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[DonTom]

Has Zero now invented the Sevcon controller as well?

There have been RC model cars for years that have the same technology

I have no idea who invented what, but yeah, as soon as a modern technology is designed, if useful, it becomes common place almost overnight no mater how complicated it was for the first few people to design it. Stuff is often very easy to mass produce after you once have all the technology required. Then prices come down fast and can even be used in toys.

-Don-  in cold Cold Springs Valley, NV

[ESokoloff]

The motor doesn't run on simple DC.

Actually it’s a 3-phase AC motor.

[DonTom]

Actually it’s a 3-phase AC motor.

See here, where is says "MY2017 Zero SR. Scope at Sevcon M3 Output Terminal".  The photo of the oscilloscope on the lower right of that page. You want to guess whose bike that is?  I have no idea how to edit the Manual, Shadow did that part for me, but that was after we checked my bike on my  oscilloscope.

The reason I did that is because of many people who do not know the difference between a "wave shape" and a "sinewave."  So  I wanted people to see it for themselves.

Such as where the Unofficial Manual says:

"This takes power from DC battery bus, encoding three-phase sine waves to match the motor's position sensor to apply torque precisely to the motor."

And:


"Motor commissioning refers to aligning the controller's sine wave programming against the motor using its position sensors."

Brian, for the sack of accuracy, please change the word "sine wave" to "wave shape". As you can see, that is FAR from a "sine wave" coming out of the controller to the motor. In fact, PWM is  a type of square wave, as you can see from my photo.

This is a sine wave.

This is a Square Wave.

Both are "wave shapes".

Anything in-between the two, just use the word "wave shape" which can even include sine and square wave as a shape can be anything.

I am not so sure if I would call it "3 phase" or not. But the motor controller is outputted in 3 phases, each 120° apart. I could accept it being or not being called "3 phase". But I personally think of three phase  as looking like this.

-Don-  Reno, NV


 

[centra12]

RC cars don't:

• Have to run in the rain.
• Be reliable for more than a mile or so.
• Run on more than low voltage.
• Pull more than a couple amps.

Yeesh.

1.  Running in the rain and mud
2.  My RC cars have been working for years with countless miles, what should be broken, is a
     maintenance-free engine?
3   The higher the voltage the easier the control 
4   Zero was too stupid to go to 300 volts with the SR/F

[centra12]

I have no idea who invented what

You would just have to learn about Zero's technology.

[Crissa]

Well, three pulse patters would be three-phase, Don.

-Crissa

[DonTom]

Well, three pulse patters would be three-phase, Don.

-Crissa

Yeah, the perfect name, IMO, for the Zero's output would be "3 phase PWM". Good info. on page 8 here.

-Don-  Reno, NV

[ESokoloff]

Actually it’s a 3-phase AC motor.

See here, where is says "MY2017 Zero SR. Scope at Sevcon M3 Output Terminal".  The photo of the oscilloscope on the lower right of that page. You want to guess whose bike that is?  I have no idea how to edit the Manual, Shadow did that part for me, but that was after we checked my bike on my  oscilloscope.

The reason I did that is because of many people who do not know the difference between a "wave shape" and a "sinewave."  So  I wanted people to see it for themselves.

Such as where the Unofficial Manual says:

"This takes power from DC battery bus, encoding three-phase sine waves to match the motor's position sensor to apply torque precisely to the motor."

And:


"Motor commissioning refers to aligning the controller's sine wave programming against the motor using its position sensors."

Brian, for the sack of accuracy, please change the word "sine wave" to "wave shape". As you can see, that is FAR from a "sine wave" coming out of the controller to the motor. In fact, PWM is  a type of square wave, as you can see from my photo.

This is a sine wave.

This is a Square Wave.

Both are "wave shapes".

Anything in-between the two, just use the word "wave shape" which can even include sine and square wave as a shape can be anything.

I am not so sure if I would call it "3 phase" or not. But the motor controller is outputted in 3 phases, each 120° apart. I could accept it being or not being called "3 phase". But I personally think of three phase  as looking like this.

-Don-  Reno, NV

Not sure about all that......  Too much to digest.


This should clear up things a bit on 3-phase AC power.

[Crissa]

Yes, I would definitey agree that it's more Pulse width Modification - since that's how we change speed - even big power generation have to modify their frequencies so that the grid remains stable.  Every time demand increases, the actual frequency begins to drag until they add more.

And while we want them to provide nice sine waves, the sine waves aren't required in the definition of three-phase.  They just work better for the purpose of providing power without hiccups.

So it's very similar, even if what we're doing with the power is different.

-Crissa

[DonTom]

Not sure about all that......  Too much to digest.

That was a pretty clear video. Notice how it said in the beginning it's "different from how a 3 phase motor uses power".  But there are accepted names, accurate or not.

IMO, the very worse case name is what they commonly call a "Modified Sine Wave Inverter". It's not even close to a sine wave, but that is the name that is commonly used and accepted. It's really a modified square wave, but then they may not sell as well to some people. In that case, I think the name  as a lie designed for marketing, but is a very commonly accepted lie.

"A modified sine wave inverter actually has a waveform more like a square wave, but with an extra step."

IAC, knowing what it really is is more important than knowing the common name it is called. But it can lead to confusion in some manuals, unless explained as well as in your video.

-Don-  Reno, NV

[BrianTRice@gmail.com]

I have absolutely no idea. Isnt the controller under the seat? I bought this bike because i was sick of pulling apart my last bikes to keep them working. And here i am, i changed the handlebar, with another stock handlebar- havent screwed with or messed with anything else, and its dead anyway. I havent unplugged anything, i havent shifted or adjusted anything, i havent washed it (i havent owned it long enough to even WARRANT a washing), nothing.

As for living somewhere wet, i live in vancouver. Pretty sure vancouver is about as wet as it gets, without being underwater. Even the dealership says water isnt an issue for these bikes. then followed it up with a, "well it killed yours though" essentially. Cool. Glad i could be the one in a million.

Well, that's awful. I can't even be encouraging by pointing out that I rode my 2013 DS in the rain and sometimes snow in Seattle for almost 3 years.

Basically, water shouldn't have gotten through there.

The only thing that matters on this thread is trying to figure out what could lead to that and maybe how to prevent full damage if a symptom is detected.

The "controller plug" sounds like the Sevon's AMPseal 34-pin connector described here:
https://zeromanual.com/wiki/Unofficial_Service_Manual#Controller_Connections

I can't work out how that would fail without it being a defect in the pin insertions during assembly or an incredible torrent of water. Did water under there really damage the controller? I'd love to see a teardown if possible to prove causation.

[BrianTRice@gmail.com]

For all of the aspersions cast in this thread, know that Sevcon's Gen4 controllers, while not the most advanced at this point, are pretty solid and mostly serve the industrial forklift and light truck market.

The AMPSEAL connector ought to be IP-67 rated, but sourcing the right claim for what's on there is tricky. Sevcon rates the controller overall as IP-66. The connector shouldn't be compromised if all the pins are filled in, but again that would be an assembly defect.

If you're going to claim something, cite relevant sources.

[ESokoloff]

Not sure about all that......  Too much to digest.

That was a pretty clear video. Notice how it said in the beginning it's "different from how a 3 phase motor uses power".  But there are accepted names, accurate or not.

IMO, the very worse case name is what they commonly call a "Modified Sine Wave Inverter". It's not even close to a sine wave, but that is the name that is commonly used and accepted. It's really a modified square wave, but then they may not sell as well to some people. In that case, I think the name  as a lie designed for marketing, but is a very commonly accepted lie.

"A modified sine wave inverter actually has a waveform more like a square wave, but with an extra step."

IAC, knowing what it really is is more important than knowing the common name it is called. But it can lead to confusion in some manuals, unless explained as well as in your video.

-Don-  Reno, NV

Pure Sine Wave vs Modified Sine Wave .......



NOTE: This example is Single Phase but gives the basic example of converting D.C. into A/C.

[DonTom]

Brian,

I find the statement below to be confusing. Output of what? If you mean the motor controller, below is very inaccurate and even contradicts itself:

"The switching attempts to produce a smooth sine wave to each output terminal via Space vector modulation strategy of PWM."

The 3 output terminals of the Sevcon motor controller have NOTHING to do with sine waves.  At that point, it is PURE 100% PWM which is far from a sine wave as my 2017 SR photo in your manual shows.

But a sine wave can be used in the process to make PWM. Likewise PWM can be converted into a sine wave. But the output of the Sevcon Motor controller is far from being a sine wave. And certainly not "smooth".

Compare my M3 with my scope (in your manual here) to this "pure sine wave" and you will see NO comparison at all.

BTW, I showed M3 there, but M1 and M2 would show as the exactly the same, just timed 120° differently between each.

Please change to something such as:

"The switching circuits produce PWM  to each Sevcon output terminal via Space Vector Modulation."

-Don-  Reno, NV

[BrianTRice@gmail.com]

These controller theory posts are a totally inappropriate discussion to be having on Rangerx's thread on his bike failure.