Search found 4362 matches

by Punx0r
Jan 22 2019 3:49am
Forum: Motor Technology
Topic: Alternator into BLDC
Replies: 12
Views: 240

Re: Alternator into BLDC

IIRC many alternators are 6 phase
by Punx0r
Jan 18 2019 10:31am
Forum: Battery Technology
Topic: The "thermal management of LiPo" thread!
Replies: 91
Views: 7202

Re: The "thermal management of LiPo" thread!

For simplicity I would be looking at aluminium bus bars with a cooling passage passing up the centre and keep the flow rate up high enough to ensure the first and last cell served by the coolant aren't at greatly different temperatures. You could maybe use an off the shelf extrusion or hollow sectio...
by Punx0r
Jan 18 2019 4:09am
Forum: Battery Technology
Topic: The "thermal management of LiPo" thread!
Replies: 91
Views: 7202

Re: The "thermal management of LiPo" thread!

I have seen this exact configuration in some commercial packs, terminated onto a water-cooled baseplate. Good reason to think tab cooling on pouch cells would be more effective though (Couple of reseach papers attached)!
by Punx0r
Jan 16 2019 4:09am
Forum: Motor Technology
Topic: APL's DIY axial-flux motor
Replies: 141
Views: 2129

Re: APL's DIY axial-flux motor

Good article! :thumb: Check out the photos of the melted (transformer?) core due to a lamination short!
by Punx0r
Jan 16 2019 3:26am
Forum: General Discussion
Topic: Fiat Chrysler pays millions...
Replies: 17
Views: 263

Re: Fiat Chrysler pays millions...

Diesel cars, such as the ones you are talking about, are common in many European countries. These countries also have high urban air pollution attributable to diesel exhaust, often above legal limits. Even a modern "clean" diesel puts out unacceptable particulate and NoX emissions. Petrol/gasoline c...
by Punx0r
Jan 15 2019 3:42am
Forum: Motor Technology
Topic: Room temperature superconductors
Replies: 6
Views: 185

Re: Room temperature superconductors

Think more of one solid material held in a highly compressed state with an outer sleeve of another solid material than a waiting-to-violently-explode compressed gas.
by Punx0r
Jan 15 2019 3:24am
Forum: General Discussion
Topic: Fiat Chrysler pays millions...
Replies: 17
Views: 263

Re: Fiat Chrysler pays millions...

The cars were always capable of conforming to the required emissions standards, it was just deemed commercially advantageous to try and cheat the test instead.

The standards are not "stupid" and they do reduce urban air pollution, which is a serious health issue for millions of people.
by Punx0r
Jan 14 2019 3:46am
Forum: Motor Technology
Topic: Infinitum PCB stator AC motor
Replies: 2
Views: 112

Re: Infinitum PCB stator AC motor

Is this likely to scale to 10+ kW motors?
by Punx0r
Jan 11 2019 3:12am
Forum: Battery Technology
Topic: Phylion Prismatic Cells
Replies: 1
Views: 162

Re: Phylion Prismatic Cells

Seems like a lot of confusing the effects of cell chemistry with cell construction (and vice versa) there...
by Punx0r
Jan 08 2019 3:23am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3228
Views: 109793

Re: Wind and Solar vs Coal, Gasoline, Nuclear

Germany energy consumption has gone from 250 to 330 mtoe since 1968. 30%. In 2018 Germanys primary energy consumption has bei 12,900 PJ, the lowest since the 1970s Unless there was a huge, permanent decline from 1968 to sometime in the 70's that the swamps the changes since then, these two statemen...
by Punx0r
Jan 08 2019 3:17am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3228
Views: 109793

Re: Wind and Solar vs Coal, Gasoline, Nuclear

That's a huge error band range. So large that it could throw everything off. In theory, we could only be 0.1C hotter than it'd been before the industrial revolution. Or it could have been an ice age. Is this view based on mathematics or opinion? It's possible that it was hotter before if you believ...
by Punx0r
Jan 07 2019 6:40pm
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3228
Views: 109793

Re: Wind and Solar vs Coal, Gasoline, Nuclear

neptronix wrote:
Jan 07 2019 2:17pm
That's a huge margin of error!!
It's, at worst, approx. +/- 1°C at an uncertainty of 2 sigma (K=2). The furthest extent of the error band does no exceed the (very accurately determined) temperature of recent years.

What problem do you believe this presents in determining a general trend?
by Punx0r
Jan 07 2019 6:33pm
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3228
Views: 109793

Re: Wind and Solar vs Coal, Gasoline, Nuclear

neptronix wrote:
Jan 07 2019 12:58pm
What's more interesting to me is at least a 150,000 year timespan. Because that will show you approximately 1 climate cycle in full.
Quick Google search:
Capture.JPG
Capture.JPG (77.69 KiB) Viewed 92 times
by Punx0r
Jan 07 2019 6:23pm
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3228
Views: 109793

Re: Wind and Solar vs Coal, Gasoline, Nuclear

In 2018 Germanys primary energy consumption has bei 12,900 PJ, the lowest since the 1970s Impossible! Since 1970 the population of Germany has grown from 61 to 82 million (+34%) while the economy grew by average 0.51% per year (27.7% compounded). We have been repeatedly told population, energy use ...
by Punx0r
Jan 07 2019 6:03pm
Forum: Large EV General Discussion
Topic: Tesla M3 teardown information video - Hallbach Array Motor
Replies: 15
Views: 433

Re: Tesla M3 teardown information video - Hallbach Array Motor

So why doesn't the engine in my road car rev to 15,000 rpm like an F1 car? Do everyday vehicles perhaps have different engineering priorities compared to gram-shaving, money-no-object, balls-to-the-wall racing machines? ~400V is a common upper limit for everyday electricity in an industrial setting,...
by Punx0r
Jan 07 2019 3:20am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3228
Views: 109793

Re: Wind and Solar vs Coal, Gasoline, Nuclear

In November 2016, the day after Donald Trump won US presidential election, shares of Peabody Energy surged more than 50 percent.[38][39] On April 3, 2017 it emerged from bankruptcy and started trading on the NYSE with a ticker symbol of BTU.[16] In October 2017, a judge ruled that Peabody Energy's ...
by Punx0r
Jan 06 2019 3:44pm
Forum: Electric Aircraft
Topic: Rolls-Royce world’s fastest all-electric aircraft
Replies: 5
Views: 243

Re: Rolls-Royce world’s fastest all-electric aircraft

It's wonderful to see a commitment to advancing electric flight. Does sprinting to top speed take longer in a plane compared to a wheeled vehicle? I.e. is the burst of peak power required to be sustained for longer, leading to thermal problems with the battery and motor? I ask because the targetted ...
by Punx0r
Jan 06 2019 3:24pm
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3228
Views: 109793

Re: Wind and Solar vs Coal, Gasoline, Nuclear

Peabody did go bankrupt in 2016 :wink:
by Punx0r
Jan 03 2019 11:06am
Forum: Battery Technology
Topic: Would anyone have info on this huge cell?
Replies: 4
Views: 196

Re: Would anyone have info on this huge cell?

looks a little wrinkly!
by Punx0r
Jan 03 2019 4:10am
Forum: Large EV General Discussion
Topic: 1971 Super Beetle EV Conversion - Using a salvage Leaf
Replies: 15
Views: 366

Re: 1971 Super Beetle EV Conversion - Using a salvage Leaf

Limiting system voltage to try and limit motor torque might not work in a way that leaves you with sufficient top speed. Motor controllers can produce very high phase (motor) currents at low voltage when motor speed (and BEMF) is low by functioning like a buck converter. I fear you might find that y...
by Punx0r
Jan 02 2019 6:08pm
Forum: Large EV General Discussion
Topic: 1971 Super Beetle EV Conversion - Using a salvage Leaf
Replies: 15
Views: 366

Re: 1971 Super Beetle EV Conversion - Using a salvage Leaf

Thats the plan. My concern is if I undervolt, how it would affect the inverter and the motor itself. I researched undervoltage on AC motors last night, and it seems there's a drop in efficiency, and it CAN be damaging if the motor is running a normal load. Beware that a lot of the information you m...
by Punx0r
Jan 02 2019 5:48pm
Forum: Large EV General Discussion
Topic: Video- Excerpt from Oracle ‘s ER Larry Ellison talking about Tesla and Elon
Replies: 10
Views: 255

Re: Video- Excerpt from Oracle ‘s ER Larry Ellison talking about Tesla and Elon

Double the sales of second place is very impressive and even more so being an EV. Doe these figures include pre-orders or just the cars actually built/delivered?
by Punx0r
Dec 28 2018 6:00am
Forum: E-Vehicles General Discussion
Topic: The tipping point is just a few years out
Replies: 13
Views: 508

Re: The tipping point is just a few years out

...unless there's carbon pricing on fossil fuels.
by Punx0r
Dec 27 2018 3:46pm
Forum: E-Vehicles General Discussion
Topic: The tipping point is just a few years out
Replies: 13
Views: 508

Re: The tipping point is just a few years out

Why will the driverless taxi be so much more successful than the traditional kind that it will all but eliminate private ownership of motorised transportation?