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E L E C T R I C A L
P R I N C I P L E S
6 1
Pulse
Generator
Multlvibrator
P - w
dl
Cam Contact
Compute Start Pulse
s t a r t - Stop
Compute Stop Pulse
a f t e r 6 t h column shift
(
9 6 0 t h pulse)
Counts pulses
from M V to estoblish
basic adding cycle
of 16 pulses
I
Primary
Timer
Counts adding
cycles to establish
column shift cycle
of 1 0 adding cycles
Counts column shift cycles
Advances column shift and
causes computation to stop
ofter completing 6th Column
shif t
Carry pulse
a f t e r 16 pulses
Figure 59. Block Diagram
of
~ i k r s
but these pulses cannot pass to the timers until per-
As an example of the multiplication operation,
mitted by the electronic start switch.
The start
4 x 8 may be used as a problem.
The multiplier
switch is controlled by an electronic start and stop
4 indicates that the multiplicand 8 is to add into
control which opens the switch and closes it. For
the product counter 4 times. The 8 in the multi-
an analogy, the electronic switch may be visual-
plicand counter indicates that the product counter
Secondary
Timer
ized as a valve. An open switch permits pulses to
pass while a closed switch prevents passage of
pulses. After the factors are read into the counters
from a card passing the entry brushes, the compute
start contact P24 makes (at 11.5 on the punch in-
dex) to start computing. This is done by opening
the start switch and permiming pulses to pass to the
electronic timers (or pulse counters). On every
16th pulse entering the primary timer, a carry
pulse is passed to the secondary timer which ad-
vances 1 to indicate that one adding cycle has been
completed. When 10 adding cycles are completed,
the secondary timer carries, and a pulse is passed
to the ,tertiary timer to signal a column shift.
When 6 column shift cycles have been completed,
a pulse from the tertiary timer passes to the com-
pute stop control, and the start switch is again
closed, thus stopping the pulses from passing to the
timers after 960 pulses have been counted and in-
dicating the completion of the problem. This entire
operation requires only 27 milliseconds during
which time the punch index moves 6 teeth.
is to receive
8
impulses during each of four adding
cycles for a total of 32 pulses.
Figure 60 indicates the machine operation in
schematic form. Since the only digit in the mul-
tiplier is in the units position, not until the sixth
column shift cycle will there be signals to cause
addition in the product counter. Then during the
sixth column shift,
8
pulses are added into the
product counter during each of the last four add-
ing cycles. Observe that the machine goes through
all adding cycles and all column shift cycles even
though addition occurs only during the last four
adding cycles of the last column shift cycle.
For a more complete illustration, the same prob-
lem shown in Figure 58 is worked out in detail in
Figure 61, showing all the adding cycles through
which the machine goes to complete one multipli-
cation. Notice that during the entire first column
shift cycle consisting of ten adding cycles no add-
ing takes place because there is a 0 in 6th position
of the multiplier. During the second column shift
cycle the multiplicand is added into the product
-
Carny Pulse
otter
1 0
adding
*
cycles (160puIses)
T e r t i a r y
Timer
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