Sensitive Hall sensor for wheel speed measurement

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avandalen   10 W

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Sensitive Hall sensor for wheel speed measurement

Post by avandalen » Oct 13 2017 7:51am

Bicycle speed measurement is generally done with a spoke magnet and a reed relay sensor. If this is done on the rear wheel, there is a large spacing between the spoke magnet and the chain stay, where the sensor is mounted on. Therefore, the sensor has to be mounted on a relatively long bracket to minimize the distance. Since the sensor has to be adjusted precisely, this makes it vulnerable. With the use of a strong ring magnet and a sensitive Hall effect sensor, the distance is not critical anymore and the sensor can be mounted directly on the chain stay. A sensor-magnet distance of 30mm is allowed.
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http://www.avdweb.nl/solar-bike/mechani ... ensor.html

LanH   1 µW

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Re: Sensitive Hall sensor for wheel speed measurement

Post by LanH » Oct 13 2017 7:53am

Very nice job. I also checked your website

d8veh   100 GW

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Re: Sensitive Hall sensor for wheel speed measurement

Post by d8veh » Oct 16 2017 5:40am

You can also just stick another N52 magnet to the normal spoke magnet. It brings it a bit closer to the sensor and provides a much bigger magnetic field for it. It's own magnetism will hold it in place - no need for glue or anything like that.

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