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Entry  Wed Aug 1 11:38:36 2018, aaron, mandy, DailyProgress, Temperature Sensing, progress on FSL 
    Reply  Wed Aug 1 18:58:53 2018, aaron, DailyProgress, Temperature Sensing, progress on FSL 
Message ID: 2116     Entry time: Wed Aug 1 11:38:36 2018     Reply to this: 2117
Author: aaron, mandy 
Type: DailyProgress 
Category: Temperature Sensing 
Subject: progress on FSL 

Mandy and I made the following plan for getting to frequency stabilization:

  1. Test out Moderinger
    • Figure out all inputs
    • Measure Q of some mode
    • Compare to ringdown method 
  2. Build and test real-time frequency tracking
    • Make new soft channels in DAQ (frequency, set point, etc…)
    • Confirm this is same as tracking on diaggui 
  3. Modify or replace temperature PID loop 
    • Low pass filter (otherwise shape) the control signal from #2 
    • Pass it to existing PID loop
    • Probably make some handoff between RTD and frequency tracking 
  4. Miscellaneous
    • Step the temperature, calculate frequency difference to temperature
      • Or a frequency step 
    • Allow for sweeps
      • Or allow f to drift and integrate ModeRinger data 

I started opening up the ModeRinger model and adding some modifications of the Lock-In to let us track the eigenfrequency. I haven't tested this yet and am a bit unsure which of the built-in simulink blocks I can use, so it might need some modification.

In the meantime, we started down item 1, and noticed that when we drive with 0-150V from the HV driver, the voltage is 0-150V at the other end of the HVBNC. However, if we measure the voltage at the ESD, it has been HP filtered. The leads to the ESD are a twisted pair of manganin wires, and if we untwist them we measure 0-75V at the ESD with a 32.5V offset; some unintended combination of RLC is doing this, as well as maybe a 1/2 voltage divider? We need to measure some transfer functions to figure out exactly what's going on, but yesterday we just called that "enough excitaiton" and confirmed that we can excite with the awggui.

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