# Another motor runoff



## Tesseract (Sep 27, 2008)

glaurung said:


> ...I took hold of the cable connector and pushed it deeper, if it woud be the problem...
> Whine, smoke and sparks!!!!


Please provide more detail about what happened as right now it appears that you are saying that you pushed on the throttle connector and when it plugged back in the controller started receiving a throttle signal? That's kind of the purpose of a motor controller, you know... translating a throttle signal into motion...

Which version of the code are you running? We've had a "Disable controller" button in place since version 1.2 (IIRC). Clicking on it *before* mucking about under the hood is always a good idea.


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## glaurung (Nov 11, 2009)

Tesseract said:


> Please provide more detail about what happened as right now it appears that you are saying that you pushed on the throttle connector and when it plugged back in the controller started receiving a throttle signal? That's kind of the purpose of a motor controller, you know... translating a throttle signal into motion...
> 
> 
> Which version of the code are you running? We've had a "Disable controller" button in place since version 1.2 (IIRC). Clicking on it *before* mucking about under the hood is always a good idea.


Throttle was off when i touched the sender, so it should have done nothing before i press the pedal. No foot on pedal or anything.I saw how the lever was positioned.I was standing next the car when this happened.It was instant.

1.4 is what i have. Oh, disable.......


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## Tesseract (Sep 27, 2008)

glaurung said:


> Throttle was off when i touched the sender, so it should have done nothing before i press the pedal.


Actually, according to what you wrote in the first post, the controller was telling you that it started up receiving a non-zero throttle signal:



glaurung said:


> I changed setting on Soliton for this small motor and got a "throttle not zero" on screen....


Then, as I understand it, you exited the vehicle cab to tinker with the throttle and found that the plug was loose. You pushed the plug back in and *then* the motor took off like a banshee.

If my interpretation of what you wrote is correct then a likely sequence of events is that you briefly broke all (or just the throttle and/or +5V) connections as you reseated the throttle connector. This caused the throttle signal to briefly go to zero which is all it takes to reset the "not at zero" error reported on start-up. There's no way the code could have protected you from that - how could it tell the difference, then, between a situation like this vs. you accidentally pressing on the accelerator pedal when turning the ignition on?


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## glaurung (Nov 11, 2009)

Tesseract said:


> Actually, according to what you wrote in the first post, the controller was telling you that it started up receiving a non-zero throttle signal:
> 
> 
> 
> ...


What confuses me is why controller applies full? throttle when not receiving signal? If i break a wire/corrode a connection will that happen in that case also?

Motor is toast and i know who was there to take the blame, but i wish i could learn more of this incident. Once again i am grateful that ev motors are so cheap

Harri


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## Tesseract (Sep 27, 2008)

glaurung said:


> What confuses me is why controller applies full? throttle when not receiving signal?


Why do you assume the controller applied "full" [motor current] when you re-seated the throttle connector? It would only take 10-20% throttle to spin an unloaded series wound motor to death... The fact of the matter, Harri, is that you made multiple mistakes here:

1. you ignored the controller telling you that it was receiving a non-zero throttle signal when you started it up;

2. you exited the vehicle with the controller in running mode to investigate why the throttle wasn't at zero;

3. you fiddled around with the throttle while the controller remained in running mode.



glaurung said:


> If i break a wire/corrode a connection will that happen in that case also?


That depends on which of the 3 wires breaks. If it is the THROT or 5V wires then the throttle signal goes to 0%; if it is the SGND wire then, yes, the throttle will go to 100%. We have been testing a new feature to block throttle when the signal is above the calibrated 100% point but it isn't quite ready for prime-time.

That said, what happens if a floor mat gets jammed up under your accelerator pedal?

If you have a Soliton controller and you wired up the brake input then simply applying the brakes will override the throttle signal. This provides a pretty good level of safety in my opinion, but it does require that you *remain in the car* whenever the controller is running!


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## GerhardRP (Nov 17, 2009)

Tesseract said:


> This provides a pretty good level of safety in my opinion, but it does require that you *remain in the car* whenever the controller is running!


Can you add a disable the controller when the hood is opened?
Gerhard


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## Tesseract (Sep 27, 2008)

GerhardRP said:


> Can you add a disable the controller when the hood is opened?
> Gerhard


That can be done now, either by wiring a switch to one of the programmable inputs configured as a throttle limit (set to 0%) or by OR'ing the output of said switch along with the wire from the brake lights to the BRAKE input. 

I don't see this as being terribly practical compared to simply disabling the controller - or turning the ignition off - prior to exiting the vehicle, particularly when trying to troubleshoot a throttle problem!


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## ElectriCar (Jun 15, 2008)

Tesseract said:


> If you have a Soliton controller and you wired up the brake input then simply applying the brakes will override the throttle signal. This provides a pretty good level of safety in my opinion, but it does require that you *remain in the car* whenever the controller is running!


You guys have done a great job with this thing incorporating all this stuff into your controllers. It's obvious the things you guys do, the features you incorporate and ever evolving improvements to the software that you guys are driven to make the best product out there, at an affordable price nonetheless. I applaud your efforts and think that is why your products seem to be taking over the EV DC market. That is why I decided on your controller over others that were less expensive.


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## glaurung (Nov 11, 2009)

Most of the mistakes that i made are from ice days.If something does not work you poke around engine compartment and see it helps!
I have set throttle to zero by hand before, then i installed extra return spring to throttle.Never had that after that.
To be safe in future i will install tachometer to Soliton and limit rews, i just could not find any details or values on required pullup resistor. Is there only one or doesn´t it matter?
I have a proximity sensor.
Harri


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## ElectriCar (Jun 15, 2008)

I have an industrial proximity switch operating an automotive tach. See my thread for details. 

I don't know if I'd need a resistor in the circuit somewhere or not. I'll find out soon enough.


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## glaurung (Nov 11, 2009)

Thanks ElectriCar, i mean tach for Soliton to use rew limit.
Harri


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## Tesseract (Sep 27, 2008)

ElectriCar said:


> You guys have done a great job with this thing incorporating all this stuff into your controllers....


Thanks for the kudos; much appreciated! Now I must continue my merciless beatdown of Harri, here...




glaurung said:


> ...
> I have set throttle to zero by hand before, then i installed extra return spring to throttle.


There are already two springs on our throttle assembly - one inside the pot and the other outside - so if you had to add a *third* spring then maybe your throttle cable or linkage is damaged/broken. That is to say, if it takes *any* help to return our throttle to zero then there is something mechanically wrong with your setup.



glaurung said:


> To be safe in future i will install tachometer to Soliton and limit rews, i just could not find any details or values on required pullup resistor. Is there only one or doesn´t it matter?
> I have a proximity sensor.


Page 10 of our fine manual explains how to use an industrial prox for the tach sensor while p15 has more detail on setting up the tach in the web interface. Then there is the instruction sheet for the actual proximity switch you intend to use...


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## glaurung (Nov 11, 2009)

I stand corrected!
For some reason i opened the the old user manual every time. And there actually seems to be numbers that you point out! Maybe there are too many long sentences on this chapter for me to read. New manual had numbers shown in very clear way, i think the air humidity has something to do with me not seeing those.
So it is a resistor 220-3300 ohm value, right? 

I will remove extra spring and calibrate throttle. You know, it is easier to take spring from drawer and attach it than it is to walk to house to get a computer.

Thanks, Harri

I will post my findings from motor when it has been dismantled.


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## Batterypoweredtoad (Feb 5, 2008)

It is interesting reading about the few motor runaways that have happened in conversions. My natural instinct is to say the controller manufacturer should somehow stop it from happening but I think that is just the typical "Grumpy Consumer" mindset rearing its ugly head. When playing keyboard warrior it is easy to forget that converting a vehicle to an entirely new powerplant is a fairly spectacular process that may not respond well to the "throw it in and see if it works" type of mechanic. I keep thinking something simple will fix it and should be expected but everything I can think of has its own issues. The best I can come up with is if the controller sees a non-zero throttle signal when powered on, the controller will require a power/key off-power/key on cycle before it will send power to the motor. That is of course only if it gets a zero throttle signal on the new power/key on cycle. Does it already do that? Is there an ugly consequence I am not considering?


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## Tesseract (Sep 27, 2008)

glaurung said:


> ...
> So it is a resistor 220-3300 ohm value, right?


That is the range of values which I recommend from the perspective of the controller; you need to make sure the range of values for your particular proximity switch overlaps the above range with the additional recommendation that the lower the value of resistance the more resistant to noise the installation will be.



glaurung said:


> I will remove extra spring and calibrate throttle. You know, it is easier to take spring from drawer and attach it than it is to walk to house to get a computer.


...and it's easier to turn off the ignition or disable the controller before messing with its throttle than it is to replace an exploded motor. 




Batterypoweredtoad said:


> ...The best I can come up with is if the controller sees a non-zero throttle signal when powered on, the controller will require a power/key off-power/key on cycle before it will send power to the motor. That is of course only if it gets a zero throttle signal on the new power/key on cycle. Does it already do that? Is there an ugly consequence I am not considering?


Our controllers do not handle a non-zero throttle at start up in this manner now because it is extremely annoying if you are the type of person that routinely "gooses the gas pedal" when starting your car (even though an EV doesn't need to be started, pe se, old habits are hard to break sometimes).

We have considered this approach but in the end we decided to simply block throttle until it was returned to the calibrated zero position at some point after starting the controller up. We are revisiting this approach as a consequence of Harri's misadventure here, but I must say my personal philosophy on this is ultra-Libertarian - you are solely responsible for the consequences of your actions, especially those actions you did not carefully think all the way through before acting.


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## Batterypoweredtoad (Feb 5, 2008)

Maybe an option to turn the key/throttle lock out on or off? 



So to prevent motor over rev due to any reason: 

1) Have a tachometer and over rev protection turned on. 

That would take care of every scenario right?


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## Tesseract (Sep 27, 2008)

Batterypoweredtoad said:


> Maybe an option to turn the key/throttle lock out on or off?


That's what we call "feeping creaturism" - adding features to a product until it becomes unwieldy and difficult to use. And just imagine trying to describe this particular feature in the web interface... A check box next to the phrase "More Draconian throttle-lockout?" Doesn't sound encouraging, does it?



Batterypoweredtoad said:


> So to prevent motor over rev due to any reason:
> 
> 1) Have a tachometer and over rev protection turned on.
> 
> That would take care of every scenario right?


Correct.


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## dladd (Jun 1, 2011)

All throttle issues aside, this would be a non issue if the user has an rpm sensor wired into the controller with a max RPM value set. Seems like a perfectly sensible solution, no software 'fixes' needed. 

my controller won't finish precharge if the throttle is not zero. You have to cycle the key off then on again. It's no big deal, but it IS one more thing to make a note of for people other than myself who drive the car.


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## ElectriCar (Jun 15, 2008)

Jeff I think a LARGE RED WARNING LABEL in the manual informing the user that "A working motor speed sensor connected to the "_whatever_" terminals is required to avoid motor destruction..." would be a good thing to do. Idiot proofing is a good thing to help preserve your reputation in the community. If you've ever worked in industry you know that's more than desirable!


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## MPaulHolmes (Feb 23, 2008)

You don't actually need a tachometer for basic motor overrev protection. You can just use sensorless software overrev protection. It's only a few lines of code. All you need is the motor amps and the pwm duty. It works very well.

// if current_feedback > MIN_MOTOR_AMPS, 
// then rpm = k * V / current_feedback
// else rpm = k * V / MIN_MOTOR_AMPS

You have to calibrate k for your motor, but it's not hard. Just try different k values while in neutral, and rev it up until it shuts off at the point you want it to shut off at.


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