Hi Henrik,

Thank you for your help and my apologies for not making myself clear.
I am in need of a modulated high frequency source. The main frequency (carrier) should be between 250 kHz and 4 MHz pending some results of testing in progress. I will start with 1 MHz and move up or down on carrier frequency.
I need to be able to turn this carrier ON and OFF in bursts of 15 mS ON and 5 mS OFF.

My project is still in its infant stages, so right now I’m at the point of poking around to see what can be done with a minimum amount of components.

The larger project this is part of is a non-contact power and data transfer. This week and next week I will be doing a lot of testing on the power transfer part to find an optimal frequency that will make it easier to do both with as little loss as possible.

My first power transfer test is encouraging (I can transfer about 1.5 W which is more than I need) with about 66% efficiency. For this I’m using a Mosfet driven by a variable gated oscillator. It serves the purpose for testing but in the final design I would like to have something much simpler especially at the slave unit side where I have a lot of limitations space being one of them.

My research also shows that for power transfer lower frequencies (100 – 400 kHz) are better. For data transfer I would prefer to use higher frequencies since I already tested a wired 4 MHz power and data transfer. Also I understand that higher carrier frequency will allow higher data transfer rate. I must have 9600 but 19200 will be better.

This week I will do some research on employing the CCP module to do most of this part.
I will also study Dave’s example which seems to be doing almost what I need only at lower frequencies.

Dave, you are right and thanks for the suggestion, I will look into it. I am familiar with PIC12F683 but if I must learn new tricks I will.

So many things, so little time.

Thanks again for your help.

Regards,

Nick