A high pass filter is just opposite to a low pass filter. It is employed to avoid or retain frequencies which are lower than filter’s cutoff frequency. It is also [[wysiwyg_imageupload::]]known as low-cut filter since it provides a difficult passage to low frequency signals from source to output. High pass filters find their applications in multimedia circuits such as audio tweekers etc. Also, the concept of high pass filtering is used in digital signal processing of images and animated data.It is, however, pretty interesting to know that a low pass filter can be converted to high pass and vice versa just by shuffling the combination of resistance and capacitance. The cutoff frequency is the design parameter of the filter and depends on the value of capacitor C and resistor R according to the relation f = ½(pi)RC. Let’s make an interesting circuit project on high pass filter.