Subject to change without notice
12
The instrument can be toggled from its active to its inactive state by pressing
the DUT key repeatedly; simultaneously the DUT will be disconnected from
the internal test circuitry. The inactive state is indicated on the LCD by the
message -off-.
3. 1. Choosing the DUT type
The
HM6042
has to be set-up according to the type of DUT (Device Under
Test) to be proved.
To test NPN bipolar transistors switch BIP/FET
(15)
and switch NPN/PNP
(16)
has to be in released position. When working with PNP transistors
switch NPN/PNP
(16)
has to be set into the locked position. As usual, the
measurement is performed using the common-emitter circuit.
To test FETs set switch BIP/FET
(15)
into the locked position.
Diodes are tested with the same set-up as FETs using terminals E and C.
3. 2. Setting the test ranges
Through its range settings the instrument is enabled to limit the test voltage
(U
CE
, U
DS
) and the test current (IC, ID) to predefined values. The ranges for
current, voltage, and power can be selected by use of the push buttons for:
Imax
(19)
200 mA
20 mA
2 mA
Vmax
(21)
40 V
10 V
2 V
Pmax
(23)
4.0 W
0.4 W
.04 W
The corresponding LEDs
(18)
,
(20)
, and
(22)
indicate the maximum value
of the range as set. In test mode BIP the rotary knob enables the user to
adjust the base current in incremental steps according to the selected
range as defined below:
Range
Current (I
B
)
No. of steps
Current / step
1
0.3 µA ... 100 µA
127
0.8 µA ± 10 %
2
3 µA ... 1 mA
127
8 µA ± 10 %
3
30 µA ... 10 mA
127
80 µA ± 10 %
The base current at the indica-
ted cursor position is displayed
on the LCD with IB/IG selected
by the push buttons (
← →
← →
← →
← →
← →
, 5).
When FETs are under test the
rotary knob
(8)
allows adjus-
ting the gate voltage U
G
bet-
ween -10V to +10V in 256 in-
cremental steps. This means
80mV/ step approximately.
Figure 1
