Mounting GTS - how close is close?

[emmell]

Okay, based on trying to mount our GTS next to Andy Mark transmission gears, it appears that our GTS has to be touching the gear in order to count accurately.

Yes, we have the fixed GTS with the right parts and it is wired correctly because we are getting readings. We're just worried that we will chew our sensor alive.

The range (according to specs) is from 0.5mm to 3.0mm to get a reading and yet we can't get a reading unless the sensor is close to 0.1mm away from the gear.

All help is appreciated.
Mannie Lowe

[TubaMorg]

Are you talking about the kit GTS? Have you tried aiming a different face of the sensor at the gear? Can you post a picture of your setup?

[Matt H.]

Using the kit GTS we have gotten readings from about 1.5mm away. have you tried taking the sensor out of the gear box and spinning a gear on a shaft at variable distances from the magnetic reader and seeing what you get?

[Al Skierkiewicz]

Mannie,
The GTS is sensitive in only one plane. You might want to reorient to gain the max output. The data sheet is here...
http://www.allegromicro.com/en/Products/Part_Numbers/0642/0642.pdf
Page 5 shows the corrrect orientation to the package for gear tooth reading.

[Tom Bishop]

Aha, Al, so you would mount it sort of like this?:

l
l pcb
l
l
SSS sensor
GGGGG gear

we had it in a different orientation...OOOPPPPPPPs

[MrForbes]

that's right...you might be able to see it in this picture, too.

[Al Skierkiewicz]

We don't use one so it has been a long time since I played with it. But I think you will find it works if you change the orientation. Passing a screwdriver tip past the device ought to give an output as well.

[emmell]

To everyone that answered our question here, thank you very much. Indeed, we did have our sensor mounted incorrectly. We are counting teeth like mad now and are very happy.

Thank you again and good luck at your regionals.

Mannie