magnetic proximity sensor

In message , Jon writes

Near something magnetic? :-)

Hmmmmmmm...........

Not such a silly reply; a magnetic proximity sensor has a myriad of uses. Please explain what you wish to do.

Regards Jeff

It's for a Speedo pickup. (I think that they're mounted in the bellhousing of modern vehicles and count the teeth.) Jon

On bell housing it would measure RPM, not MPH, unless it knew what gear you were in and made allowances for ratio!

Only a little more help than AndyG, I fear.

David

"> >It's for a Speedo pickup. (I think that they're mounted in the bellhousing

I once had an mpg meter that used a magnet ty-wrapped to the drive shaft, so I guess you could try the same on the propshaft on a L/R, as long as it was not large enough to unbalance it.

Jeff

"Jon" wrote in news:bnb62v$aj8$ snipped-for-privacy@thorium.cix.co.uk:

You may get some help from someone who sells and fits aftermarket cruise control (like Conrad-Anderson -

AIUI, they use magnetic pickups to govern CC where there is no suitable sensor already on the vehicle. HTH,

A cheap alternative is the variety used for distance and speed calculation/metering for bicycles.

Extremely easy to adapt on vehicles either on a halfshaft or a propshaft.

Take care Pantelis

In message , Jon writes

Ahh! I was partially right then - near something magnetic rather than necessarily near a magnet ...

Try somewhere like on a diff nose - it'll need lots of protective gaffer tape but you should be able to pick up a prop-shaft bolt or a corner of the flange. The handbrake drum is possible but is more difficult to get a permanent fixing to.

I wouldn't know how to wire one up but I think you need a Hall effect transistor. I know we use these to count the turbine vanes going past on a lucas apu.

AJH

If it is the same thing you are talking about, when fitting the cruise control speed sensor to my 110 I used the front prop shaft just in front of the top universal. It is fairly well protected by the cross member there, and has survived nearly ten years so far, including a lot of off road. JD