# Go Kart Controller



## Qer (May 7, 2008)

Not that I know much about P&S, but...



Snakub said:


> buying a programmer


Cheapest AVR-programmer out there is an old printer cable if your computer is old enough to still have a parallel printer port.



Snakub said:


> I take off under the controllers power but have a relay bypassing the controller to allow the motor to see the entire 72 volts of the pack.


This sounds like a great attempt to be mentioned at the Darwin awards. Yes, it's a stupid idea.


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## Snakub (Sep 8, 2008)

What from what I understand Kawashocki had an all relay control and I was using relay control on the kart to bypass the motor controller to get more speed. How would this be any different??


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## Dennis (Feb 25, 2008)

Snakub said:


> What from what I understand Kawashocki had an all relay control and I was using relay control on the kart to bypass the motor controller to get more speed. How would this be any different??



On 24 volt motor systems I use direct across the line start up with a contactor because the inrush current was not high enough to melt the contacts together of the contactor. In your case I do not know when you switch in the contactor, but if you switch it in too early then you are stuck in situation where a contactor will weld shut and you are screwed with no way of stopping a runaway go kart that brakes will do nothing to stop unless you have a mechanical kill switch to kill motor power. I will only say it's better safe than sorry, but I am not your boss. I can only give you advice.


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## Snakub (Sep 8, 2008)

I do have a mechanical disconnect switch. But the question I have is will the motor seeing 72 volt overvolt the controller?


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## athomas03 (Jul 13, 2011)

Snakub said:


> I do have a mechanical disconnect switch. But the question I have is will the motor seeing 72 volt overvolt the controller?


What you have to worry about is the back EMF of the 72v after you bypass? It could come back into controller and fry it. Some controllers have diodes built in and some don't, but a good diode somewhere in between is needed to protect the 48v controller from the extra voltage. I'm not an expert but, I have studied bypasses and extra voltage boosts for golf carts.


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## Snakub (Sep 8, 2008)

I think I will have the atmel problem figured out so I might have the controller issue figured out just in case I don't though would an external diode block rated for higher voltage work in the case of the relay control?


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