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IOO (Laser Bench)

masayuki.nakano - 3:06 Tuesday 21 August 2018 (5848)

FSS with the new TTFSS servo

I installed a modified TTFSS servo and close the FSS loop with the new configuration. The measured OLG and the calculated OLG is shown in the figure.

Because of the unknown notch, the UGF cannot be higher than 200 kHz, and it is lower than the previous configuration. I guess it is because I touched the variable capacitance on the circuit board accidentally, which changes the notch frequency. I will check it tomorrow.

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Comments to this report:

masayuki.nakano - 1:17 Friday 24 August 2018 (5894)

There seems an unknown loop in the FSS.

I measured OLG again with two different gain of the servo. At the high frequencies, the OLG does not change even the servo gain is different. That might mean that there is a loop independent from the FSS loop.

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