Tektronix 576 - Page 21

a dd
e
d to
t he ap p roximate estimate, yielding α value of 8 .4
for th
e Zener voltage
of t
h e d io de . T h e same process ca n
also be carrie d
out using vertical d isplay offset and magnifi-
cation .
Ste p Generator
Β
47 . Set t h
e
following Ty p
e
576
controls
to :
DIS PL AY O FF S
E
T

NORM (O FF )
Selector
C EN T ERL I NE VA LUE

0
V ertical
P
OSITIO N Switc h centere d
P O L A R ITY
+(
ΝΡΝ )
V A R IA BLE CO LLE C-

F ully Cou n tercloc k wise
TO R S UPPL Y
LEF T-O FF-R IG H T O FF
48 . R emove t h e d io d e ad apte r an d re p lace it wit h t
h e
unive r sal tra n sistor a d a p ter (Te k tronix
P
art Νο .
013-0098-00) .
49 . P lace an ΝΡΝ silicon transisto r into t he rig h t tran-
sistor test soc k et of t he u nive r sal transistor a dap ter .
50 . Set t he LEF T-O FF-R IG HT switc h to RIGHT and
t u rn t he V A R IA BLE CO LLE CTO R S UPPL Y cloc k wise un-
til t he p ea k collector-emitter voltage is about 10 volts .
51 .
Tur n t he A M PL IT UD E switc h until α ste p a pp ears
on
t he CR T . Note t h at t he g r eate r t he ste p am p lit ud e, t he
g r eater t he collector current (see F ig . 2-12) . Setthe A MPL I-
T UD E fo r t he minimum ste p am p litu d e w h ic h prod uces α
noticeable ste p in t he d is p lay .
M :
Ρ
Εν
R
7
DIV
PER
Η
Ο
R
Ι
οιν
PER
7
? ο
Ρ μ
Α
β
9m
PER
DIV
ΜΑ
100
F ig . 2-12 . Collector current vs .
Col l ector- E m i tte r voltage for various
settings o f t
h
e
A MPLITUDE switc h .
52 . Turn t
he NU M BER O F STEP S switc h cloc k wise . B
e
su r
e
t h
e
PEAK
P
O
WER W ATTS switc h is set wit h in t h e
p ower d issi p ation rating of
t he transistor being used . Note
t
he dis p lay of collector cu r rent vs . collecto r -emitter voltage
fo r ten diffe r en t values of b ase current (see F ig . 2-13 Α ) .
Ope r ati ng Inst r uctio n s-Ty pe 576
;IC
ι
~( Α )
ί
Ι
Ι
Ι
ι .
_
IC ν V άε
Ι
;( Β )
i
Ι
r
ι
ι
Β
@ 50 μΑ
/s
μΑ /s, ep ;
R
Τ
DIV
MR
Ο
R
DIV
PER
s
Τ
Ε
Ρ
β
PER
DIV
Ρ
ε
R
τ
DIV
PER
β
ο R
5
IRA
Ι
50
j& A
WA
ΡΕΛ
Η ηη
R
ι 00
i
Ιιπν
DIV
s
50
τ
υΑ
9 .
ιΓ h η
PER
DIV
F ig . 2-13 . ( Α ) IC vs .
VICE
f or 10 ste p s o f b ase current at 50 μΑ per
step
; ( Β )
IC
vs . VBE
for 10 ste p s of lease current at 50
μΑ
per step .
53
. Set t h e H O R IZO N TA L switc h to .1 V B AS E . N ote
t
he d is p lay of t he collector curre n t vs . base-emitter voltage
fo r ten
different values of base cu r re n t (see F ig . 2-13 Β ) .
54 . Set t he VER TICA L switc h to STEP G EN and t he
H O R IZO N TA L switc h to 1 V CO LLE CTO R . N ote the d is-
p lay of th e basec u rrent, one ste p p er vertical division, vs .
t h e collecto r
-emitter
voltage
(see F
ig .
2-14
Α ) .
55 . Set t h e H O R IZO
N
TA
L switc h to .1 V B ase . N ote
th e disp lay of base cur r ent,
one
ste
p p er vertical d ivision,
vs
. base-emitter voltage (see F ig . 2-14 Β ) .
56 . Set t h e VER TICA L switc
h
to
5 mA an d th e H O R I-
ZO N TA L switc h to ST
EP
G
EN . N ote t he d is p lay of collec-
tor cur r ent vs .
base-current, one step p er h o r izontal division
(see F ig . 2-15)
.
57 . Set t h
e
following Ty p
e 576 cont r ols to :
H O R IZO N TA L 1 V CO LLE CTO R
R AT E

.5 Χ
Note
t
h
at t
he step rate is slower t h an t he no r mal rate .
2-1 3
vs .
V ςε ΙΒ @ 50 ( . . ΙΑ /S
" r
1=ii~~~- " Ι
710 . a
m
~~iy γ ~YY~Y W WY ~
J im