Nicolas Farah (3349738)- Foundation Engineering at University of Southampton
Introduction: The aim of this experiment is to build an RC high-pass filter circuit and to measure its frequency response over a range of frequencies around the cut-off frequency.
Very often, small AC signals of interest lying in one frequency range are obscured by additional, unwanted noise signals which lie in another frequency range. If such a mix of signals is connected to the input of a suitably designed AC filter circuit, then the output of the filter will enhance the wanted signals relative to the unwanted signals, thereby usefully enhancing the signal-to-noise ratio. As illustrated by the frequency response curves in Figure 4, there are three types of AC filter circuits: high-pass filters which pass high frequencies and reject low frequencies; low pass filters which pass low frequencies and reject high frequencies; band-pass filters which pass a range of frequencies and reject both higher and lower frequencies. The simplest form for a high-pass or low-pass filter consists of a capacitor in series with a resistor as shown in Figures 1 and 2. The signal to be filtered is applied to the 'input' terminals on the left and the filtered signal appears across the 'output' terminals on the right.
Figure 1 - high pass filter
Figure 2 - low pass filter
Apparatus:
Method: