Original Brompton electric 2021 hack with trottle

[enry75]

This is an original Bronton electric from 2021.
How could I tweak an accelerator or an on/off button without pedaling?
here are my findings:
crankset with torque sensor equipped with 16 magnets.

Five wires connector :
1 white (10v+)
2 black (Gnd)
3 blue (PAS sinus) 0v-4v
4 brown (PAS cosinus) 0v-4v
5 Gray (Torque) 2.5v-????? 0v


test 1: connecting (PAS sinus) via a led to (Gnd) it turns on and off at the frequency of pedal revolutions and that by turning forwards or backwards it is the same
test 2: exactly the same thing by connecting the led between (PAS cosinus) and (Gnd)

PAS sinus and PAS cosinus are ON in opposite mode.


test 3: connecting it between (torque) and (gnd) the LED remains aligth without turning the pedal but the more a load is applied to the pedal the more the LED becomes less and less bright until it goes out.

could anyone advise me?

 

[Chalo]

The easy way is to replace the controller with a cheap and simple generic one that supports a throttle. If you want to use the controller you have (and assuming the controller doesn't support a throttle), then you have to set up an Arduino or something to convert the throttle signal to a fake PAS signal.

 

[enry75]

the problem is that the motor is an no brushed two-phase halls sensor; technically very very rare;
difficult to find a two-phase controller for ebike hub motor with trottle

 

[Oli.Hall]

the problem is that the motor is an no brushed two-phase halls sensor; technically very very rare;
difficult to find a two-phase controller for ebike hub motor with trottle

What makes you think it is a two phase motor and controller?

If it is an original Brompton Electric from their factory, then it is definitely a three phase motor. However, what might have thrown you a curve-ball is that the motor controller is built inside the hub-motor assembly.

The 6-pin connector which connects the battery via the the luggage block assembly to the motor contains two larger power connectors and four smaller signal & data wires. I do not know the exact pin-out of the connector but I would take a guess that two of the data / signal wires are CANBUS for communication with the battery and the other two are from the torque sensor.

You’re onto the right track in that the model of torque sensor which Brompton use is made by NCTE/THUN and it does not have a CANBUS output. It outputs a traditional analogue torque signal and a 2-wire style (sine/cosine) PAS signal for cadence.

To do what you want to do, you will need to program an Arduino or similar microcontroller to output a torque, and the sine & cosine PAS signals. If you connect the Arduino to the luggage block where the torque sensor usually plugs in, it can emulate the output of the torque sensor and trick the controller into thinking you are pedalling so that the motor turns even if you aren’t actually pedalling. The Arduino would be connected to a throttle to control the outputted ‘pedalling speed’.

https://github.com/stancecoke/Minimal_E-Bike_Torquesensor_Precontroller
The project above does what you want, but in reverse! I.e. it takes a torque sensor signal input and makes a throttle signal output. However, the hardware would be very similar and just require the code to be changed to take a throttle input and make a torque sensor signal output.

The Brompton motor is physically quite small and it may not be able to develop much power for a long time before it starts to get hot and gets throttled back by the controller. This is all speculation and would certainly invalidate any warranty that you may have with Brompton.

Good luck!
Thanks,
Oli.

 

[Infolk]

Any sucess on modding your Brompton Electric in the end? i am doing some research on how to do the same but nothing so far