Measuring a voltage in any system is a “passive” activity as it can be done easily at any point in the system without affecting the system performance. However, current measurement is “intrusive” as it demands insertion of some type of sensor which introduces a risk of affecting system performance.
Fig. 2: A Diagram Explaining the Principle of Direct Sensing
Fig. 3: A Diagram Illustrating the Principle of Indirect Sensing
Current Sensing Techniques
Fig. 5: A Diagram Explaining the Sense-FET Technique
Fig. 6: A Diagram Explaining the Average Current Flow
Fig. 7: A Diagram Explaining the Filter-Sense the Inductor
Magn. Field Based Sensing Tech.
Fig. 8: A Diagram Explaining the Half Effect Principle
Fig. 9: A Diagram Explaining the Half Voltage as a Low-Level Signal in a Magnetic Field
Fig. 10: A Figure Explaining Current Sensors based on Open Loop Hall Effect Technology
probe placed in the airgap of the magnetic circuit provides a voltage proportional to the magnetic flux. This voltage itself is proportional to Ip is amplified and is used for further processing.
Fig. 11: A Figure Explaining Current Sensors based on Closed Loop Hall Effect Technology
Fig. 11: A figure Explaining Current Sensors based on Electronic Technology
In contrast to open loop and closed loop technology, they do not use magnetic circuit. Primary current Ip creates magnetic flux and different hall probes included in the sensor provides a voltage proportional to the magnetic flux.
Fig. 12: A Diagram Demonstrating the Rogowski Coil
Fig. 14: A Diagram Demonstrating Fiber Optic Current Sensors
High Side v/s Low Side Sensing
Fig. 15: A Figure Illustrating Low-Side Current Sensing
Fig. 16: A figure Illustrating High-Side Current Sensing