Magneto-Resistive Speed Sensors

Similar to Hall Effect sensors, MR sensors are highly sensitive devices that can detect very small changes in magnetic fields caused by a passing target (ferrous or magnetic), and convert this into a digital output. Versions are available for quadrature (bi-directional) or single direction sensing.

Versions are available that can provide quadrature (bi-directional) or single direction output. Both Hall Effect and Magneto-Resistive sensors are true zero-speed sensors. Magneto-Resistive sensors, because of their higher sensitivity, are better suited for sensing ferrous metal targets at substantially longer distances; up to .250" or greater. The tradeoff is that they are more susceptible to producing false pulses from inductive fields. This might make them unsuitable for applications where they will be in close proximity to large motors or generators, etc. These sensors are built on a custom basis to satisfy specific application requirements.

MSI welcomes the opportunity to develop a product specifically suited to your application or to modify an existing product to suit your needs. They have extensive experience in designing custom products and pride ourselves on the ability to provide high quality custom products at reasonable prices.

When the Sensor is moved along a magnetic scale with a N/S pole pitch of 5mm the two Wheatstone bridges generate differential sinusoidal output voltages (PSIN – NSIN) and (PCOS – NCOS) phase-shifted at 90°. One sine/cosine cycle averaged using a pair of N/S poles is thus produced for a pole width. The absolute magnetic field strength must be large enough for the sensor to go into saturation and for the magnetization of the iC-SM5L's resistor to assume the direction of the outer magnetic fields.

The amplitudes of the differential output voltages are largely independent of the magnetic field strength and thus not sensitive to changes in distance

iC-SM5L is resistant to strong magnetic fields and not sensitive to external homogenous magnetic fields.

Applications

• Linear position sensing
• Length measuring systems

Features

• Magneto resistive position sensor based on the AMR effect
• Strong field sensor for 5 mm N/S pole pitch
• High interpolation due to a sine signal with few harmonics
• Low saturation field strength
• High amplitude consistency with changes in distance
• Resistant to strong magnetic fields
• Not sensitive to external homogenous magnetic fields

When the Sensor is moved along a magnetic scale with a N/S pole pitch of 2mm the two Wheatstone bridges generate differential sinusoidal output voltages (PSIN – NSIN) and (PCOS – NCOS) phase-shifted at 90°. One sine/cosine cycle averaged using a pair of N/S poles is thus produced for a pole width. The absolute magnetic field strength must be large enough for the sensor to go into saturation and for the magnetization of the iC-SM2L's resistor to assume the direction of the outer magnetic fields.

The amplitudes of the differential output voltages are largely independent of the magnetic field strength and thus not sensitive to changes in distance

iC-SM2L is resistant to strong magnetic fields and not sensitive to external homogenous magnetic fields.

Applications

• Linear position sensing
• Length measuring systems

Features

• Magneto resistive position sensor based on the AMR effect
• Strong field sensor for 2 mm N/S pole pitch
• One sine/cosine cycle per pole width (averaged using a pair of N/S poles)
• High interpolation due to a sine signal with few harmonics
• Low saturation field strength
• High amplitude consistency with changes in distance
• Resistant to strong magnetic fields
• Not sensitive to external homogenous magnetic fields

Bimba Manufacturing Company is pleased to reintroduce a new Giant Magneto Resistive (GMR) Switch. The Bimba GMR Autoconfigure Switch's patented auto-detect feature automatically configures switch circuitry to function as a sinking or sourcing switch. This switch is now applicable to EF1/EF2 cylinders; Twin Bore and PneuMoment actuators; Ultran Slide and High Load Ultran Rodless cylinders;and 5/16" and 7/16" bore Original Line cylinders. Benefits to GMR technology include:

Low symmetrical hysteresis yielding equal operating windows independent of travel; 4mm round sensor slides in a track in the envelope of the actuators, does not protrude; Solid state reliability and built-in fault protection; Fast response rate — 0.10 millisecond. This solid-state switch uses new giant magnetoresistive (GMR) technology to offer more features and functionality in the smallest package of any actuator position-sensing switch. In fact, the switch fits in a track located within a cylinder's geometry and does not protrude. GMR Autoconfigure Switch models are available in two pigtail lead lengths or Quick Connect option with two cable lengths.

For more information, please contact a representative at Bimba Manufacturing Co.

Temper Corporation manufactures custom magnetic speed sensor assemblies using magnet ring technology which can be supplied with various sensor technologies icluding hall effect, reed switch, and magneto resistive switches. These assemblies can also be supplied with industry standard connectors including fly leads, cables, Turck, Deutsch, Amp, Packard Electric, Yazaki, JST, Molex, and others. The Temper Speed Sense Magnet Ring is typically press fitted onto a shaft or hub. Materials include a stainless steel body with a range of magnet materials. Diameters are from 25mm to over 2 meters with low to high multi pole resoltuions. These rings are ideal for speed control, direction and steering sensing, counting applications, and incremental encoders. Typical applications include hydraulic motors, elevator systems, fork lifts, power transmission, and other heavy equipment.

Ultra MSI's revolutionary MAGTRACK™ trackball has the ability to be completely submersible. Its non-contact magneto-resistive sensors and PCBs are fully encapsulated in a waterproof resin to ensure that the unit is fluid-proof. What makes MAGTRACK™ different from competing trackball products is the fact that it utilizes encapsulated magnets and electronics in place of encoders. Also, there are no foam drive units to get worn.

MAGTRACK™ can be used in commercial and military applications that encounter wet environments such as construction vehicles, amphibious vehicles and naval vessels. It is ideal for commercial or industrial applications where fluids like coffee, liquid cleaners or other types of liquids can infiltrate existing electronic controls.