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Section IV
4-3.
GOLUMN BOARD OPERATION.
Model S62A
4-2
The following theory is for operation of a -1248 code column board.
Assume
a data source has initiated a print command, the AND GATE in the control
board conducts, and the clutch solenoid starts to energize.
A signal is then
applied to the 2 MS DELA Y lY1ULTIVIBRA TOR by the clutch binary.
After
2 ms, the nlultivibrator applies a positive reset pulse to the column boards.
The binaries reset as follows:
A BINARY:
Q
101, on; 0102, off
B BINARY: a 1 03, off; 0104, on
G BINAR Y: a 105, on; a 106, off
D BINARY:
Q
107, off; a 108, on
The data source is supplying bcd information to the four binarie s.
Suppose
the bcd information supplied is for the decimal number 8.
According to
table
3-1, "0" level information will be supplied to the G, B, and A binaries.
The D binary will have "l" level information supplied.
The "0" or "l'" do not
change the state of the binaries.
The - and
+
transfer pulses cause the binaries
to change state if the 1t0" or
II
lit levels needed are present.
At the D binary,
if the "1" level is pre sent GR 1 04 is forward biased and - transfer pulse will go
through diode gate GR 1 04.
Since a 107 is off, the D binary will change state,
a107 on and a108 off.
The G binary has "0" level information applied to diode gate GRI03.
A
+
trans-
fer pulse is applied to GRI03.
Since the
"a"
level information applied to GRI03
is equal to the
+
reference voltage, the diode will pass the
+
transfer pulse.
Thus QIOS is off and al06 is on.
The B binary has" 0" level information applied to diode gate GR 1 02.
Since the
"Olt level information is (at least 4 volts) more positive than the -reference
voltage, diode GRl02 is reverse biased and will not pass the - transfer pulse.
The
binary will not change state.
Transis tor a 103 re mains off and a 104 re nlains on.
The A binary has
"a"
level information applied to diode gate GRIOI.
The "0"
level mllst be equal to the positive reference voltage.
This causes GRlOI to
be forward biased and pass the + transfp.r pulse.
The A binary changes state,
QIOI off and QI02 on.
Three of the halves of the binaries that are "on" will return, through matrix
resistors, to pin 11 of connectors XAl-l to XA12 -1.
This is the line which
corresponds to the decimal number 8.
In this case, R161, R175, and Rl99
return to the line for the decimal number 8.
These resistors make the line
for the number 8 go to app roximatel
y
+
15 volts.
Diode gate G Rl
a
5 and G Rl Oh
sense when the line gets to approximately +15 volts and cause amplifiers al09»
a 110, and Q III to de -energize the pawl magnet.
The pawl then locks the
01081-1
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