USING
THE
MODEL530
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IN-CIRCIIT TESTING
CAI.]"fION
Makesure
all power is turned off in the circuit
being tested, and that all capacitorsare dis-
charged.
A. Transistors
andFET's:
1. Setthe DRIVE Switch(5) to the LO position.
2. Connect the three test leads
(in any manner) to
the threeleadsof the device
you wishto test.The
test leadsmust be pluggedinto their respective
color Testkad Sockets
(6).
3. Move the Test Switch (4) slowly through its six
positions
until oneof thetwo red
lamps
(1) or(2),
glows. A tone also will be heard if SPEAKER
Switch (8) is ON. The lamp that glows
indicates
whetherthe deviceis NPN (l) or PNP
(2) or N oi
P channel.
In LO drive, most transistors
that test
good will do soin only one Test Switch position
(see
"THINGS TO KNOWABOUT THE 530"). In
this Test Switch position, all the leads of the
transistorcan be identified asshownin the I-ead
Identification Window (3). Most FET's will test
good (LO or HI drive) in two Test Switch
positions having the sameBASE color shown in
the IBad Identification Window (3), since
practi-
cally all junction FET's are symmetrical. The
BASE color indicatedis the gate Ieadof the FET.
4. If thereis no goodindication (neitherof the two
lamps glows) as the Test Switch (a) is slowly
movedthrouglrits six positions,
in LO drive,then
the deviceundertestisoneof the following:
a. Device with high leakage or very low gain
(-uy not function properlyin circuit).
b. Devicewith open/shortedelements.
c. Device with excessive
circuit shunting (see
"SPECIFICATIONS").
d. FET that will not testwith LO drive.
5. Re-testthe device,using HI drive. In HI drive,
most transistors
that test good will do soin /wo
adjacent Test Switch positions having the same
BASE color shown in the kad Identification
Window. Only the base
leadof the transistor
can
thenbeidentified.
6. If thedevicetests
good
usingHI drive,then4(a)or
4(d) above
couldbetrue.
7. If the device
doesnot testgood
in anyTestSwitch
position, in HI drive,lemovethe device
from the
circuit and re-test using OUT-OF-CIRCUIT pro-
cedures.
B. SCR'S:
1. Set
theDRIVE switch
(5) to theHI position.
t0
2. Connect
the threetest leads
(in any manner)
to
thetfuee
leadsof theSCR
you wishto test.
3. Move the Test Switch (4) slowly through its six
positionsuntil the NPN lamp (l) glowsin one
position and PNP lamp (2) glows in another
positionhaying
adifferent BASE
color asshownin
the Lead
IdentificationWindow(3).
4. The SCR
is good
only if the followingindications
are
obtained:
a. One
NPN.
b. One
PNP,
NOTE:indications
must
not have
sameBASE
color.
LEAD IDENTIFICATION:
a. The BASEcolor shown
in the kad ldentifica'
tion Window (3) is the gate lead when the
NPNlamp
(1)glows.
b. The BASEcolor
shown
in thekad ldentifica'
tion Window is the cathode lead when the
PNP
(2) lampglows.
5. If the SCR testsbad, then it shouldbe removed
from the circuit and testedagain
(muy be subjebt
to excessiveshunting in-circuit), using out'of-
circuit
procedures.
C. Diodes:
l. Set
LEAKAGEVOLTScontrol(14)to zero.
2. Set Test Switch(a) to top position(Green
base
identification).
3. Set
NPN/PNPSwitch
(12)to PNP.
4. Connectthe blue andyellow testleadsacross
the
diode
to betested.
5. Adjust the LEAKAGE VOLTS Control (1a) to
approximately
l0 volts,asindicatedon the con'
trol panel.
6. Depress
the PUSH-TO-TEST
Switch (13) and,
whilekeeping
thisswitch
depressed,
rotatethelest .
Switch (a) to eachof the upper two positions.
(Green
base
identification.)
7. While performing step 6, observe
the resultson
LEAKAGE/GAIN Meter(19). The meter
reading
will beapproximately
full scale
for one
positionof
Test Switch ( ) while the other position of the
Test Switch will givea lower reading,depending
on the shunting effect of the circuitry. In the
position givingthe highest
reading,
the
cuthodeof
ihe diode
under
test
is connected
to thetestlead
having
the collector (C) color in the Lead
Identifi'
cation Window (3). If both positionsproduce
full-scalereadings
the diode is either shorted or
heavily shunted by low-resistance
circuitry; for
example,a transient suppressor
diode across
a
relay
-or a solenoid coil. In this casethe diode
should be disconnectedfrom the circuit and
re-tested
using
OUT-OF-CIRCUIT
procedures.
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