> > Hello everyone.
> >         I have a few 3 terminal hall effect sensors which i would like
> > to
> > use, but i dont know how to hook them up. any suggestions?
> > thanks.
> >
>         you'll have to give more information than this.
>         they're pretty much all 3-terminal devices :)
>
>         Hall Effect sensors come in many forms. The
>         ones i tend to use are open-collector, and
>         look similar to a transistor (though smaller).
>         Thus, you'd need a pullup resistor.
>
>         There are also open-emitter versions, which
>         generally require pulldown resistors. some
>         have additional output circuitry, such as
>         a totem-pole output stage. There's linearized
>         devices, which put out a signal porportional
>         to the magentic field sensed...
>

> Andre Abelian wrote:
>
> > I use hall effects a lot.
> > there are 2 kinds.
>
> I have worked with a few Hall Effect Detectors (HED), and I am aware of five
> types:
>
>         Unipolar
>         Bipolar
>         Differential
>         Linear
>         Latching
>
> > 1. latched               will turn on(+ north)  will turn off (- south)
> > 2. none latched       will turn on on (+ north) and will turn off when
> >                              there is no magnetic filled or (- south).
>
> I would rather say "goes high or to high impedance" instead of ON, and "goes
> low" instead of OFF.
>
> The Bipolar type is an open drain device, that goes LOW when a magnetic South

> no magnetic field present.
>
> Unipolar devices essentially have a built-in pull-up resistor and thus go LOW
> for South and HIGH the rest of the time.
>
> Latching goes low when it detects a South pole and remains there.  It is my
> belief (but not my experience as I have not used this type) that it will stay
> LOW until the next power-up of the device.  But don't quote me!
>
> Differential has two internal HED's and goes HIGH or LOW depending on which ha
s
> the greatest South pole flux density.
>
> The Linear flavor also has two internal HED's.  But it outputs a differential
> voltage that is analagous to the flux density and the polarity of the
> differential signal will represent which pole.  This is, if the South pole is
> presented, then one output will have the higher voltage, if the North pole is
> presented, then the other output will have the higher voltage.  The voltage
> differential will be proportional to the flux density.
>
> > left pin is +v  | middle pin is GND| right pin is output|
>
> This has been true of the Bipolar, Unipolar, and Differential HED's that I hav
e
> worked with, but I beleive that it is not the case for Linear which have two
> outputs.  In this case (at least with ITT/Micronas) 1 = Vdd, 2 = Out1, and 3 =
> Out2.
>
> I have not used a latching type.
>
> There is a heck of a nice page at:
>
>         http://www.intermetall.de/sensors/overview.html
>
> Best regards,
>
> Michael
>
> * TAKE THE ".NOSPAM" OUT OF MY ADDRESS TO REPLY
> ***********************************************
> It's not what you are that holds you back,
> it's what you think you are not. --Denis Waitly

>Andre Abelian wrote:
>
>> If you ware front of me I would explain it to you with
>> a few words but when I am typing it is different.
>> as long as you understand what I am saying that is
>> the most important thing. I do not use fancy words in electronics
>> unless I am with the girl for me low or off is the same and high
>> or on is the same too.
>
>I wasn't attacking you Andre.  I didn't say that you were stupid or
>ignorant or YELL at you to RTFM.  I said that I would say "high or high
>impedance", which to my mind is clearer than ON.
>
>I believe that different people read and interpret words in different
>ways.  If you have an open drain device, when you say ON, it may mean to
>some that the FET is ON and the output is LOW.  For instance, if there is
>no magent near the HED is it ON?  To my way of thinking (and arguably
>others) the thing is ON when it is LOW.
>
>You are only half right that IF folks understood what you were saying,
>that would be the most important thing.  Equally or maybe more important
>is that you dispense accurate information.  Let's look:
>
>> there are 2 kinds.
>
>Not in my experience.  There are more than two kinds.  I named five.
>
>> 1. latched               will turn on(+ north)  will turn off (- south)
>
>Not in my experience.  It is HIGH at power-up, and goes LOW when a south
>pole is near it -- and then stays LOW.  That is why it is called LATCHED.
>
>> 2. none latched       will turn on on (+ north) and will turn off when
>>                             there is no magnetic filled or (- south).
>
>Not in my experience.  Forgetting momentarily the confusion about what
>"on" is, it will go LOW in the presence of a south pole and turn HIGH or
>high impendance when there is a north pole or no magnetic field.
>
>> all of them have same pin out .
>
>Not in my experience.  As I said in my previous post, the Linear type
>have two outputs.
>
>> most important thing is that output is open drain you need
>> to put pull up resister.
>
>Not in my experience.  This is only true of the bipolar variety.
>
>> assuming that the writing is facing you
>> left pin is +v  | middle pin is GND| right pin is output|
>
>Almost true -- except with the Linear type again.
>
>I am very tired this evening.  It is after midnight and I am in the
>lab trying to apply salve to wounded ego of some poor insecure $#%#@ a
>half a world away who has been slighted by my mildly and politely
>correcting his inaccuracies.  No matter that he didn't have a single
>sentence correct.  It is really too much.  It seems to me that every time
>I post to this list any more at least one dog nips at my heals about
>something.
>
>And what is ROTFL supposed to mean?  Pathetic.
>
>I, for one, have had enough.  I will SIGNOFF PICLIST this evening and let
>the inmates run the asylum.
>
>Ta Ta For Now,
>
>Michael

> Andre Abelian wrote:
>
> > If you ware front of me I would explain it to you with
> > a few words but when I am typing it is different.
> > as long as you understand what I am saying that is
> > the most important thing. I do not use fancy words in electronics
> > unless I am with the girl for me low or off is the same and high
> > or on is the same too.
>
> I wasn't attacking you Andre.  I didn't say that you were stupid or
> ignorant or YELL at you to RTFM.  I said that I would say "high or high
> impedance", which to my mind is clearer than ON.
>
> I believe that different people read and interpret words in different
> ways.  If you have an open drain device, when you say ON, it may mean to
> some that the FET is ON and the output is LOW.  For instance, if there is
> no magent near the HED is it ON?  To my way of thinking (and arguably
> others) the thing is ON when it is LOW.
>
> You are only half right that IF folks understood what you were saying,
> that would be the most important thing.  Equally or maybe more important
> is that you dispense accurate information.  Let's look:
>
> > there are 2 kinds.
>
> Not in my experience.  There are more than two kinds.  I named five.
>
> > 1. latched               will turn on(+ north)  will turn off (- south)
>
> Not in my experience.  It is HIGH at power-up, and goes LOW when a south
> pole is near it -- and then stays LOW.  That is why it is called LATCHED.
>
> > 2. none latched       will turn on on (+ north) and will turn off when
> >                             there is no magnetic filled or (- south).
>
> Not in my experience.  Forgetting momentarily the confusion about what
> "on" is, it will go LOW in the presence of a south pole and turn HIGH or
> high impendance when there is a north pole or no magnetic field.
>
> > all of them have same pin out .
>
> Not in my experience.  As I said in my previous post, the Linear type
> have two outputs.
>
> > most important thing is that output is open drain you need
> > to put pull up resister.
>
> Not in my experience.  This is only true of the bipolar variety.
>
> > assuming that the writing is facing you
> > left pin is +v  | middle pin is GND| right pin is output|
>
> Almost true -- except with the Linear type again.
>
> I am very tired this evening.  It is after midnight and I am in the
> lab trying to apply salve to wounded ego of some poor insecure $#%#@ a
> half a world away who has been slighted by my mildly and politely
> correcting his inaccuracies.  No matter that he didn't have a single
> sentence correct.  It is really too much.  It seems to me that every time
> I post to this list any more at least one dog nips at my heals about
> something.
>
> And what is ROTFL supposed to mean?  Pathetic.
>
> I, for one, have had enough.  I will SIGNOFF PICLIST this evening and let
> the inmates run the asylum.
>
> Ta Ta For Now,
>
> Michael

> >I do not use fancy words in electronics
> >unless I am with the girl for me low or off is the same and high
>
> ROTFL!
>
> Sean
>
> |
> | Sean Breheny
> | Amateur Radio Callsign: KA3YXM
> | Electrical Engineering Student
> \--------------=----------------
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