you "should" have some clue how inductance works. Yet here you are asking how to modify an inductor.

 

I got here by trial and error, also learn stuff by reading, I'm not in the field, doing a fun project. I don't know much about inductance, still learning.

Thanks for any advice..

 

Most of these I have seen depend on the resonant frequency of the transmitter and receiver being the same. Maybe you could post your circuit. If it is as I stated you can make the inductance lower ((smaller coil) and the capacitor higher and keep the same resonant frequency. It is important that they both have the same frequency to get the maximum output which may require a scope.

 

on the transmission side i have a .033 capcitor, a .001 cap, and a .047 cap with 10k ohm resistor, h331 transistor, also a 100uf capacitor 16v, this produce frequency of about 123khz (primary side). Then the receiving side (secondary side), I don't really know how to calculate the frequency to come to the exact amount of turns & how what capacitor to use on the receiving side... i did find a few formula online but based on that I can only calculate to a guesstimate turns and capacitor, from there, I have to do trial and error by reducing the amount of capacitor value by plugging in all different capacitors or decreasing the amount of coil turns little by little. I know it sounds like a lot of work, but if someone has an exact formula to calculate the turns and capacitor to use on the receiving side, would greatly appreciate..

Thanks again.

 

Here is a site with a good example:

http://www.discovercircuits.com/dc-mag/Issue-1/issue-1-receiver-construction.htm

Inductor calculator:

http://www.daycounter.com/Calculators/Air-Core-Inductor-Calculator.phtml

Or you can buy factory wound coils that might be easier.

http://in.mouser.com/Passive-Components/Inductors/Wireless-Charging-Coils/_/N-cbt1u/