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Matlab question by Reuben Peblingman - Mon, 23 Dec 2013 20:17:09 EST ID:NOawd64H No.6045 Ignore Report Reply Quick Reply
File: 1387847829013.png -(7707B / 7.53KB, 585x448) Thumbnail displayed, click image for full size. 7707
I'm trying to write the following in Matlab

function [m] = calculatem(n)
syms x,
m = round (fzero('(x^n)*exp(-x) - 10^(-n)', 100));

but I keep getting the error,

Error using fzero (line 289)
FZERO cannot continue because user supplied expression ==>
(x^n)*exp(-x) - 10^(-n)
failed with the error below.

Error in inline expression ==> (x^n)*exp(-x) - 10^(-n)
Undefined function or variable 'n'.
Comment too long. Click here to view the full text.
>>
Nell Cricklemit - Mon, 23 Dec 2013 23:44:44 EST ID:hhXpDM2v No.6046 Ignore Report Quick Reply
If you don't explicitly give MATLAB a value for n it treats it as a string value and shits the bed when you try to use it in an equation.

Just give n a value in the script and it'll work.
>>
Jarvis Fushshit - Tue, 31 Dec 2013 20:22:36 EST ID:1toHq8IK No.6088 Ignore Report Quick Reply
>>6046
n=i


Custom PCB services by David Goodworth - Sun, 12 May 2013 21:59:26 EST ID:ZCsBFmhA No.5647 Ignore Report Reply Quick Reply
File: 1368410366720.jpg -(84180B / 82.21KB, 600x411) Thumbnail displayed, click image for full size. 84180
Anyone here know of a good site for ordering small batches (<5) of custom PCBs? Need some 4 layer boards.
>>
Jack Peddlewell - Sun, 12 May 2013 23:55:35 EST ID:4TXNiIqH No.5648 Ignore Report Quick Reply
>>5647
If time isn't an issue, try oshpark.com. It's a batch pcb service, so you're limited to the standard stackup, and the turn time can be a few weeks. but that's probably going to be one of the cheapest routes.

If you have a little more money to spend, silvercircuits.com is also a good deal with a slightly quicker turn time. Plus they are good about working with you on more complex designs (plated slots, cutouts, odd shapes, etc.)

If speed is your priority, there are services like pcbfabexpress and protoexpress that can get it done in less than a week, but prepare to pay much more for a 4 layer board.

I've used all of these services in the past and haven't had any issues.
>>
Cornelius Bivingnick - Wed, 15 May 2013 21:54:45 EST ID:pN01ULQG No.5651 Ignore Report Quick Reply
>>5648

Thanks man, I'm gonna shoot oshpark an email.


Microchip programmin' by Jack Bardman - Thu, 13 Jun 2013 20:22:27 EST ID:N2gcVF14 No.5748 Ignore Report Reply Quick Reply
File: 1371169347847.png -(31842B / 31.10KB, 764x428) Thumbnail displayed, click image for full size. 31842
Just got a microchip in the mail and I'm trying to learn my way around.

Just trying to turn on a LED right now and it's not working. My pickit 2 reads/writes/verifies just fine. It just won't light up the LED no matter where I put it.

Here's my circuit and code. I don't know if it's user error or the chip is faulty.
>>
Molly Bollertutch - Sat, 15 Jun 2013 11:53:00 EST ID:BSkmKEqx No.5755 Ignore Report Quick Reply
How much chip can current output?

You may need a buffer to drive the LED but I'm not sure, I haven't read your chip's datasheets.

So read the dam datasheets.
>>
Molly Bollertutch - Sat, 15 Jun 2013 11:54:39 EST ID:BSkmKEqx No.5756 Ignore Report Quick Reply
oh and from looking at your code, I mean I don't really know how that particular chip works but I feel like it goes through ones and done. So it might actually be turning the LED on for a fraction of a second.

Try having an infinite loop on PORTB=1 or a latch of some sort, that might fix it.

Basically play around with it.
>>
Molly Bollertutch - Sat, 15 Jun 2013 11:54:59 EST ID:BSkmKEqx No.5757 Ignore Report Quick Reply
>>5756
through once*
>>
Edwin Fivingchatch - Sat, 15 Jun 2013 17:16:51 EST ID:N2gcVF14 No.5759 Ignore Report Quick Reply
Well, I got it working.

Had no external oscillator, settings in mikroC was expecting there to be one, changed it over to use internal osc. Bam.

nb


posts by Shitting Pockville - Sat, 27 Jul 2013 03:47:59 EST ID:XObDUDiZ No.5814 Ignore Report Reply Quick Reply
File: 1374911279396.jpg -(115211B / 112.51KB, 480x360) Thumbnail displayed, click image for full size. 115211
I have some posts that I cut too short and already cemented into the ground. I need to extend them. I just need a secure way of adding an extention on top of them. Would a single dowl joint and some glue be strong enough or would there be problems with this. I want these extentions to be strong enough to handle my body weight so they can never have any structural weakness.
>>
Phyllis Blublingbark - Tue, 30 Jul 2013 06:09:04 EST ID:lDcMJVVm No.5816 Ignore Report Quick Reply
Depends on the radius and depth of the dowel joint mate, im not too sure about the material properties of that wood, or the height of the pieces your joining to these posts.
>>
Phyllis Blublingbark - Tue, 30 Jul 2013 06:19:24 EST ID:lDcMJVVm No.5817 Ignore Report Quick Reply
>>5816
I would also use more than one joint and metal pins to cnnect the pieces, do you have a budget?
>>
Betsy Heddlewell - Tue, 30 Jul 2013 11:31:10 EST ID:5ukk83ZK No.5820 Ignore Report Quick Reply
>>5814
STOP SHITPOSTING, lol.
>>
Jenny Pumbledale - Sun, 25 Aug 2013 22:20:35 EST ID:nWFNG1Eq No.5852 Ignore Report Quick Reply
>>5814
I see what you're doing. Stop plz

nb


Making a leaf-shutter by Eliza Nockledark - Thu, 02 May 2013 03:52:34 EST ID:i1S+U/Hc No.5608 Ignore Report Reply Quick Reply
File: 1367481154675.jpg -(39980B / 39.04KB, 581x300) Thumbnail displayed, click image for full size. 39980
Just asked this in /Howto/ but it definitely belongs here..

I'm looking on making something very useful, and there's a piece inside that will resemble the opening/closing action of a shutter lense.

Anybody know of where I can find schematics for making the leaf-shutter, without necessarily having the lense? I won't be using this for a camera, so don't need the complexity of it all, just need that useful open-close capability of it. Also it would likely be manually operated so no need for motors/batteries.
>>
Hannah Honeywell - Thu, 02 May 2013 13:52:41 EST ID:Jr33UkvF No.5609 Ignore Report Quick Reply
What exactly do you want from /tesla/?
I could draw that ho in 3D and make parts drawings and all that shit, but if you`re smart enough to "make something very useful" you can probaly use the pic you have there to make the shutter yourself.
what is this "something very useful" anyway?
>>
Huang Laoshi - Fri, 03 May 2013 03:26:25 EST ID:i1S+U/Hc No.5615 Ignore Report Quick Reply
>>5609

Congratulations you can make a 3D layout, as can so many people here. You've proven you're full of shit by not providing anything useful for OP,and even more so by just talking about what you "could" do.. If you actually "could" do it. You sound more like a kid who just pirated a graphic design program for the first time and thinks he's capable of anything now.


Eliza Nockledark,

I don't know much about making a shutter lense (though not claiming to be an ultimate badass running Maya,) but I know you're going to be looking at getting specialized parts for that type of project. Also this provides more of an in-depth look at what's inside the leaf shutter that gives it its capability.

http://www.monopix.co.uk/contaflexshutter.shtml

It seems difficult, but if it's not for a camera and just the shutter action is needed then it should make things a hell of alot simpler, and this would just give an idea.
>>
Henry Crangerkuck - Tue, 07 May 2013 20:57:09 EST ID:yHCyR6JU No.5628 Ignore Report Quick Reply
1367974629979.jpg -(146068B / 142.64KB, 1200x1200) Thumbnail displayed, click image for full size.
Something like this cigar cutter might be a cheaper option, if you want to macguyver it, instead of make it from scratch.

http://www.amazon.com/3-Blade-Cigar-Cutter-Scissors/dp/B003N9K44C


Future engineer by Nigel Brookworth - Sun, 08 Jul 2012 22:57:44 EST ID:442CA/QK No.4467 Ignore Report Reply Quick Reply
File: 1341802664058.jpg -(32112B / 31.36KB, 600x435) Thumbnail displayed, click image for full size. 32112
Hey, i am going to be a senior in highschool and going to start applying for schools. I know i want to study some type of engineering i am just not sure what field yet. I like working with my hands, working on computers(cad, etc), and dealing with things from a logical aspect but i also like the creative/design aspect of structural or civil engineering(i guess). Just wondering what jobs are needed in each field and why are some other fields of engineering i should look into beside the mainstream ones.

Tl:dr what fields of engineering should i look into. Creative, logical and prefer working with my hands or on computers. Going to be a senior in hs.
1 posts omitted. Click Reply to view.
>>
Wesley Dartfuck - Mon, 09 Jul 2012 10:27:35 EST ID:q9MR1sTA No.4469 Ignore Report Quick Reply
>>4467
why not software engineering?
>>
Indigo Celtic - Tue, 16 Jul 2013 06:35:27 EST ID:TWfowyOJ No.5796 Ignore Report Quick Reply
1373970927036.jpg -(4440B / 4.34KB, 160x200) Thumbnail displayed, click image for full size.
Never going to happen my friend, give up now
>>
Jarvis Drummerbare - Fri, 19 Jul 2013 18:24:03 EST ID:nl9igvSv No.5798 Ignore Report Quick Reply
I'm an electrical engineering student and I want to be a doctor or an astronaut or a race car driver...

what do?
>>
Charles Hizzleforth - Wed, 07 Aug 2013 18:02:15 EST ID:lUGyyceD No.5830 Ignore Report Quick Reply
>>5798
my ent doctor was actually an EE for a while. he decided it wasnt for him, took some classes and went to med school.
Med school dont care what degree you are, as long as you have all the pre-req classes, which are like . .. 18 hours?
>>
Hedda Benkindun - Mon, 12 Aug 2013 20:28:41 EST ID:j23CgD3m No.5835 Ignore Report Quick Reply
1376353721013.jpg -(178805B / 174.61KB, 640x448) Thumbnail displayed, click image for full size.
Engineering Student here

My school offers a bunch of engineering degrees from UGrad to Grad, are you looking to just get a BSc or maybe a Masters of PhD?

For just a BSc and getting a job somewhere:
-Petroleum, Chemical, or Mechanical are your top 3
-Civil and Electrical are good as well, but lower salaries if that's your forte but from what I understand they are 'less intense'
for a BSc in Biomedical Engineering...it's a new sector, but a BSc may leave you unemployed (talking to some former classmates) however it's just a small sector and is growing, by the time you graduate in 5 or 6 years it'll be all gravy I imagine

Going for the Masters:
Biomedical, Chemical, Petroleum hands down are the best. Then again anything engineering with a masters won't be a bad choice. These jobs are well needed in the private and public research sector at Master's level

Mechanical and other engineerings I didn't list will be good here, but IMO better off cashing out at BSc and going to work unless you want more schooling

Ph
Comment too long. Click here to view the full text.


Getting into electronics by Clara Clenningdale - Sat, 20 Jul 2013 06:45:59 EST ID:o9cZTHsI No.5803 Ignore Report Reply Quick Reply
File: 1374317159421.jpg -(81345B / 79.44KB, 480x574) Thumbnail displayed, click image for full size. 81345
Hey /tesla/,

since it's summer over here and I've got some free time, I would like to get into electronics in general and later Arduino, but I've got pretty much no idea where to start. I had to take a course dealing with boolean logic, so I know stuff like relational logic, graph theory, boolean algebra (functions, normal forms, Karnaugh maps), logic circuits and the basics of finite-state automata and flip-flops, but never got to actually use them - thought this might come in handy. I also know C/C++, Java, some scripting languages and I've started messing with reverse engineering/assembler lately.

Where should I start? Anyone got some book recommendations? What should I buy if I want to mess around with this kind of stuff?

Thanks.
>>
Ernest Madgekick - Tue, 23 Jul 2013 13:13:52 EST ID:KH36wMpB No.5811 Ignore Report Quick Reply
Titles of the books should be something like basic analog electronics and amplifiers

Multimeter+ PSU + fuses+ breadboard + pliers


Concrete walls with ridges by Ian Nerringbury - Sat, 11 May 2013 02:00:51 EST ID:qDfqjsMS No.5635 Ignore Report Reply Quick Reply
File: 1368252051592.jpg -(15327B / 14.97KB, 275x183) Thumbnail displayed, click image for full size. 15327
Is there any structural purpose for this? It's not supposed to be for aesthetics, is it? It's ugly, and shit builds up in the crevices.
1 posts omitted. Click Reply to view.
>>
Nigger Susslechuck - Sat, 11 May 2013 15:45:42 EST ID:xoknM1yD No.5639 Ignore Report Quick Reply
It's stronger than a flat wall using the same amount of concrete. It's just the concrete equivalent of corrugated cardboard...
>>
Eugene Pondlehetch - Sun, 12 May 2013 08:12:01 EST ID:Jr33UkvF No.5643 Ignore Report Quick Reply
>>5639
sounds legit, could you tell me more?
>>
Matilda Fettinghock - Sun, 12 May 2013 10:53:06 EST ID:nwxojBqh No.5645 Ignore Report Quick Reply
>>5643
http://en.wikipedia.org/wiki/Second_moment_of_area
>>
Ebenezer Figglefield - Mon, 13 May 2013 16:26:06 EST ID:LoGagJJL No.5649 Ignore Report Quick Reply
>>5645
>The specific problem is: The article is fundamentally wrong and packed with errors based on the authors' poor understanding of the subject.

:/
>>
Nigger Hongerfield - Tue, 14 May 2013 09:49:15 EST ID:AInfxL6X No.5650 Ignore Report Quick Reply
>>5649
didn't proofread, but the formulas are right, that's really about the limitation of my intrest, if you want a better/more accurate verbal explanation just torrent a statics book.


I wasn't shipped the right cord for the ballast. Grow light kit by Cyril Blammlehadge - Fri, 19 Jul 2013 23:09:37 EST ID:RWCdnLk6 No.5799 Ignore Report Reply Quick Reply
File: 1374289777320.jpg -(85876B / 83.86KB, 800x600) Thumbnail displayed, click image for full size. 85876
I got a cord that plugs into a European outlet that came with the ballast but I live in North America and so that doesn't work, the European cord is 300v but I happen to have another cord lying around that is also 300v, plugs into the ballast, and would fit into my North American outlet.

Should I use this cord I found or have the seller ship me a new cord and wait a week just to be safe?

I was going to post this on /crops/ but I assume you people would be better with electricity and stuff.
>>
Cyril Blammlehadge - Fri, 19 Jul 2013 23:11:36 EST ID:RWCdnLk6 No.5800 Ignore Report Quick Reply
Another thing thing to note is that the European cord is 14AWG, and the North American cord is 16AWG.
>>
Cyril Blammlehadge - Fri, 19 Jul 2013 23:16:56 EST ID:RWCdnLk6 No.5801 Ignore Report Quick Reply
The cord in my picture plugs into a North American outlet, just to give you an idea.
>>
Faggy Nickleshit - Sat, 20 Jul 2013 02:25:14 EST ID:RULusGa2 No.5802 Ignore Report Quick Reply
>>5801
>>5801
You need to make sure the ballast is rated for a 120V/60Hz input. European power is generally 240V 50Hz. And the wires are a thiner gauge, so they'll get hotter than normal. If you end up using it, check how hot the cable gets for the first few minutes. If it even gets warm, stop using it.
>>
Cyril Blammlehadge - Sat, 20 Jul 2013 11:54:41 EST ID:RWCdnLk6 No.5805 Ignore Report Quick Reply
1374335681320.jpg -(205531B / 200.71KB, 700x935) Thumbnail displayed, click image for full size.
>>5802

>120V/60Hz input. European power is generally 240V 50Hz.

It's rated both 120/240v and 50/60Hz, so I guess it 's a European/North American ballast.

Thank you for the advice, you're awesome.
>>
Faggy Nickleshit - Sat, 20 Jul 2013 18:17:13 EST ID:RULusGa2 No.5806 Ignore Report Quick Reply
>>5805
no problem, sounds like you're good to go.


How? by Martin Sepperridge - Fri, 14 Jun 2013 00:31:06 EST ID:3jq8QS32 No.5749 Ignore Report Reply Quick Reply
File: 1371184266041.gif -(695760B / 679.45KB, 300x194) Thumbnail displayed, click image for full size. 695760
I saw this gif in /pol/ and I was wondering how does it even work?
>>
Sidney Sunningstutch - Fri, 14 Jun 2013 00:58:48 EST ID:WrkcMEA2 No.5750 Ignore Report Quick Reply
When the switch is turned on, AC electricity from the wall outlet is converted to DC through a transformer and bridge rectifier. The DC voltage causes current to flow through a light emitting diode and current limiting resistor, causing the diode to emit a soft blue light.
>>
Ernest Snodwill - Fri, 14 Jun 2013 02:31:37 EST ID:84WsgVqj No.5751 Ignore Report Quick Reply
Basically what Sydney said, it's electronic snake oil.
>>
Basil Gucklepodge - Fri, 14 Jun 2013 12:21:34 EST ID:qmmmZXt+ No.5753 Ignore Report Quick Reply
It kind of works if you're using it like guy in the gif; save electricity by blocking your power outlets
>>
Walter Buzzfield - Tue, 25 Jun 2013 02:43:42 EST ID:EbmglSmN No.5766 Ignore Report Quick Reply
How to reduce energy costs:

Step 0: Don't be retarded.

Step 1: Use higher voltage mains. I switched from 120 to 230v, big improvement.

Step 2: Increase power factor.

Step 3: HVDC LED lighting is stupidly efficient.

Step 4: Solar water preheating for hot water.

Step 5: Solar thermal power - because photovoltaic is not as cool as steam engines.


Lathe Reaming by Isabella Sunkinfat - Mon, 08 Apr 2013 12:22:00 EST ID:gdeb+MXi No.5553 Ignore Report Reply Quick Reply
File: 1365438120726.gif -(2958B / 2.89KB, 321x133) Thumbnail displayed, click image for full size. 2958
Don't know if there's anyone here who took the apprentice route into engineering but il ask anyway, occasionally when reaming a hole using a lathe the hole ends up a few thou' oversize e.g a 1/2" reamer producing a 0.504" hole and i dont know why because the reamer seems to be in good condition
1 posts omitted. Click Reply to view.
>>
Betsy Nublinghood - Mon, 15 Apr 2013 20:22:33 EST ID:EWvw2Li1 No.5568 Ignore Report Quick Reply
>>5553
your work may not be sitting exactly flat on the collet. make sure there's no burrs on it (or the part itself) when you clamp it down. What are your feed/speeds like? material? Like the above poster said, a slower speed might help.
>>
Betsy Nublinghood - Mon, 15 Apr 2013 20:23:09 EST ID:EWvw2Li1 No.5569 Ignore Report Quick Reply
>>5568
also make sure the part is getting enough coolant
>>
some guy with opinion - Fri, 26 Apr 2013 14:42:36 EST ID:IODwa9Nn No.5600 Ignore Report Quick Reply
is the lathe sitting on complete level ground? also try finding a good speed if its to slow it will heat up fast resulting in overusing coolant, just pay attention to the speed and the color of the metal, make sure its fairly clean of burs and don't speed up slow down whilst in motion.. test an offcut before you find the correct drilling speed
>>
some guy with opinion - Fri, 26 Apr 2013 14:46:57 EST ID:IODwa9Nn No.5601 Ignore Report Quick Reply
i can post a similar picture to you from my engineering book for you if that will help?
>>
Cyril Fimblehood - Thu, 16 May 2013 06:38:28 EST ID:kz85WsFR No.5653 Ignore Report Quick Reply
could the reamer be 2 thou of centre?


Civil Engineering by maths bro - Thu, 02 May 2013 02:54:44 EST ID:+31F/aYC No.5607 Ignore Report Reply Quick Reply
File: 1367477684461.jpg -(15091B / 14.74KB, 240x320) Thumbnail displayed, click image for full size. 15091
CivIl Engineering worth while? is there a high demand for Civil Engineers?
if not, what discipline of engineering is most sought after?
>>
Martha Grimcocke - Thu, 02 May 2013 13:56:50 EST ID:buTeoEHV No.5610 Ignore Report Quick Reply
>>5607
Check out the post about the job market below.
I don't know how accurate that is to your area, but I've heard out of all the engineering disciplines, civil and architectural are among the least in demand.

As far as highest in demand, I would probably say EE or ChemE? I'm probably a little bit biased being EE though.

Do what you want though, they can all have fairly good hire rates, and it's tough to make it through four years of engineering if you don't like what you're doing.
I spent 12 hours yesterday on a project but I don't mind because I love doing it.
>>
Hannah Honeywell - Thu, 02 May 2013 13:58:27 EST ID:Jr33UkvF No.5611 Ignore Report Quick Reply
every sort of engineers really.
I`m currently on an internship in a mechanical engineering company (I design bridges and other large metal constructions) and there`s a great shortage of people who calculate bridges. appareantly no-one wants to do that shit and the people who do it get payed fuckloads and get their dicks sucked by companies to get them working for their company. I really couldn`t care less about calculating that kind of stuff for a job so I won`t be doing that kind of stuff.
hope this helps.
ps; bridge design is sort of civil engineering and mechanical engineering combined.
>>
Trynd - Tue, 07 May 2013 03:44:52 EST ID:N4X3qNBZ No.5627 Ignore Report Quick Reply
1367912692432.jpg -(137946B / 134.71KB, 700x525) Thumbnail displayed, click image for full size.
Electrical Engineers are in very high demand. For ME's and EE's, only a Bachelor's Degree is required.

There will always be a demand for Water Resources in every community for Civil Engineers. Environmental Engineering is also on the rise.

I heard that for Civil, you're more inclined to get a Masters Degree
Civil Engineering demand is lower in the U.S. at the moment because of the recession, but US Infrastructure is in desperate need of repair.
Forecast: Govt infrastructure (Transportation, Structures, Bridges, Dams, the works) and Environmental Engineering demand ahead

Civil Engineering requires more years of experience for a job.

Honestly, go for what interests you the most.
If you really enjoy Math, go for Electrical Engineering or Computer Science
Manufacturing, Vehicles, Aerospace and Thermal systems (Heating and Cooling ) ----> ME

Bridges, Construction, Water systems, Dams, Pipes, Highways, Environmental---> Civil
I chose Civil Engineering because I enjoy working outside (EE's spend most of their time indoors). Water Resources and Environmental Engineering interests me because they are essential to maintaining a sustainable community.


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