a weird hub motor

[snickerzz]

I have a hub motor from a smartdrive MX-1 wheelchair assist. I want to use it separately from it's controller. I can't find too much information. I know its a 250w 24v geared brushless motor. the connections have 3 standard phases and a 6 contact connector for the hall sensors. I think one of the wires is temp or speed feedback (probably temp). the weird part is that the connector on the original drive board for the hall effect sensors says 3.3 volts instead of 5. I can't find any motors that use 3.3 as a comparison or much information on common hall sensors that will normally operate on 3.3v. I'm not sure what to do since so many controllers like to output 5v for the hall effect sensors. what to do???

(what I am trying to do is route around the given controller to just use a throttle and a dead man's switch cutoff for a caregiver to drive from the back of the chair. the motor is a omni wheeel which allows turning while still providing forward power).

thanks,
snick

 

[e-beach]

You could put a resistor inline on the voltage input wire. Check out this website and see if it helps. Also look at other resistor voltage calculators and see if they concur. Just know that a 3.3v return on a 5v wot throttle expectancy from the controller will give you less then wot speeds.

https://elecurls.tripod.com/drop-res.htm

The other thing you can do is to open up the motor and try to identify the actual hall sensors and check their data sheet for actual specs.

 

[amberwolf]

the connections have 3 standard phases and a 6 contact connector for the hall sensors. I think one of the wires is temp or speed feedback (probably temp). the weird part is that the connector on the original drive board for the hall effect sensors says 3.3 volts instead of 5. I can't find any motors that use 3.3 as a comparison or much information on common hall sensors that will normally operate on 3.3v. I'm not sure what to do since so many controllers like to output 5v for the hall effect sensors. what to do???

You can check the hall sensor part number actually installed in the motor to find it's spec sheet. It's very likely that they can be powered with 5v, but I'd check first before trying it. (some can handle well over 5v on the power supply, and most are open-collector output so handle much more than that on the signal wires).


Note that there are some rotor position sensors on powerchair motors that are not UVW hall sensor systems at all, but rather SIN/COS (and possibly some systems use other sensors); these are not compatible with typical ebike controllers, but you could use a sensorless controller on them and just ignore all the sensor wires.

As an example I have an invacare brushless direct drive motor using SIN/COS, but I was able to add UVW hall sensors to it to operate it from a standard ebike controller: (didn't have a sensorless to try back then)
https://endless-sphere.com/forums/viewtopic.php?t=32838

 

[snickerzz]

I just threw a couple of 1n4001 diodes inline with the 5 v. this seemed to do the trick, but then I realized that my sensors had disconnected and it still worked. I decided to go sensorless for now. I suspect these sensors could handle the 5v since I can't find any sensors that would only accept 3.3 and burn at 5v.

thanks for the advice. It spurred me to just get started.

R,
snick