Theory of Operation— 2230 Service
HORIZONTAL
The Horizontal Amplifier circuit, shown on Diagram 7,
provides the signals that drive the horizontal deflection
plates of the crt. Signals applied to the Horizontal
Preamplifier may come from either the A or the B Miller
Sweep Generator (for sweep deflection) or from the XY
Amplifier (when Nonstore X-Y display mode is selected). A
and B Sweep switching is controlled t y signals from the
Alternate Display Switching Logic circuit discussed earlier.
Either the Nonstore sweeps or the Storage horizontal
deflection signals are passed to the Horizontal Output
Amplifier via a diode gating circuit. Signal selection by the
Horizontal Mux circuit is controlled by the Channel Switch
Logic output signals (located on Diagram 2). See Figure 3-
6 for the block diagram of the Horizontal Amplifier.
The Horizontal POSITION control, X I0 Magnifier cir
cuitry, and the horizontal portion of the Beam Find circuitry
are also part of the Horizontal Amplifier circuitry.
H o rizo n ta l P re a m p lifie r
The Horizontal Preamplifier switches the Nonstore hor
izontal drive signals and amplifies input signals for applica
tion to the Horizontal Output Amplifier.
The A and B Sweeps are applied to the emitters of
Q732 and Q742, through Sweep Gain potentiometers
R730 and R740. Switching of the A and B Sweeps is con
trolled with these transistors. Using the A DISP and B
DISP signals obtained from the Alternate Display Switch
ing Logic circuitry (Diagram 6), 0732 and Q742 are either
biased into the active or cutoff regions via CR732 and
CR742. The POSITION control (R726) horizontally adjusts
the crt trace position by supplying a variable dc offset volt
age, through pin 14, to the output of the preamplifier. The
position offset voltage from the wiper of R726 also goes to
the Vector Generator circuitry (Diagram 20) to horizontally
position the STORE mode waveform displays. Readout
displays are not affected by the Horizontal POSITION con
trol. Preamplifier output bias current levels are set by
R751 at pin 5, and frequency compensation for X-axis sig
nals is provided by C751, connectd to pin 13.
Nonstore horizontal X I0 Gain is set by the resistor net
work between pins 3 and 6 of U760. When the X I0
Magnifier is on, S721 is closed, and the amplifier gain
increases by ten times. Magnified timing accuracy is
adjusted using X I0 Gain potentiometer R754. MAG REGIS
potentiometer R749 is adjusted for no horizontal shift at
the center of the graticule as X I0 Magnifier is switched on
and off. A second set of contacts on S721 informs the
Microprocessor whether X I0 Magnification is off or on.
The SEC/DIV readout is automatically set to the correct
scale factor, and STORE mode waveforms are digitally
modified to reflect X I0 magnification.
X-Y Amplifier
The X-Y Amplifier amplifies the Nonstore Channel 1 sig
nal (X-AXIS) from the Internal Trigger circuitry (Diagram 4)
and passes it to the Horizontal Preamplifier.
When the Nonstore X-Y mode is selected, Q737 is
biased on 1o place a HI on U760 pin 12 to internally
disconnect_the A and B Sweep and the HORIZ POS input
pins. The XY signal line is LO, biasing Q756 off to let the
X-AXIS signal drive the noninverting input of U758. The
output of U758 is a combination of the X-AXIS signal on
pin 3 and the Horizontal POSITION voltage applied to
pin 2 via R758. The X-Axis deflection accuracy is adjusted
by X-GAIN potentiometer R760. The single-ended X-AXIS
signal at pin 11 of U760 is changed to a differential signal
at the preamplifier output pins. The differential signal is
passed through the Horizontal Mux circuit to the Horizon
tal Output Amplifier for final amplification. When the X-Y
mode is not selected, Q756 is biased on, and the X-AXIS
signal is shunted to ground through the transistor.
H o riz o n ta l O u tp u t A m p lifie r
The
Horizontal
Output
Amplifier
provides
final
amplification of the horizontal Nonstore sweep signals or
the Store mode deflection signals to drive the horizontal
crt deflection plates.
In NONSTORE mode, signals from the (+ ) and (—)
SWP outputs of U760 drive the Horizontal Output
Amplifier. In STORE mode, horizontal LH OUT or RH OUT
deflection signals are passed through the diode gate to
drive the amplifier. Drive signals for STORE mode and
readout character displays are selected by the Display
Controller. Either Nonstore sweeps or Store deflection sig
nals are selected by the diode gating using signals from
the Store/Nonstore Multiplexer (U7201 on Diagram 2)
through inverters U7202A and U7202B.
The selected signals drive a differential shunt-feedback
amplifier. Due to the feedback, the input impedance of the
amplifier is low. The base voltages of Q770 and Q780 are
biased at nearly the same dc level by forward-biased
diodes CR768 and CR768 located between the two
emitters.
REV DEC 1986
3 -2 3
Содержание 2230
Страница 12: ...2230 Service X The 2230 Digital Storage Oscilloscope 4998 01 ...
Страница 32: ...Operating Information 2230 Service 4998 04 Figure 2 4 Power and display controls and power on indicator 2 5 ...
Страница 33: ...Operating Information 2230 Service Figure 2 5 Vertical controls and connectors 2 6 ...
Страница 48: ...Operating Information 2230 Service Figure 2 11 X Y Plotter interfacing ...
Страница 56: ...Theory of Operation 2230 Service 4999 01 3 2 Figure 3 1 Simplified block diagram ...
Страница 68: ...Operating Information 2230 Service Figure 2 11 X Y Plotter interfacing ...
Страница 76: ...Theory of Operation 2230 Service 4999 01 3 2 Figure 3 1 Simplified block diagram ...
Страница 82: ...Theory of Operation 2230 Service 510 499 9 02 Figure 3 2 Block diagram of the Channel 1 Attenuator circuit 3 8 ...
Страница 98: ...Theory of Operation 2230 Service 499 9 06 Figure 3 6 Horizontal Amplifier block diagram 3 24 ...
Страница 111: ...Theory of Operation 2230 Service 3 37 Figure 3 9 Acquisition Memory timing ...
Страница 190: ...Maintenance 2230 Service 999 14 Figure 6 3 Isolated kernel timing 6 9 ...
Страница 218: ...Maintenance 2230 Service 4999 37 Figure 6 7 Location of screws and spacers on the Storage circuit board 6 37 ...
Страница 329: ...PUT Figure 9 2 S em ico n d u cto r lea d co n fig u ratio n s ...
Страница 332: ...2230Service CHASSIS MOUNTED PARTS ...
Страница 334: ...A14 CH 1 LOGIC BOARD ...
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Страница 344: ...u sr z z o 1 ...
Страница 347: ...i n 5 a O Q q o u S a o h UJ s a b c d e f g h j k l m n ...
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Страница 355: ...WAVEFORMS FOR DIAGRAM 5 4999 83 ...
Страница 358: ...I W L U O U rc a 4 2 s ...
Страница 361: ...WAVEFORMS FOR DIAGRAM 6 S 84 ...
Страница 362: ...2230 Service TEST SCOPE TRIGGERED ON U665 PIN 8 FOR WAVEFORMS 31 THROUGH 33 ...
Страница 365: ... I I ...
Страница 366: ...A 1 6 S W E E P R EFEREN CE BOARD FIG 9 17 2230 Service Figure 9 17 A16 Sweep Reference board ...
Страница 369: ... o 0 UJU sa eg aiu c u J in su eg 5 C sis n g e s o N QO ...
Страница 371: ...Static Sensitive Devices See Maintenance Section CM I rv CD o 2230 Service ...
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Страница 388: ...H K L M N 7 8 8 2 2 3 0 INPUT OUTFUT WIRING INTERCONNECT ...
Страница 392: ...W A V E F O R M S F O R D IA G R A M 14 ...
Страница 393: ...2230Service 0 0 d s t 4 9 9 9 9 5 ...
Страница 394: ...2230 Service TEST SCOPE TRIGGERED ON U911 PIN 21 FOR WAVEFORMS 64 THROUGH 69 4999 92 ...
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Страница 397: ...WAVEFORMS FOR DIAGRAM 15 TEST SCOPE TRIGGERED ON U9111 PIN 21 FOR WAVEFORMS 70 THROUGH 77 ...
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Страница 406: ...2230 Service n CD O O i 0 s a f s s o m O F ig u re 9 5 D e ta ile d S to ra g e b lo c k diagram 4999 22 ...
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Страница 415: ...IMF PU TPR A IR TM FQ U I W A V E F O R M SF O RO IA G R A M1 5 W A V E F O R M SF O R i ...
Страница 417: ...4999 9S ...
Страница 419: ...i s 5 0 C C p F 2 CC p 2 a u 4 I s c c O 2 e e o 5 a o 5 i 2 i f 2 E C 52 ...
Страница 421: ...TEST SCOPE TRIGGERED ON U4105 PIN 9 FOR WAVEFORMS 121 AND 122 TEST SCOPE TRIGGERED ON U4227 PIN 10 i 4999 97 ...
Страница 423: ...W A V E F O R M SF O RD IA G R A M1 8 O c n ...
Страница 424: ...Figure 9 22 A11A1 Input Output board ...
Страница 427: ...WAVEFORMS FOR DIAGRAM 19 TEST SCOPE TRIGGERED ON U6103 PIN 1 FOR WAVEFORMS 126 AND 127 4999 98 ...
Страница 430: ...Figure 9 23 A11A2 Vector Generator board ...
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Страница 437: ...22 3 0 S ervice W A V E F O R M S F O R D I A G R A M 2 1 m f n h ...
Страница 442: ...WAVEFORMS FOR DIAGRAM 22 4999 78 ...
Страница 443: ...XY PLOTTER BOARD DIAGRAM 22 See Parts List for serial number ranges ...
Страница 444: ... u i o IO U J J i o D U I 1 t ir u j t O 0 X I c a a 3 4 2230 4999 71 REV FE8 1987 XY PLOTTER BOARD 22 ...
Страница 447: ...A21 RS 232 OPTION BOARD Flfi A 9 K 01 01 W M ...
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Страница 452: ...COMPONENT NUMBER EXAMPLE ...
Страница 455: ...r n n i i i i n O T IA ll D A A o n XY PLOTTER BOARD P in A23 OPTION MEMORY BOARD FIG 9 27 A22 GPIB OPTION BOARD ...
Страница 459: ...A16 SWEEP REFERENCE ADJUSTMENT LOCATION ...
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