Hello everybody ;-),
I am a beginner about Arduino and its possibilities and I want to know if the Arduino can produce a sine wave signal to transmit wireless energy via a first coil connected to the Arduino and another coil connected to a LED. In this view, I saw the function tone() but do i have to use transistors or condensators to enhance the current ?
Thank you 
What is your application and why does it have to be wireless? Wireless transmission in the manner you're suggesting will only be fractions of an inch and would need more current than an Arduino can supply, unless you consider using a transformer as being "wireless".
if the Arduino can produce a sine wave signal to transmit wireless energy via a first coil connected to the Arduino and another coil connected to a LED.
Yes it can.
but do i have to use transistors or condensators to enhance the current ?
Yes you have to use a transistor to drive the coil. Use the PWM output set at 128 and change the PWM frequency to about 125KHz just like an RFID circuit.
Grumpy_Mike:
Use the PWM output set at 128.
Technically 127 for 50% duty cycle. In fast PWM, Duty% = 100*((OCR+1)/256).
But I never said that it was a 50% duty cycle, I just said use it.
Ok thank you :), I will try this !