MG Series magnets

The MG Series magnets offered by Honeywell Sensing and Control includes several bar magnets in various sizes and strengths for actuating Hall-effect and magnetoresistive sensor ICs. These bar magnets are for use in sensors with unipolar or omnipolar magnetic characteristics.

Made from different magnetic materials and available in a variety of sizes and shapes, the MG Series magnets can be used for evaluation and design of magnetic systems, and in numerous potential applications across a variety of different industries. Some of these magnets are offered with threaded bushings for easy installation and have a good resistance to demagnetization which could be caused by magnetic shock. These magnets are designed to provide minimum magnetic fields at a specified distance to help system designers match the appropriate magnet to their requirements.

The MG Series consists of a range of magnets based on varying dimensions and packaging types to help customers identify the most appropriate magnet that can be used to evaluate Honeywell’s Hall-effect and magnetoresistive sensor ICs in their applications.

Magnetic sensing characteristics of Hall-effect sensor ICs are specified within particular ranges.

For example, assume an application with a temperature range of -40 °C to 125 °C [-40 °F to 257 °F] using an SS443A. The operate point may be up to 215 Gauss [21.5 mT] and the release point may be 60 Gauss to 190 Gauss [6.0 mT to 19.0 mT]. To ensure reliable operation, at least 215 Gauss [21.5 mT] must be presented to the sensor. For a robust activation, the flux from the magnet at the maximum operating gap should be 20 % to 100 % higher than the sensor’s maximum operating point over temperature. The Gauss level must then be reduced below 60 Gauss [6.0 mT] to ensure that the sensor will release. Therefore, it is necessary to know the flux density (Gauss) measured at the chip to be able to:
• Select a device with the best magnetic characteristics for the application
• Select the best magnet
• Verify the desired mechanical characteristics