Lucast85
Member level 3
Hi all,
we have a system that uses an open-loop hall effect sensor to measure the current (LEM DHAB s/133). During the EMC tests, precisely the IEC61000-4-3 and IEC61000-4-6, at frequencies of 120 MHz and 67 MHz we have bad read values of current (error >> 100% of real current). We're almost sure that the harness is ok because we've replaced the hall sensor with a divider and the read value was stable despite the EMC disturbances.
This is the output of the all effect current sensor with the coupled noise when I = 0A.
In this case (real current = 0 A and RF disturbance ON), we can see the RF noise but the DC value is correct (about 0 A)!
This is the output of the all effect current sensor with the coupled noise when I = 10 A.
In this case (real current = 10 A and RF disturbance ON), we can see the RF noise but the DC value of the output is NOT correct (about 58.8 A instead of 10 A)! This is the cause of the bad reading.
The bad read values seems due to a sort of ""polarization effect" of the hall effect sensor caused by the RF disturbance.
Anyone has some experiance on these sensors with EMC tests ?
Thank you all!
we have a system that uses an open-loop hall effect sensor to measure the current (LEM DHAB s/133). During the EMC tests, precisely the IEC61000-4-3 and IEC61000-4-6, at frequencies of 120 MHz and 67 MHz we have bad read values of current (error >> 100% of real current). We're almost sure that the harness is ok because we've replaced the hall sensor with a divider and the read value was stable despite the EMC disturbances.
This is the output of the all effect current sensor with the coupled noise when I = 0A.
In this case (real current = 0 A and RF disturbance ON), we can see the RF noise but the DC value is correct (about 0 A)!
This is the output of the all effect current sensor with the coupled noise when I = 10 A.
In this case (real current = 10 A and RF disturbance ON), we can see the RF noise but the DC value of the output is NOT correct (about 58.8 A instead of 10 A)! This is the cause of the bad reading.
The bad read values seems due to a sort of ""polarization effect" of the hall effect sensor caused by the RF disturbance.
Anyone has some experiance on these sensors with EMC tests ?
Thank you all!