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d2:laser_controller [2019/08/29 10:20]
Michael Radunsky
d2:laser_controller [2019/10/23 14:56] (current)
Michael Radunsky
Line 411: Line 411:
   - Turn on temperature loop.   - Turn on temperature loop.
   - Adjust set-point to approximately desired temperature.   - Adjust set-point to approximately desired temperature.
-  - Turn up the gain. Keep increasing the gain until the temperature error (front panel BNC) just start to oscillate or ring with very little damping. If oscillation too large, reduce gain. Measure the period of oscillation.+  - Turn up the gain. Keep increasing the gain until the temperature error (front panel BNC) just starts ​to oscillate or ring with very little damping. If oscillation too large, reduce gain. Measure the period of oscillation.
   - Turn off the Laser Controller. Measure resistance between "​GAIN"​ testpoint and "​GND"​ testpoint. ​ Turn down the "​PROPGRAIN"​ until this resistance reads 1.7 times less than its original value (i.e. from 500Ω to 295Ω).   - Turn off the Laser Controller. Measure resistance between "​GAIN"​ testpoint and "​GND"​ testpoint. ​ Turn down the "​PROPGRAIN"​ until this resistance reads 1.7 times less than its original value (i.e. from 500Ω to 295Ω).
   - Take the measured oscillation period in step 6 and divide by two. Set the Integrator time constant to this value. For instance, if you measured a period of oscillation of 14 seconds, turn on the 4<​sup>​th</​sup>​ (2.2s) and 5<​sup>​th</​sup>​ (4.7s) switches in the integrator bank, to get a time constant of 6.9s.    - Take the measured oscillation period in step 6 and divide by two. Set the Integrator time constant to this value. For instance, if you measured a period of oscillation of 14 seconds, turn on the 4<​sup>​th</​sup>​ (2.2s) and 5<​sup>​th</​sup>​ (4.7s) switches in the integrator bank, to get a time constant of 6.9s. 
d2/laser_controller.txt · Last modified: 2019/10/23 14:56 by Michael Radunsky