LETTER TO US GOVERNMENT FROM (Sanitized)

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B05171A000400030052-3
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 9
• Document Creation Date: December 28, 2016
• Document Release Date: June 7, 2005
• Sequence Number: 52
• Publication Date: July 27, 1971
• Content Type: LETTER

STAT
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A-1747A
27 July 1971
U. S. Government
Gentlemen:
STAT
Enclosed is our revised proposal A-1747A with changes to
specifications and additional features ns disrussec~ hetwPPn
Government personnel and representatives 21 and 22
July 1971. This proposal will remain valid for a period of
sixty (60) days from this date,
If you have any questions regarding this proposal, please
STAT
contact either or the undersigned.
Very truly yours,
STAT
Supervisor, Contract Administration
WGB:eh
Enclosure; as stated
Declass review by NGA/DoD
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MLT-1540 LIGHT TABLE
BRIDGE MODIFICATION
By
Proposal No. A-1747A
July 1971
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A -1747A
MLT-1540 LIGHT TABLE BRIDGE MODIFICATION
1.0 INTRODUCTION
Two requirements relative to the use of the MLT-1540
Light Table have recently been stated by users of these tables. These requirements are
in the areas of the microscope mount and bridge and were not included in the initial
specifications of the MLT-1540. Use of the light table has shown a capability in the
areas of the fi Im transport and light source far beyond that originally expected, pro-
viding an instrument which can uti line a high performance microscope bridge and mount.
Specifically, the requirements for such a bridge are;
An improved drive to allow scanning at high magnification.
A mount capable of providing a mensuration platform including the
required stability and the ability to point, i.e., align reticles with
a target.
This proposal provides two alternatives for meeting these requirements. The
first provides improves scanning on iv, the second provides both improved scanning and
a mensuration platform. A third alternative is included to allow disconnection of the
bridge from its Y drive providing lower force for manual movement.
2.0 ALTERNATE ONE -IMPROVED SCANNING - ~,:= ~r
This modification may be applied to any model MLT-1540 with motorized
bridge .
2.1 Approach
An improved scanning capability is obtained on the MLT-1540 Light Table
through incorporation of circuitry providing an equalization in the X and Y speeds and
smoother movement of the bridge in both the X and Y directions. This capability is
accomplished through the use of detection of the bridge drive motor currents. These
motor currents are fed back to appropriate control circuitry to maintain an equalization
of speed and to provide a degree of constancy to the speed of the motor giving smoother
bridge movement.
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A -1747A
Modification Description
This modification will consist of replacement of theX-Y control card. The
new card will contain all of the necessary circuitry fo provide: the current sensing and
feed back. No other modifications of the light table will be required. Control relays
wi II not be provided with the modification card. Relays from the replaced card wi II be
utilized in the modification, thus reducing overall material c?st.
2.3 Performance Specifications
MLT-1540 Light Tables incorporating this modificati?n wi II meet the following
specifications;
Minimum starting speed 0.015 in.~sec.~f 20% ~`~`/"/
Maximum X-Y speed
> .250 in./sec.
Speed of X travel of bridge equal to speed of Y travel of bridge within
20?lo throughout entire range
- --.- _ _
X-Y speed con tropshall have no dead band; i.e., minimum speed shall
--
r n~ r.. e~~~r.r~. ..~ r.~nFr~~
X-Y direction switch shall be lever actuated. -~ /l~eur
3.0 ALTERNATE TWO -MENSURATION PLATFORM
This modification may be applied to the model MLT-1540-4 only.
Approach
Requirements for a mensuration platform may be divided into two basic areas
as follows;
2.
1. The ability to provide a stable fixed platform for the mensuration
instrument.
The ability to align the reticle of the mensuration instrument with an
appropriate point on a target, e.g., pointing.
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STAT
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A-1747A
Present MLT-1540-4 Light Tables provide an adequately locked platform in the
X direction. The proposed modification wi II provide locking in the Y direction through
a change in the drive point for the bridge in the Y direction thus eliminating those
elements in the present drive system which introduce a slackness of movement. Drive
elements from the present fa i I safe clutch through the cross rod at the back of the table
are eliminated, The new drive point is directly to the chain attached to the bridge with
drive being transferred from one side to the other through the cross rod.
If a drive capability for pointing is provided through the electrical drive system
the capability for tracking is also satisfied, This approach to solution of the overall
problem has been taken by Solution to the capability of
pointing and tracking combined is through the use of velocity servo drives for the
bridge motion. This is accomplished by adding velocity sensing tachometers to both the
X and Y bridge drive and the appropriate circuitry to maintain aconstant-low speed of
bridge motion.
3.2 Modification Description
Modification to the Y drive point is accomplished by adding the appropriate
drive sprockets and shaft supports to the chain attached directly to the bridge. The fail
safe clutch is relocated between the drive motor and the drive point and the present
sprocket and chain drive to the cross rod is eliminated.
Modification to the bridge drive electronics is accomplished by the addition
of velocity sensing tachometers to the X and Y bridge motions, installation of appropriate
harnessing to carry the signals from the tachometers to the control circuitry, and re-
placement of the X-Y control card with a new card containing the necessary control
circuits.
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A -1747A
X-Y minimum starting,~speed
0.005 i n . /sec . f 10% - ~~' ha "~
X-Y maximum speed
> .250 in ./sec .
Time to attain set speed
0.5 to 1.0 sec . ~/'eP~,~~
Time from release of control to stop
0.1 sec . or less ~~/~~ ~~y-'c?~
Speed of X travel of bridge equal to speed of Y travel of bridge with- ~fi~~~`