aLIGO LHO Logbook

H1 SUS (DetChar)

richard.mccarthy@LIGO.ORG - posted 07:47, Thursday 26 March 2015 - last comment - 19:52, Thursday 26 March 2015(17479)

ETMY ESD drive

Loss of lock probably due to my work at EY on ESD drive.  

Following up on last nights report I went down to EY to investigate problems with the ESD.
Much to my surprise aside from the unit being in the off state I could not find a problem.  The HV supplies were on and at nominal current draw for no drive (3.2mA).  Went in to check the ESD Chassis and all the lights were green. The only indication of a problem was the main indicating light for the unit showed it to be in the off state.  I had disabled all of the DAC inputs to the driver so I turned it on.  Went over to computer and enabled outputs and immediately saw a response on the OpLev.  I am not sure what interlock could have shut the unit down but further investigation is warranted.  I have left the unit on for now.  please keep me Richard McCarthy informed if this or more problems arise.

Comments related to this report

rainer.weiss@LIGO.ORG - 19:52, Thursday 26 March 2015 (17498)

Link

When I was characterizing the ESD several years ago I noticed that the
microprocessor that controls the device would turn off the system when a spike
in either + or - direction on the 430 volts input occurs. You might want to check
the tolerance on the input voltage of both the positive and negative input voltages.