5.3 The DC voltage measuring instrument
Operating elements
1. Illuminated 3 1/2-position
17 mm high LCD display
2. Voltage adjustment
3. V/A display switch
4. AC power main switch
Attention! Safety measures!
Protect the instrument from being dropped and from external mechani-
cal damage by falling objects.
Do not short circuit the "+" and "-" terminals.
Never go beneath the maximum permitted load of 2.5 Ohm at the 5V/2A
output and 15 Ohm at the 15V/1A output.
Basic settings
a) Before connecting the AC power cable, ensure that no load is pre-
sent on the output terminals of the power supply.
b) Centralise the (CURRENT) current-limiting control knob.
c) Switch the AC power switch (POWER) on.
d) The LEDs under the legends 5 V and 15 V light up.
e) Connect the loads to the 5V and 15V output.
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5. Adjustable current limiting
6. Ground connector
7. Fixed voltage output 5 V / 2 A
8. Fixed voltage output 15 V / 1 A
9. Adjustable output 0-30 V / 0-3 A
f) Switch the display switch to "V" (voltage) and set the desired
output voltage.
g) Now connect the load to the output terminals "+" and "-" of the
adjustable output. While doing this, observe the polarity of the load.
Attention!
All outputs are floating. Other outputs can either be grounded through
the ground socket (= chassis) on the front panel (bottom right) or
remain floating.
Current limiting characteristics
All 3 outputs are independently protected against overload and short
circuit by means of a separate current limiting circuit.
a) Output 0 to 30 V, 3 A: protected by means of current limiting. If the
output current increases due to a load of more than 3 A, the output
voltage is reduced (with a short circuit to approx. 0.2 V).
b) Fixed voltage output 5 V / 2 A: protected by a fixed current limit
(stabilising circuit).
Should the load current exceed the value of 2.2 A, the output vol-
tage is reduced.
c) Fixed voltage output 15 V / 1 A: protected by a fixed current limit
(stabilising circuit).
Should the load current exceed the value of 1.2 A, the output vol-
tage is reduced.
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