PAS Sensor polarity

[DGL]

Waiting to get the "proper" Lishui Controller out of Kudos (may be a long wait) I've put in a generic ("Brainpower") controller to be going on with. After sorting out connectors all is fine except that the PAS only works pedalling in reverse. I know the magnet disc is the right way round, it worked correctly with the old controller and hasn't been moved. It's a simple 3-wire sensor but I don't know what's inside. Presumably the controller responds to pulses of the correct polarity and I'm tempted to think that reversing the right two wires might sort this out. But which two? Signal and ground? Can I cause damage experimenting? Thanks, David.

PS - the other suspicious thing is that at the controller output, before connecting to the sensor, there is 5v between Black and Blue but only 4.3 Black and Red. Black is 0v. However swapping Red and Blue disables PAS altogether.

 

[Nealh]

Try reversing the magnet disc face or try rotating the sensor by 180 degrees.

 

[DGL]

Thanks Nealh, I appreciate that reversing the magnet disc will do the trick but it means pulling the crank and I was looking for an electrical solution. I haven't been able to find any circuit diagrams of what goes on inside the sensor head. I know it generates signals in both directions of the crank and suspect that the problem may be a functional difference with the controller, e.g. previously the interface rested low and initiated PAS on positive spikes, now it rests high (as I have measured) and initiates PAS on negative spikes. Anyway, I've ordered a crank puller ...

 

[Nealh]

Most sensors just have a hall enclosed, any programming will be within the controller.