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Discussion Starter #1
So I bought a new controller for my PR200 because the original one would only spin the wheel if no weight was on the bike. I bought this one
[silly hotlink]

Here's my question/problem. The motor connector wire is one red and one blue and both are putting out full 36v without throttle. Ideas? I know this is for a xp-700 but I would imagine their motor also takes a ground and a progressive voltage based on throttle.
 

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So I bought a new controller for my PR200 because the original one would only spin the wheel if no weight was on the bike. I bought this one
[silly hotlink]

Here's my question/problem. The motor connector wire is one red and one blue and both are putting out full 36v without throttle. Ideas? I know this is for a xp-700 but I would imagine their motor also takes a ground and a progressive voltage based on throttle.

The controller might be watching the the throttle for some signal, maybe the signal is bad?

DC needs to have both! a positive and a negative! hit it with a meter one way it should be +36v and switch the leads to the other way, and it could show -36v

I think....
 

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Discussion Starter #3
What's really odd is when I opened up the controller the red wire that goes to the motor is soldered on to the same spot as the battery wire. Therefore it would always be full voltage. The blue wire is soldered on a separate spot which could be controlled differently. I just can't wrap my head how a controller could ever work with even one of the connectors to the motor as a always full on.
 

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Discussion Starter #5
I believe I understand what you are saying and how it works. I would assume that there would be a stable ground and then the power wire that regulates the voltage based on the throttle signal.
Having a wire that is directly connected to the same spot that the positive battery wire connects to would not make sense as is in this controller.
 

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I must be missing something, the battery is power, (gas) the motor is the engine!

The controller and the throttle work together to send different amounts of current to the motor!

power from the batts to the controller, signal from the throttle to the controller, and (POWER) out of the controller and into the motor.

Right? :confused:
 

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Discussion Starter #7
Just to confirm this is an electric bike. No gas. What I'm explaining is the two wires that connect from the controller to the motor are putting out 36 volts. This seems wrong. One wire should be ground. One wire should go from 0 to 36 volts based on throttle off to full twist.
 

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Touchy, Simple test. Disconnect the throttle. If the voltage at the motor is 36v then the controller is bad (it has an internal short). If that is not the case then you probably need a new throttle.

Hugh
SDscooters
 

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Discussion Starter #11
Thank you for your response. I don't mean to disagree because I would think this test would work to except that the motor wire is connected to the same exact spot as the battery power wire so it will always have 36v right?
 

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Touchy,

If the input side of the controller is shorting causing it to act as if the throttle is always on then yes you will see 36v doing this test. If its not shorted then you wont see a voltage on the motor side of the controller. The common wire is normal, almost all of these controllers use a similar setup. The controller acts like an on/off switch between the motor and the (-) battery terminal, if its off then no voltage, if its on then full voltage. Disconnecting the throttle takes a stuck throttle out of the equation leaving you with just the controller to test.

I think wikipedia has a good article explaining how a pwm motor controller works in detail. Essentially its just a high speed on/off switch.

Hugh
SDscooters
 

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I believe I understand what you are saying and how it works. I would assume that there would be a stable ground and then the power wire that regulates the voltage based on the throttle signal.
Having a wire that is directly connected to the same spot that the positive battery wire connects to would not make sense as is in this controller.
most controllers use a main live feed and regulate though the negs(-) as it is one of the easiest and cheapest ways of making a speed control!! as it saves having two control chips for the postive terminal and negative terminal!!! hope that helps:thumbsup:
 
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