Why Amplitude of PWM signal reduces after Filtering operation

[sayaf]

Hi,
I need help to solve this problem, As I'm acquiring sine modulated PWM signal & performing filtering operation on it to remove the pulses & obtain a pure sine wave of 6oHZ, in this process the amplitude of the filtered signal is reduced considerably from 300V to 40V.I would like to know why is this happening & to avoid this what can i do.
I've attached the pwm signal , the filtered signal & the Block diagram of filter..
Please help me out
Thanks in advance
sayaf

[sayaf]

I've attached the pwm signal , the filtered signal & the Block diagram of filter..

[johnsold]

What are the minimum and maximum duty cycles in your actual PWM signal? The JPEG image lacks the resolution to tell.

Lynn

[rpursley8]

I'm guessing the original signal's amplitude consists of a broad frequency content and all of them are contributing to the maximum amplitude. Once you filter most of them out, the amplitude should be reduced. Take a look at the FFT of the original signal and see what the magnitude of the peak is at 60 Hz. You might find that what you see is what you should see.