only full speed on 406

[29a]

hi all been a while,

I'm riding a 406 with 72V 35A controller all clite parts.
First I changed controllers and the same result.

The scenario is I plug my batteries in then after about 5 seconds the motor just takes off on full power running normal with no juddering even with no throttle connected and of cause will not stop untill i disconnect the batteries.

any ideas as to cause and remedy

 

[Drunkskunk]

Sounds like a bad throttle. does it do it with the throttle unplugged?

 

[29a]

The throttle was also my first thought but when the throttle is disconnected (unplugged) it does the same

 

[fechter]

That's bizzare...

I'd assume a throttle problem, but the motor should not run with the throttle disconnected.

Is there a cruise control attached?

Do you have brake cutoff switches? Do they work?

Unlikely-but-possible: Is there any source of RF nearby, even a cell phone or WiFi device? RF could possibly get into the wiring and cause bizzaro behavior.

 

[29a]

No cruise control.
The controllers i've tried are the clite brick type and I think should be shielded from rf by the totally enclosed steel case, and this has happened in different locations so can't be a local high power rf .

While cruising the forum i found a similar thread from Johnbear on the tongxin motor and wonder was the cause ever found ?
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=340&st=0&sk=t&sd=a&start=15

 

[Drunkskunk]

... Well I typed up a long response on why it had to be the throttle side of the controller, and why it couldn't be the motor, and checked a few diarams, and then erased everything I wrote. It "might" be possable, if there was a high resisatance short between the hall sensors and the main power leads, for it to unbalance the voltage in the controller enough for it to see a diffrence in potential across the throttle pins. that depends on how the chip interprets the diffrence between voltage and ground internaly, and on the short on the hall sensors wire being high enough resistance to not let full power through. full power would fry the path, or the chip.

The likelyhood of that happening is 1 in a million. But it could possably be the motor.

 

[29a]

Thanks Drunkskunk

That went right over my head.
It has been suggested to me that a faulty throttle could have screwed both controllers
Quote "maybe a bad throttle blew up the input error amp on the controller and this is causing the runaway"
and of course that is also right over my head.
does this sound realistic to you guy's

I'll do the motor phase wire and hall tests and report back

 

[fechter]

I suppose it is possible for a bad throttle to fry the input part of the controller. That would suck.

You might try removing the throttle and putting jumper wire from the ground to signal pins going to the controller to see if that makes it stop.

 

[29a]

Hi all thank's for your help much appreciated.

I took everything apart and started testing all tests to wires show'd correct values
Put everything back together and now it works properly with either controller
I'm putting it down to moisture or rust on the throttle line overheating the input error amp on the controllers (would explain the five second delay) allowing the runaway
I have noticed on one controller if the throttle connection isn't solid I still get the runaway, but stops if throttle disconnected.
On the other controller which has Fechter's current adjuster mod the runaway still exists only if the throttle is disconnected (It could have allway's been like this as i never tested previously) but the current adjuster still works even in runaway.
Is that normal Fetcher

8)

Of course it could have been one of those lycra guy's with some sort of rf/emp gun, anyone got a lead on faraday cages to encase the whole bike
:wink:

 

[lazarus2405]

Of course it could have been one of those lycra guy's with some sort of rf/emp gun, anyone got a lead on faraday cages to encase the whole bike
:wink:

Now, we all know that the lycras are too technophobic for that. Besides, how would we use GPS inside the cage?

 

[Link]

Of course it could have been one of those lycra guy's with some sort of rf/emp gun, anyone got a lead on faraday cages to encase the whole bike
:wink:

Now, we all know that the lycras are too technophobic for that. Besides, how would we use GPS inside the cage?

29a: Make one out of cheap metal screen. Painting it gold might help, too.

Laz: They may have become more militant of late. They are evolving .

And just cover the controller/BMS. :wink:

 

[knoxie]

Hi

I have seen this a couple of times with the led throttles, people connected the LED battery gauge throttles on systems with higher voltages, this tended to blow the throttles but whilst doing so it would melt the insulation in the lead, check continuity between the throttle wires, you will need to open the controller unplug the throttle cable from the board and check continuity between the wires, i moved the cable about a bit and the meter would read a short, closer inspection revealed 2 to 3 strands of wire between the wires were shorting!through the insulation this caused exactly the same problem you were seeing, I cut the lead down this solved the problem.

So a failing throttle could no doubt do the same, the controller is now repaired and works great, it was scary indeed, double check the wires!

Knoxie