Preamps and flex circuits for FDC prototype (fwd)

[Elton Smith <elton@jlab.org>]

---------- Forwarded message ----------
Date: Wed, 05 Feb 2003 15:01:26 -0500
From: Elliott Wolin <wolin@jlab.org>
To: Mehmet Bektasoglu <mehmet@jlab.org>, Elton Smith <elton@jlab.org>,
     Howard Fenker <hcf@jlab.org>, Dave Doughty <doughty@jlab.org>
Subject: Preamps and flex circuits for FDC prototype

Hi,

I talked with Fernando today:


Preamps
-------

He just received 5000 new hybrid preamps for Hall B.  The circuit has a bipolar design so 
they can handle either polarity.  If the FDC signals are anywhere near the size of the 
Hall B DC signals these should work fine.  We can use HV ceramic capacitors to couple to 
the sense wires (there are other possibilities).

How many channels do we need?



Flex circuits
-------------

Flex circuit technology is rather standard, typically copper on kapton.  You can choose 
the thickness of each within certain limits.  They cost about 3 times as much as regular 
circuit boards per square inch.  The FDC's need rather large ones, but Fernando thinks 
there should be no problem getting them.  He has procured a few diffent types over the 
years, usually much smaller than we need.



				Sincerely,
					Elliott


================================================================================

     "Science plays a major role in satisfying the minor needs of mankind"

                "Secular man, by playing God, becomes the devil"


Elliott Wolin
Stalag 602-11
Gulag ARC-ipelago

================================================================================