Hi, I have a Chinese Noname 36V, 250W brushless ebike controller which works fine. I have now decided to connect brake levers with switches in order to implement the braking function on the controller. Like many controllers mine has "Brake High" and "Brake Low" connectors. I only recently discovered that 'high' and 'low' refer to the degree of braking, but that is not the problem.

The Brake High has two wires, which I measure as Ground and 5 volts; I had assumed that the 5 volt line was from a pull-up resistor to one of the microcontrollers inputs, and using the brake lever switch to connect this to ground would cause motor power to be cut, but in fact nothing happens! Does this mean the controller is faulty in this function? I'm also puzzled as to how the Brake Low function would be connected, as there is only one wire in the connector, which is neither Gnd or Vcc; no doubt I'm missing something here?

Any advice or suggestions would be most welcome.

High and low refers to the brake signal. High is 5v and low is 0v. You should use the low signal one. Assuming it's a normal 2-wire one, one wire is the signal wire, which is connected directly to an input on the controller's CPU (protected by a resistor) andn is pulled up to 5v by a pull up resistor, the other is ground. Any brake switch will short the 5v to the ground, which drops the signal to 0v. When the controller sees 0v on that input, it cuts power to the motor.

 

In all the controllers I've seen, the high brake is a single wire and the low is two wires, though it shouldn't make any difference because you can pick up the ground from anywhere. I've never seen a bike where the high signal wire is used, presumably because it's not fail-safe.

Thanks for the response, every little helps as they say! From what you say it would seem that my original assumption was correct, that is, the two wire connector with 5v and Gnd would simply need to be shorted together, by the brake lever switch, to cut power to the motor. But this doesn't happen, so must presume there is a fault with the controller? Oddly, the single brake wire does not have any voltage on it, but has no effect when grounded. Another fault, perhaps?

A couple of points that puzzle me; I've seen somewhere that the reference to brake high and low refers to the degree of braking. I assumed from this that that 'high' would cut power completely and 'low' perhaps down to just a lower power, although this seems rather arbitrary. Also, you mention that brake high is rarely used as it's not fail-safe - so is brake low fail-safe and how is that achieved?

Best regards.

I've seen somewhere that the reference to brake high and low refers to the degree of braking.

That's complete ball-cox.

Some controllers have EABS, but that's a completely different connector.

From what you say it would seem that my original assumption was correct, that is, the two wire connector with 5v and Gnd would simply need to be shorted together, by the brake lever switch, to cut power to the motor. But this doesn't happen, so must presume there is a fault with the controller? Oddly, the single brake wire does not have any voltage on it, but has no effect when grounded. Another fault, perhaps?

Try shorting the wires directly. Maybe your switch is faulty. I've never heard of a controller where the brake cut-off didn't work. It has a direct connection to the CPU, so the software in the CPU would have to be faulty for it not to work, but then nothing would work.

 

If that doesn't work, show us what you have. You must be doing something wrong.

Hi hope I'm at the correct discussion I need help I have just received a controler I ordered but didn't pay good attention to it I now see the light connectors only have a single wire but on my bike they have 2 please could anyone help me solve this problem I'm not that technical so if somebody could draw a diagram or have photos how to solve this issue I would really appreciate it .

Hi hope I'm at the correct discussion I need help I have just received a controler I ordered but didn't pay good attention to it I now see the light connectors only have a single wire but on my bike they have 2 please could anyone help me solve this problem I'm not that technical so if somebody could draw a diagram or have photos how to solve this issue I would really appreciate it .

Yes thanks I did it never tried anything like this before but your diagram worked for me thank you .