I need clarification re the sensor wires on a brushless DC motor and how to test them.

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sapo
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I need clarification re the sensor wires on a brushless DC motor and how to test them.

I have a 250W 36V brushless motor and I want to check that the hall effect sensors are functioning. I read on this site that it is possible to use the diode setting on a multimeter to detect the on/off state of a hall effect sensor. They said put the red lead on the sensor wire and the black lead on earth.

Am I correct in assuming that the black wire in the sensor socket is earth? I tried that and turned the wheel and could not get a low voltage reading which I would expect when the sensor conducts due to the presence of a permanent magnet near it.

I am also puzzled about the role of the red wire if the sensor is merely a magnetically activated diode... Maybe someone could draw a circuit diagram or how the red, black and sensor wires connect to the sensor... is there a pull-up resistor in there or what?

Please enlighten me about the sensor circuit and how to test it.

sapo
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Re: I need clarification re the sensor wires on a brushless ...

Ah! I found an answer here:
http://www.orientalmotor.com/resources/technical-articles/article166-1e.html
See the connection diagram at Fig 14.

So does that mean I *have to* connect a dc supply to be able to check the sensors? Or should I be able to test it with the diode setting on my multimeter. I will measure the supply voltage coming from the controller...

www.beyond-oil.com for electric bikes and scooters.

sapo
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Re: I need clarification re the sensor wires on a brushless ...

Hmmm. Could I have blown the Hall Effect Sensors by putting the multimeter with the diode setting on them? I was under the impression that they were robust. But now I can't get much action out of the motor... :(

www.beyond-oil.com for electric bikes and scooters.

antiscab
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Re: I need clarification re the sensor wires on a brushless ...

the hall sensors should have been fine being measured on the diode circuit.

it is possible they were already dead.

in any case, the way to test them is to have 5v between negative and positive (black and red wires) and measure the output voltage between negative and each phase while the wheel is spinning.

each phase should vary 0-5v or there abouts with the wheel rotation.

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
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Deputydaves
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Re: I need clarification re the sensor wires on a brushless ...

Here's acouple of sites. Good luck!
http://elescooterparts.com/scooters/Schematics/EleThroTest.html

search this site it's very informative you just have to search.
http://www.instructables.com/id/Electric-Bike-Hub-Motor---How-to-Replace-a-Hall-ef/step4/Remove-Failed-Sensor/
I get around without joining.
Good luck
Dave C Stout

Dave C. Stout
STOUT PRODUCTIONS
Low Carbon Products

sapo
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Re: I need clarification re the sensor wires on a brushless ...

Thanks for your help. As it turns out I was laboring under the illusion that connecting the PAS sensor was optional.

No... everything worked fine when I connected it... hmmm.

www.beyond-oil.com for electric bikes and scooters.

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