40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  PSL  Not logged in ELOG logo
Entry  Mon Oct 3 13:59:40 2016, awade, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board 20161002_D980401_PSLTempBox.epstemp_AD590TransImpedanceBox_PSDs.zipD980400-B.pdf
    Reply  Mon Oct 3 18:15:23 2016, not awade, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board 
       Reply  Tue Oct 4 11:49:53 2016, awade, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board 20161002_D980401_PSLTempBox_Vrms.eps20161002_D980401_PSLTempBox_Vrms.fig
          Reply  Sun Oct 9 09:01:27 2016, not awade, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board 
             Reply  Mon Oct 10 11:32:27 2016, awade, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board 20161002_D980401_PSLTempBox.pdf
    Reply  Fri Sep 1 13:36:20 2017, awade, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board 
       Reply  Sun Sep 3 14:10:38 2017, awade, Kira, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board LIGO-Temperature-Sense-Board-SingleChannel.pdf
          Reply  Mon Sep 4 23:07:41 2017, Kevin, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board TemperatureSensingCircuit.pdfTemperatureBox.jpg
             Reply  Tue Sep 5 23:54:45 2017, Kevin, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board p1.jpgp2.JPG
          Reply  Wed Sep 6 19:58:21 2017, awade, Kira, DailyProgress, TempCtrl, Modified LIGO temperature sensor interface board 
Message ID: 1889     Entry time: Fri Sep 1 13:36:20 2017     In reply to: 1730     Reply to this: 1893
Author: awade 
Type: DailyProgress 
Category: TempCtrl 
Subject: Modified LIGO temperature sensor interface board 

While we are waiting for a final design of a new temperature sensor board we can make use of the old LIGO Temperature Sensor interface board (D980400) that was used to sense temperature before.  I had put it aside because I didn't understand the modifications (chips glued upside down with dead bug wiring) and it was noisy (ringing) when plugged into acromag. But we can debug this to get a temp sensor up and running quickly while the Kira and Kevin build something better.

When we plugged in the AD590s to the board and then attached this to the acromag slow inputs the circuits went into ringing mode. Rana has suggested that we look into adding more (100 Ω) series resistance on the output so that the output op amps are not overloaded (pulling more current than they can handle). I understand we need to choose low noise thin metal film surface mount type. I seem to recall a comment from Frank in the elog that he didn't have any no precision resistors at the time and that he only wanted to use it for monitoring anyway: we can fix this when we debug. We need to work out what the true schematic is and why, with a ~ 100 kΩ load connected, the circuit is in an unstable state.   As you can see in the picture attached below the dead bug job uses axial resistors (non-surface mount) on a mystery chip.  

I think post PSL:108 summarizes the main modifications that Frank made to the board. There are other tit-bits of information that can be found with a search of AD590 back throught the elog

Also, I found the box and lid, which were being used as storage for screws and bits: we'll put foam inside the reduce thermal fluctuations of electronics.

Kevin and Kira should come over and we'll look at it with a scope.

ELOG V3.1.3-