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Hall effect threshold circuit? Answered

For a project that I'm building, I'm using an A1302 hall effect sensor. My goal is that if the sensor senses a magnet closer to it than a fixed threshold, it will pass a voltage through a relay (that would act as a Z axis endstop for my 3d printer). What would be the simplest way to achieve it, without using any microcontroller or anything more complicated than resistors capacitors and transistors, , without frying the components with the PSU, and with a high sensitivity?
Thanks in advance!

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iceng

Best Answer 3 years ago

Please click on the pic to see the entire image...

hall-effect-switch.png
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yonchiceng

Answer 3 years ago

Thank you so much! I'll try it as soon as the parts arrive. Will it work for 5V/12V? That's what my PSU supplies.

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icengyonch

Answer 3 years ago

5v to 6v Yes... 12v NO ! because the A1302 is a only a 6 volt device..

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Downunder35m

3 years ago

Just as an alternative:
All good 3D printers either use mechanical or optical endstops for a good reason - you might want to try it ;)

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yonchDownunder35m

Answer 3 years ago

After about a year with a micro switch I've decided to find a different method. I had to re-adjust it after every few prints. What kind of optical switch is normally used?

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iceng

3 years ago

You will need a disengage feature to be able to move out of the overun axis Estop.

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Downunder35m

3 years ago

Simply use a purpose build sensor, available from many suppliers....
Connect to 12 or 24V, adjust the output as (distance) as required and off you go.
Easier to use on a metal bed than trying to produce a magnetic field throughout the plate that a hall effect sensor can detect.
Keep in mind they detect magnetic fields ;)