MarcP/HughR

DeIsolated the platform to investigate the concerns on the Coil Driver.  Running an sine excitation into the H2 OUTF, things looked fine until the I_INMON reached about 50-60 counts; this occurred with an excitation of 2500 counts.  At that point, the I_INMON reversed direction and went very large (340cts.)  Looking at the actual platform motion though, this was not happening to the Actuator.  This is similar to what we observed in the second attachment of 28621. It never was observed to do anything crazier than that though such as suddenly driving the platform off to tripping.

Next step was to disconnect the output from the coil driver and confirming that what we saw on the monitors was what was going out, even though looking at the response of the platform, it was moving in a nice sinusoidal pattern and not abruptly reversing when the current hit 60 counts.  About that time is when Marc noticed that the -15V led was not illuminated on the coil driver chassis.  He pulled the coil driver and found the SG7915 Voltage regulator was producing -2V rather than -15V.

Pulled coil driver S1103341 and replaced with S1600116.  This unit had the hardware watchdog power supply enable circuitry so that enabling voltage was patched over from ITMY.

The ISI reisolated first attempt.  Took the platform back to Isolated Damped and again ran the sine (0.05Hz) until the I_INMON was surpassing ~75cts.  No clipping/flipping/scaling seen on the I_INMON signal.  Attached is this after picture, sadly the ugly before picture may be lost as we had frame writer issues during the morning and afternoon.