Hall sensors in a Bionx hub motor

[Mark-Uwe]

Hello everyone,
please help me to identify the hall sensors in a Bionx hub motor (see picture).
I bought the motor on ebay as "not working", i want to build an own controller for it.
It looks similar to e.g. Honeywell SS361RT (pls. google for the datasheet).
I measured resistance between the pins of 2 sensors on the circuit board:
R(pin1-pin1) = 100 Ohm
R(pin2-pin2) = infinity
R(pin3-pin3) = 100 Ohm
R(pin3-GND) = 50 Ohm
Thus, I assume following pin configuration of the device:
pin1 - Vcc (power supply)
pin2 - output signal
pin3 - GND
I applied 10 V between pin1 and pin3 and measured about 0 V to 3 mV between pin2 and pin3 while moving the sensor between 2 magnets. Isn't this output voltage too low?
Did someone handle with this sensors?

 

[Ykick]

Sorry I don’t have anything specific to Bionx but this might help you better grasp Hall sensor operations and a simple, basic, eliminate the controller test.

https://endless-sphere.com/forums/viewtopic.php?f=3&t=57053&hilit=+hall+sensor+resistor

Hall switch sensors can function with minimal components over a wide voltage range. The main thing is around 10k resistor between 5-30V B+ and signal output so that the switching signal has reference to “pull-up”, so to speak… Without that pull-up resistor you probably won’t see any change of state when applying/reversing magnetic field.

As I understand some newer Hall switching sensors may have the pull-up resistor internally but I’ve yet to see one.

 

[slowhands]

You cannot tell from the marking what type or brand of sensor. And you can't tell using an ohmmeter much of anything about this complex integrated circuit. But let's assume that the industry follows some conventions for pinout. Then your guess about power, ground and signal is probably correct. It may be similar to the following TI part:
http://www.ti.com/lit/ds/symlink/drv5053.pdf
This should have a signal swing of 0 to 2V, assuming this is analog. It may be digital, we don't know. But you would have to isolate the sensor, cut it from the circuit, to control power and have the output unloaded. And that is just a tiny part of the controller.

I'm not sure that would be helpful. You don't have schematics for this somewhat complex controller. You don't have code listings. How on earth do you expect to do anything by dissecting it? Even a Bionx tech might be challenged to repair this, having the documents and instruments needed.

You are better off to bypass the internal controller and run this motor using an external sensorless controller. These are not very powerful motors, and I wonder if it is worth the effort?

 

[Mark-Uwe]

@Ykick: Thanks a lot for the advice! I added a 10k pull-up resistor between the pins assumed to be Vcc and OUT, the voltage on OUT changes between two states: 0V and applied Vcc. Its a digital one!

I am interested in a Bionx motor, because it has a sensor which measures the axle bending during pedalling. I wand to use it as input to my controller (that is to be built...). Probably I'll need to put some preamp circuit inside the motor close to that sensor, because of its very weak signal. I'll see...

Thank you very much for the answers!