3B SCIENTIFIC PHYSICS 1017781 Manual De Instrucciones página 6

by adding times together.
Three RC pairs can be formed from the three
built-in resistors and the internal capacitor, se-
lected via INTERN 1, INTERN 2 and INTERN 3.
There is also an EXTERN setting which connects
the voltage comparator to the terminals for exter-
nal resistors and capacitors.
Charge and discharge apparatus 1017781 is
provided with a plug-in power supply for 230 V
(±10%), whereas model 1017780 has one for
115 V (±10%).
3. Technical data
Internal capacitor:
Internal resistors:
Voltage U :
0
Digital counter:
Maximum time:
Resolution:
Power supply:
Dimensions:
Weight (incl. power supply)
4. Accessories
For carrying out measurements on external resis-
tors and capacitors, the following plug-in compo-
nents are recommended:
Capacitor, 1000 µF
Resistor, 4.7 kΩ
Resistor, 10 kΩ
Resistor, 22 kΩ
5. General instructions
When the selector switch is set to INTERN 1,
INTERN 2 or INTERN 3, the internal capacitor
will be connected to the terminals used for an
external capacitor.
•
Do not connect an external capacitor when carry-
ing out measurements on the internal RC pairs.
The charging and discharging times measured
are affected by bounce periods, which can be
made worse if the charge/discharge switch is
turned tentatively.
•
Always turn the switch quickly.
•
To determine the time more accurately, it
may be advisable to carry out each meas-
urement at least three times and take the av-
erage.
•
Only choose external RC pairings which
have a time constant
2000 μF ±10%
2.2 kΩ, 5.1 kΩ, 10 kΩ
10 V
4-digit, quartz-controlled,
1 place of decimal
200 s
100 ms
Plug-in supply, 12 V AC,
2000 mA
260 x 220 x 55 mm
1700 g
1017806
1012920
1012922
1012924
R C ⋅ > .
4 s
6. Operation
6.1 Turning on
•
Connect the charge and discharge apparatus
to the mains via the plug-in power supply pro-
vided.
6.2 Measurements
capacitor pairs
•
Remove any external resistors or capacitors.
•
Set the selector knob to INTERN 1, INTERN 2
or INTERN 3.
6.3 Measurements
capacitor pairs
•
Plug an external resistor and capacitor into the
relevant terminals.
•
Set the selector knob to EXTERN.
Fig. 1 Measurement on an external resistor-capacitor
pair
6.4 Measurement of charging time
•
Set the function switch to CHARGE – STOP.
•
Set the reference level selector to the required
voltage.
•
Briefly press the the RESET button to reset the
digital counter to zero.
•
Set the function switch to CHARGE – START,
to start charging and measurement of time.
•
Make a note of the time measured as soon as
the counter stops.
6.5 Measurement of discharging time
•
Follow a similar procedure as for the charg-
ing curve, except that the function switch
should be set to DISCHARGE – STOP and
then DISCHARGE – START.
2
on internal resistor-
on external resistor-