Subject:
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Re: hall effect
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Sat, 15 Jun 1996 18:44:32 GMT
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Original-From:
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Chuck McManis <cmcmanis@IHATESPAMnetcom.com>
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Reply-To:
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CMCMANIS@NETCOM.COMsaynotospam
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Viewed:
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1985 times
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I've found the Hall Effect switches that All Electronics sells to be
quite useful. Their part number is the HESW-2 and they are 75 cents
each, or 10 for $6.50. (100 for $60.00). They are easily activated
by the micro magnets that Radio Shack sells (part #64-1895). These
magnets are about .25" in diameter and .125" thick. They are
Neodymium-Iron-Boron and put out 35,000 Oersteads.
Connecting the hall effect switches is easy, they have V+, Gnd,
and Out, leads. They look like transistors and are sensitive to
flux passing through the side of the case. Nominal hookup is
+5, Gnd, and then output connected to an input port that is
pulled up by a 47K resistor. This is identical to the miniboard
input set up. **NOTE** however that these switches are mostly
_latching_. Thus when the north pole of a magnet passes near them
they go "high" and when the south pole of a magnet passes near them
they go "low". This meant on the Cougar that four magnets in the
wheels alternately south pole up and north pole up, would produce
a two up and two down transistions per revolution. And I say mostly
since out of the approximately 30 I've gone through I've found two
that were *not* latching. So check them before wiring them in.
All Electronics' number is 1-800-826-5432 (orders) and
1-(818) 904-0524
--
--Chuck McManis http://www.professionals.com/~cmcmanis/index.html
All opinions in this message are those of the author. No warranty as to
the suitability or accuracy is stated or implied. Use at your own risk.
cmcmanis@netcom.com +1.408.524.4805
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Message is in Reply To:
 | | Re: hall effect
|
| Hi Ya, I'm looking at the Digi-Key catalog (also availible at (URL) and they have several flavors of rotary encoders from $3.38 (24 pulses/360 degree mechanical encoder) to $41.20 (128 pulses/360 degree optical encoder) with the cheapest optical (...) (28 years ago, 15-Jun-96, to lugnet.robotics.handyboard)
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