KU123 controller wanted

[jhinshel]

Hi,
My converted bike seems to have stopped responding to the throttle and my suspicion is that the controller has junked itsef again.
Has anyone out there got a KU123 controller suitable for a bafang 500w bldc motor.
If so please let me know details.

Other than that I suppose I'd better get the thing apart and start testing it - any advice on where to begin?
The battery is fully charged (36v nomimal) and the controller has got power going to it.

Sometimes there is a twitch of the motor when the throttle is depressed, other times nothing at all.

Regards,
Justin

 

[Sacko]

All the screws on the outside of the controller need to be removed, then slide the board out of the case.

Might be a bad phase/hall connection, or a rogue throttle.

In my experience, if a controller fails there is no power at all.

 

[Deleted member 4366]

They seem to be pretty reliable, but external things can kill them. The easiest way toknacker them is when the phase wire connectors melt and short out, which blows the FETs. The standard bullet/barrel type should always be replaced. they can't take 30 amps. Any short on the 5v rail, like water in the throttle or pulled wires on the throttle or PAS, will blow the 5v regulator.

Twitching when you operate the throttle implies blown FETs.

If the controller was completely dead, I'd start by checking whether the 5v is live on the throttle or PAS. That tells you that the controller is switched on and has power to the CPU. After that test the FETs. I have one of these ebike testers that are really handy for quick testing:

1PC Rapid Electro Scooter E-bike Car Brushless Motor Controller Tester 24V-60V | eBay

If you can't wait, you can test the FEts by measuring their resistance from the red battery wire and the black battery wire to each phase connection in each direction to produce 12 results. That table of results should indicate if something is wrong.

 

[averhamdave]

Looks a useful bit of kit Dave. Hope the instructions are good! Have just ordered one.

 

[Deleted member 4366]

Instructions are poor, but this should help:
Brushless Controller, Motor, Throttle Tester Manual
Endless-sphere.com • View topic - Ebike motor/controller hall/phase/throttle tester $29