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Topic: Mopeds (Read 2336 times) previous topic - next topic

TomGeorge

Hi,
Here in Australia we have a problem with the states each having their own legislation on E-Bikes.
This link is from a company that sells addon kits as well a E-Bikes.

https://dillengerelectricbikes.com.au/blogs/news/electric-bikes-and-the-law

200W without pedal assist.
250W with pedal assist.
Also motor must be speed limited to 25kph

Each state has a different regulation on where you can ride them.

Tom... :)
Everything runs on smoke, let the smoke out, it stops running....

GoForSmoke

I looked at Australian ultralight rules and wonder if ultralight rotorcraft fit in there since they can take winds better or so I read.
By those rules I saw mass limits 300kg to 480kg but no speed limits and once you're up there's no stop signs. 

1) http://gammon.com.au/blink  <-- tasking Arduino 1-2-3
2) http://gammon.com.au/serial <-- techniques howto
3) http://gammon.com.au/interrupts
Your sketch can sense ongoing process events in time.
Your sketch can make events to control it over time.

xiander

I often see electric bikes on the streets of new York. This is not the future, this is reality.

GoForSmoke

I've seen here e-bikes that look and move like motorcycles only thinner.

Hack-a-day has an article on converting car alternators to 3A motors.
1) http://gammon.com.au/blink  <-- tasking Arduino 1-2-3
2) http://gammon.com.au/serial <-- techniques howto
3) http://gammon.com.au/interrupts
Your sketch can sense ongoing process events in time.
Your sketch can make events to control it over time.

Robin2

Hack-a-day has an article on converting car alternators to 3A motors.
Should that be 30A?

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

GoForSmoke

https://hackaday.com/2020/01/16/car-alternators-make-great-electric-motors-heres-how/

Quote
Given a controller, there is one more requirement for our alternator to become a motor, it must have a DC supply to its rotor winding. It needs to have about 2 or 3A flowing through it, for which a current-limited PSU module performs the task admirably. Having to use that power makes the motor a bit less efficient than a permanent magnet one, but the cost of a scrap alternator is hard to beat.
That's Amps converted to 3-phase AC through an ESC.

https://hackaday.com/2016/08/14/alternator-becomes-motor-for-this-electric-go-kart/

While the frame for [Adrian Georgescu] and [Masoud Johnson]'s build was a second-hand find, the powertrain is all custom. They targeted a power output of 3 kW but found no affordable motors in that range. So, in true hacker fashion, they rolled their own motor from a used Subaru alternator. The three-phase motor controller came from an electric scooter, three LiPo packs provide the juice, and a pair of Arduinos takes care of throttle control, speed sensing, and sending data to the virtual dashboard on an Android phone. Some lights and a snappy red and black paint job finished off the build. While the video below shows that the acceleration isn't exactly neck-snapping in the Tesla style, the e-kart can build up to a good speed - 53 km/h. Not too shabby, and no deafening engine right behind your head.

GFS


1) http://gammon.com.au/blink  <-- tasking Arduino 1-2-3
2) http://gammon.com.au/serial <-- techniques howto
3) http://gammon.com.au/interrupts
Your sketch can sense ongoing process events in time.
Your sketch can make events to control it over time.

Robin2

#21
Jul 06, 2020, 07:34 pm Last Edit: Jul 06, 2020, 07:36 pm by Robin2
That's Amps converted to 3-phase AC through an ESC.
That 3 amps is just to energise the electrormagnet that is the rotor

You also need lots of amps at 36v or 48v for the stator. For 3kW input at 48v that would be 62.5 amps. If the 3kW is the output then you would need a lot more amps to offset the efficiency.

When working on the car the alternator may have been designed to produce 60 or 70 amps at 12v DC.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

GoForSmoke

I should have quoted more from the link yinz didn't read:

Quote
We've found that an alternator drives well as a motor from a 36V or a 48V supply, and as long as a controller with enough power is used then they do so reliably. A quick AliExpress search for "brushless motor controller 1500W" turns up plenty of choice.

Given a controller, there is one more requirement for our alternator to become a motor, it must have a DC supply to its rotor winding. It needs to have about 2 or 3A flowing through it, for which a current-limited PSU module performs the task admirably. Having to use that power makes the motor a bit less efficient than a permanent magnet one, but the cost of a scrap alternator is hard to beat.
I don't think they're trying for more than 3HP. 
Weaker DC motors cost a lot more.

Yes the 2-3 Amps is for the rotor and covers the field needed for low-RPM torque to start with.
1) http://gammon.com.au/blink  <-- tasking Arduino 1-2-3
2) http://gammon.com.au/serial <-- techniques howto
3) http://gammon.com.au/interrupts
Your sketch can sense ongoing process events in time.
Your sketch can make events to control it over time.

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