Tektronix 7704A User Manual

F ig . 2-36 . O u
tp u t waveforms of Timer stage .
Circuit Description -7704A Service
T h e next signal to be pro duced is t
h
e V -
Η ( V
ertical-
H
orizontal) In
h i
b it at
p i n 13 . T h is p ositive-going signal
d isconnects t he plug-in signals from t he vertical a nd
h orizontal deflection systems so t he p l u g-in units do n ot
control t h e p osition of t h e C R T b eam during t h e rea d out
d is p lay . T he R ea d y signal d erive d from t h is out put is
connecte d to t he Decimal
P
oint L ogic and
C h
aracter
P
osition Counter stage and t
h
e
F
ormat
Generator
stage
.
T h e Ζ R eadout output at pin 12 is pro d uced next . T h is
current
is connecte d to
t h e CR T Circuit to un b lan k t h e
CR T to the intensity level d
etermine d by t he RE ADO U T
intensity control . T h e C h aracter Scan
ramp at p in 16
starte d to go negative as t
h
is
timing se q ue n ce b egan .
H owever, ch aracter
generation d oes not start until the
rea dout
intensity level h as been establis hed . T he tria n gular
C h aracter Scan
ram p runs from about -2 volts to about
-8 .5 volts, t
hen returns bac k to t h e original level . T h is
waveform
provi d es t h e scanning signal for t he C h aracter
Generator stages .
F ull C h aracter Scan ad j ustment R 3437
sets t h e DC
level
of t
h e C h aracter Scan ram p for complete
c h aracters on t
he d isplay
.
C ha r acter Scan
P i n 16
Ζ -Axis
I nh i b it
P i n 14
Limited
at- 6 V
V - Η
I nh i b it
P i n13
z
R ea dou t
Pin 12
MEMMEMMEME
"Φ """ ~ "" C
:
""""~_ """
M=
a
ΝΟΤΕ : Test
oscilloscope exter n ally triggere d
fr
om
ΤΡ 3450 .
O V
O V
0
F ig . 2-37 . Detail of output at p i n s 12, 13, 14, and 16 of U 3433 .
2- 45
ο
ν
P i n6
!M
7 ΛΛ "" r
Ι "
; ι
Ι
Ι Ι Ι 1
Γ ~
s ι
ο
ν
Ι " Ί/11 Ι /1% έΙ / Ι 1111
Ι /1
,
P
i n 10 - -
Ι
r~ "
r ι r ~ r O " r r
_
Ι ~ Ι
- 7777
r
.
τ : ιπ r / τ ~~
r . r .-
Trigger , ι
Pin 5
__ ι ~ ιϊ " ίιιι ~~ ϊ ~
ιί ~ ιι _ ι ~
-O
V
MMMMMiM
C ha r acte r
Scan
0 ~" ~ Ί ~ Ί
HEMMOMEMMU
Ί 0 "
~~
MCM
',_
ο ν
Pin
M
"
Γ Ι
_
Ι ~
Ζ -Axis
".
In h i b it
P i n 14
Ο V
Limited
at- 6 V
Inhibit
MMMMMMMMCM
ω
"" ι " M " ι E ""
ω
ιιι " ιι " ι "
ιιι , ιι " ι " ιι " ιιι
ον
Pin 13
___ Ι -_ _ :
"""
1
Ι
Ι _
" M
'+6
ν
z
R eado u t
P in 12
ΝΟΤΕ
: Test oscilloscope exte rn ally triggere d f r om ΤΡ3450 .

Tektronix 7704A Specifications

General

Brand	Tektronix
Model	7704A
Category	Test Equipment
Language	English