hall effect switch question

[smpaladin]

Based on this description at
http://www.allelectronics.com/cgi-bin/category.cgi?item=UGN-3030T
I can't tell if the sensor is bi-polar or unipolar. Also, about how
far must a magnet be in order to turn the switch on?

 

[smpaladin]

cfoley1064@aol.com (CFoley1064) wrote in message news:<20041004124612.08241.00001369@mb-m10.aol.com>...

Subject: hall effect switch question
From: smpaladin@yahoo.com (smpaladin)
Date: 10/3/2004 4:57 PM Central Daylight Time
Message-id: <6753235c.0410031357.203f8df0@posting.google.com

Based on this description at
http://www.allelectronics.com/cgi-bin/category.cgi?item=UGN-3030T
I can't tell if the sensor is bi-polar or unipolar. Also, about how
far must a magnet be in order to turn the switch on?



It will work for N or S magnets (I think that's what you mean). If you're
asking about output, it's NPN open collector -- current sink only when on, no
current source.

If you can measure magnetic field strength in gauss, you can look at the data
sheet which is accessible from the link you provided. Otherwise, just get one
and measure it with your magnet. By looking at the data sheet, you'll see
there's some difference between max. and min. turn-on and turn-off values. If
you're looking for extreme positional accuracy, this might not be the part for
you. But for most small magnets, the turn-on points for these integrated hall
effect sensor/amplifiers should be within a few mm. of each other.

Good luck
Chris

So if it's an NPN open collector, it will be turned on only when a
magnet is held over the sensor?