AH49E Hall Effect Sensor Connections

AH49E Hall effect sensor - breadboard
AH49E Hall effect sensor – breadboard

Two lots of linear Hall Effect sensors arrived from halfway around the planet, labeled AH49E and OH49E, and roughly corresponding to the original Honeywell SS49E. The Honeywell datasheet has a non-obvious pinout diagram (that one is better), so I poked one of them into a breadboard and tried it out.

Fortunately, I got it on the first try. Facing the tapered side, with the leads downward, pin 1 is on your left:

  1. Power – typically +5 V
  2. Ground
  3. Output – 0 gauss = 2.5 V

The chip [may | may not], depending on which datasheet you use and which part you have, include an internal 65 μA load on the current source, so you [may not | may] need an external load resistor.

Without a load resistor, this one worked fine. Old-school ferrite and ceramic magnets push it about 1 V off-center, neodymium magnets saturate the output.

That Honeywell / Micro Switch handbook should dispel many misconceptions about proper use, calibration, polarity, and suchlike.

Memo to Self: verify the output voltage for both units with typical load resistors.

9 thoughts on “AH49E Hall Effect Sensor Connections

  1. I like your blog, but here are my thoughts. Your continued use of ‘that’ when referring to hyperlinked objects irks me. I think you should use ‘this’, just like everyone else on the planet. Naturally, you are free to disagree, but you might not even know you are doing it (or that it irritates anyone).

    1. you might not even know you are doing it

      Oh, no, that’s a very deliberate decision.

      The word “this” identifies an object right here in front of me that I can touch: this calculator, this book, this pencil. The word “that” specifies an object at a distance: that chair over there, that car in the driveway.

      Hyperlinks, by their very nature, identify information out of the narrative flow which you must leave to visit: they refer to that page over there, not this page right here.

      Believe it or not, I’m not making, mmm, this stuff up. More than you probably want to know is, uh, over there.

      So, as far as I’m concerned, everybody else has it wrong… and I can prove it! [grin]

      1. I figured you were doing it on purpose, just to annoy everyone. And I don’t doubt you believe you can fully justify it.

        Furthermore, I agree. The information isover there. But the link is right here.

        1. Sounds like we’re in violent agreement over everything except whether the demonstrative refers to itself or the target.

          In common use, pronouns transfer a characteristic of the object into the sentence. For example, “Those smell bad!” requires a plural verb even though there’s only one pronoun. If I understand your (and, I suppose, everyone else’s) reasoning, every pronoun would require a singular verb regardless of the object number, because there’s only one pronoun: “Those smells bad!”

          Similarly, I think “This manual has more details.” just doesn’t work, because the manual isn’t right here. The pronoun certainly appears here, but if that’s the criterion we wouldn’t need any demonstratives signifying distant objects over there. So I go with “That manual has more details.” and generally trim it to “that manual”.

          I’m pretty sure you say it that way, too, and might even point across the room to show me which manual you mean.

          If we keep this up, neither of us will ever read a web page in peace again… [grin]

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