ebike sensors

[newmanoid979]

will an e bike motor work without sensors

 

[saneagle]

will an e bike motor work without sensors

If you mean hall sensors, the answer is yes if you use a controller for sensorless motors that have "sensorless" or "dual mode" in the description.

 

[StuartsProjects]

Maybe.

Perhaps provide us with a bit more detail as to what exactly you mean by 'sensors' ?

 

[newmanoid979]

many thanks for your help

 

[newmanoid979]

good afternoon what do hall sensor do and what is the results of leaving them out
many thanks
Bill

 

[AGS]

In a sensored motor there are 3 hall sensors in a motor positioned 60 degrees apart. A small voltage is created on the output of each hall sensor that is sent to the controller when the magnetic field changes by the motor rotating.

There are 3 sets of windings in the motor (green, blue, yellow) and when a hall sensor triggers the controller it supplies current through two of the windings, eg. green and yellow, in through green and out through yellow.

This makes the motor rotate a little because the current through the windings creates a magnetic field that is repelled by the magnets.

When the motor rotates the first hall sensor switches off and the second hall sensor switches on. This tells the controller to supply current through two of the windings eg, green and blue, in through green and out through blue, so the motor rotates a little bit more.

Then the second hall sensor switches off and the third hall sensor switches on. This tells the controller to supply current through two of the windings eg, blue and yellow, in through blue and out through yellow.

The process repeats 6 times during one rotation of the motor and the hall sensors keep switching on and off telling the controller to pass current through all of the combinations of two phases.

I can’t easily explain how a sensorless motor works, but the controller monitors the current and voltage in and out of each phase and works out where the rotor is and then does its switching accordingly.

You can run a sensored motor in sensorless mode, but you must use a controller that is designed to either run sensorless or both sensored and sensorless.

I’m sure I will be flamed by some egotistical git on here who will tell me that I’m talking absolute rubbish. I‘m usually beasted by one or more of the mafia on here, which is why I don’t post very often.

 

[saneagle]

good afternoon what do hall sensor do and what is the results of leaving them out
many thanks
Bill

Hall sensors send the position of raotatio to the controller so that it knows when to fire pulses of electricity at the motor to make it work. Brushless motors run with precisely timed pulses of electricity, not continuous power, like you get from a battery. the controller looks after all that.

Without hall sensors, dual mode and sensorless controllers use an alternative means to figure out the timing of the pulses, which is not so precise, so the motor runs less smoothly (hardly noticeable) and can judder a bit at very low speed, like when starting from a stop. Some motors don't run very well sensorless.

Normal controllers for sensored motors don't have alternative means to get the timing, so they won't work without hall sensors.

 

[newmanoid979]

Good morning
Where would i buy a PCB board with Hall Sensors for a 250 watt 36 volt e bike front hub as the only ones i have seen on the internet are of the wrong arc
kind regards
Bill

 

[AGS]

It will be really difficult trying to retrofit hall sensors to a motor that was designed to run sensorless. They have to be positioned in exactly the right place for the motor to work properly. And then you will have to rewire the motor so you can feed the 5 hall sensor wires in.

Another issue is will a pcb fit without rubbing on the motor casing and how are you going to secure it?

And is there enough space between the windings to mount the sensors?

 

[newmanoid979]

hi
the hub was fitted with Hall sensors but i had a miss-hap when the wheel dropped out the front forks and ripped out the wiring i have taken steps to ensure this should not happen with the replacement wheel but i would like to rebuild the original wheel hence the need for a pcb board and hall sensors

kind regards

Bill

 

[matthewslack]

Good morning
Where would i buy a PCB board with Hall Sensors for a 250 watt 36 volt e bike front hub as the only ones i have seen on the internet are of the wrong arc
kind regards
Bill

One route, although an awful lot of trouble, would be to buy a pcb of the wrong arc, cut it into pieces and then reassemble at the correct arc and spacing, resolder the pcb tracks as needed....

It just might be better to buy a sensored motor, although I'm all in favour of learning by doing.

Edit: overlap with your explanation! Sounds more doable now! Good luck.

 

[saneagle]

Look on Aliexpress, there are many different hall sensor pubs there.