Figuring hall sensor pinout based on these numbers

[badboy1999]

I've got a secondhand wheel with Tranz-X motor (250w 24v it says) but I'm trying to figure out the hall sensor pinout. The motor looks exactly like this BTW from the inside:

Which maybe isn't really relevant since I'm just trying to figure out the Hall pinout which my Kelly controller needs. I took a lab power supply set to five volts, attached a 1000 Ohm resistor to the + of the power supply to limit current to max 5mA, and connected this 5v with a resistor and the 0v to the hall sensor connector in every possible way (6 possiblities for where I put the 0v, 5 for the 5v -> 30 combinations. I measured the voltage over these two hall sensor pins and wrote them down.

My theory is, the voltages are a measure for how much current these two pins are drawing, and I was expecting to find two wires that had a current consumption that was different from the rest and no current consumption (measured as 5v) when wired in reverse. This is based on my understanding the expected behaviour of the power wires going to the hall sensors.

I also expected to find the three signal-wires (it's a standard three phase ebike motor), because I expected them to be closed connections to one of the power pins (lots of current drawn, so maybe 0v it it's a fet inside the hall sensor or ~0.7v if its a bipolar transistor) and open connections to the other power pins. I hope everyone is still following here, my understanding of electronics is not the greatest so please correct me if I'm wrong.

These are the measurements I've got and I'm confused:

Pin 2 and 5 seem special. But they're also drawing current in reverse when only connecting these two pins. In addition, these pins don't have 'special' voltages when hooked up, their voltages (meaning their current draw as well, Ohms law) are very much the same as the suspected sensor pins.

Another confusing thing: they're drawing a lot of current. Either a total of ~2.4mA or 4.3mA.

Third confusing thing: I was thinking one of the six wires was a temperature sensor. But there's just 2 strange wires, and then 4 suspected sensor wires.

I tried using a LED to find out if the suspected sensor wires indeed are sensor wires (rotating the wheel backwards so it doesn't freewheel, 500 Ohm resistor between LED and gnd/plus, tested this on multiple pins, but no combination gets the led blinking when spinning the wheel).

What can I do? All thoughts appreciated!

 

[nutnspecial]

I'm very novice, but was thinking I'd check by taking it apart to trace wires first?
If not, I'd begin continuity testing between the 6 wires while spinning the wheel. 5v power wire should have continuity thru each of the 3 hall wires at certain wheel positions. The 6th wire likely being a temp sensor will only change continuity depending on temp I think. Ground should test to ground I guess.

 

[badboy1999]

Thanks for the suggestions! I tried the continuity testing, with a LED, but with power on 2&5 (and the power in reverse) I couldn't get the LED to light up any which way.
I guess I'll take it apart, but to do it like this seemed more elegant to me

 

[nutnspecial]

Yeah you may be on to something but I can't quite follow.
Did you try your continuity testing with only a standard DMM?

 

[badboy1999]

No, because the hall sensors are supposed to get 5v to power on, so before that continuity testing is a bit moot.

 

[nutnspecial]

Lol, my 'testing' wouldn't have got anywhere then! Applying voltage should/shoulda worked but I was scared to reverse polarity or apply voltage to a possible thermistor. If nobody else chimes in please post up what you end up finding!

 

[docw009]

What's the connector look like? Does it have the typical 2x3 plastic connector? Or is it just bare wires?

I've only seen about a half dozen motors. Some of them had round connectors combined with the phases. Some had rectangular 2x3 connectors with exposed wires. The exposed wires were like this:

red: +5
blk: GND
yellow, blue, green: Hall outputs.
white: either not present or is a speed sensor.

While I didn't open any round cables to the motors that had them, they came with an extender cable that terminated in 2x3 rectangular connector, and those colors were the same.

 

[badboy1999]

It's a round connector combined with the phases. The small pins look like this, I named them like the numbers on the right:

. . 56
. 4
. . . 123

I opened the motor, scraped off some insulation, and then it was easy to find out that 2 and 5 were indeed the power wires. When 5v is on them the whole thing consumes the ungodly amount of 15mA (I expected a few mA, or less than 1 mA) so that's why I didn't find it out by testing with just a power supply and a resistor. The bike works now! I'll post a few pics when I get around to it.