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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">Subject:
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<td>Re: Power supplies and relays for monitoring. Corrected.</td>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">Date: </th>
<td>Fri, 09 Nov 2012 11:50:24 +0200</td>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">From: </th>
<td>Georgios Voulgaris <a class="moz-txt-link-rfc2396E" href="mailto:gboulgaris@phys.uoa.gr"><gboulgaris@phys.uoa.gr></a></td>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">Reply-To:
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<td><a class="moz-txt-link-abbreviated" href="mailto:gboulgaris@phys.uoa.gr">gboulgaris@phys.uoa.gr</a></td>
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<td>University of Athens</td>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">To: </th>
<td>Elton Smith <a class="moz-txt-link-rfc2396E" href="mailto:elton@jlab.org"><elton@jlab.org></a></td>
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Hi Elton,<br>
I checked the design as realized and is using 4 trigger lines
not 1 trigger and 2 select. So I corrected some numbers in
paragraph 4 but the scenario is the same. Please ignore the
previous mail. <br>
<br>
George.<br>
<br>
<ol>
<li> I checked the specifications for the MPOD 8008L. It is
programmable 0 to 8 V with 12 bit accuracy that is 2 mV. This
is very good. So its easy to scan the voltage range. </li>
<li> In order to pulse different chains of leds its easy and
cheap to switch on - off this voltage because its DC. The
relay boards are cheap but they are slow devices (in the
millisecond range) and they need another external interface
like I2C etc.</li>
<li> On the other hand if the Lab stocks programmable output
modules it is more elegant to use them. They are addressable
directly through the VME and they are fast , microsecond
response time. The outputs are pulsed according to the bit
pattern loaded on the unit. So we don't need an external
pulser and all operations are completely synchronized by the
data acquisition.</li>
<li> We need 4 triggers (pulse signals) per wedge total
signals. In order to reduce the number of signals we can
send the same signals to a group of wedges in parallel ( on a
bus cable). I assume that 8 wedges per group is a reasonable
number, so we need 52 outputs. The trigger pulse is
regenerated on the wedge board so the shape is not affected.
Bigger groups are possible depending on the fan-out ability of
the modules. I think that timing issues in the data
acquisition should be examined too . Its possible to use a
single bus per side of bcal, if we introduce termination and
regeneration boards along the bus. </li>
<li>So the preferable scenario is VME programmable output
modules plus one or more bus cables. <br>
</li>
</ol>
<p>Bye,<br>
George.<br>
<br>
</p>
<br>
<br>
στις 7/11/2012 3:33 μμ, O/H Elton Smith έγραψε:
<blockquote cite="mid:509A6328.9060704@jlab.org" type="cite">
<div class="moz-cite-prefix">Hi George,<br>
<br>
Sorry we could not hear you yesterday during the meeting (was
your microphone turned on?). <br>
<br>
Thanks for these comments. They will be useful in confirming
our requirements. The present thought is to use the same
supplies that we use for the SiPM bias and power. (Wiener MPOD
8008L and ISEG EHS F 205 PF). You could double check the
specifications, but I think they should be ok since they
satisfy the requirements for the SiPMs. There are 8 outputs
per module. <br>
<br>
Thanks, Elton.<br>
<pre class="moz-signature" cols="72">Elton Smith
Jefferson Lab MS 12H5
12000 Jefferson Ave
Postal Suite #16
Newport News, VA 23606
(757) 269-7625
(757) 269-6331 fax </pre>
On 11/7/12 6:07 AM, Georgios Voulgaris wrote:<br>
</div>
<blockquote cite="mid:509A40D6.7060202@phys.uoa.gr" type="cite">
Hi Elton,<br>
I have some suggestions about the PS for biasing the LEDs.
What we need are precision programmable supplies. <br>
i) quantity : 2 (one per side) Most 2 per side if this
improves the flexibility.<br>
ii) Power : the required power is very small. The common PS
type of 60 W is acceptable.<br>
iii) Interface : All programmable PS come with serial and USB
interface some include LAN.<br>
iv) Distribution and switching of voltages. I suggest to use
programmable relay boards .<br>
The accuracy of the voltage setting is important.
Recently I bought a supply from Thurlby-Thundar, with setting
accuracy of 10 mV for 650 Euro. This PS has serial, USB, LAN
interface and can be rack mounted. I consider this accuracy
adequate for the monitoring. On the other hand one can buy PS
with 1mV setting accuracy from brand names like Agilent or
Tektronics and other at a price range from 900 to 1200 Euro.
These prices are retail prices but I suppose that JLAB is
getting discounts of 20-30%.<br>
All these devices come with driver for integration in Slow
Controls software.<br>
The link for TTi is: <a moz-do-not-send="true"
href="http://www.tti-test.com/">TTi</a><br>
Programmable Relay boards are cheap. I haven't use any
of them lately so I dont;t have a suggestion. I include couple
of links so as to get an idea.<br>
<a moz-do-not-send="true"
href="http://www.ereshop.com/shop/ei2c9ai-p-605.html?gclid=CIOMiJW2vLMCFUW_zAodSDQAEg">http://www.ereshop.com/shop/ei2c9ai-p-605.html?gclid=CIOMiJW2vLMCFUW_zAodSDQAEg</a><br>
<a moz-do-not-send="true"
href="http://www.apogeekits.com/usb_relay_control_board.htm">http://www.apogeekits.com/usb_relay_control_board.htm</a><br>
During the last meeting I had a good sound reception but my
voice was not getting through! So my comment was not heard!<br>
Bye,<br>
<br>
George.<br>
</blockquote>
<br>
</blockquote>
<br>
<div class="moz-signature">-- <br>
George Voulgaris, Nuclear & Particle Physics
Sector,University of Athens Tel: (30)2107276949 Fax: (30)
2107276949 Mobile: (30)6944692936 Home: (30)2106516713</div>
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