Instructables

I need help identifying a hall effect sensor

I'm working with a brushless motor with a 3 hall effect sensor feedback ring and I messed up one of the sensors while removing some potting. I need a replacement. I've tried contacting the manufacture of the motor but they won't respond.

The sensor looks like a flattened version of a TO-92 with chamfered edges instead of a rounded face to indicate the front side and .1" lead spacing. The only markings are U18 020 (or possibly U1B). It looks like it might be from http://www.utc-ic.com/product/db/hall.php but the part numbers don't all match although the datasheet looks like it might match. http://www.scribd.com/doc/52101789/U18-Hall-Sensor-Fan

It doesn't seem like places like DigiKey or Mouser sells Unisonic parts so I may need an compatible alternative which would be fine If I can figure out the specs.

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samaddon1 year ago
try this!
i don't know where it's available but i have an alternate option just take a heavy soldering iron at it's highest temp. and try to solder the broken pin its may work!
Try here
http://www.maxim4u.com/
or
UTC Unisonic Technologies
the data sheet at the second link looks right.
Okay, this may or may not be what you are looking for. Similar shape, and same package but it is a bit different. Supposedly, it is manufactured by a company known as Melexis. I am no expert but it seems that this may lead you in the right direction...hope this helps.
frollard2 years ago
I googled 'u18 hall effect sensor'
and got digikey suggesting 3-sip piles of components...

http://www.allegromicro.com/en/Products/Part_Numbers/1324/1324.pdf
being the datasheet for the first result, which has the chamfered edges like the one pictured... I would guess its a good start.

1.86 each, minimum purchase 1, with 1500 in stock.

AnotherBrian (author)  frollard2 years ago
I did search for that but I found that apparently there are linear and latch sensors, also with different sensitivities. I have never worked with these sensors before so I'm not sure how critical these properties would be when used with a brushless motor controller.

I did hook it up to 6v and slowly turned the motor with a volt meter on the output. It puts out between .3 and 15 mV and it sure looks like it has a latched output.
Ahh, the google-fu is strong in this one!

But, ...
even though I tend to agree and the device might work, it is probably not the one depicted by the OP:
On page 11, it says about the marking on the UA Package
A = Supplier emblem
N = Last three digits of device part number
(depicted is the Allegro-Logo-A above the N)

So the device number should end in 020 (according to the given photo) while the PDF is for devices A1324..25 and there is no Allegro-A.

So, AnotherBrian, if you can get no better advice and you can get hold of the Allegro part easily, just try it.
Indeed, I didn't DIG in the results, just found that indeed many exist and digikey carries all of them :D

Searching the parts deeper will definitely help