At the MeetUp last Sunday I mentioned the concept of an electric transmission called "Wye-Delta" (aka Star-Delta.) Basically it means that the coils in the motor are re-wired with an external switch so that the rider has a selectible choice between torque and RPMs. In fact the theoretical difference is 1.73... The Delta mode is 73% faster but the Wye mode has 73% more torque.

The technique was first developed for industrial motors where manufacturers were looking to reduce the power surge seen when starting up motors from zero rpms.

Unless you are DIY, you would be looking at taking your motor to a competent motor shop for them to open up the motor case and install the extra connections and wires, then ya need a fairly heavy-duty contactor switch that can switch 48V(?) 20A(?) DC loads.

Hard for me to explain all this, but here it is in the words of the very capable Doctorbass from Quebec:

Part 1 -



Part 2 -




...and the pudding (proof as speed trials on the street):



Hope you like
Lock

that is pretty cool

probably not worth mentioning as it is ancient history but when I started selling Hub Motors in 2001 it was the Crystalyte Dual Speed motors kits. Sold a bit under 1,300 motor kits before 2008 when they went out of fashion.

You could have also got a 5 Speed Hub Motor but people didn't like it because it needed several relays and handlebar selector switches.

Crystalyte never saw a reason to take their Dual Speed Controllers higher than 20A which drove a nail into the Dual Speed motor kits fate. Everyone and his dog wanted 35A as the Minimum on 72V.

The chap who designed the Crystalyte Dual Speed motor is a Toronto native who worked for the Federal government as an Engineer.

I actually offer this service if anybody is interested. My bike goes 48km/h on 72v, but with this I can go 84km/h. I'm giving a discount off of a discounted price to members here and charging $150 including all of the parts required and a shunt mod of your controller to allow for those top speeds (55km/h on 48v). If you've already modded your controller I'll do it for $120.

http://toronto.kijiji...

I hope I'm not spamming here, if anybody feels that way please let me know and I will remove my post.

Thanks,

Stewart Robb

seems like lock and a former member?who is he?ancient history?? are trying to trump you Stewart because they think they invented it and maybe they are hurt because you brought it back up and you deliver it and maybe they didn't at the time they wanted to???

don't know why lock is ignoring me?

don't care really,cause life's too short and i just want to go forward and i can see and i have some vision for all of us unhappy old fools?

always remember- that when you are at the top of the mountain-kids will always try to knock ya off-

called bullying,no?

locks got a lot off pull around here cause he has a lot of posts?


come on hit me-or double me...backgammon slang,lock...


you disappear when things aren't going your way?

maybe when i said your the hero for fixing rays bike he got hurt

guess thats why lock hasn't contacted you and escorted you to become a sponsor?

i thought you were bigger than that lock
your next post will prove your right or my wrongs

remember the post were we will all split up and start clammmoring for the rights or throngs?

please don't go there cause we will all loose...

themas fighting words and i hope you like me are peacemakers and we wont make stew feel bad for being good guy,like we are peacemakers and good guys/

who the hell has an avatar-former member?watt did they cut it off and you don't have a member anymore?

Jesus H Christ give me a break and please help me before i drown,again,pleas?

seems like lock and a former member?who is he? are trying to trump you Stewart because they think they invented it and maybe they are hurt because you brought it back up and you deliver it and maybe they didn't at the time they wanted to???

The theory of delta-wye (star) circuits and its practical application to reducing startup loads in industrial motors has been understood for decades... a hundred years perhaps. The "former member" was Joshua Goldberg, one of the fathers of the modern ebike movement in North America. The first person to import Crystalyte hub motors from China for example.

Tks
Lock

The electrics are still the area in which I'm very much a student.

What is described here - Performance aside - Is this similar to what Motorino is doing with what they call "CCT gears"?

http://motorino.ca/cc...

I don't think so, but the easy way to check is to count the number of phase (power) wires exiting the motor... Most of what they talk about seems to be marketing-speak about PWM controllers and perhaps their design is more efficient than others at varying PWMs as conditions change. The mention of more/larger magnets suggests mainly a "bigger" motor (higher magnetic density) de-rated as "500W" but able to handle much higher amp loads when called for... Delta-Wye is about achieving more with less, and I expect Motorino just "went big" w/motor and controller, which is not a bad thing. Fred is seeing 1800-2000W peaks from his Motorino which is pretty exceptional for most "500W" rated controllers.
http://www.ebikerider...

Lock

Toronto_Joe

Wye-Delta is NOT what Motorino uses for CCT. Wye-Delta may actually be rather difficult to fit into the Motorino design.

What Motorino uses is modified pulse shaping (PWM - pulse width modulation), instead of sine waves. Also, the motor is massive, and the controller can deliver 40 to 41A peak (on startup). Basically (as Lock has mentioned), almost 2000W (1979.1 measured peak Watts at 41 peak amps, so the voltage was 48.27V at the time) is delivered when needed. I believe that the three position switch also tells the controller to limit current (especially for the economy mode). The controller used in the Motorino is a fairly standard part, and is programmable (one of the "unused" connectors is used for this purpose). I believe that the processor uses some Motorino specific coding that drives the pulse shaping. Which is why I wouldn't try standard controller reprogramming software on it.

Now Wye-Delta involves extra motor taps, but, as far as I know, the Motorino motor is wound to facilitate the PWM trickery instead. It is extremely likely that one will interfere with the other. But, it would be reasonable to "shunt mod" the Motorino.

I don't know how effective the pulse shaping actually is -- I would have thought there would be a larger difference between "torque" and "speed" mode when hauling up a hill. My guess is that the torque actually peaks in a much narrower band and I haven't caught it yet. I do know that "speed" mode in considerably more power-hungry. So far, I have measured "speed" mode as 15% more power-hungry than "torque" mode (keeping other conditions as close as possible, and with the caveat that my measurements may be too coarse to be accurate). Of course, if you remove the current limiter, the difference is enormously magnified at higher speed.

With that in mind, I think Wye-Delta would provide a more significant difference, with the drawback of (1) additional motor winding complexity, and (2) switching complexity. A simple shunt mod could give MOST of the benefit, without the complexity. It is (in my opinion) more important that the Motorino comes with a massive motor (and, therefore, I have been thinking about the possibility of over-volting the thing to 60V). Stew, on the other hand (and I don't want to put words in his mouth -- this is my interpretation) appears to believe that over-amping is ok, but is hesitant to over-volt.

FredW

PS. Don't take me as an "expert" though -- I have only been using ebikes for two years, and have only had the Motorino since April. Its my commuter vehicle, but is rapidly becoming my hobby as well.

If you guys wish to read a technical discussion about delta-wye, knock yourselves out:
http://endless-sphere...


1oCk