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Cyclocomputer Sensor & Anemometer Answered

Hy guys, good work here!!! I've an issue to build a sensor for the magnet of a computerbike.. How i have to proceed? I hope i have to connect a solenoid to the computer.. ?

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Gargiuseppe (author)2007-09-14

Ok, i don't want to create problems... i don't know nothing in electronic.. BUT.. The FET transistors have more than 1 input & 1 output... Tomorrow (it's late night in italy) i see if the two pins on the rear side of the cyclocomputer generate a circuit

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Goodhart (author)Gargiuseppe2007-09-14

A little more on Hall Effect Transistors: Hall Effect Transistors

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Gargiuseppe (author)2007-09-14

Yes but... will it work with my outdated Cyclocomputer?? Seems that the way to work is the same... By the way, the central axis with the bearing is ready :D I've also some cups of 2 dimensions.., maybe tomorrow i'll build the anemometer without the sensor :( Ps: Sorry 4 my BAD english.. CIAO da NAPOLI :D

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Goodhart (author)Gargiuseppe2007-09-14

According to this: The sensor A magnet is attached to a spoke of either the front or rear wheel. A Hall effect sensor is attached to the fork or the rear of the frame. The sensor detects when the magnet passes once per rotation of the wheel. Alternatively, a sensor may be attached to the wheel hub. Distance is determined by counting the number of rotations, which translates into the number of wheel circumferences passed. Speed is calculated from distance against lapsed time period. To measure cadence, a magnet is mounted to the crankarm, and a sensor mounted to the frame. it a Hall Effect Transistor (specialty FET) should work as sensor.

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Gargiuseppe (author)2007-09-14

Yes, i want to build an anemometer. I have an old speedometer (for bicycles), and i haven't the sensor...

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NachoMahma (author)Gargiuseppe2007-09-14

. The bicycle speedos I've seen are either mechanical or use a coil/magnet sensor.

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Goodhart (author)2007-09-14

Hmm, on that note, one could incorporate an FET (field effect transistor) to sense the magnetic field, if some degree of sensitivity and speed is needed.

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Gargiuseppe (author)2007-09-14

Ok guys, thanx 4 your replies.
I've found A LOT of infos :D :D
I've a '''Cyclocomputer''' with 2 contacts on the rear side.

I've learned that the sensor work for the [url=http://en.wikipedia.org/wiki/Hall_effect '''Hall effect''']

And how work an '''Hall effect sensor'''

Now i've to think something to realize it

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R3D_EYE (author)2007-09-14

a Reid switch is most likely what you need. Reid switch are activated by magnetic field this process is typically used in by microprocessors in dust or wet environment to detect states (high or low) the Reid switch switches a very small current on and off and the on-board microprocessor counts the pulses to determine how fast the wheel is turning

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Goodhart (author)2007-09-14

The following link may provide some information you need: Forced balance anemometer or not.

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NachoMahma (author)2007-09-13

. What are you wanting to measure? Field strength? Use it as part of a speedometer? ???

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Goodhart (author)2007-09-13

Computerbike, explain please.

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