Search found 4423 matches

by Punx0r
Mar 16 2020 4:10am
Forum: Motor Technology
Topic: 60kW 400V EV Motor Controller
Replies: 6
Views: 1798

Re: 60kW 400V EV Motor Controller

It was running from 3-phase 400V AC mains but I think it could also take a lower voltage single phase AC input and boost the voltage and convert to 3 phase. No idea if it could take a DC input - suspect it might but it wasn't in the manual. It was a WEG unit. IGBT based thing.
by Punx0r
Mar 15 2020 6:41am
Forum: Motor Technology
Topic: 60kW 400V EV Motor Controller
Replies: 6
Views: 1798

Re: 60kW 400V EV Motor Controller

I'm pretty sure the last 3 phase 400v industrial induction motor drive I messed with could also drive permanent magnetic motors via a sin/cos resolver. It was about 30kW and about the size of 1.5 shoe boxes
by Punx0r
Mar 15 2020 5:33am
Forum: General Discussion
Topic: Bitcoins
Replies: 359
Views: 68609

Re: Bitcoins

Image
by Punx0r
Mar 12 2020 7:07pm
Forum: E-Vehicles General Discussion
Topic: France bans illegal eMTB tuning with fines up to € 30,000
Replies: 38
Views: 3911

Re: France bans illegal eMTB tuning with fines up to € 30,000

"the dyno result is 251 watts - bring out the guillotine!"
by Punx0r
Mar 11 2020 8:27am
Forum: General Discussion
Topic: Need help with 80v Greenworks/Kobalt/Stiga chainsaw speed controller
Replies: 17
Views: 2244

Re: Need help with 80v Greenworks/Kobalt/Stiga chainsaw speed controller

My guess was going to be a simple thermistor return in the "dumb" battery to the controller in the "smart" tool to provide battery temperature protection, but if it's a PWM signal serving some purpose or other that's a bit of a nuisance. You might be able to salvage the board fro...
by Punx0r
Mar 10 2020 8:35am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 132
Views: 8744

Re: Electric Racing Chainsaw Build, Help Please

Boo. Although I wonder if doing so would exceed some design safety margin or whether they know from experience it will instantly grenade...
by Punx0r
Mar 10 2020 4:03am
Forum: EBike Technical
Topic: How to disassemble motor adapter from sprocket/freewheel?
Replies: 21
Views: 2197

Re: How to disassemble motor adapter from sprocket/freewheel?

Or a pair of digital or vernier calipers and a good eye
by Punx0r
Mar 10 2020 4:02am
Forum: Motor Technology
Topic: Hunstable HET Electric turbine
Replies: 10
Views: 1085

Re: Hunstable HET Electric turbine

If it does work then it perhaps neatly answers the question of whether flux from end turns in a normal radial motor produces torque or not. I mean, it doesn't, but in the past certain people have insisted it does. There'd presumably be no point to this "HET" design if end turns normally di...
by Punx0r
Mar 10 2020 3:44am
Forum: E-Vehicles General Discussion
Topic: France bans illegal eMTB tuning with fines up to € 30,000
Replies: 38
Views: 3911

Re: France bans illegal eMTB tuning with fines up to € 30,000

The earliest commonly cited speeding fine for a motor vehicle is from 1896 in Kent, England where the driver was doing 8mph in a 2mph limit. I'm sure I've seen an earlier one from Germany, though, where the driver's speed was simply stated as being so furious it caused the curtains of a nearby build...
by Punx0r
Mar 08 2020 6:10am
Forum: General Discussion
Topic: Fatal ebike crash trial
Replies: 31
Views: 3655

Re: Fatal ebike crash trial

Hmm, you mean in Australia and elsewhere, passengers can be consuming alcohol having a grand old time while traveling in the vehicle so long as the driver passes the blood test? Yes, but most countries as well as far as I know. Here the old bill would take a dim view of a driver swigging from a can...
by Punx0r
Mar 07 2020 5:32pm
Forum: General Discussion
Topic: Fatal ebike crash trial
Replies: 31
Views: 3655

Re: Fatal ebike crash trial

That "open containers" law is AFAIK a peculiarly U.S. thing
by Punx0r
Mar 07 2020 5:56am
Forum: E-Vehicles General Discussion
Topic: Adding capacitors for long battery wires
Replies: 29
Views: 2844

Re: Adding capacitors for long battery wires

Ebike style controllers already have plenty of onboard capacitors. It's the smaller, RC style controllers that don't
by Punx0r
Mar 06 2020 2:39pm
Forum: E-Vehicles General Discussion
Topic: Adding capacitors for long battery wires
Replies: 29
Views: 2844

Re: Adding capacitors for long battery wires

They do, but your cells are not at risk - it's the controller out there on the other end of the wires on it's lonesome. That's why any caps have to be as close to the controller as possible.
by Punx0r
Mar 05 2020 10:01am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 132
Views: 8744

Re: Electric Racing Chainsaw Build, Help Please

Looks like a good candidate. Any idea on pricing and availability?
by Punx0r
Mar 05 2020 3:39am
Forum: EBike Technical
Topic: How to disassemble motor adapter from sprocket/freewheel?
Replies: 21
Views: 2197

Re: How to disassemble motor adapter from sprocket/freewheel?

They're all listed in the link I posted above
by Punx0r
Mar 05 2020 3:16am
Forum: General Discussion
Topic: Fatal ebike crash trial
Replies: 31
Views: 3655

Re: Fatal ebike crash trial

The punishments for cycles are usually lower than for motorised vehicles: the drink drive limit doesn't apply, you just have to not be shitfaced, running red lights, going wrong way down a one-way street, cycling on the pavement(sidewalk) carry a fixed fine of £50.
by Punx0r
Mar 04 2020 11:04am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 132
Views: 8744

Re: Electric Racing Chainsaw Build, Help Please

speedmd wrote:
Mar 04 2020 9:13am
The Avid claims 12000 rpms on the AF125 https://avidtp.com/product/evo-motors/
Shame they don't do an AFR62.5, it'd be perfect!
by Punx0r
Mar 04 2020 8:52am
Forum: Motor Technology
Topic: What's so bad about low impedence?
Replies: 30
Views: 2203

Re: What's so bad about low impedence?

It all goes back to supply voltage. The power you can get out of a load is given by its resistance (at DC) or its impedance (at AC.) well there's the flaw in your thinking. generally power goes into a load. hard to believe you actually went to MIT. This is irrelevant semantics. A motor is a load fr...
by Punx0r
Mar 04 2020 8:30am
Forum: Battery Technology
Topic: Just found 2000 LiFePo 18650 cells in the recycler
Replies: 9
Views: 818

Re: Just found 2000 LiFePo 18650 cells in the recycler

If it won't cost you to take them back to the recycler if they turn out to be no use then you might as well take them ;) Even with diminished capacity they're potentially useful for stationary storage if you (or someone you sell them to for cheap) can be bothered to spot weld them all together.
by Punx0r
Mar 04 2020 8:23am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 132
Views: 8744

Re: Electric Racing Chainsaw Build, Help Please

We may have a winner! https://www.autocar.co.uk/car-news/industry/uk-firm-launch-worlds-most-power-dense-ev-motor I guess the claimed weight is the rotor and the motor's part of the housing shared with the controller & diff and it'll be a year even before prototypes are made, but it's 220kW for ...
by Punx0r
Mar 04 2020 4:27am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 132
Views: 8744

Re: Electric Racing Chainsaw Build, Help Please

For dickering about the world of RC motors taps out at 10-12kW (input power, shaft power will be less): *Hacker make some nice (but expensive) motors: -Their largest inrunner: https://hackermotorusa.com/product-category/hacker-brushless-motors/outrunners/hacker-q100-9500-watt-brushless-motors/ 1.8/2...
by Punx0r
Mar 04 2020 3:30am
Forum: General Discussion
Topic: Fatal ebike crash trial
Replies: 31
Views: 3655

Re: Fatal ebike crash trial

I imagine the difference would have been large: causing death by dangerously driving something defined as a motor vehicle is a well-defined offence that carries relatively stiff penalties, whereas there is often by such specific offence for bicycles and "dangerous cycling" penalties are re...
by Punx0r
Mar 03 2020 9:13am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 132
Views: 8744

Re: Electric Racing Chainsaw Build, Help Please

Incremental prototypes would be a great way to get a feel for the technology and which direction to head in. Some 12S lipo packs, a big ~5kW RC motor and a sensorless controller on a smaller saw would be an easy way to dip a toe.
by Punx0r
Mar 03 2020 9:08am
Forum: General Discussion
Topic: Trouble With the Car You're Still driving?
Replies: 64
Views: 4718

Re: Trouble With the Car You're Still driving?

Yes, fuseboxes have traditionally been (and should be) readily accessible with no tools required. Anything else is lazy design.
by Punx0r
Mar 03 2020 5:33am
Forum: General Discussion
Topic: Electric Racing Chainsaw Build, Help Please
Replies: 132
Views: 8744

Re: Electric Racing Chainsaw Build, Help Please

If you think you can get away with not having to have controller and batteries mounted on the saw then it will make things much easier (if the rules get rewritten to accommodate electric saws I could see them stipulating everything has to be on the saw - no umbilicals). I'd go for a backpack rather ...