Hi Meredith,
the lx1358 circuit is exactly the same used in the lx922 with few=20
small variations.
The LX922 and LX1358 coils are the same.
I think that the coils are wound for the pourpose of the seismometer
and not re-used from an another application.
They are very large to make easier the assembly of the mechanic.
That squared hole keep easy the assembly of the nucleus that is
needed to insert for last when you assemble the mechanic components.

Regards
Mauro

  ----- Original Message -----=20
  From: meredithlamb=20
  To: psn-l@.................
  Sent: Saturday, November 16, 2002 11:32 PM
  Subject: Re: STM 8 (LVDT subject)


  Hi Mauro and all,=20
  Thanks for the notes.  I see your reference to the LX922 &=20
  LX1358 on the web:  The obsolete LX922 seismometer in its=20
  entirety, certainly was a large unit.  Is the same LVDT coil and =
circuit=20
  board used on such, the same as on the small pendulum LX1358=20
  that you know of?=20

  http://mariottim.interfree.it/doc13_e.htm=20

  Yes, if you can, and want to, it would be interesting to see=20
  just what they used in the LVDT squarish transformer/s inasfar=20
  as whether its precision laid out, or more ~jumbo wound.=20
  They are somewhat large, and I suspect they are salvaged=20
  coils meant originally for another use....but I could always be=20
  wrong.  In a sense, even if they are not precision, it kind of=20
  suggests that other transformers could work also.....but with=20
  a reduced sensitivity compared to precision wound LVDT's=20
  (but still very good overall).=20
   =20

  Mauro Mariotti wrote:=20

    Hi All, I worked very much with this LVDT.It is based on the Phllips =
NE5521N phase comparator.I can supply you the schematic if needed.The =
cost of the unit is 50$ for the circuit and 50$ for the mechanic tobuild =
up a complete horizontal sensor like to S-G type.I never disassembled =
the LVDT coils to but I can do it I have some sparepart in my lab.





Hi Meredith,
the lx1358 circuit is exactly the same =
used in the=20
lx922 with few 
small variations.
The LX922 and LX1358 coils are the=20
same.
I think that the coils are wound for =
the pourpose=20
of the seismometer
and not re-used from an another=20
application.
They are very large to make easier the =
assembly of=20
the mechanic.
That squared hole keep easy the =
assembly of the=20
nucleus that is
needed to insert for last when you =
assemble the=20
mechanic components.
 
Regards
Mauro
 

  
----- Original Message ----- 
  From:=20
  meredithlamb 
  
To: psn-l@.............. 
  
Sent: Saturday, November 16, =
2002 11:32=20
  PM
  
Subject: Re: STM 8 (LVDT =
subject)
  

Hi Mauro and all,=20
  
Thanks for the notes.  I see your reference to the LX922 & =

  
LX1358 on the web:  The obsolete LX922 seismometer in its=20
  
entirety, certainly was a large unit.  Is the same LVDT coil =
and=20
  circuit 
board used on such, the same as on the small pendulum =
LX1358=20
  
that you know of?=20
  
http://mariottim.inter=
free.it/doc13_e.htm=20

  
Yes, if you can, and want to, it would be interesting to see =

just what=20
  they used in the LVDT squarish transformer/s inasfar 
as whether =
its=20
  precision laid out, or more ~jumbo wound. 
They are somewhat large, =
and I=20
  suspect they are salvaged 
coils meant originally for another =
use....but I=20
  could always be 
wrong.  In a sense, even if they are not =
precision,=20
  it kind of 
suggests that other transformers could work =
also.....but with=20
  
a reduced sensitivity compared to precision wound LVDT's 
(but =
still=20
  very good overall). 
 =20
  
Mauro Mariotti wrote:=20
  

    
    Hi All, I worked very much with this LVDT.It is based on the =
Phllips NE5521N=20
    phase comparator.I can supply you the schematic if needed.The cost =
of the=20
    unit is 50$ for the circuit and 50$ for the mechanic tobuild up a =
complete=20
    horizontal sensor like to S-G type.I never disassembled the LVDT =
coils to=20
    but I can do it I have some sparepart in my=20
lab.