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Hi Christina,<br>
<br>
I presume you are referring to the forward voltage across the LEDs
not the BIAS voltage input, correct? If so, it would be more
appropriate, considering the monitoring function, to look at the
light output variation among the LEDs for a given bias setting. I
believe that Kappos looked at this sometime ago.<br>
<br>
Regarding the power supplies, each supply channel has a maximum 5A
output. It would be useful to have the specifications for current
draw for the +5V and BIAS supplies per board for the control board
and for the LED board. The power supply modules that we will use are
Wiener MPV8008L (8V, 5A, 8 channels) or MPV8016 (15V, 5A, 8
channels) if needed for the BIAS. I am using these for all LV in the
experiment and they work very well.<br>
<br>
Best regards,<br>
Fernando<br>
<br>
<br>
<br>
On 11/8/2012 8:49 AM, Christina Kourkoumeli wrote:
<blockquote cite="mid:509BB867.9010309@phys.uoa.gr" type="cite">
<br>
Dear Elton,all,
<br>
Further to our discussion of Tuesday I attach a plot produced by
Stratos showing the number of flexible strips versus the voltage
of the contined 10 LED's .As you we if we supply them by r 9
supplies, then the output difference between LED's -under their
nominal voltage-is 0.25 Volts.So presumably we will supply them
with a median value of DC voltage in that particular group.
<br>
We have to be careful, though, since we have a large number of
strips with values of voltage between 2.75 and 2.5 Volts. This
means that one supply would have to supply about 900
LED's.Fernando can tell us if this is feasible currentwiseor we
need more than one supply.Also we may need additional ones since
the strips may be located on either sides of the modules.
<br>
In any case, if we decide now on the number of supplies we will
ship the strips grouped likewise to Jlab.
<br>
Cheers,
<br>
Christine
<br>
<br>
<br>
-
<br>
<br>
<br>
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