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BASIC CIRCUIT FUNCTIONS
Circuits for tetting PNP transistors are identical to NPN transistor circuits, except that
meter and DC voltage polarities are reversed. Therefore, to avoid repetition, simplified sche
matics are shown only for NPN tests.
IIShorts" Test Circuit (Figure 15)
Emitter and base ofthe transistor are tied together and a small DC voltage (approximately
4.5 volts) is applied between them and collector. Meter readings for good transistors should
not be greater than the maximum indicated in the test data under "Short Max. Settings of "A
It
,
liB",
and "C
If
switches have no effect during the shorts
t~st.
,;
27.Ln..
640n.
YEllS
TRANSISTOR
FIGURE 15
IIlcbo" Test Circuit (Figure 16)
The emitter circuit is left open for this test. Proper voltage is selected by the setting of
the "A" switch. Collector polarity is positive with respect to base. Meter reading should not
be greater than a certain maximum quoted in test data for that transistor. "C" switch setting
governs the meter shunt value.
5.Y,·'. :'
~...,
"c"
FIGURE 16
ilL" Test Circuit (Figure 17)
Voltage for this test is not affected by the "A" switch setting. Meter shunt value is gover
ned by !lB" switch setting. "C" switch setting has no effect on the test.
IIG" Test Circuit (Figure
18)
The basic circuit for the "GX1" and "GX5" tests is shown in Figure 18. The only differ
ence between the two tests is that a 6400n resistor is added in series with the meter lead for the
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