hbs-36 pinout / schematic - how to control it??

[greenenergytechnologies]

Hi guys,

I want to find out about the hbs-36 500W motor. I have a power controller from these guys http://www.scimar.co.uk/splitpi.html that allows me to acurately control voltage and current supplied to a motor. My plan is to use two of the hbs-36 hub motors, one front and one rear on my bike with a couple packs of 36V lithiums. With 20" wheels thats enough torque to get your average sized guy up a 1 in 8 hill at 9mph.

Basically I want to know what all of the wires are for on the hbs-36 motor before I buy. Does anyone have a datasheet for the motor? I have the drawing and performance curve, but need to know how to interface to the motor. As it's BLDC it must have some kind of commutator built in or the wires are fed from hall sensors and you have the commutator control on the outside?

thanks,
Andy

[philf]

Hi Andy...

I haven't taken a motor apart yet, but I can tell you that there are 8 wires going into the hub.  Three of them power the electromagnets, and the other five connect to an array of three hall-effect sensors.

These are brushless motors, and to this day I'm not sure how many actual electromagnets are in there.  I believe it's 51, but I've seen other claims that there are 46 (strange number).  Either way, these radially mounted around the axle.  Someone else who has had one of these open can probably very quickly fill in the blanks, here, and probably correct me - a schematic of how these three power wires connect to the group of coils would be handy to have.

The hall sensors are easy.  You have a +5V and ground to supply the group, and one wire to return the signal from each of the sensors.

Jeremy Nash has some details of the motor's innards in his instructable at:  http://www.instructables.com/id/Electric-Bike-Hub-Motor---How-to-Replace-a-Hall-ef/.

He goes through some hoops to map out the "firing order", as he calls it, from the hall array - which is as interesting as it is perplexing.

If a better answer isn't forthcoming, I'm just going to have to pull the cover on one of these things myself to satisfy my curiousity.

Cheers!

[philf]

Sorry for the back to back posts...

You got me thinking...

As there are only 3 "power" wires to the motor, I'm guessing at the arrangement.  If one wire were a return, that would only allow you to divide the magnet array into two groups - I'm pretty sure you're going to need three to be able to make the thing spin consistently in one direction.

So here's a guess...

Suppose there ARE 51 coils (as I believe) arranged in three alternating groups of 17.  If those three series are then wired in a loop - output of group one goes to input of group 2 whose output goes to the input of group 3 whose output goes back to the input of group 1 - and you then tap your 3 "power" wires at each of these unions - you'll get the ability to control each of the three groups at will.  That is, as long as you can turn any wire into a "source" and any other wire into a "sink".

If the coils are numbered 1 - 2 - 3 - 1 -2 - 3 - 1 - etc., then you could fire the groups sequentially according to the following repeating logic:

- Wire 1 source/Wire 2 sink

- Wire 2 source/Wire 3 sink

- Wire 3 source/Wire 1 sink.

To make it work, there would need to be a number of permanent magnets in there that are divisible by three, but less than the number of coils.  That's where the hall sensors tell you where you are and how to start firing to give spin in the desired direction...

Does anybody know the answer?  Is this a reasonable guess?

Cheers!

[OneEye]

The 3 wires providing power to the windings work like a 3-phase system--the outbound current in two legs match the return current in the third.  The net sum of current in all three legs is zero.  There isn't a designated + or - wire, they all serve as + or - at different times.

[OneEye]

Brushless motors do not have a commutator--they are "brushless".  The power flow through the windings is controlled in a 3-phase sequence by the controller.  The firing sequence of the coils is intimately related to the position and speed of the motor, and the controller gets that information from the hall sensor array.

The power control you linked to in your original post might work with a brushed motor, but not for a brushless one.

[philf]

Thanks, OneEye...

I'm still digesting that...  The state of the third wire during any phase of what I described is what was puzzling me.  You're suggesting that it's actually 2 out of 3 sets of magnets that are working at any time?  That could make a great deal of sense as I'm visualizing it...

Cheers!

[ahend]

I took some internal photos of my 36V 500W front wheel hub just after I received it.
To be clear, there are 51 electo-magnets and 46 permanent magnets

[Mel in HI]

Basically this guy has a controller for a brushed motor and is trying to use a non-brushed motor with it.