Circuit
Description—
7623/R
7623
Service
Time-Slot
Counter
Time-Slot
Counter
U2126 is a sequential switch which
directs
the trapezoidal
waveform input
at pin 8 to one of its
10
output lines.
These time-slot pulses are used to
interrogate
the
plug in
units to obtain data for the Readout
System. The
Trigger pulse at
pin 15 switches the Time-Slot
Counter
to
the next output line; the output signal is
sequenced consecutively
from time-slot 1 through time-slot
10. Fig.
3-31 shows the time-relationship of the time-slot
pulses.
Notice that
only
one of the lines carries a time-slot
pulse
at any given time.
When time-slot 10 is completed, a
negative-going
End-of-Word
pulse is
produced at pin 2. The
End-of-Word pulse
provides a
drive
pulse for the Word
Trigger
stage and also provides an enabling
level to
the
Display-Skip
Generator
during
time-slot
1 only.
Pin 16
is a
reset input for the Time-Slot Counter. When
this pin
is
held
LO, the Time-Slot
Counter resets to
time-slot
1.
The Time-Slot Counter can be reset in
this
manner
only when a Jump signal is received
by U2155C
(see
following discussion).
Word
Trigger
The
Word Trigger
stage is made up of the 4 two-input
NOR
gates
contained in U2155. Quiescently, pin 2 of
U2155A
is LO
as established by the operating conditions of
U2155D and
U2155C. Therefore,
the LO End-of-Word
pulse
produced
by
the Time-Slot Counter results in a HI
level
at pin 1
of U2155A.
This level is inverted by U2155B
to provide
a negative-going advance pulse to
the Channel
Counter.
An
advance pulse is also produced by
U2155A when a
Jump signal is
received at pin 8 of U2155C. This condition
can
occur during any
time-slot (see Row Decoder for
further
information
on
origin of the Jump signal). U2155D
and
U2155C are connected
as
a
bistable
flip-flop. The
positive^oing Jump signal
at pin
8 of U2155C produces
a
LO
at
pin 10. This LO is inverted by U2155D to produce a
HI at
pin
13, which allows pin 9 of U2155C to be pulled HI
through
R2155. The
flip-flop has
now been set and it
remains
in
this condition until reset, even though the Jump
signal
at
pin 8
returns
to its LO
level. The HI output level at
pin 13 turns on
Q2159 through R2158
to pull pin 16 of the
Time-Slot
Counter
LO. This
resets the Time-Slot Counter
to time-slot
1
and holds it there until U2155C is reset. At
the
same time,
a HI level is applied to pin 4 of the Timer
through
CR2125 and CR2124. This HI level causes the
Timer
to operate in the
display-skip
mode so that a
character is not
generated.
The
next Trigger
pulse is not recognized by the
Time-Slot
Counter since U2159 is
locked in time-slot
1 by
U2155.
However, this Trigger pulse resets the
Word Trigger
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Timo-slot
pulse
1
Pin
3
Time slot
pulse
2
Pin
13
Time-slot
pulse
3
Pin 12
Time-slot
pulse
4
Pin
11
Time-slot
pulse
5
Pin 10
Time-slot
pulse
6
Pin
9
Time-slot
pulse
7
Pin
7
Time-slot
pulse
8
Pin
6
Time-slot
pulse
9
Pin
5
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Time-slot
pulse 10
Pin
4
NOTE:
Test oscilloscope externally
triggered from
TP2251
, Sweep rate uncalibrated.
Fig.
3-31. Time relationship of the time-slot ITS) pulses produced
by
U2126.
3-39
Summary of Contents for 7623
Page 1: ...MANUAL 7623 R7623 STORAGE OSCILLOSCOPE SERVICE MANUFACTURERS OF CATHODE RAY OSCILLOSCOPES ...
Page 51: ...Fig 3 2 Block diagram of Logic circuit Circuit Description 7623 R 7623 Service ...
Page 72: ...W NJ 00 Fifl 3 22 Low Voltage Power Supply detailed block diagram ...
Page 73: ...Circuit Description 7623 R 7623 Service ...
Page 74: ...CO NJ CD Fig 3 22 Low Voltage Power Supply detailed block diagram cont ...
Page 75: ...Circuit Description 7623 R 7623 Service ...
Page 97: ...Circuit Description 7623 R7623 Service 3 51 ...
Page 98: ...Circuit Description 7623 R7623 Service Fig 3 39 Output Pulses for the Storage Circuits 3 52 ...
Page 103: ...Circuit Description 7623 R7623 Service 3 57 ...
Page 108: ... Ç À Fig 4 2 Location of circuit boards in the 7623 ...
Page 109: ...Fig 4 3 Location of circuit boards in the R7623 Maintenance 7623 R 7623 Service ...
Page 113: ...Maintenance 7623 R7623 Service Fig 4 6 Circuit Isolation Troubleshooting Chart 4 9 ...
Page 165: ...7623 BLOCK DIAGRAM ...
Page 166: ...7623 R7623 Service Front of Board ...
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Page 173: ...7623 Logic ...
Page 175: ...Vertical Interface A4 ...
Page 178: ...Vertical Interface ...
Page 180: ...Vertical Amp A5 ...
Page 184: ...Horizontal Amp A6 ...
Page 186: ...7623 TO P450 VERT AMP 3 HORIZONTAL AMPLIFIER ...
Page 188: ...Output Signals A7 ...
Page 190: ...FROM 7G23 Output Signals g ...
Page 195: ...FROM LV POWER SUPPLY 7623 CRT CIRCUIT ...
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Page 202: ...Storage Output A14 ...
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Page 205: ...7623 R7623 Service Fig 6 14 A15 Cal Storage circuit board ...
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Page 209: ...7623 R7623 Service Fig 6 15 A16 Readout System circuit board ...
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Page 242: ...7623 R7623 OSCILLOSCOPE b ...
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Page 247: ...7623 R7623 OSCILLOSCOPE 112 ...