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Thread: What signal do I get from a Hall sensor?

  1. #1
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    Question What signal do I get from a Hall sensor?

    Just wondering about the possibility to control my power seats with Hall sensors connected to the actuators and make a memory function.

    Each seat has 8 actuators and a pump with 4 valves for lumbar support. I already gathered it is possible to control this from a touch screen using the Fusion Brain.

    It would be neat to make the memory function work too. But how? There would have to be a set memory-function and a way to make the computer go in the right direction when the memory position is called up.

    Could this be done with one module? I guess not, 8 analogue i/o is not enough?

    What signal is the Hall sensor putting out?

    Dont think the lumbar support has Hall sensors so it can be left out.

    Oldspark r u out there? It´s the other swede here again. Worked fine with the transistors and all but now I´ve moved up to car computers

  2. #2
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    I believe Hall sensors measure magnetic variation through voltage. In a DC motor (probably what your actuators are using), the voltage varies when the motor spins. Counting the variances gives you a precise measurement of the number of turns the motor makes.

    So, if I'm right (ha!), your Fusion Brain should measure the voltage from a Hall sensor and increment a counter each time it varies. It should also know which direction the motor turns so it can increment or decrement the counter.

    You can probably calculate that something like 100 turns = 1" or some ratio you want. You store those values in a location that you can retrieve and you can set the seat to the desired location.

    Hall sensors can also be used as proximity sensors, so there may be some in the actuator that tell you if it is extended or retracted. There may be some way to determine from the readings exactly where each actuator is located, but that will take some figuring.
    Quote Originally Posted by ghettocruzer View Post
    I was gung ho on building a PC [until] just recently. However, between my new phone having internet and GPS and all...and this kit...Im starting to have trouble justfiying it haha.
    Want to:
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  3. #3
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    The output depends on the Hall Sensor.

    The Hall sensor itself puts out a DC signal - eg UGN3503.
    But Hall Modules include circuitry to convert this to a pulse or step output - eg HKZ101 (for vane-type automotive ignitions).

    (Stricly speaking, the sensors all output an offset-AC (ie DC) signal, but Modules are often called Sensors, hence more confusion - ie, AC, DC or Digital outputs.)



    PS... NOW that I read your post in detail.... (Tjäna!) (Spelling?)

    I was thinking stepper motors...
    Then I figured if they are power seats, wouldn't they be using stepper motors? (Steppers are controlled by pulses - each pulse is x-degrees rotation.)

    Otherwise if dc motors....
    Maybe optical pickups on shaft or disc (chopper or white mark etc)?
    Or Hall Effect (spinning rotor or shaft magnet)?
    Or maybe back-EMF sensing (to determine number of motor rotations) - but I'm real rusty on that stuff.

    But steppers would be ideal.
    And some Reference marks/system to know where you are....

    That's just off the cuff...

    (Måste fika först!)
    (And for others - "Must fika first" is not as disgusting as what I first thought when my cousin first suggested it. Spelling errors aside, it merely means "to coffee". Honestly, does the rest of the world still think Sweden is.... All those movies were Danish; now they are American. Besides, I had a girlfriend at the time!)

  4. #4
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    Great-now I know less then before

    I will do the right thing and measure every way I can to see if I can get any lead on the sensors. Then you will have the a better way to figure it out. I understand the question is not easy to answer from the data given in my first post.

    I think DC motors. I run them with polarization change (spelling?) and they work fine. There is two more cables from each motor so I figure this is the Hall sensor cables.

    But I was under the impression the sensors were changing value in one range from min to max witch would have been easier to get to work with the memory function. Like a potentiometer I mean. If they count pulses-how do they know were they are when you start your car and call up your favourite seat position?

    Off thread:ku--akr- the one and the same-but you figured that out already Oldspark? Now it´s fikatime.

  5. #5
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    Update from wiki about hall sensors: They are used in brushless DC electric motors to detect the position of the permanent magnet.

    Seems they need some interface too.

    And they count pulses.

  6. #6
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    You don't know less - you just realise more.
    That's the beauty of intelligence - improvement. (It made a misery of my life though!)

    You are quite correct about Hall Sensors outputting a variable signal. Even the UGN3503 "sensor" that I mentioned is a Hall sensor with added circuitry - though its output voltage still varies with magnetic flux density.
    There are some good Hall pics somewhere - but not the Wiki nor UGN3503 datasheet references that I was thinking of.

    (Vane sensors like the Siemens HKZ-10x series are a magnet on one side and a UGN3503-type sensor with "squaring" circuitry on the other. A ferro-metal vane with slots passing in between changes the output to high or low. It's like a photo-interuptor, but magnetic. They are about $20 each compared to the $4-$5 UGN3503.)


    But motors are confusing these days.
    If they are brushless, they are really AC motors. Computer fans are brushless and - although DC powered - are dc-ac converters that drive an ac motor. Modern fanshave tacho outputs so the PC can measure their speed. (I think these measure the rotational speed - not the AC pulses - ie, if you stop the fan, it measures zero RPM - not the x00 RPM the dumb-controller is sending it.)


    Stepper motors use pulses. Each pulse rotates it a certain angle. To keep rotating it, you send a stream of pulses. The frequency varies the speed. (To reverse direction, reverse the winding polarity; two methods/types exist.) You can usually "feel" steeper motors by their "clicky" rotation (when done manually).


    And then there are dc motors, usually commutated (brushed) series wound motors...


    Maybe if I/we find the type of seats and their motors....
    Or if they are the common motors as found in window winders etc (probably not for position-knowing seating systems..??)...?


    Tangentially... I'm better now after my fika. And after taking yesterday's missed (distemper) tablet.

    But I'm non the wiser with ku.... - all I can think of is kuk....
    And I'm also thinking jfets. But give me time....
    As long as it isn't a repeat of so-called LED-expertise - that made even the Danes look intelligent. Despite the serious nature of that national embarrassment, it isn't hard for any Swede to make up for that. Just like women beating men - it's so easy! (Even when we put up a guard LOL!)

  7. #7
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    Well I didn´t see that one coming.....but good you remember some swedish
    (don´t jump on the danes-they make good beer...and I´m not the led guy)
    I used to ask dumb questions on the 12v forum. The solution I got from there helped me to a working solution with manual control of the seats. But that´s not fun anymore so it´s tim for fusion brain.

    I will see if I can find any markings on the motors and look into the wds scematics if I get any clues there.

  8. #8
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    If you know how to control the seats manually, can't you simply replicate that control using a PC and Fusion Brain?
    Quote Originally Posted by ghettocruzer View Post
    I was gung ho on building a PC [until] just recently. However, between my new phone having internet and GPS and all...and this kit...Im starting to have trouble justfiying it haha.
    Want to:
    -Find out about the new iBug iPad install?
    -Find out about carPC's in just 5 minutes? View the Car PC 101 video

  9. #9
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    The issue is the memory...

  10. #10
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    You are both right! And maybe I will stick with the control from FB. Just have to build it first............

    But getting the memory to work..............cooooooooool

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