PRINCIPLES OF OPERATION AND DESCRIPTION OF TIME EVENT MARKER

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03424A000400040015-9
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 11
• Document Creation Date: December 27, 2016
• Document Release Date: April 30, 2014
• Sequence Number: 15
• Publication Date: April 1, 1958
• Content Type: MISC

Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03424A000400040015-9
PRINCIPLES OF ERATION AND DESCRIPTION OF
TIME EVENT MARKEM
I. Purpose of Equipment
This equipment measures elapsed time from a zero time reference in
one minute intervals for 99,999 minutes. The elapsed time is continuously
stored in binary-decimal combination and may be extracted (in coded
electrical form) at will upon insertion of an electrical command pulse.
II. Principles of Operation (Refer to Electro-Mechanical Schematic,
TEM, Project 74A)
A. Once-per-minute Time Base
1. The time base consists of a standard 8/0 watch movement nowered
by a Negator spring and started manually at to. A cam, mounted
on the fourth wheel of the watch, closes a single pole normally
open contact for three seconds each minute.
B. Calendar Coded Storage
.1.a. Normal operation of the Calendar is controlled by the once-per-
minute contacts. When these contacts close, solenoid 1CR is
pulsed through RiCi, indexing Calendar Disc No. 1 through 3.6�
(1/100 part of a circle). This disc stores units information
(minutes) on contact tracks #12, 11, 10 and 9, coded to represent
one, two, four and eight, respectively, in a binary yes-no arrange-
ment. As the disc indexes over the stationary contact fingers,
those fingers touch either metal or plastic on the printed circuit
calendar disc. If a given contact finger touches metal, its
track is in "yes," (or closed) condition, and vice-versa. The
points where contact fingers touch the discs are shown on the
schematic by the intersections of the two lines of a "T." Thus
on disc No. 1, contact fingers #12, 11, 10 and 9 are all shown
on plastic, so the units digit is zero. (The entire apparatus
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is shown reading 00,000 minutes.) After the disc indexes one
division, #12 will go to "yes," all others staying "no." But
#12 is the code for one, so one minute has gone by. Similarly,
after another pulse, #12 goes to "no," +11 to "yes," and all
others remain "no." But #11 corresponds to two, so two minutes
have elapsed. After the next disc index, #12 goes to "yes,"
+11 remains "yes," #10 and #9 remain "no." #12 is one, #11 is
two, so one plus two equals three, or three minutes have elapsed.
The following table summarizes the decimal coding:
On the tenth pulse, contact finger #2 makes contact with #1
through the disc. This pulses #2CR, which indexes Calendar
disc #2 3.6�. Here contact tracks +12, 11, 10 and 9 correspond
to tens of minutes exactly as minutes were stored on disc #1.
Contact fingers 8, 7, 6 and. 5, meanwhile, store 100s of minutes
in an exactly analagous fashion. On the one-hundredth index of
disc f2, or 1000 minutes after to, contact finger #1 becomes
energized through finger #3 and pulses 3CR, which in turn, indexes
disc +3 3.6�.
Contact fingers +12, 11, 10 and 9 here, store 1000s
of minutes, while fingers f8, 7, 6 and 5 store 10,000s of minutes.
To summarize, Solenoid 10R indexes disc #1 1.60 every minute
through the once-per-minute contact. Solenoid 20R indexes disc
#2 3.60 every ten minutes through contact track #2 on disc #1.
Finally, Solenoid 3CR indexes disc #3 3.6� every 1000 minutes
through contact track #3 on disc #2. So one revolution of disc
-2-
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#1 occurs every 100 minutes, one revolution of disc #2 every 1000
minutes, and one revolution of disc #3 every 1009000 minutes,
1.b. When the respective control circuits are close, the solenoids
are pulsed through series capacitors (C1, C2, C3) connected in
parallel with high resistances (Ri, R2, 113). The capacitors
charge rapidly, giving a pulse of current through the solenoids
of about 20 MS duration, and thus limiting the overage operating
eurrents to small values although the control circuits may remain
closed for substantial times. When the control circuit opens,
the capacitor discharges through the resistor at a rate which
Insures discharge in one-fifth of the time available before the
circuit is reclosed for another solenoid pulse.
2. Provision is made for testing the solenoids and calendar disc
Index system. External test leads are brought from each solenoid
which, when energized through a switch from the minus terminal of
the 6 volt D.C. source, will index the respective calendar disc
3.6� for each closing of the switch, and will advance the coded
elapsed time storage accordingly. CAUTION: When testing a solenoid,
avoid leaving the tent Twitch closed as solenoid heating (and
possibly coil burnout) will result. Use of a "momentary" switch
is advocated.
C. TEM Sweep
1. This assembly literally "sweeps" over the 20 contacts corresponding
to the coded time storage outlined in B. above, and yields an
electrical readout corresponding to the yes-no condition of the
20 successive contacts versus the sweep time base. The sweep also
provides a reference yes contact just before, and another just
after the 20 coded bits. Following the latter reference contact
is another contact used for resetting auxiliary equipment. The 24th
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Declassified in Part - Sanitized Copy Approved for Release 2014/05/01 : CIA-RDP78-03424A000400040015-9
and final position of the sweep is a rest position.
The sweep is driven by solenoid CSR which, in turn, is actuated
at a 10 cps (nominal) rate by a 10 per second multivibrator.
The sweep pickup arm, then, takes 2.24 seconds to make a complete
revolution and return to rest, pausing 95 milliseconds on each
contact and taking about 5 milliseconds to traverse the interspaces.
2. Sweep Start Circuit
The sweep start is initiated by the insertion of minus six volts
at the START SWEZP COMMADD point for a duration of 40 milliseconds
minimum, two seconds maximum. If a shorter command is given, the
sweep may fail to start or a slow start mey occur, so that the
first reference bit nay be longer than succeeding bits. If a
longer command in given, the sweep may repeat.
The command voltage energies the free-running multivibrator which,
in turn, energizes CSR, indexing the sweep bridge 15�. Since the
innermost (solid) sweep ring (connected always to �6 volts) is
now connected via the short arm of the bridge to the broken ring
(which is tied to the multivibrator input point) the command
voltage may now be removed and the multivibrator continues operating,
indexing the sweep bridge 150 ten times per second.
3. Sweep Readout
A. As the bridge indexes, each of the 24 outermost contacts is
successively connected, via the long arm of the bridge, to
the outermost solid, ring. This is permanently connected to
one end of R5, acrose which the sweep readout occurs as a time
function. The ether end of R5 is the sweep reference level,
which is tied to the two sweep reference contacts (discussed
in Paragraph II.C.1.), and also to contact finger +4 of each
of the three calendar discs. The track for this contact
lo
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is a solid ring having zero resistance to every eyes" position
of contact tracks 412, 11, 10, 9, 8, 7, 6 and 5. Therefore,
when the pickup arm of the sweep bridge moves onto any given
one of the 20 coded sectors, 115 is shorted out if that particular
sector is in the "yes� condition, an unaffected "f the sector
is in the nno'3 condition.
B. Readout of the time code through the sweep may be accomplished
by using a 1000 cycle A.C. voltage or a D.C. voltage. The result
will be two levels of A.C. or D.C. depending upon the condition
of the contacts. For example, an input of 1 KC alternating
current at 6 volts peak to peak will show an output of approxi-
mately 3 volts representing zeros and 6 volts representing ones
in the binary code.
Appendix II illustrates a system of readout using direct current
excitation.
4. Sweep Stop Circuit
The sweep breaks its own energization at the completion of one
revolution, when one end of the short sweep arm stops in the
break of the broken sweep ring. This, the rest position, is
the one shown in the electromechanical schematic of T.
5, Coincidence Circuit
Since the initiation of TEM sweep may occur at any time, a means
of preventing calendar indexing while sweep is in progress, has
been provided. (If calendar indexing occured during sweep readout,
the coded readout could become meaningless.) A relay, ST2, is
connected in such a way that it is energized whenever the sweep
10 per second multivibrator is energized. A normally cloted
contact of this relay is in series with the once-per-minute watch
contacts. Thus, during sweep, these relay contacts open and 1CR
-5-
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(and therefore. 2CE and 3 CE) cannot operate even if the once-
per-minute contacts close. However, since this relay is energized
for 2.4 seconds (sweep duration) and the once-per-minute contacts
close for three seconds, calendar indexing (if blocked by ST2)
would occur immediately following completion of sweep operation.
Thus, no time is lost by this coincidence "lock-out" circuit.
III. Description of Hardware
A. Once-per-minute Time Base
1, Negator Spring: This spring, located in the bottom plate assembly,
powers the watch movement through a step-up gear, for a minimum of
sixty days. The spring exhibits essentially a constant-torque char-
acteristic over its entire travel.
2. Watch and once-per-minute Contact Assembly: This assembly is drawer
mounted in the rear of the unit, just below the center plate. The
balance wheel may be observed from below, and the entire assembly
is accessible when the drawer is removed. Removal entails un-
soldering the leads from the two feed through terminals at the
outer bottom side of the drawer. CAUTION: When removing the watch
drawer, the NEGATOR SPRING must be firmly FELD to avoid violent
uncoiling with resultant damage to the unit. The contact-assembly
consists of gold-plated phosphor bronze contacts, insulated from
the watch plate, and designed to reduce closing and opening bounce
to less than 1 millisecond duration. These contaets are closed by
the action of a cam on the 4th wheel of the watch movement. This
wheel rotates once per minute.
3. Starting Watch: The watch is started (unhacked) by pushing in
firmly on the rubber covered lever at the rear of the TEM unit.
�6�
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The unit is suprlied with the watch stopped (hacked), and once
it has been unhacked, there is no provision for rehacking unless
the unit is removed from its case and the hacking lever pulled
out firmly.
B. Calendar Assembly
1. Solenoid drive and ratchet assembly: When the solenoid is energized,
the plunger closes and the driving arm, being an extension of the
plunger, advances the 100 tooth ratchet wheel a distance of one
tooth. Overtravel is prevented by a stop pin located near the
ratchet wheel, which rin squeezes the driving arm between itself
and the ratchet wheel. At the completion of the stroke, a detent
spring on the opposite side of the ratchet wheel falls into the
root of the next tooth, preventing the ratchet wheel from backing
un when the driving arm is withdrawn. When the solenoid is de-
energized, a return spring (located at the front of the solenoid
and mounted to the solenoid housing) pushes the plrnger and driving
arm 'back to the open position, where travel is stopped by a pin
attached to the solenoid mounting. Another pin, running throrgh
the back of the plunger and affixed to the housing is used to
prevent plunger rotation within the solenoid.
2. The ratchet wheel shaft turns in a jewelled bearing at its lower
end (on the center plate) and has a shouldered bearing at its top
end (upper plate). This shouldered bearing acts as a thrust bearing;
since the calendar disc and hub assembly is mounted transversely on
the top of the shaft and is pushed upward by the pressure of the
printed circuit contact fingers. CAUTION: Removal of the calendar
� disc, or of the disc and hub assembly, entails a difficult re-
alignment of the calendar ratchet assembly. CAUTION: The calendar
�7�
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ratchet assembly should, under no circumstances; be turned
backward (clockwise as viewed from the top of the TEM unit)
as damage to delicate parts will result. It is advisable
never to attempt to turn the discs manually, in view of the
above.
3. Calendar disc and contact assembly: The calendar disc is a
circular brass�backed printed circuit composed of rhodium plated
copper, gold flashed, in a smooth, hard transparent plastic bed.
The disc rides face down pressing against the contact fingers
which are of Paliney 0 on dice 1 and of gold alloy
on discs 2 and 3. These contacts are electrically connected to
the circuitry of the printed circuit plate and mechanically
fastened to the plastic body of the plate. This plate is of
epoxy, with photoetched plated copper circuitry. (An improvement
in the construction and material of thls plate is anticipated
for future units.) The disc is held to a hub with three screws
visible from the top of the unit. The hub, in turn, is threaded
down to the top of the ratchet shaft. This action draws the disc
down to bear against the contact fingers.
C. TEM Sweep Assembly:
1. Solenoid drive and ratchet assembly The sweep solenoid is
electrically and mechanically identical to the calendar solenoids,
with the exception that no series capacitance is used to operate
the sweep solenoid
2. The sweep ratchet shaft mounts a large gear which drives the
sweep bridge shaft through a speed up gear. All shafts are
jewelled at the center plate bearings.
�8�
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3. The sweep bridge is a rectangular plastic block screwed down to
the top of the weep bridge shaft. The two arms of the bridge
are composed of four contact finger assemblies fastened to the
bridge and cross-connected by wiring on the bridge block. These
fingers ride on the appropriate parts of the sweep circuit, which
is printed (on the printed circuit plate) and hardened with rhodium
plating. The contact fingers are of Paliney #7 wire.
4. Coincidence Circuit Hardware
The coincidence relay, ST2, is a Neomite 200 NM mounted on the
bottom side of the center plate.
IV. Cover Case
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APPENDIX II
TIME EVENT MARKER VEEP READOUT USING D.C. EXCITATION
Purpose: This test setup can be used for reading out the time stored
in the TEM Calendar as a series of two level marks on an
oscillograph tape. These marks can be readily decoded to
show the time in minutes.
Equipment: Equipment used includes a pen t e oscillographic recorder,
(A brush type P-04 was used at which can be operated STAT
by 6 volts D.C., a 6 volt D.C. supply and a 600 ohm resistor.
Circuit:
r 0
5
TEM
_.
600 To Oecillograph
_IL f Head
I 111 I- --0
6 Volts
Operation: Operation of the time event marker sweep readout shorts and
unshorts R5. When a current is passed thru TEM from the
6 volt supply, the shorting allows more current to pass,
giving a higher voltage across the 600 ohm resistor. The
oscillograph pen circuit is set to operate on ,tie differential
between the two resulting voltages. The attached chart
illustrates the result.
I' 4 ?j 1, :- �
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(-- Ci.,,,D, Ref: iji ictoi ii610AL:)0i10. .,c ii ,57--me-r
') pv,sc--A7111101.!,1hill.i..;11 r,vzsa
,,, nir-V___FIVTIILTA__
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3/24/58
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STAT