My PAS is very slow and jerky

Aussie Steve

Finding my (electric) wheels
Oct 13, 2014
5
0
75
My bike is a Commencal Meta 55 with a GNG 450w Brushless Mid Drive connected to a 9FET 3077 Mark II (Sensored) LYEN Edition Controller. I have just installed a PAS Sensor to the crank and the response is not what I expected. There is no continuous power as I pedal. I am only getting a very low power and brief motor response with each revolution of the pedals causing a slow forward jerking motion. I have the sensor less than 1mm from the magnet ring. I have spliced the PAS wiring into the throttle cable and have double checked my wiring colours and connections.
Can someone please advise where I am going wrong or is it that the controller I have is not suitable for a PAS system. Your advice would be appreciated but please keep it simple as my tech knowledge is only basic I’m sorry to say.
Many Thanks
 

Zebb

Esteemed Pedelecer
Jun 13, 2012
371
12
Has someone said to splice the pas into throttle wiring, fair to say throttle and pas work different. What is the controller designed for, pas or throttle ?
 
D

Deleted member 4366

Guest
The PAS works as switch. It switches on the 5v for a short time each time a magnet in the magnet disc goes past. What you've done is to short the throttle signal wire to the 5v for a short time 5 or more times a second. The PAS is only supposed to send the pulsing signal to the controller to let it know that you're pedalling, then the controller uses an algorithm to give the right amount of power. The CPU has two different inputs connections for PAS and throttle, and it deals with them in different ways.

If you want to use PAS with the GNG, you need a proper PAS controller. Even if yours did work, it would be useless because it would just give maximum power when pedalling. You need a controller that will give at least 5 levels. I used the 750w Conhismotor controller with mine. It has 5 levels of PAS, which are selectable through the LCD. Another forum member couldn't get it to work. I heard other people struggling to get the S12S to work. I think it's because the GNG has 60 deg phase angle rather than the normal 120 deg.
 

Aussie Steve

Finding my (electric) wheels
Oct 13, 2014
5
0
75
The PAS works as switch. It switches on the 5v for a short time each time a magnet in the magnet disc goes past. What you've done is to short the throttle signal wire to the 5v for a short time 5 or more times a second. The PAS is only supposed to send the pulsing signal to the controller to let it know that you're pedalling, then the controller uses an algorithm to give the right amount of power. The CPU has two different inputs connections for PAS and throttle, and it deals with them in different ways.

If you want to use PAS with the GNG, you need a proper PAS controller. Even if yours did work, it would be useless because it would just give maximum power when pedalling. You need a controller that will give at least 5 levels. I used the 750w Conhismotor controller with mine. It has 5 levels of PAS, which are selectable through the LCD. Another forum member couldn't get it to work. I heard other people struggling to get the S12S to work. I think it's because the GNG has 60 deg phase angle rather than the normal 120 deg.