Circuit Description—475
(Channel 1) of U 370. The logic levels connected to pins 1,
12, 13, and 16 determine what signals are presented at
output pins 14 and 15. The following logic truth table
defines the switching function of U 370.
Pin
Pin
Pin
Pin
Output
1
12
13
16
Signal
1
0
1
0
Channel 1
0
1
0
1
Channel 2
1
1
0
0
Algebraic sum of CH 1
& CH 2
U 370 also makes available samples of the Channel 1
signal at pins 8 and 9 and samples of the Channel 2 signal at
pins 4 and 5. The output signals at pins 4, 5, 8, and 9 are
always present when signals are applied to the channel
inputs regardless of the switching logic levels applied to
U 370. The Channel 1 signal present at pin 9 provides drive
to the Horizontal Amplifier in the X -Y mode of horizontal
operation. The Channel 1 signal at pin 8 and the Channel 2
signal at pin 4 are used by the Trigger Generator circuits in
the appropriate positions of the Trigger SOURCE switches.
The Channel 2 signal at pin 5 connects to the Channel 2
Vertical Signal Out Amplifier.
Switching Logic Flip-Flops
U 350A and U350B are edge-triggered flip-flops that
derive the switching logic for the Channel Switch 1C U370.
In the CH 1, CH 2, and A D D positions of the V E R T MODE
switch the output logic from U350A and U350B is
determined by the voltage levels applied to the clear (pins 1
and 13) and preset (pins 4 and 10) inputs. In the A L T
mode of operation the flip-flops are switched by the
alternate-trace sync pulse applied to their clock inputs
through Q338 and U 330B. In the CHOP mode, the clock
pulse generated by U330C and U 330D switch the flip-flops
at a one-megahertz rate.
Two Megahertz Clock
U330C and U330D form an astable multivibrator having
a repetition rate of two megahertz. The rectangular output
waveform connects to the Switching Logic Flip-Flops
through nand gate U330B. Only in the CHOP position of
the V E R T MODE switch is a LO level applied to the input
to inverter U 330A . This puts a logical HI on pin 13 of
U 330D , which permits the astable multivibrator to free-run.
A t the same time, Q338 is biased on, which puts a logical
HI on pin 5 of U330B. Thus, the signal present at pin 6 of
U330B will be the two-megahertz clock signal.
CH
X.
PREAMP SIGNAL
C H 2
PREAMP SIGNAL
X -Y SIGNAL
CH 1
TRIGGER SIGNAL
CH 2
TRIGGER SIGNAL
S375B
TRIG
V IE W
H >
L X
ve
—
'O l/ iK I A
^
VERT
- O) SIG OUT
VERTICAL T
SIGNAL OUT
AMP Q420 Q430
S300
VERT I
MODE
T '
l
I
1
SCALE FACTOR
TWO
SWITCHING
SWITCHING
MEGAHERTZ
LOGIC
CIRCUITS
CLOCK
FLIP-FLOPS
Q3I2 Q3I4
0322 Q324
U 330
U350A<|B
DELAY
LINE
DL380
J-----------------
1 1
► \
to
VERTICAL
) OUTPUT
J AMPLIFIER
FROM TRIGGER
VIEW A M P L IF IE R
NORMAL TRIGGER
PICKOFF AMP
Q390 Q336
NORMAL
►TRIGGER
SIGNAL
CH O P B L A N k IN G
CHOP BLANKING
AMP
U340 Q348
3-6
Fig. 3-4. Detailed block diagram of the Vertical Channel Switching circuit.
Summary of Contents for 475
Page 6: ...475 475 Oscilloscope ...
Page 20: ......
Page 46: ......
Page 151: ...A B C D E F G Fig 7 4 P 0 A4 Vertical Mode Switch circuit board ...
Page 152: ...n m m m 1 t siumm c ii im ...
Page 154: ...Diagrams 475 A B C D E F G ...
Page 155: ...GRID LOCATOR Fig 7 8 P O A3 Vertical Preamp circuit board ...
Page 157: ...Diagrams 475 ...
Page 158: ...GRID LOCATOR 2 3 4 5 6 7 8 9 1 10 11 1 12 Fig 7 10 P 0 A3 Vertical Preamp circuit board ...
Page 160: ...Diagrams 475 GRID LOCATOR Fig 7 11 A5 Vertical Output circuit board ...
Page 163: ...Diagrams 475 GRID LOCATOR Fig 7 12 P O A8 Trigger Generator And Sweep Logic circuit board ...
Page 167: ... 415 OSCILLOSCOPE B T R IG G E R G E N E R A T O R g B TR IG G E R GEN ER A TO R ...
Page 168: ...Diagrams 475 GRID LOCATOR ...
Page 172: ...SWEEP G E N ER A TO R S ...
Page 175: ...TIM IN G HORIZONTAL DISPLAY SWITCHING ...
Page 177: ...A 011 HORIZONTAL AMPLIFIER 8 l j k J Ll J Ol Z o N C O X U 1 C L O o v O o _J V v P O in r ...
Page 179: ... 476 OSCILLOSCOPE ...
Page 180: ...POWER SUPPLY ...
Page 182: ...CRT CIRCUIT ...
Page 185: ...C A L IB R A T O R A N D F A N C I R C U I T 4 C A LIB R A TO R FAN MOTOR C IR C U IT ...
Page 189: ......
Page 190: ...4 T 475 OSCILLOSCOPE FIG 1 FRO NT PANEL ...
Page 191: ...475 OSCILLOSCOPE FIG 2 MAIN FRAME ...
Page 199: ......
Page 200: ...FIG 3 RIGHT SIDE l 475 OSCILLOSCOPE ...
Page 201: ...V S X O t l B O T T OVJ 8 8 ...
Page 209: ......
Page 210: ...5 ...
Page 211: ...4 4 75 O S C ILLO S C O P E FIG 5 CAB IN ET ...
Page 215: ......
Page 237: ......
Page 241: ... 1 I R I II9A po S IT I o n f i n e I R l 130 PAGE 4 OF 5 R 1234 Ml 9 91 9 473 ...