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Speed sender
tom_loughlin - 26/8/05 at 06:00 PM

Hi chaps,
i have 2 wires coming from my revotec speed sender (both blue) and am not sure what to do with them.

Im guessing one goes to earth, and the other to the Blue red (revotec) wire at the back of the gauge.

Am i also right in thinking that rather than use the magnets, i can use the diff flange bolts to trigger the pulses.

Im starting to get frustrated at my lach of progress today.

Thanks

Tom


Brook_lands - 26/8/05 at 06:49 PM

Tom

I'm assuming you have the small magnetic reed switch sender. As far as I understand it it acts just as an on/off switch as the magnets on the propshaft pass it. In that respect it doesn't matter which way round it is wired.

I suspect that the bolt heads on the propshaft will not produce a sufficently large magnetic field to close the switch. For that you need a hall effect sensor (3 wires) which generates it own magnet field and then counts the number of disruptions, so to speak, caused by a ferrous object ie the propshaft flange bolt head passing through the field.

Possible word of warning, I bought a set of instruments from Revotec at the Stoneleigh show along with the magnetic sensor complete with 4 (very strong magnets) but didn't get round to fitting them until mid July Despite my best efforts I just couldn't get it to function with any sized gap. The chap at Revotec who sold me the set was great, straight-up he said they have had some problems with one of the batches of magnetic sensors, after a number of calls during which he suggest things I might like to try (which I was happy to do) he sent me a hall effect sensor which worked fine first time. Its got a little LED on it which flashes to show its generating a pulse. Only disadvantage is it needs an additional wire to supply the 12v ignition switched supply.

If you still with me on this one. If you've tried the sensor with the magnets on the prop with an air gap of between 1 and 3mm, start at about one and back it off in .5mm steps to 3+mm and you are getting no joy, you could have the same problem as I had.


cerbera - 26/8/05 at 08:46 PM

Hi,
I have just fitted a revotec speedo with the magnetic sender. One of the two wires goes to the speedo the other goes to 12V supply., doesnt matter which way.
I have the gap between the magnets and sender set at 3 - 4mm and everything works fine. Use all 4 magnets supplied otherwise you may get an erratic speedo reading.

HTH