vibration from Phoenix?????

[joystix2]

System:
Phoenix kit
36/48v Nimh
36-72v 35a Xlyte controller

Scenario:
Throttleing up on 48v when I get to about 31-32mph the system start to vibrate or hum and won't go any faster. I throttle down a little then throttle back up slowly and it goes away most of the time and then it'll climb to 34-35mph. Same on 36v but at about 25mph. Throttle down a little then throttle back up and it goes away sometimes and will top out about 28-29mph......

Has anyone experience this and whats causing it? It might be electrical. Not sure? any feedback would be appreciated.

Ric

 

[Ypedal]

http://endless-sphere.com/forums/viewtopic.php?t=427&start=0


Similar to this thread by any chance ?

 

[xyster]

Mine does the same thing at lower voltages. It's telling you it wants more juice. Try a higher voltage and I bet it'll speed right through that zone of shudder. I have no clue the actual cause.

 

[joystix2]

I think Xyster nailed it. It usually happens when I open her up when I've used up 60% or more of my useable voltage on my 48v pack. Or it happens when I'm going into a stiff head wind full throttle on 36v. Batterspace states on paper that the 36v10ah pack can handle a continuous 30amp but thats pushing it.

 

[Stevil_Knevil]

Ric,

That sounds like the same reaction that I experienced when the pack voltage sagged down to the low-voltage limit that I had programmed into one of my Alltrax/eTec machines. The motor would make an audible groaning sound as the Alltrax began bouncing off of its LV limit. It felt as if every third Pulse Width just stopped getting to the motor.

During a visit to the Alltrax factory, Damon explained that this is how the AXE will prevent the pack from over-discharge, and provide feedback that it was doing so.

It sounds like the C-lyte controller is slipping into the same kind of pack protection mode.

The Cut off Voltage on the C-lyte 72V-35A controller is 29V (+/- 1V).
Could your NiMH pack be drooping that low? I can imagine the 36V pack doing that, but if it's doing that on your 48V pack.. that could be bad.

Do you monitor your running voltage with a DrainBrain/guage/DVM?


-S

 

[xyster]

Stevil, at 84 peak volts, my 5304 still groans through part of the powerband like Ric is describing his does. But at higher voltages, it's a much smaller part of the powerband, and easy to blast right through. I've ridden my bike at 30 volts and 48 volts too, and the groan effect is much worse than at 80 volts. It's not even a minor annoyance now. So this motor groaning doesn't seem to have anything to do with the controller.

 

[Ypedal]

IF you gun the throttle the voltage of a new un-cycled pack will sag by a few volts.. enough to give a varyation in top " unloaded " speed...

I expect you won' t notice this when in use.

 

[Stevil_Knevil]

Got it, thanks guys! I'm expecting the spokes, which I will need to cut and thread to build my 24" 5304 front wheel before weeks end.

I have very little (16") experience with these BLDC motors/controllers, and expect to get "up to speed" in a hurry.


Patience is for fishermen.

:lol:

-S

 

[RatoN]

Heh,

I have BIG vibrations coming from my 5304, now.

The 96v controller experiment is NOT going according to plan. Probly missed a weld somewhere on the mosfets...
no i meant to say... the @#$%? mosfets!

It's like one of the phases is totally off. It's surly one of the small resistor thingy that is not soldered on one of the legs of the @#$%?% mosfet.

Do not try this at home folks btw, it is a nighmare.

and if you do try it anyway, good luck to you

:wink:

 

[Lowell]

Should be easy to track down the problem just be glad no smoke came out. The 5304 at 96v should be a monster... well as far as ebikes are concerned.

 

[RatoN]

lol, yeah,

I was expecting it to go BOOM. Had so many probs removing them ... and soldering the new ones in. On the first power on, the red light of the ctrl came on and nothing blewup... i just sat there looking at the little red light, puzzled.

I’ll get back on this with good news or with a failure report.

 

[knoxie]

Hello Raton

A few things to watch out for, the high and low transistors often fail as well as the gate resistors, use a DVM and check the resistor values around each phase, it takes steady hand and eye but is easy to do, the drive transistors are cheap and easy to change.

I have modified the controller to 150V now, I have also found a major problem in the penny pinching department with these controllers as well.

They are using screws with some simple silicon sleeving and a fibre washer to hold the fets to the heat sink, I have found on some controllers that the tabs of the fets are conducting through to the base of the heat sink, this is not good and may be a cause for fet damage esp. when running higher voltages.

I have replaced all of the fibre washers with nylon insutaling screw inserts (as on the voltage regulator) I have also for safe measure fitted insulating sheets under each fet as well.

Now pressing hard as I can there is no leakage, you need to test between the screw and the tab on the fet, I have seen varying readings from 30 meg ohms down to total short circuits.

Yo are right though modifying the controllers is very very time consuming and fault finding is even more so, its not something I would recommend unless you really feel the need, however if the controller hold up well at 100V then it will have been worth it, its looking fine and dandy now.

Good luck

Knoxie

 

[RatoN]

Hey Knoxie,

Read your post many times, and do understand some of it, but I'm afraid that i'm such a complet n00b at this that i don't even understand half of the explanation.

Just gonna try and figurout what is the problem and i will get back at you with precise questions, or at the very least explanation of the problem with pics. Or send it out to someone who knows how to test electronics, cause I don’t.

Thx

 

[Lowell]

The important part is the 1 piece shouldered washer which replaces the cheesy stock flat washer and piece of plastic? tubing. Go t you favorite local electronics shop and they should have them.

Click Here for Link

 

[RatoN]

It's already on there. It's made of white rubber. I don't think it will be a prob.

I'll try to post pics later.

btw sorry about the off topic folks.

 

[knoxie]

Yes Lowell

This is important also you don't need the heatsink paste if you use the washers as well.

Its working great so far, I am testing the controller at 37v 40A at the moment and its working great, once its run for a week or 2 I will run 72V again.

Good luck with the controller, you can chase your tail with them, if you have one of the fets sticking on coz a gate resistor has blown, it will shoot through and blow a fet straight away, I would always change the 5401 and 551 transistors, you will see them in pairs next to each phase.

Testing resistances between phases and phases and the gates of others fets will quickly let you diagnose if there is anything wrong. I spent 2 hours checking it through before i powered it up! it was worth it as I found a couple of short circuits!!

Good luck

Knoxie