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Fried Hall Effect Throttle Sensor

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cdw3423vesc
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Joined: 2018-09-28 02:59
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Fried Hall Effect Throttle Sensor

I have built a power assist device for manual wheelchairs similar to a commercial product called SmartDrive MX2.  I was running my first test the other day and after hitting a bump at speed.  After which the throttle stopped responding.  After I power cycled the VESC the throttle started working again.  Later after hitting the same bump at about the same speed the throttle stopped working again.  This time I couldn't get it working again.  I hooked the VESC to my computer and it runs just fine.  A volt meter across the contacts of the hall effect sensor didn't show any change in voltage when moving it.  I also checked the resistance on the contacts.  It was about 1.2k From either black or red to white and and 400k from red to black.  My new hall effect sensor has 500m ohms from red or black to white and open circuit between red and black.  I haven't had a chance to test the new throttle.  

I'm using a Flipsky 6 VESC to run an APS 6374S 60KV Sensored Outrunner Motor.  The Throttle was a basic thumb throttle I bought from APS with the motor.

The Throttle was mounted to a hinged handle bar with brake levers for disk brakes I use to steer with.  So I don't think hitting the bump would have caused a significant shock to the throttle.  However the way the drive is mounted to the wheelchair, the wheel could have easily come off the ground for a short time unloading the motor and then of course putting back under high load when it came down again.  I was wondering if this could have caused some kind of voltage spike that fried the hall effect sensor, or do you think it was just a fluke that it happened when I hit the bump?

Any ideas?

Chris W

cdw3423vesc
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Last seen: 5 years 7 months ago
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Quick update.  It seems the AD channel 1 on the VESC is fried.  It always has about 2.8V on that pin no mater what I do with the new thumb throttle, however if I disconnect the signal wire for the Throttle from the VESC the voltage on the signal wire does vary as expected when you move the throttle.  I moved the wire over to ADC2 and it seems to work there.  Is there a way to tell the VESC to use channel 2 for the throttle?   It shows the voltage on channel 2 on with vesc-tool I can see what is happening with channel 2 but I don't see how to tell it to use that channel for the throttle.

sam.vanratt
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Last seen: 1 year 5 months ago
Joined: 2018-11-18 14:09
Posts: 83

Hi cdw3423vesc

what voltage do you supply to the throttle? 5V and more should be OK as most HALLs starts at 3,8V power supply (up to 30V and more). 3,3 is normally too low. A small voltage divider (10k+20k in serie and get the signal at the crossing) helps to level the ADC input to the max 3,3V it allows (more could damage the input....maybe that's what happend)

I already have two failed (Wuxing and some brand called Shutseng or sth. like that) throttle with both HALL controlled. For a magnetic controlled device the failure is quite unbelievable, but after measuring the output it was pretty clear.

I'm still figuring out how to connect my VESC to my equipment, so I cannot tell you anything about remapping of inputs, sorry.

Cheers

Sam

 

Pedelec usage in combination with a GoldenMotor MagicPie3 BLDC