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Message ID: 650     Entry time: Wed Jun 26 22:58:44 2013
Author: Giorgos 
Type: DailyProgress 
Category: SUS 
Subject: Hall-effect sensors and transfer functions  

Today, I wired up the power PCB boards for the DC motors and then talked and read about Hall-effect sensors. The box that will hold the sensors is too small, so we spent some time figuring a way to combine two boxes into one to fit all of our components. Then, we spent a lot of time talking about transfer functions, Laplace transforms and how they help us disentangle linear, time-dependent equations from their time-relationship and yield convenient equations that describe the behavior of a system at different frequencies.

We want to apply a high-pass filter to "remove" the low-frequency noise from the signal in our Hall-effect sensors and achieve low frequency seismic noise isolation. So, we used the following high-pass filter circuit and found its transfer function Vout/Vin. It is my homework to find the values for R1, R2, R3, C1, and C2, so that our transfer function gives large output at high frequencies (above 50Hz) and small output at low ones (below 5Hz).

High-pass_filter.png

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