Download Hall Probes for Magnetic Field Measurement

Hall Probes for Magnetic Field
Measurement
Bias Voltage
y
Ix
z
x
t
Uy
Hall element
-
Voltage
+ meter
Bz
I
U y  RH x Bz
t
Bz  U y
t
RH I x
 U y
– By setting up the bias current (Ix) flowing into the
Hall element and monitoring the traverse Hall
voltage output (Uy), the input magnetic field (Bz)
can be “sensed” (figured out backwards).
Jun Zou
Hall probe and Gauss
meters
Department of Electrical Engineering
Dwight Look College of Engineering
Non-contact or Wireless position
sensing by measuring field strength
– When a tooth of the magnetic gear moves closely to the Hall
sensor, it gives out higher output voltage (Uy) due to increased
magnetic field (Bz).
UUyy BBzz
Ix
U y  RH B z
t
– By carefully designing the pitch and width of the teeth, a very
specific waveform of Uy can be created to trace the rotation
speed and angle of the gear and shaft.
Uy
Magnetic gear
Bz
Hall sensor
Jun Zou
Department of Electrical Engineering
Dwight Look College of Engineering
Digital Compass
Bz
Uy
Ix
Honeywell at digikey.com
– Hall sensor is most sensitive to the magnetic field perpendicular to the plane
containing the bias current and Hall voltage terminals.
– Using two or three Hall sensors allows 2-axis or 3-axis detection of the
magnetic field direction.
– Hall sensor can be readily integrated with microelectronics.
Jun Zou
Department of Electrical Engineering
Dwight Look College of Engineering