Step 5: Thoughts, and Explanation
However, in this case, the reason it works is because the ZVS driver begins by oscillating at around 50 - 60 khz. We can't hear it since it's above our hearing range.
Resonance can be thought of like a Pendulum. If you hit a pendulum, it will move forward, and then back. If you hit the pendulum again, right as it starts to swing downwards, the pendulum will travel faster and higher than before. It's very much the same in electronics, just instead of speed and height, it's voltage and current! You can observe it pretty easily with a cup of water. If you shake it just the right way back and forth the water will spill right out of the cup, due to resonance.
Due to this magic called resonance, the voltage swings in the tank (between the 3 + 3 coil and the 2 uF capacitor) are much higher than what the input voltage is. Resonance helps with transmission distance, and also, as a result of how the MOSFETS turn on, they're in what's called Zero Voltage Switching, where they turn on and off when the voltage across them is zero. (meaning, they generate little/no heat due to switching losses). However, due to on-state resistance, they still make a little bit of heat.
ANYWAY, going away from the complicated bits of it, the reason it can transmit power is caused by magnetism. As the coil oscillates, it sends an alternating magnetic field through the air, which is picked up by the receiving coil (and again, due to resonance, the voltage rises upwards!) and thus, power is transmitted through air! The same basic concept is behind radio waves; though, amplifiers are needed to get the audio out of the air, and the frequency is much higher!
I made all of the pictures shown in, though, the transmitter picture is a modified version of the famous Mazzilli flyback driver. (a great, versatile circuit... Used for so much, thanks Vladmiro Mazzilli for this!)
And, one more thing; In another instructable, once I get some protoboard, I'll explain how to make a buck converter. It's relatively easy, and requires just a few parts.
And as a safety note; I'm not responsible for any "oopsies" you make if you decide to construct this circuit. You NEED to make sure everything is connected properly!
If I do somehow end up winning the Epilog contest, I would use the laser etcher to first and foremost, make PCB's. I don't like the traditional way of etching (with chemicals and nasty fumes) and plus, I could additionally sell the PCB's to other electronics enthusiasts for smaller amounts of money, than most etching companies make you pay. I'll try my best to bring this hobby back into the spotlight!
Thanks for reading, and please rate, and vote :)