Prelab: LC Oscillators
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In last week's lab we saw an RC relaxation oscillator, in the pset we saw an RL relaxation oscillator. In this week's lab, we'll explore a different type of oscillator, built out of an inductor, capacitor and resistor.
Here is the oscillator circuit we are going to build:
1) Thevenin
At first glance this circuit might be overwhelming, so let's use one of our trusty circuit analysis techniques to break it down. Let's start by removing the inductor and capacitor and finding the the Thevenin equivalent circuit looking through their port (labeled below with voltage and current measurements). We can also ignore the supply voltages for now and we will come back to them during the lab. Lastly, lets model our output voltage as a voltage source with a magnitude of v_{o} referenced to the midpoint voltage as shown below.
What is the equivalent Thevinin voltage?
What is the equivalent Thevinin resistance?