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Message ID: 16939     Entry time: Wed Jun 22 17:04:06 2022
Author: Deeksha 
Type: Summary 
Category: Electronics 
Subject: Characterising the AUX control loop 

[Cici, Deekha]

Setup loop to measure transfer function of control loop - the aim is to find the open loop gain of the system using the SR785 to inject noise (a swept sine) into the system and taking observations using the scope. We tried to calculate the gain algaebraically, in order to understand what our readings meant and what we can determine from them. Need to figure out how to run python script for the SR785, but took readings from cmd today.

Included - changes/additions made to circuit; frequency reponse obtained (need to check the frequency response as it does not look like the expected result, need to correct the loop itself, or increase the magnitude of the inserted noise as its possible that the noise is currently being suppressed by the system).

To do - circuit needs to be checked + laser lock improved - laser keeps leaving resonance while trying to take readings.


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