Variable reluctance

MMT has developed a family of position sensors using a variable reluctance to generate the required magnetic amplitude variation. In that case, the permanent magnet and the Hall probe are stationary and the motion of a rotor made of soft magnetic material is detected according to the variation of the airgap. Such variable reluctance sensors have the following characteristics:

• Digital or analog output signal according to the choice of the Hall probe
• Zero Gauss principal (bi-polar magnetic field variation allow the use of the most standards Hall probes and ASICs)
• True Power On sensors
• Compatible with automotive requirements
• Programmable through the connector (gain, offset, temperature compensation,...)
• Specific features for analog design:
• Minimum mechanical gap up to 3 mm
• Target profile variation up to 3.5 mm
• Rotary stroke up to 320°, linear stroke up to 200 mm
• Possible adaptation of the target profile to customize output signal variation (linear, quadratic, exponential, ...)
• Non linearity below +/-1% of the stroke on the automotive -40°C to 150°C temperature range
• Specific features for digital designs:  
• Extended mechanical gap operation from 0 to 3.5 mm between Hall probe and one teeth
• Typical error: +/-0.2° (mainly linked to the target dimensions) 

More information available on demand

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