Author Topic: Hall Sensors  (Read 8636 times)

Offline Just

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Hall Sensors
« on: January 25, 2013, 09:44:47 PM »
Hi All,

Is it possible that ALL of the Hall Sensors fail at the same time? How may it happen?

Thank you!

Offline Lollandster

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Re: Hall Sensors
« Reply #1 on: January 25, 2013, 09:54:05 PM »
They do share common +5V and GND, you should check those.
« Last Edit: January 25, 2013, 09:56:00 PM by Lollandster »
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Offline Just

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Re: Hall Sensors
« Reply #2 on: January 25, 2013, 10:02:44 PM »
yes, I checked GND and +5V coming to the sensors and they are okay... But, the sensors are not responding to the motor rotation - their outputs are always 0V... Should one of them provide 5V in any motor position, should them? How may it happen that all of them failed at once? I don't understand that...

Offline MAGICPIE3FOCUSPOWER

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Re: Hall Sensors
« Reply #3 on: January 25, 2013, 10:38:23 PM »
How did you meaure?

Offline Just

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Re: Hall Sensors
« Reply #4 on: January 25, 2013, 10:53:36 PM »
1) firstly connected 5v supply to BLACK and RED wires coming from the motor
2) tested that all the sensors receive this 5V supply
3) output wires from the sensor are coded with BLUE, GREEN and YELLOW colors. So, I measured voltages between the following pairs:
BLACK-BLUE
BLACK-GREEN
BLACK-YELLOW
All these pairs gave me 0V. I trietd also to slowly spin the motor in both directions - nothing was changed...

Are my measurements correct?

Thank you!

Offline MAGICPIE3FOCUSPOWER

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Re: Hall Sensors
« Reply #5 on: January 25, 2013, 10:59:24 PM »
You have to measure between red and the hall outputs.

Offline Just

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Re: Hall Sensors
« Reply #6 on: January 25, 2013, 11:17:54 PM »
Why between the RED and Sensor Outputs?  Why will measurements between the BLACK and Sensor Outputs not work?

What voltages should I measure between the RED and Sensor Outputs?

Should one or more of the hall sensors provide 5V in any motor position?

Thank you!

Offline Morgen 3Eman

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Re: Hall Sensors
« Reply #7 on: January 26, 2013, 01:14:20 AM »
Hi Folks,

Did you connect  the positive 5VDC supply to the red or the black?  Which lead you use as reference for the meter makes no difference except for the signal sense will be reversed. 

TTFN,
Dennis

Offline Morgen 3Eman

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Re: Hall Sensors
« Reply #8 on: January 26, 2013, 01:19:45 AM »

one more note: 
Conventionally, Voltmeters are connected with the negative or ground lead (usually colored black,)  connected to the neutral, ground or negative power supply.   But in actual usage, it doesn't matter electrically, only to your brain.  By the way, did you have the meter set to measure Volts DC?

TTFN,
Dennis

Offline Just

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Re: Hall Sensors
« Reply #9 on: January 26, 2013, 01:56:48 AM »
Quote
Did you connect  the positive 5VDC supply to the red or the black?
5VDC to RED, GND to BLACK

Quote
Which lead you use as reference for the meter makes no difference except for the signal sense will be reversed. 
BLACK from Multimeter to BLACK of the Sensor, RED from Multimeter to Sensor's Output pin.

Quote
did you have the meter set to measure Volts DC?
sure
« Last Edit: January 26, 2013, 01:58:28 AM by just »

Offline MAGICPIE3FOCUSPOWER

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Re: Hall Sensors
« Reply #10 on: January 26, 2013, 08:32:57 AM »
Why between the RED and Sensor Outputs?  Why will measurements between the BLACK and Sensor Outputs not work?

What voltages should I measure between the RED and Sensor Outputs?

Should one or more of the hall sensors provide 5V in any motor position?

Thank you!

Between black and hall outputs you will see hall outputs, but it's only from 0.7V to 0V because of the design of the sensors?

Between red and hall outputs you should see the hall outputs voltages.
This voltage should almost the same voltage that is supllied to the sensors.

This is how I had measure my motor.

Yes one or more sensors should give a output.
« Last Edit: January 26, 2013, 08:36:41 AM by MAGICPIE3FOCUSPOWER »

Offline Morgen 3Eman

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Re: Hall Sensors
« Reply #11 on: January 26, 2013, 11:51:34 PM »
Hi Folks,

Sorry if I'm becoming a pain, but I have to disagree again.  The output swing of Hall sensor signals should be from nearly zero Volts to nearly the positive supply voltage.  That is about 0 VDC to about +5VDC.   My experience makes me think of "about" to mean +/- .1-.3 volts.  If you are actually measuring 0.0 VDC at the sensor output, that reading leads me to think you have no voltage applied to the sensors. 


Have you actually measured +5VDC at the sensor?  From the measurements so far, you could have an open circuit in the supply side to the Hall devices, or, less likely, a short which is shutting down the 5 V supply. 

TTFN,
Dennis


Offline Just

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Re: Hall Sensors
« Reply #12 on: January 27, 2013, 12:06:41 AM »
Quote
Sorry if I'm becoming a pain
you are, but we are very patient and polite  ;) your helpful comments are always welcomed :-)

Quote
Have you actually measured +5VDC at the sensor?
Yes

Quote
you could have an open circuit in the supply side to the Hall devices, or, less likely, a short which is shutting down the 5 V supply
could you please explain it a bit more?

Thank you!
« Last Edit: January 27, 2013, 12:11:09 AM by just »

Offline Morgen 3Eman

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Re: Hall Sensors
« Reply #13 on: January 27, 2013, 04:09:21 AM »
Hi Just,

For reference sake, I used to be very well paid to trouble shoot problems ranging from electronic devices to manufacturing processes.  And, of course, I'm much taller on the internet.

That being said:

The probability of three semiconductor devices failing at the same time are much lower than the probability of a single failure that affects three semiconductor devices.  For instance, if there was a bad solder joint in the +5VDC supply line that prevented the supply of current to the three Hall devices, your symptoms would be the result.  If you have measured +5 vdc at the power input pin of the Hall device, and the ground pin measures 0 VDC, and you still get 0.0 VDC at the output pin of that device, then the device has failed or the  53 ? magnets in the rotor have failed.   Being mislead by symptoms many times has taught me to be suspicious of readings of exactly supply voltage or 0.0.  Being mislead by people has taught me to be suspicious of human error in obtaining readings.  Like not having the ground lead of the meter actually connected to ground, but an open pin,or the meter set to VAC while measuring a DC circuit,  etc.  I'm sure you are too smart to commit such a silly error, but when I was young and terribly stupid, I made such simple mistakes.  Is there any chance you may have momentarily applied reverse voltage to the devices?  That would likely fry the three devices.   A high static charge on your body when touching the power or signal lines could kill them, etc.

TTFN,
Dennis








Offline Bikemad

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Re: Hall Sensors
« Reply #14 on: January 27, 2013, 08:36:11 PM »
The probability of three semiconductor devices failing at the same time are much lower than the probability of a single failure that affects three semiconductor devices.

As all three hall sensors are connected in parallel with each other on the power supply and ground connections, it would seem likely that a high voltage has somehow been applied to all three sensors via the red +5V lead.
Human error (or a momentary voltage surge from the 5V regulator chip on the controller circuit board) could easily allow full battery voltage to go directly to the sensors, which would destroy all three of them in a fraction of a second.  :o

Incidentally, the +5V supply to the hall sensors is also shared by the throttle hall sensor and the pedelec sensor. The throttle sensor is housed within the throttle control unit, which also has full battery voltage being supplied to circuit board of the LED battery gauge.
There have been instances where the motor has suddenly started to run at full throttle when water has accumulated inside the throttle control, or throttle connector.
If the water can allow the voltage to flow from the battery gauge feed to the throttle output, presumably this could allow excessive voltage on the +5V supply which could ultimately damage the motor's hall sensors if it became too high.
If the +5V wire and the Battery Gauge supply wire chaffed against each other, this could cause a similar problem if the insulation became damaged enough to allow the inner copper wires to touch.

Alan