Circuit Description—
7623/R7623
Service
Logic
stage is shown in Fig. 3-3. Only the components
essential to operation of
this stage are shown in this
simplified schematic.
Transistor
U99C is connected in the common-base
configuration
to provide the output for this stage. The
collector load for
U99C
is provided by the Z-Axis Amplifier
in the
CRT Circuit. Transistors U99D and U99E provide a
current-limiting action
for this stage. The collector current
of
U99D, represented
by lt, is the maximum amount of
current
that can
flow in the circuit. The amount of this
current
is
determined by
the relationship between the
Intensity
Limit and
Vertical Chopped Blanking. When both
of these
inputs are
HI the collector current of U99D, lt, is
maximum.
This maximum
level
of I, is determined by
current
I,
in the
base circuit of U99D established by
networks R76-R77
and R62-R63 into R110
and the
collector
of
U99E. During Vertical Chopped Blanking,
the
respective input
level goes LO. This shunts the current lj
from
the base of U99D so the collector current of U99D,
lt
,
drops
to minimum
to blank the
CRT display during
vertical
trace switching.
The Intensity
Limit
function limits the output
current
of
this stage
to protect the CRT phosphor whenever the
time-base
unit is set to a slow sweep
rate. For conditions
that do not
require
limiting, quiescent current is added to
Ij
from
the +15-volt supply through R76-R77. When the
time-base unit
is
set
to
a sweep rate which
requires intensity
Fig.
3-3. Simplified schematic of Z-Axis Logic
stage.
3-8
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 ...
Page 167: ......
Page 168: ...FL ...
Page 169: ......
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 ...
Page 197: ......
Page 200: ......
Page 202: ...Storage Output A14 ...
Page 204: ......
Page 205: ...7623 R7623 Service Fig 6 14 A15 Cal Storage circuit board ...
Page 208: ......
Page 209: ...7623 R7623 Service Fig 6 15 A16 Readout System circuit board ...
Page 213: ......
Page 242: ...7623 R7623 OSCILLOSCOPE b ...
Page 243: ...151 ...
Page 246: ...20 ...
Page 247: ...7623 R7623 OSCILLOSCOPE 112 ...