Jeulin 302047 Manuel D'instructions page 7

Electricity
Teaching scale model for Ohm's law
Ref :
302047
ENGLISH
3 Technical characteristics
Connection: Power supply for the ammeter and voltmeter on a safety socket
diameter 4 mm.
Protection: Against reversal of polarity, against overheating: voltage
regulator.
Accuracy: +/- 5%.
Pmax: 1W.
Dimensions: 105 x 65 x 50 mm.
4 Assembly and installation
Connection of the ohmic conductor
A multipurpose connector of the loud speaker type is used to connect all types
of resistances.
A support is also delivered for screwing in a 6 V, 100 mA bulb.
Measuring
Follow the instructions on the unit:
The ammeter at A: Rating 200 mA for a resistance of ~ 120 Ω and 20 mA
for resistances between 400 – 1000 Ω.
The voltmeter at B: Rating 2 V.
Power supply
Use a 12 V DC power supply.
The potentiometer allows varying the input voltage continuously between 1.25
and 9 V.
Example:
1. U constant, R varies
Thanks to the dipole support, at fixed voltage (here adjusted to 5 V using the
potentiometer), we measured the intensity with 3 different resistances. The
calculation R (resistance value) x I (measured) gives us the original voltage.
Resistance
120 Ω
470 Ω
1 kΩ
6
measure I versus the ohmic dipole:
U I measured
(mA)
5 V 41.2
5 V 10.8
5 V 5.05
R x I
calculated
(V)
4.94
5.07
5.05