Tektronix 576 - Section 2 Operating Instructions

General
T
h is section of t he instr u ction
manual p rovi d es informa-
tio n necessary for operating t
he Ty p e 576 and for using it
to test va r ious semicond uctor
d evices . Include d are set u p
p r ocedu res, α d escription of t h
e Type 576 controls an d
con n ecto r s, α d iscussion of t h
e
t heory
of t he i n st r ume n t, α
first time o p eration p roce du r e, a n d
general op erating info r -
mation
. Also i n clu d ed is α section d
esc r ibing t he use of t he
Ty p e 576 for measu r
ing t he ch aracte r istics of various semi-
con d ucto r d evices .
Cooling
S
E CTIO N
2
O PER
A TI N G
I
N ST
RU CTIO
N S
C h ange info r mation, if any, affecti ng
th is section will b e found at
t h e rear of t he ma n ual .
I N ITIA L CO N SID ER
ATIONS
T he Ty p e 576 maintains α safe
op e r ating tem p e r atu r e
w h en op erate d in an ambient
tem p e r atu r e of 0 ° C (122 °
F) . A d e q uate clearance on all
si d es of t he instrume n t
s hou l d be p r ovide d to ass
u re f r ee air flow a nd d issi p atio n of
h eat away f r om t h e instrument
. Α t h ermal cu tout in t he
instrument p
r ovides t he r mal p rotection by d isconnecting
t h e p owe r to t h
e i n strument if t h e i n ternal tem p eratu r
e
excee d s α safe op
e r ating level . Power is au tomatically
resto r e d w h en t h
e
tem p
eratu
r
e r et u rns to α safe level . It
shou ld be noted t h at t he instrument
will tur n off un d e r
ce r tain conditions of h ig h collector su pp
ly cur r ent ou t p ut
or
h ig h ste p gene r ator cu r rent Output
even t h oug h t he
inst r ume
n
t is
being op erate d in an ambient tem p
erature
w h ic h is wit h
in t he s p ecifie d r ange . See footnotes in t h
e
Specification section for furt h er info r mation .
O p
erating V oltage an d F re q uency
T he Ty pe 576 ca n be ope r ate d fr om eit
h
er
α 115-volt or
α 230-volt
line voltage source . T he L I NE VO L TAG
E S E-
LE CTO
R assembly, locate d on t he rear panel, allows co
n -
version
of t he instrument so t h at it may be o p
erate d from
one line voltage or t he ot h er . In a dd
ition, t h is assembly
c h anges t he connectio n s of t h e p ower
transformer p rima r y
to allow
selectio n of one of t h ree
regulating ranges (see
Table 2-1) . T he assembly also includes
t he two line f u ses .
Wh en t h e i nstrument is converte d from
115-volt to 230-volt
ope r atio n or vice versa, t h e assembly
selects t he p ro p er fuse
to p r ovi de t he correct p rotection for
t he inst r ument .
T h
e
Ty p
e
576 may
be ope r ate d f r om eit he r α 50
Hz or α
60 Hz line
f
r
eq uency .
In
o r der to sync hr onize t
h e ste p
ge ne r ato r wit h t he collecto r su p ply,
t he 60 H z-50 Hz
switc h , locate
d
on
t he Ty pe 576 r ea r p
anel below the L I NE
Ty pe 576
V O L TAG ES ELE CTO R assembly, must be set
to t he posi-
tion w h ic h corres pon d s to t he line fre q uency
being u
se d .
U se t he
following p r oce d u re to conve r t t h is instrument
between line
voltages, regulating ranges or line fre que n cies :
1 . Disconn
ect t h e inst r ument from t he p ower source .
TA BLE 2-1
R egulati ng R anges
F ig . 2-1 . Line V o
l tage Selector assembly an d 60 H z -50 Hz sw i tc h
on t h e rear
panel (s h own wit h cover removed) .
R eg u lati ng R an ge
R an ge Selecto
r 115 V olts
230 V olts
Switch
P ositio n N omi n al
N
omi
n al _
L O (switc
h bar in 90 to 110 volts
180 to 220 volts
left h oles)
Μ (switc h ba r in 104 to 126 volts
208 to 252 volts
mi dd
le h oles)
Η Ι (switc h bar i n 112 to 136
volts 224 to 272 volts
rig h t holes)