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 V_out/V_in. 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).