ECE5320 Mechatronics Assignment #1: Literature Survey on Sensors Through Loop Current SensorsOutline for ShowReference SourcesTo explore furtherThough Loop Current SensorsSlide 6Sense Resistor TypeHall EffectCurrent Transformer TypeOpen Loop Hall Effect TypeSlide 11Open Loop ApplicationOpen Loop Hall Effect Pros and ConsClosed Loop Hall Effect TypeSlide 15Closed Loop Hall Effect Pros and ConsClosed Loop Motor Control ExampleCurrent Sensor HookupPicking a SensorMore ApplicationsECE5320 MechatronicsAssignment #1: Literature Survey on Sensors Assignment #1: Literature Survey on Sensors Through Loop Current SensorsPrepared by: Robert SilverDept. of Electrical and Computer Engineering Utah State UniversityE: ; T: (435)797-; F: (435)797-3054 (ECE Dept.)Website: http://mechatronics.ece.usu.edu/ece5320/3/10/200601/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-2Outline for Show–Reference sources–To probe further–Sensor description–Basic working principal–Different types–Examples–Pros and cons of each type–Choosing correct sensor for different applications01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-3Reference Sources•http://content.honeywell.com/sensing/prodinfo/current/•http://www.allegromicro.com/Isolated Open Loop Current Sensing Using Hall Effect Technology in an Optimized Magnetic Circuit by: Richard Dickinson & Shaun Milano •Current Sensing in Electric Drives A Future and History Based on Multiple Innovations by: Eric FAVRE01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-4To explore further Internet sites to find sensors at:Honeywell: http://content.honeywell.com/sensingAllegro Microsystemshttp://www.allegromicro.comGMW: http://www.gmw.com/electric_current/currmeas.html01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-5Though Loop Current Sensors Type: Sense Resistor and Hall Effect, Open and Closed Loop Linear http://content.honeywell.com/sensing/prodinfo/current/01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-6Basic Working Principal:Provides a linear output voltage that tracks the waveform of the sensed current.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-7Sense Resistor Type•Sense resistors are simply a resistor placed in series with the load. By ohms law, the voltage drop across the device is proportional to the current.•For low currents these devices are accurate when the resistance values have a tight tolerance. •Also require other components to give appropriate output, such as amplifiers to modify and enhance the signal out.Isolated Open Loop Current Sensing Using Hall Effect Technology in an Optimized Magnetic Circuit Richard Dickinson & Shaun Milano01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-8Hall Effect•“According to the Hall effect, a magnetic field passing through a semiconductor resistor will generate a differential voltage proportional to the field”•Figure 1: Representation of the Hall effect in 3d“Concentric magnetic field lines are generated around a current carrying conductor. Approximating the primary current conductor as infinitely long, the magnetic field strength may be defined B = µoI/ 2pr, where µo is the permeability of free space, I is the current and r is the distance from the center of the current conductor.”Isolated Open Loop Current Sensing Using Hall Effect Technology in an Optimized Magnetic Circuit Richard Dickinson & Shaun Milano01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-9Current Transformer TypeCurrent carrying conductor By Faradays law, the current in the conductor going through the loop sensor will generate a magnetic field in the secondary coil of the loop sensor. The current induced in the secondary coil is proportional to the number of turns in the coil. This current is then sensed by a sense resistor and converted into a voltage, which is the output of the sensor.Isolated Open Loop Current Sensing Using Hall Effect Technology in an Optimized Magnetic Circuit Richard Dickinson & Shaun Milano Sense resistor01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-10Open Loop Hall Effect TypeIsolated Open Loop Current Sensing Using Hall Effect Technology in an Optimized Magnetic Circuit Richard Dickinson & Shaun Milano For an open loop design using Faradays Law the Hall Effect device output is amplified and sent out as a voltage that is a scaling factor of the sensed current of the I-primary in the wire through the toriod.Current carrying conductorHall effect semiconductor01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-11Open Loop Hall Effect TypeIsolated Open Loop Current Sensing Using Hall Effect Technology in an Optimized Magnetic Circuit Richard Dickinson & Shaun Milano This open loop design doesn’t have a feedback control loop and is therefore subject to some errors caused by eddy current errors and collapsing magnetic fields due to varying current draws caused by, for example, the varying magnetic fields in an electric motor.Current carrying conductorHall effect semiconductor01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-12Open Loop Application Here an open loop current sensor is used to start a fan whenever the oven is on. This also shows how a through hole type current sensor is advantages, because it’s output and control voltages are separate from the rest of the high voltage circuit being sensed.http://www.ssac.com01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-13Open Loop Hall Effect Pros and ConsPros: Very low power consumption Small weight and size for high current sensing abilities Resistant to current overloads No break in main line when sensor installed and used Fairly inexpensiveCons: Moderate bandwidth, response time Larger temperature dependence for measurement accuracy High frequency eddy-current losses01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-14Closed Loop Hall Effect Type For this closed loop type current sensor it uses the output of a Hall device that drives a secondary coil and this will make a magnetic field to cancel the primary current field induced by Faradays law into the coil by I-primary. The secondary current is then
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