Brain power controller

[DJG]

I have fitted a brain power controller and display to a Dawes Swift with a Dapu mid mount motor. The dawes speed sensor fits to the rear wheel and has 2 wires and the pedal assist is built into the motor and has 4 wires. I can only get the bike to run with a throttle and the speed displayed on the screen is only there when the motor is turning and is based on motor speed and not wheel speed. Is there any way to get the speed reading from the wheel and if the padal assist is faulty can it be fixed or replaced with some other type?

 

[vfr400]

You need to connect the white wire in the motor connector to the speed sensor. One wire goes to the white and the other probably to any 5v. If that doesn't work, connect the second wire to ground.

You'll have to find some way to bodge a normal pedal sensor onto the crank if you want pedal assist.

 

[DJG]

You need to connect the white wire in the motor connector to the speed sensor. One wire goes to the white and the other probably to any 5v. If that doesn't work, connect the second wire to ground.

You'll have to find some way to bodge a normal pedal sensor onto the crank if you want pedal assist.

 

[DJG]

It is picking up the speed from the motor at the moment, there is a white wire to the motor and a a white wire to the controller do I connect it to the motor and leave the controller wire blanked or the other way round?

 

[vfr400]

It's not using any speed sensor in the motor. Instead, it's picking up the speed signal from a motor hall sensor. Maybe your motor doesn't have a speed sensor in it. You can check by measuring the voltage on the white wire while you turn the wheel backwards. It would pulse once or 6 times per rotation.

If the white wire doesn't pulse, you can use your external one, like I explained above. It makes no difference whether you leave the white wire connected or not because if it doesn't pulse, it's not connected to anything in the motor.

 

[DJG]

OK thanks , will try what you have suggested

 

[DJG]

Hi
I have checked the white wire from the motor and I get a pulse of voltage when turning the wheel backwards. I also checked for continuity across the red and black wires from the speed sensor which showed continuity when the magnet passed the sensor.
Can this be used to give a speed reading when wired into the controller?

 

[vfr400]

You need 5v on the red wire, black connected to ground and the signal wire from the speed sensor connected to the white on the controller.

 

[DJG]

The speed sensor only has 2 wires

 

[vfr400]

The speed sensor only has 2 wires

One wire to white, the other to 5v. If that doesn't work, the second wire goes to ground. Don't forget that you need to set the number of pulses in the settings (P07) to 1. If it's zero, the controller will probably use a motor hall instead.

 

[DJG]

I have tried the different combinations that you suggested and changed PO7 to 1 but still no display of speed.

 

[vfr400]

Can you measure the pulses on the white wire when you turn the wheel?

 

[DJG]

The white wire is showing 5v I thought it was pulsing when checked before

 

[vfr400]

The white wire is showing 5v I thought it was pulsing when checked before

Put the other wire to ground, and see if it pulses up or down. Also, the way it is now, check whether it pulses to zero volts when the magnet goes past. Basically, with the white wire not connected, measure it on the controller side. if it measures zero volts, you connect the second wire to 5v and it'll pulse up, and if it measures 5v, you connect the other to ground and it'll pulse down.

 

[DJG]

Connected the white of controller to black of speed sensor and an earth to red of speed sensor and I get a reading on the display, going to road test and check speed against a gps and adjust P18 to suit. Have ordered pedal assist sensor and magnet disc and will fabricate it to fit and hopefully all will then work.
Many thanks for your assistance.

 

[vfr400]

Connected the white of controller to black of speed sensor and an earth to red of speed sensor and I get a reading on the display, going to road test and check speed against a gps and adjust P18 to suit. Have ordered pedal assist sensor and magnet disc and will fabricate it to fit and hopefully all will then work.
Many thanks for your assistance.

Thanks for that. It's the first time somebody has confirmed the wiring despite about 10 people had the same problem.

 

[DJG]

Hi there, I got a pedal assist disc and sensor and have tried it before making any brackets to fit it and have connected it as per photos, I have a 5v feed to the red and take a neutral from the black and when moving the disc across the sensor get a pulse of 5v on the blue but the motor doesn't turn, I have set P13 to 12 . Should the motor attempt to turn?

 

[vfr400]

Another 12 pole PAS! Why do people keep buying them? Try pushing out every other magnet to see if that fixes it.

 

[DJG]

How many pole is the best, and do I leave the magnet setting on 12 when using six magnets?

 

[vfr400]

How many pole is the best, and do I leave the magnet setting on 12 when using six magnets?

Set it to 6 if you can. It's always the 12 pole magnet discs that cause problems. My theory is that there's not enough gap between them so the next magnet is switching it back on before it has a chance to switch off or something like that. I'm not saying this is your issue, but it's easy to test by pushing out some of the magnets. You can always put them back in afterwards.