SDSU (ARC) CCD controller documentation
29 November 2018
(and updated SDSU PSU section at end on 12/11/2023)
Following Dave Atkinson's visit to Thailand, we realised that the
documentation for ULTRASPEC is in a dire state. To rectify this, Dave
collated the following set of circuit diagrams and user manuals for the CCD
controller boards in ULTRASPEC, as well as providing a change history
document. Note that all of the drawing versions should now be correct
with the exception of the power control board (ARC73). Bob Leach
does not have any 6B documentation on file, but he suggests that 6C
will be as good as "identical".
I've now also added the circuit diagram for the SDSU PSU (ARC80) that
we use for both ULTRASPEC and ULTRACAM. I also added updated information
on PSU situation and the spare CCD controller, following Dave's and my visit
to the TNT from 23-29 Nov 2018.
On 12 Nov 2023 I added some new text to the SDSU PSU section at the
bottom, in light of the PSU testing and general sorting out I did at
the TNT on this date.
ULTRASPEC has the following boards in its 6-slot chassis:
- Slot 1: UKATC HV CLOCK BOARD. Labelled "BRD2" (sticker) and
marked "UKATC L3CCD HV Clock Rev 3.0".
- Slot 2: ARC-32 IR & CCD CLOCK DRIVE BOARD, REV. 6A
6/6/2006. On the back it says (in pen): S/N 176, Rails = 13V, Rise
Time = 10ns.
- Slot 3: Empty.
- Slot 4: SDSU CCD VIDEO PROCESSOR BOARD, REV. 3B 7/3/97. On
the back it says (in pen): S/N 53. The board has two ADCs. One has a
PAT testing sticker on it (!) and says "From right NO2" (?). The other
has a printed sticker saying "VD NoO". The ADCs are code number
9745. None of the PALs have any stickers on them - not sure if any are
exchangeable. Note that the SMA connector marked "LS" goes on the
connector nearer the centre of the board, and the one marked "HR" goes
on the connector nearer the edge of the board.
- Slot 5: Empty.
- Slot 6: ARC, INC., ARC-22 TIMING BOARD, R5D 7/10/02. On the
back it says (in pen): S/N 368. There is an EPROM with a
(UKATC-provided) sticker saying "utim 3.4". There are three PALs. The
smallest has a white sticker with "U3R52". The middle-sized one has a
sticker saying "U16R53". The largest has a sticker saying "U37R53".
- Power control board: This is located at the end of the SDSU
chassis. It says: SDSU ASTRONOMY, POWER CONTROL BOARD, R6B 4/8/98. It
has a sticker saying "S/N 124". There are no exchangeable PALs or
EPROMs on it. It has jumpers JP6 and JP9 removed.
The drawings and manuals for the various SDSU boards are below:
- ARC22r5D_Layout.pdf
- ARC22r5D_Sch.pdf
- ARC32r6A_Layout.pdf
- ARC32r6A_Sch.pdf
- ARC32_UsersManual.pdf
- ARC45r3B_Layout.pdf
- ARC45r3B_Sch.pdf
- ARC45_UsersManual.pdf
- ARC73r6C_Layout.pdf
- ARC73r6C_Sch.pdf
- ARCControllerHistory.pdf
- ARCControllerHistory.xls
- ARC-22: 250 Mhz Fiber Optic Timing Board, Gen III: User Manual
During visits in Nov 2017 and Nov 2018, Dave and I configured our
spare SDSU 6-slot chassis with the following spare set of boards:
- Slot 1: Spare UKATC L3CCD HV CLOCK BOARD. Labelled "BRD1"
(sticker). A visual inspection comparing this board with the one in
the controller reveals no differences, with all jumpers set the same.
- Slot 2: Spare ARC-32 IR & CCD CLOCK DRIVE BOARD, REV. 6A
6/6/2006. On the back it says (in pen): S/N 185, Rails = 13V, Rise
Time = 20ns. A visual inspection comparing this board with the one in
the controller reveals no differences, with all jumpers set the
same. Testing in Thailand with Dave demonstrates that this spare works
perfectly when swapped with the existing board.
- Slot 3: Empty.
- Slot 4: Spare video board (SDSU CCD VIDEO PROCESSOR BOARD,
REV. 3B 7/3/97). The components on this board had to be modified
slightly by Dave so that it gave the same bias voltages as the main
video board. On the back it says (in pen): S/N 385. The board has two
ADCs, with no stickers on them. There are two PALs, both of which have
"R3.1" stickers on them. Note that the SMA connector marked "LS" goes
on the connector nearer the centre of the board, and the one marked
"HR" goes on the connector nearer the edge of the board.
- Slot 5: Empty.
- Slot 6: Spare timing board (ARC, INC., ARC-22 TIMING BOARD,
R5D 7/10/02). The original was given to me by Derek ages ago, but Dave
found it didn't work during testing at UKATC in Oct 2018. So Dave gave
me an identical board he had in his lab, and I intend to return the
original board to Bob Leach for repair in Dec 2018. When I get this
back, I will give it to Dave to pay him back. The final (Dave's) board in the
spare controller has the latest version of the UKATC code ("utim
3.4"). On the back it says (in pen): S/N 66 (the broken original was
S/N 1064). There are three PALs. The smallest has a white sticker with
"R5.4". The middle-sized one has a sticker saying "R5.2". The largest
has a sticker saying "R5.5".
- Spare power control board (SDSU ASTRONOMY, POWER CONTROL BOARD,
R6C 5/1/9). I bought this from Bob Leach in 2013. This is located
at the end of the SDSU chassis. It has a sticker saying "S/N
256". There are no exchangeable PALs or EPROMs on it. It has jumpers
JP6 and JP9 removed.
We use an ARC80 (large) PSU for ULTRASPEC, the same as we do for ULTRACAM.
We currently have 3 of these SDSU PSUs in Thailand. These are:
- Original SDSU PSU: The circuit diagram for this is given
here: ARC80_Sch.pdf. This is the original
PSU that Derek gave me with the instrument back in 2006. During
testing in Sheffield in 2013 prior to shipping to Thailand for first
light, we discovered this PSU to be unreliable, sometimes not allowing
a successful PON. It eventually failed completely (never allowing a
PON) in March 2017, so it was swapped for the Old Spare SDSU
PSU - see below for details, which we have used since then. I
intend to return this to Bob Leach for repair in Dec 2018.
- Old Spare SDSU PSU: The circuit diagram for this is given
here: ARC80_Sch.pdf. I bought this PSU
from Bob Leach around February 2013, prior to shipping to Thailand for
first light. We have been using this PSU in the instrument since Mar
2017, when the Original SDSU PSU failed.
- New Spare SDSU PSU: The circuit diagram for this is given
here: ARC80R2A_Sch.pdf. I bought this
PSU from Bob Leach in 2017 as a new spare, to replace the
Original SDSU PSU which had failed. (I also bought a second
such PSU at the same time to act as a new spare for ULTRACAM at the
NTT). This PSU behaves differently when you probe it with a
multimeter. The two older PSUs give 6.5V when you probe pins B-C and
P-N. This PSU, however, gives the expected 6.5V for pins B-C, but
pins P-N gives 3V which gradually ramps down the longer you probe it.
After much discussion with Bob Leach, it turns out that he has
recently changed the funtionality of pin N so that it is no longer the
6.5V return within the PSU. However, this doesn't affect the
functionality of the PSU and it should work identically to our older
two PSUs. You can check by probing pins P-a, which does give the
expected 6.5V. However, Dave and I found in Nov 2018 that this PSU
does not work with the 10m SDSU PSU cables - the PON only works when a
shorter SDSU PSU cable is used. Fortunately, Dave swapped this PSU
with one that he had in his lab that does work with 10m cables. So
I restickered Dave's PSU as New Spare SDSU PSU and put it in
the crates.
I have 3 SDSU PSU cables. Two are 10m long and one 5m long. One of the
10m long ones is currently being used on the instrument. It is showing
some signs of wear in its outer sheath where it rubs against the NARIT
cable twister, so I may have to replace this with the spare in the
future.
Update on SDSU PSUs and cables on 12/11/2023 during TNT visit by VSD:
I brought out a new SDSU PSU and 10m PSU cable to the TNT with me on
this visit. These are the final purchases I made from Bob Leach in Feb
2023 before he closed his company down for good (due to his
retirement) - hence it will be impossible to order any more in the
future. I tested the new PSU and 10m cable with ULTRASPEC and it works
perfectly. In order to be consistent with the previous naming scheme,
I've named the latest PSU the Newest SDSU PSU and stickered
the PSU and its box accordingly (and similarly the 10m cable and its
box), and put them in the ULTRASPEC crates.
The Old Spare SDSU PSU had been in use since March 2017, but on 6
November 2022 it failed (it was unable to PON), and was replaced
with the New Spare SDSU PSU. I decided to check the
Old Spare SDSU PSU during this visit and found to my surprise
that it worked! Weird - the previous error must have been a glitch (it
occurred right at the start of the 2022/23 observing season when the
system was powered on for the first time in months, so maybe that
explains it). I put the Old Spare SDSU PSU back in the crates, removing
the "broken" stickers from it! I decided to leave the New Spare SDSU PSU
in the rack as this possibly shows a slightly lower RNO and pickup (but
marginal). Note that I stuck the G10 insulation mounts on the underside of the
New Spare SDSU PSU to ensure they don't slip off, and found
the best RNO is when the PSU is slid slightly back from the rear of
the rack unit it is in - you need to make sure it doesn't make contact
with the sides to prevent ground loops. (Only the Old Spare SDSU
PSU has threaded holes in its base for the G10 insulation mounts
- I left the nylon bolts for this in a bag taped to the inside of the
PSU 4U rack unit it is mounted in.)
This left one problem - I could not find the Original SDSU
PSU anywhere at the TNT! On checking my emails I realised that
Apichat sent 2 boxes back to me in the UK after Dave Atkinson and I
visited the TNT in November 2018. One box contained the PSU I bought
from Bob Leach in 2017, which didn't work when we tested it with
ULTRASPEC and which I gave to Dave in return for him leaving his SDSU
PSU, which did work, out here at the telescope in Nov 2018. Dave's PSU
then became the New Spare SDSU PSU described above. The
second box Apichat sent back to me contained the Original SDSU
PSU and the faulty SDSU Timing Board described in the description
above of Slot 6 of the spare SDSU controller. I returned both to Bob
Leach for repair in Feb 2019, intending to return the Original
SDSU PSU to the TNT to act as a (fourth!) spare PSU, and the
timing board back to Dave in Edinburgh to pay him back for giving me
his UKATC timing board (the one currently in slot 6 of the spare SDSU
controller).
Bob Leach received the items and reported that neither were broken and
both seemed to work fine - weird. I had a bit of email to-ing and
fro-ing with myself, Bob and Dave, and then silence after Mar 2018. I
completely forgot to chase this up with all that was happening with
HiPERCAM at the time, and then completely forgot about it, until
now. So I believe what has happened is that Bob never returned
the Original SDSU PSU or the timing board back to me, and now
Astro Cam has closed down for good and Bob Leach has retired and these
items are lost forever. Damn. So this means we have only 3 working
SDSU PSUs for ULTRASPEC, not 4, which is fine, and I owe UKATC a
timing board...
So, in summary, we're now operating with the New Spare SDSU PSU.
We have 3 working SDSU PSUs for ULTRASPEC, and we now have 4 SDSU PSU
cables - three are 10m long and one is 5m long.