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Re: FADC progress
Hello Peter,
I agree with that and wish you a nice play.
Now, our engineer has already started the 8 channel board design
reproducing was was done on the prototype card + corrections, except
for the input stage where we plan, for easy use, easy production and
space saving, to put only differential inputs (pin connectors as for
twisted pairs). This means that the FADC will accept real differential
signals (with 12 bits conversion) or mono-polar signals with eventual
overshoot (= single ended) but with only 11 bit conversion or more in
case of overshoot.
To adapt the range of the ADC, we need to know if the highest signals
of 0.8 volts coming from the TPC are saturated ones and if 0.8 volts
will correspond to the maximum converted value. Or do we need more gain
to look at low signals and accept to saturate the ADCs? No variable
gain are provided. The hight precision quality and well balanced
resistors needed for that makes it difficult.
The fixed gain has to be decided at soldering stage.
This new 8 channels prototype board could then also be tested in early
November. A decision could be take at that time for an eventual
different input stage if really needed.
Best regards,
René
Le 01-sept.-05, à 16:16, Peter Kammel a écrit :
> Dear Rene,
>
> Brendan and I will be at PSI for 3 weeks starting next week. As time
> permits and with Fred's help we hope to gain user experience on the
> functionality of your new ADCs with the neutron detectors during this
> time. Let's just postpone the decision by 3 weeks.
>
> Best regards
>
> Peter
>
>
> On Thu, 1 Sep 2005, René Prieels wrote:
>
>> Hello Fred,
>>
>> It is exact, one zero stayed in the keyboard. The expense is
>> effectively about 10000 EUR.
>> I have money provided for that. The only thing was to be sure that we
>> are going on the right track.
>> If one waits to test the 8 channels prototype, it sends us very late
>> on November. Then the chance to be delivered by MAXIMS components
>> before January becomes very weak.
>> On the other end, the two 2 channels prototype boards can be used to
>> confirm the method for neutrons and the benefits for the TPC by
>> looking at one or two TPC channels. Can this be done sooner? Before
>> your departure?
>> Then I will wait before ordering the ADCs
>> Best regards,
>> René
>>
>>
>>
>> Le 30-août-05, à 23:45, Frederick Gray a écrit :
>>
>>>> I'm afraid you've missed a zero here (i.e. it's ten thousand Euro,
>>>> not
>>>> one thousand). Is that still in a range that you can support???
>>> Hi, Rene,
>>> I just talked with Peter...he also didn't realize that we were
>>> discussing such
>>> a large expense on our teleconference this afternoon. He says that,
>>> while of
>>> course you will need to make the decision (it's your money!), he
>>> would
>>> recommend waiting for the large ADC purchase until we have had the
>>> chance to
>>> test a prototype.
>>> By the way: at some point, Eric Hazen of the Boston University
>>> electronics group
>>> ordered five MAX1213s, which we can have if we want them.
>>> -- Fred
>>> -- Fred Gray / Visiting Postdoctoral Researcher --
>>> -- Department of Physics / University of California, Berkeley --
>>> -- fegray@berkeley.edu / phone 510-642-2438 / fax 510-642-9811 --
>> ---------------------------------------------------------------------
>> René PRIEELS Universite Catholique
>> de Louvain
>> email: R.Prieels@fynu.ucl.ac.be Departement de Physique / FYNU
>> Tel : ++ 32 (0)10 / 47 32 09 Chemin du cyclotron, 2
>> Fax : ++ 32 (0)10 / 45 21 83 B-1348 Louvain-la-Neuve -
>> BELGIUM
>> ---------------------------------------------------------------------
>>
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René PRIEELS Universite Catholique
de Louvain
email: R.Prieels@fynu.ucl.ac.be Departement de Physique / FYNU
Tel : ++ 32 (0)10 / 47 32 09 Chemin du cyclotron, 2
Fax : ++ 32 (0)10 / 45 21 83 B-1348 Louvain-la-Neuve -
BELGIUM
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