Search found 4433 matches

by Punx0r
Mar 19 2019 10:59am
Forum: General Discussion
Topic: Boeing 737 Max 8 failures..an explanation ?
Replies: 10
Views: 198

Re: Boeing 737 Max 8 failures..an explanation ?

Grantmac wrote:
Mar 19 2019 10:07am
The best analysis I've seen is pointing to a lack of basic piloting skills which leads to not disengaging the autopilot then manually trimming the plane when there is a runaway trim.
Is this something they're likely to have time to do if they're not ready & prepared for it happening?
by Punx0r
Mar 19 2019 3:56am
Forum: Alternative Energy
Topic: Energy storage
Replies: 4
Views: 166

Re: Energy storage

The greater the temperature difference between your storage (thermal mass) and the useage temperature, the physically smaller/lighter your storge will be (but the requirement for effective insulation will increase). It's why we store hot water above the temperature we want to use it with and then di...
by Punx0r
Mar 18 2019 4:33am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

jonescg wrote:
Mar 17 2019 6:25am
A someone who worked in agriculture for many years, I can tell you that ridge is pretty barren and only suitable for light grazing of sheep. Seems a good use of the area to me.
:thumb:

It's a use the land can still perform perfectly well after installation of the turbines.
by Punx0r
Mar 17 2019 6:05am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

Now, I'm no geologist or cartographer, but on that google maps screenshot, the wind farm seems to occupy a hilly outcrop that doesn't look like it was even suitable for agriculture, let alone building on. But wind turbines work well on elevated areas like this. So, how can it be argued that wind tur...
by Punx0r
Mar 14 2019 3:13am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

Any time you quote gCO2/KWh that's a specific emissions measure.

Has China actually completed any commercial nuclear plant (from placing order to full operational status) in 10 years?
by Punx0r
Mar 13 2019 4:52am
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 145
Views: 6584

Re: Revolt RV-series motor review and comparisons

Help me understand this: Vout always equals Vin at any RPM or duty cycle. There's no high current voltage regulator or step down circuit in a controller. The mosfets either apply full battery voltage to the phases or they don't. Speed and torque control is not done by adjusting the voltage, but by ...
by Punx0r
Mar 12 2019 6:08am
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 145
Views: 6584

Re: Revolt RV-series motor review and comparisons

AP 12090 Battery amps: 3.2A Phase amps: 22A I'm not looking for an argument here, but as a spectator to this thread it looks like it might help to point out the crux of the problem here: If 20S li-ion (call it 72V) then controller power in is: 3.2 x 72 = 230W Controller efficiency is going to be ab...
by Punx0r
Mar 11 2019 5:00am
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 145
Views: 6584

Re: Revolt RV-series motor review and comparisons

Phase amps and battery amps do not necessarily track each other. You can have 6 battery amps and 90 phase amps. On my XB-502 scooter, the battery amps are usually 30-50% what the phases show under load. This is not unusual at all. I agree that you can have high phase currents at low battery current...
by Punx0r
Mar 09 2019 6:41pm
Forum: General Discussion
Topic: Clip - Drastically improved 3D printing technology?
Replies: 10
Views: 340

Re: Clip - Drastically improved 3D printing technology?

Interesting! This CLIP printing is what 3D should be/what it promised to be. Current 3D printing mostly sucks: It's not a production technique and only very limited use for prototyping. I'n principle I'm a fan of additive manufacturing, but each time I try to use it for prototyping it ends up being ...
by Punx0r
Mar 08 2019 9:14am
Forum: Battery Technology
Topic: LiFePO4 in 18650 format?
Replies: 64
Views: 2115

Re: LiFePO4 in 18650 format?

Simple solution: establish test variability by taking repeated measurements of the same cell in the same condition(e.g. test every day at different times for a week), assuming normal distribution of error, calculate standard deviation and multiply by 2 (standard coverage factor). That gives a +/- fi...
by Punx0r
Mar 07 2019 4:56pm
Forum: Battery Technology
Topic: LiFePO4 in 18650 format?
Replies: 64
Views: 2115

Re: LiFePO4 in 18650 format?

Assuming I'm looking at the correct datasheet, the manufacturer claims 70% capacity after 500 cycles: https://eu.nkon.nl/sk/k/29E.pdf
by Punx0r
Mar 02 2019 2:57pm
Forum: E-Vehicles General Discussion
Topic: New Nissan Leaf.. 50kw more power and 62kwhr battery
Replies: 28
Views: 1151

Re: New Nissan Leaf.. 50kw more power and 62kwhr battery

:bigthumb:

Would be interested to know who you get on especially regarding any issues with the OE electronicals playing ball (or not)
by Punx0r
Mar 02 2019 5:04am
Forum: E-Vehicles General Discussion
Topic: New Nissan Leaf.. 50kw more power and 62kwhr battery
Replies: 28
Views: 1151

Re: New Nissan Leaf.. 50kw more power and 62kwhr battery

Seems like an opportunity for a third party to offer aftetlrmarket refurbished packs...
by Punx0r
Mar 01 2019 2:43pm
Forum: Motor Technology
Topic: HyMag tech boosts magnetic flux density of permanent magnets by 10-30%
Replies: 25
Views: 1106

Re: HyMag tech boosts magnetic flux density of permanent magnets by 10-30%

I'm not arguing against segmented magnets, just saying that sometimes there is surprising room for improvement in certain aspects of what, overall, looks like a thorough design.

Just general experience, not related to motor design. Often worth keeping an open mind to plausible-sounding ideas.
by Punx0r
Mar 01 2019 2:38pm
Forum: EV Business World
Topic: Tesla Model 3
Replies: 739
Views: 45785

Re: Tesla Model 3

There are a lot of people though who go into a dealership with no intention of buying a new car but end walking out with one :D

It's disappointing to hear Miramar is a dump. The Top Gun film clearly promised too much :|
by Punx0r
Mar 01 2019 2:32pm
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

I have a feeling (but cannot check right now) that cycling is more efficient/lower lifetime impact over walking... Walking burns around 100kcal/mile and food production is a big deal for climate change. Of course, that's further complicated by what food you eat :wink: Either form of locomotion is fa...
by Punx0r
Mar 01 2019 3:50am
Forum: Motor Technology
Topic: HyMag tech boosts magnetic flux density of permanent magnets by 10-30%
Replies: 25
Views: 1106

Re: HyMag tech boosts magnetic flux density of permanent magnets by 10-30%

Stator field leads the rotor field by some angle of course, but is not spinning quicker. I have to disagree. The higher the pole count, the quicker the stator field will spin in relation to the rotor or motor shaft, which means the magnets and back iron does also see an alternating magnetic field. ...
by Punx0r
Mar 01 2019 3:42am
Forum: EV Business World
Topic: Tesla Model 3
Replies: 739
Views: 45785

Re: Tesla Model 3

Interesting to reflect on the many comments saying Tesla would "never" offer the $35k model, that it was all a scam. Closing of dealerships is a bold move, though. Currently Tesla has enough of an Apple-style fan following that they're not competing for, or need to attract, customers, so it will pro...
by Punx0r
Mar 01 2019 3:31am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

I mostly buy "orgnaic" food, when possible Not only is this more sustainable, but increases significantly my chnace for a Long and healthy life. What's not to like about that? I applaud your actions but the one on eating organic demonstrates how difficult it can be to do the "right" thing: Organic ...
by Punx0r
Feb 28 2019 3:38am
Forum: General Discussion
Topic: Myths about Electricity
Replies: 16
Views: 573

Re: Myths about Electricity

I have seen the statements that an electric motor is completely different from every other electrical device in that if you apply less voltage it will pull more current from its source. And there is no exception or I have never seen any of the cases. But this is far from the truth. It is counter-in...
by Punx0r
Feb 26 2019 3:14am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

Electrical pricing by region August 2017. https://stopthesethings.files.wordpress.com/2017/08/sa-highest-power-costs-table.png?w=460&h=659 Please remove any costs that are not inherent to the generating technology, such as taxes. Although, then you'll end up at something akin to LCOE, which doesn't...
by Punx0r
Feb 25 2019 8:56am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

It seems you havnt bothered , or dont want, to understand what the chart displays .! I certainly bothered and I'm fairly comfortable I have grasped what it appears to show. Namely that greater correction has been applied to temperature measures recorded when CO2 levels were lower. What do you belie...
by Punx0r
Feb 25 2019 5:03am
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

The chart is self explanatory to anyone with a passing interest in climate data. A simple plot of CO2 concentrations against temerature adjustments made by USHCN to historical records ..before publication. You are aware of the difference between correlation and causation, right? Ref: Bill's chart o...
by Punx0r
Feb 24 2019 7:20pm
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

You post a chart with no context, reference or description and demand people provide an analysis of it when they can only guess what it is? That's either plain lazy or baiting. I went over and above by googling the chart title. I got only partial matches and they were all junk denialist blogs crying...
by Punx0r
Feb 24 2019 7:01pm
Forum: E-Vehicles General Discussion
Topic: Wind and Solar vs Coal, Gasoline, Nuclear
Replies: 3514
Views: 124592

Re: Wind and Solar vs Coal, Gasoline, Nuclear

Reference something from a source that isn't patently utter garbage and you'll get a better response. Scientists really do critique the statistical analyses of each other. See the doubts and criticisms raised recently through official scientific channels about the LIGO data. Transparency in science ...