hi all,
once again a new thread for rms current calculation , i am working on induction heating machine of primary load 100amps and frequency range from 20khz to 80khz depending upon value of heat fixed for job to be heated.
the basic principle for induction heating machine is to control current(heat) by varing frequency of choped dc(square wave) through primary of transformer to control induction field of inductor fixed across the secondary of transformer.
current feedback is taken from primary of transformer using C.T.,now as machine will run at frequency any where in the range from 20khz to 80khz depending upon value of heat set and and type of job to be heated like brass,iron,steel. C.T. will give feedback at the same frequency now my problem is i know only frequency range of operation do not know the opertaing frequency of machine for particular job as it is variable depending upon job,microcontroller automatically select frequency depending of heat and job,now how to calculate rms value of current from C.T. for 20khz to 80khz range,i tried it by converting it to DC voltage but capacitor always charge to peak and give wrong results.

thanks
kuldeep singh