Chapter TwoVoltage and Current Measurement

CONTINUE

بسم الله الرحمن الرحيم

04/20/23 1A. Prof. Magdi El-Saadawi

2.4. Current Measurement

Current measuring devices are selected for: Precision Stability Frequency response, including dc Galvanic isolation بعدم التام العزل من التأكد

تيار مرور Presentation of the data Effect on measured circuit

04/20/23 A. Prof. Magdi El-Saadawi 2

Using an Ammeter as a Voltmeter and vice versa

04/20/23 3A. Prof. Magdi El-Saadawi

Using a Voltmeter as an Ammeter

By using a shunt resistance to reduce the large internal resistance of the voltmeter, so that it can be connected in series in the circuit

04/20/23 A. Prof. Magdi El-Saadawi 4

Using an Ammeter as a Voltmeter

By using a series resistance to enlarge the small internal resistance of the ammeter , so that it can be connected in parallel in the circuit

04/20/23 A. Prof. Magdi El-Saadawi 5

Figure 2.34 Changing the range of a Voltmeter using a number of high resistance resistors connected in series

with meter coil and known as multiplier

04/20/23 A. Prof. Magdi El-Saadawi 6

Figure 2.35 Changing the range of a Ammeter using a number of low resistance resistors connected in parallel

with meter operating coil and known as multiplier

04/20/23 A. Prof. Magdi El-Saadawi 7

04/20/23 A. Prof. Magdi El-Saadawi 8

04/20/23 A. Prof. Magdi El-Saadawi 9

Solution

04/20/23 A. Prof. Magdi El-Saadawi 10

Solution guide

2.4.2. The Moving Magnet Meter

04/20/23 A. Prof. Magdi El-Saadawi 11

2.4.3. The D’Arsonval Meter

04/20/23 A. Prof. Magdi El-Saadawi 12

2.4.4. The Electrodynamometer

04/20/23 A. Prof. Magdi El-Saadawi 13

2.4.5. The RF Ammeter and True rms

04/20/23 A. Prof. Magdi El-Saadawi 14

2.4.6. The Current Transformer

04/20/23 A. Prof. Magdi El-Saadawi 15

04/20/23 A. Prof. Magdi El-Saadawi 16

Current and potential transformers for High voltage measurements

04/20/23 A. Prof. Magdi El-Saadawi 17