Hey everyone,
I'm new to this forum, looked around a little but didn't find what I was looking for. So here's my question, maybe someone has experience in similar stuff.
I am planning to build a series of small plastic toys/figures that would light up from the inside (transparent plastic) when placed on their substrate, and dim when lifted higher than let's say 10mm. So basically what I am looking for is some sort of small inductive coils and surrounding components that would do the job and transfer enough energy to light up one SMD LED at a short range.
I want to place the coil and an LED inside the toy (on it's bottom), and another coil and other components inside the substrate.
Dimensions: The figure's bottom has only 25 mm radius (So the receiving coil can be 25mm max in radius, the smaller the better!). The substrate is a bit larger, around 35mm (So the transmitting coil can be 35mm max, also the smaller the better).
I did a little research, and it seems like all the coils are much larger than 25mm. Saw some projects on the internet where people build coils to light up LEDs at home, but those are too big aswell.
Another question is, what frequency should I choose for the best performance? Again, I'm not interested in increasing the range, quite the opposite, I want it to start dimming almost the moment I lift the toy from the substrate.
Thank you very much in advance for your answers, any help is much appreciated!
