Filter the DC component (square/triangular wave)

Thread Starter


Joined Sep 21, 2011
Hello. I'm an electronic student and i'd like to know a bit more about DC filters. How can i filter a DC component of a low frequency square or triangular waveform. I already tried to simulate a simple CR filter but i don't know why this type of waveforms tend to change their shape in its presence.



Joined Sep 20, 2005
How low frequency is low frequency? In the order of 100hz and up, a simple capacitor in series with the signal will filter DC.

Audio amplifiers, which use much lower frequencies than that so the output capactior would be too large, use a technique called DC servo which averages the DC content and outputs negative feedback signal to compansate for it.


Joined Nov 30, 2010
The wave forms change shape because of the relative impedance of the resistor and the capacitor. Higher resistance allows the capacitor to have more effect on the wave form.