Stefan, Sheila, Nic, Evan
We remeasured the relative strength of the EX and EY ESDs in full lock. EX was driven with the high-range driver (40 V/V dc), and EY was driven with the low-noise driver (2 V/V dc). All other things being equal, we expect a relative strength of 20 V/V between the two actuation chains.
We found that the relative strength is instead 30 V/V (see attachment, which includes a digital gain of 30 ct/ct in the EY path). When we first did this measurement (back in May, pre-discharging), the relative strength was more like 50 V/V. So we are closer to the nominal value.
We successfully transitioned control of DARM from EX to EY with this new digital gain. We also took a quick DARM OLTF, both before an after the transition. The attachment shows an old, pre-vent OLTF (blue), today's OLTF with EX (green), and today's OLTF with EY (red).
A relatively small point, but the LV ESD Driver DC gain is actually closer to 1.9 V/V at low frequencies. There's a pole just above 150Hz.