Search for class 2 in Topics


TKCC - 2 contestants needed!!!

The TKCC (the knex class championship) is a contest with 15 entrants, including me, and three impartial Judges to judge every one of the 5 rounds to see who is the greatest knex builder. The 5 round elimination process is as follows: Round 1 - 3 people off 2 - 3 people off 3 - 3 people off 4 - 3 people off 5 - 2 people off, final winner! The first 14 people that enter will be contestants, and anyone can enter for judging too. ENTRANTS 1.The Jamalam 2.Snipercrazed 3.I_am_Canadian 4.yannyboy 5.Benfoxg 6.Barrax 7.rofl495 8.dsman 195276 (I hope that's right!) 9.loyamann123 10.Dj Radio 11.Knexgunner 12.Knexguy 13.Ajleece 14.--- 15.--- JUDGES 1.(head judge)Bartboy 2.King_Banana 3.Darth Gecko Man When all contestants are chosen, Round one shall be chosen by our head judge Bartboy!

Topic by The Jamalam    |  last reply


Where is the robotics class??

I had let my Premium membership slip, but then I saw an offering for a series of classes on robotics.  That was interesting to me, so I renewed my Premium 2-year membership specifically for that class.  But now when I look into the class selections there is no mention of robotics at all and I can't navigate back to when I first saw the offering.  So, where is the robotics class? I'd hate to think that I bought 2 years premium membership and not get access to the main reason that I renewed.

Question by bkucheran    |  last reply


Call of Duty: Custom Classes.

Post your Call of Duty Custom Classes below for everyone to see. Post anything from Black Ops Machine guns or World at War Assault Rifles.     I'll show you an example with one of my classes.                         Example: Game:                   Black Ops Primary:                Submachine Gun Weapon:               Ak74u w/ grip and rapid fire. Secondary:           CZ75 w/ extended mag. Lethal/Tactical:     Frag and Nova Gas. Equipment:            Claymore.   Perk 1:                    Scavenger Pro. Perk 2:                    Warlord Pro.                 Perk 3:                    Marathon.  Just Have Fun With it.       

Topic by Drew99-KGB    |  last reply


Back to School 2: More instructables to help you in class

School has started for most of you and to help you out joshf posted The Top 10 List for going Back to School. But school is complicated and we feel that students can use all the help they can get. So we're helping you out with 10 (+1) more Instructables. Good luck in school this year. Learning is awesome. Minimalistic Desk by arte.sano Planning on renting a room, decorating with a single mattress, and studying on the floor? Time to make your own desk and act like a grown-up. Your back will thank you. Moleskine Hipster PDA case by atman Be ready to take notes at any time and keep your life together, analog-style. Who says you only learn in classes? The world is your classroom, buddy. Make a $5.00 "Space Pen" for your wallet by doctor_wu Even if you forget your Moleskine Hipster PDA Case, with this tiny pen you'll always be sure that you can write those thoughts down if you can just find a scrap of paper. Laptop sleeve from a zippered three ring binder by cmrc Laptop bags can be crazy expensive for what is just some fabric and a zipper. Strip out a zippered binder instead and you're all set! Vinyl Pencil Case by splityarn Store your fancy mechanical pencils and fine point pens in style with this custom case for your binder. The one you didn't rip up for a laptop sleeve, that is. Collegiate meals by trebuchet03 You're on your own and your idea of cooking is boiling water for ramen? That's sad. This collection of easy recipes will keep you eating well without stress. That's good. Office supplies trebuchet by Scissorman We recommend that you work on your verbal sparring with classmates before you resort to violence, but if you do need to get some agression out this tiny medieval weapon will help you launch your assault. The Paper Catapult by Kiteman So you don't have any office supplies for a trebuchet? Then print up this file and you'll have a scaled-down war going on in no time. Lego USB Stick by ianhampton If you're worried about accidentally using your Pinky USB Drive and destroying your homework you can make a flash drive with a sturdier bit of LEGO plastic. Just don't lose it by burying it inside your model of Helm's Deep. How to "Steal" Your Textbook by TimAnderson OK, we don't think you should really steal any textbooks, but you can turn them into PDFs by destroying them. You lose the resale value, but you can now keep all your books on your laptop and only carry one item to classes! Wikipedia in your pocket by PKM Afraid of getting into an argument in the cafeteria without the Internet to back you up? Take it with you by cramming Wikipedia in your pocket!

Topic by fungus amungus    |  last reply


Nerdman's Ships: Round 2

Hello! It's been awhile since I was here (was working on other things), but I've finally gotten around to making screenshots and renders, along with a bunch of new sketches (3D). I apologize for the amount Short List: (In order) - Assault Destroyer - Barracuda Class Frigate - Knife's Edge (now with new features) - Barracuda Class Frigate - Sky Razor (Sister ship of the above) - Falcon Class Heavy Cruiser - Hieroglyph Class Multi-role Fighter - Manta Class Bomber - Dolphin Class Artillery Frigate ::WIP:: - Mark XII - Light Torpeto Link to better images- http://s1206.photobucket.com/albums/bb441/nerdman234/ Minor side note: Thank you ibles for having an multi-uploader.  This is much easier than the other site I post on. :D - Nerdman  ------------------------------------------------ Expanded List:: ------------------------------------------------ - Assault Destroyer - Armed With 7 Medium Rail Guns - Designed for both direct assault and defense of large vessels against smaller ships (Frigates, bombers, etc.) - Barracuda Class Frigate - Knife's Edge (now with new features) - Designed for both exo-atmosphere and in-atmosphere operations - Armed with 4 light torpedo tubes, 3 triple AA turrets, and 2 solid mounted railguns in the nose - Barracuda Class Frigate - Sky Razor (Sister ship of the above) - Designed more as a heavy fighter than a support frigate, this can both keep up with standard fighters but even out maneuver them due to it's massive engines - Armed with 2 triple AA turrets, 6 light torpedo tubes, 2 solid mounted and 2 partially mobile railguns in the nose - Falcon Class Heavy Cruiser - Designed as fast attack ship, the falcon can reach incredible speeds while still being able to turn very sharply - The falcon is primarily armed with 512 packs of multi purpose launcher tubes, it can hold up to almost a thousand missiles or nearly 6,200 un-guided rockets. - Hieroglyph Class Multi-role Fighter - Carries two multipurpose modules (similar to the Heron) which hold quite literally anything that fits inside the power, weight, and computing restrictions. - Designed using spare Heron frames which were useless due to constant space combat. - Armed with a triple AA turret (rear), all other weapons/ offensive abilities come from the pods. - Manta Class Bomber - The Manta Class Bomber, created about the same time as the Hieroglyph, was made from XUAP hulls which were useless in space and were unused because of it. - Armed with 6 light torpedo (single use tubes), 3 triple AA turrets, and a minor ECM package, this bomber can hold it's own against even heavy fighters. - Dolphin Class Artillery Frigate ::WIP:: - The Dolphin Class of frigate was created when the fail "General Frigate" was unable to meet expectations. - Armed with 2 heavy plasma cannons capable of shots up to 400km away. - The Dolphin is also nimble enough to avoid long range missiles, but is unable to enter atmosphere and is unable to avoid fighters. - Mark XII - Light Torpeto - The Mark XII was created strictly for bombers, but soon showed extreme success in both heavier fighters, and light frigates. Being powerful for it's size, it was also reasonably light and nearly as maneuverable as some missiles. 

Topic by ry25920    |  last reply


Modern Warfare 2

Yes, the game has just came out on November 10th, but do any of you people have any good classes? Like combinations? I hear the Riot Shield blocks out any bullets, but it replaces primary weapon. It also goes on your back when you are using your pistol/rocket launcher/shotgun. and NO it does not break :D. But you are vulnerable from the sides (?). When the Riot Shield gets riddled with bullets it makes it harder to see.

Topic by Colonel88    |  last reply


2 eggs walk into a fridge

This is an animated joke I made for class. I heard the joke from this 14 yo German girl and laughed so hard. Hope you enjoy it and please share if it makes you smile :)

Topic by Bungi-bun    |  last reply


Arduino D1 WeMos with LabView

Hey, I want to build a project that gets information from the "Temp102" sensor connected to the D1 WeMos Board. This board sends the information received from the sensor via WiFi. I want this information that sends to the computer that has the LabView software and it will display the temperature in a termometer. I have a program that I found in one of the sites that does what I want but with one problem! The program is written for module Esp8266, which is connected to board Arduino Uno and therefore has different classics. I need help converting the classics of module ESP8266 to relevant classes for Board D1 WeMos (This board has ESP8266 but it is built-in so there is no need to set it up in the program). It's important to note that I tried to change it and make a "mix" but without success. I would be happy if someone could check in the program what should be changed, which orders should be replaced? (I believe it's 2 minutes work for anyone who knows) Thank you very much for your help ! I appreciate you very much !! I attached the programs (for arduino and for labview).

Topic by OriaA    |  last reply


Survey About the Value of Gym Class

I am doing a sort of personal research paper (meaning, it's not a school assignment or anything) on the education system and gym class.  For the gym class portion, I am doing a survey, and so I have brought it here.  If you could answer these questions, I would greatly appreciate it.  Thank you very much! 1. What is your gender? (Optional) 2. Age? (Optional) 3. Do you view PE as a worthwhile class in middle and/or high school? 4. Why or why not?

Topic by StarscreamClone    |  last reply


power supply for LED's? Answered

I have a strip of LED's that have a warning that's says use only with a 12v class 2 power supply. Is this referring to an AC/DC transformer? Should I be able to run them straight from a 12v battery? If I am using a 12v battery is the class 2 circuitry still needed?

Question by MDheliMech    |  last reply


REPLACEMENT FOR AUBTM-20 / BLUETHOOTH V2.0 CLASS 2 MODULE. HELP!

I have a project due for my microprocesor's class. The project I am doing needs a AUBTM-20, a serial converter. I am not able to find one, or at least a good replacement. I'm still kinda new at this and would really appreciate the help!    Thanks!!

Question by gwise505    |  last reply


Instructables Classes on iPad? iOS App Removed?

I've enrolled for a class and wanted to view it on my iPad (my preferred method for viewing video content). However, following any class link off the main site shows only a blank page. I went to the App store hoping to download the Instructables App I'd read about, but that seems to have been removed from the iOS store (at least in the US).  Is it impossible to use Instructable classes on the iPad? I'm on an iPad Air 2.

Question by montressor    |  last reply


The ultimate knex gun

This is a competition for the ultimate knex gun, with a difference - you vote for the best parts of any knex gun on the site, and i mod them a bit and put them together! voting ends december 31st and i will post a picture on january 1st! Class 1:handle Class 2:stock Class 3:barrel Class 4:Hand grip Class 5: sight Happy voting! :D

Topic by The Jamalam    |  last reply


Advice on preparing/presenting a Python Master Class?

I am preparing a master class to present to a group of Technical Artists# at work. Everyone in the group has previously programmed in C/C++/MEL/MAXScript/Python. The purpose of the class is to collectively bring everyone's skill levels and technical understanding on variety of Computer Data Science topics to a common level.I would like some advice as this first time I've delivered such a class. I am planning on structuring the course to be two 2 hour sessions, with 30 minute blocks of content interspersed with Q&A;, code-review, and individual assistance. I know this a multi-part question, so don't feel you need to be able answer everything, just contribute what you can. Any links to articles, SO questions, or reflection on personal learning experiences is greatly appreciated. Questions/Advice/Links to Further Reading- What CS topics should I attempt to cover?- Examples of other Python training courses? - What do you wish someone taught you when you first started programming?- Python programming best-practices- Tips for delivering technical content to creative/artist audience? Using Dive Into Python as a textbook and referencing the MIT Open Courseware Introduction to Computer Science on Academic Earth. I have also been given a 2 minute overview on adult training (Malcolm Knowles), i.e., working the students through the cycle of: identify the problem, determine the cause, researching a solution, and applying.

Question by emmablisa    |  last reply


Need a suitable Class D amplifer for transformer application

Hi,Hope this post find you well.My intention is to make an 3-phase power calibrator !Similar to this link, https://us.flukecal.com/products/ele...wer-calibrator My current AMP design might be class AB type. I am not worried to much about PWM generation ruther I am thinking how can I move class AB to Class D amplification. A lot of the design effort relates to maintaining linearity and avoiding crossover distortion. In this case, 2 amplifiers( current, voltage) output will feed to CT and PT! Lets consider transformer load .REQUIRMENTS :1. The amp input should be plus and minus 7volt AC, 45-65Hz( 1 Hz has been converted to 1024)2. Amp operating voltage should be more or less 24v. 3. 2 channel signal (not sure PWM) should be use , one for current, one for voltage. 4.Can run current transformer(input 16.5 V/1.5 A) and potential Transformer (input15v/2A). PT output may be 15VAC.5. If possible both voltage and current amplification is required in one IC.6. Both positive and negative half signal should be amplify

Question by Hasan2015  


Science of Baking class project doesn't work

When I go to the last step of the Science of Baking class to post my class project picture, I get one of two things: 1) The "Class project" / "I made it!" box is missing entirely, and the class questions are visible as normal or 2) The "Class project" box is visible, but contains only the text "Share a photo of your finished project with the class!" and a "Show more" button, which does nothing when I click it, and meanwhile the class questions are missing entirely.  I've tried refreshing the page, re-starting the computer (it re-started itself because that's how it rolls, and then I re-started it intentionally to see if it would help), and trying on two other computers, all with the same results.  The operating systems and browsers I've tried are Windows XP with Chrome, Windows XP with Firefox, and Windows 8 with Chrome. The class projects in the Knitting class are working fine, and the one for Science of Baking was working fine last time I saw it, which was Wednesday. EDIT: Added Screenshots from the first computer (XP w/ Chrome). Apparently sometimes the non-working "Class Project" box disappears and the questions appear when the page finishes loading (hence the loading indicator in the screenshot), but not always. EDIT2: Added link to class project page

Topic by christa627    |  last reply


Object-oriented programming in Unity?

Hi people, My name is Cynthia and I need some help with Object-oriented programming. I have a project for school where I'am making a 2D platformer game with Unity. Where I have to make a base class and two child classes that inherits from it. I have to work with constructors, properties, etc . The problem is I kinda know what the constructors, properties etc do but I don't know how to put them together to make a game. Can someone help me, push me into the right direction cause now I don't know where to begin with. What I like to make is a Enemy base class with two sub classes (enemy 1 and enemy 2) or base class Item (sort of coins or power ups) with two sub classes (item 1 and item 2). If there is someone who can help I would be so grateful. (I program in C# and the game must be made in Unity). Sorry if this is not the right place for asking such a thing. Thanks Cynni

Question by Cynni    |  last reply


Upcoming Welding, Mechanical Sculpture, Woodturning, Glass Classes etc at The Crucible

Want to expand your repertoire of Instructable skills so you can weld, make fun kinetic sculptures with your creations or re-use old stuff, make jewelry, glass etc? If you're in the SF Bay Area, check out the upcoming classes at The Crucible, a non-profit in West Oakland, CA. It's easy to get there off of 880 or by BART.Some classes have "family packs" where 2 people can get a discount when you take a class together, which could make for an interesting Father's Day or graduation gift. You can see all the classes and start dates on these postings:http://sfbay.craigslist.org/search/cls/eby?query=crucible&neighborhood;=Or browse around on The Crucible site - http://www.thecrucible.orgHave fun!

Topic by susie    |  last reply


How to connect 2 motors in series so both work? Answered

I've connected two motors in series and only one will work at once. Both motors seem to be fully functional. Do I need to add more power? Both normally take 3 double As and I currently have it connected to only 4. Please be gentle, high school physics class seems like a million years ago.

Question by ModMischief    |  last reply


Finished with online German

Yeah!!!! done with online german!!!! just had to tell somebody... I can honestly say I've learned almost nothing from an online german course... But next year I get to be in german 2 and I won't be stuck with the same lame class i had this year. The principle actually had to come in for about 2 weeks it was that bad. As in students revolting, walking out the class, not doing assignments, etc.

Topic by guyfrom7up    |  last reply


how to bend a bubble?

I got this Brita water filtration system and it came with a plastic storage unit to keep it inside the box correctly.How would i bend this into a small airtight bubble about 1 1/2"in. high and around 2 1/2'ft in diameter,please help!?

Question by kolf3500    |  last reply


What is the strength of the other charge?

I need help with solving this problem in physics class. I know Coulombs equation F= k(q1q2)/r^2 The force between two charges is 2 newtons. The distance between the charges is 2 x 10 ^ -4 meters. If one of the charges is 3 x 10 ^ -6 C, What is the strength of the other charge?

Question by Baseball24_7    |  last reply


Very basic electronics kits for 2 yearolds!?

My 2 year old daughter appears to enjoy the very basic geeky things that she's gotten her hands on so far.  Things like plugging headphones into the iPad to listen to music; building things with large Lego blocks; turning torches on and off; playing with little remote-controlled-cars etc etc. I'd like to see how she gets on with some sort of basic "electronics kit" which allows her to experiment a little while teaching her some very basic principals (like circuits require both a power source and a load). All existing electronics kits I've seen would be way to advanced for her.  For example, she's years away from being able to understand what "completing a circuit" means (i.e. any kits which require you to connect both a negative and positive cable from power source to actuator would be way to abstract for her). I'm thinking of making her a very, very basic "electronics kit".  Each component would be in its own little tinted, semi-transparent box. There would be several "sources" of electrical power (small battery pack, PV cells, little hand-cranked dynamo etc).  Each source module would have a single large DC socket to send power to another module.  Each source would produce about 3 volts and would have short-circuit protection. There would be several "actuator" modules like a lamp, motor, door bell, volt meter, radio etc.  These modules would each have a single small DC socket. Cables would have a large DC socket on one end and a small DC socket on the other.  The use of large DC sockets on the power source modules and small DC sockets on the actuator modules should make it mechanically impossible to create a "wrong" circuit (like connecting a battery pack to a  PV cell). And maybe some basic "control" modules like a switch, light-operated switch, oscillator etc.  Each  control module would have both a small DC socket (power input) and a large DC socket (power output to actuator). Each class of module (actuator, controller, power source) would have its own colour. My first question is: does a similar kit exist for purchase? If not, I'll make the kit for my daughter, unless anyone has good evidence that such a project would still be way to advanced for a 2 year old.  Of course, I'll start with the real basics like just a battery module, switch, light and two cables to see how she gets on with it.

Topic by jack_kelly    |  last reply


Rate My Drawing!

Ok so this my art portfolio for my art class and a recreation of one of my previous works. This one is an improved version, of course, and done in Ink Dot Stippling. Please let me know what you think. 

Topic by FoxyPenguin94    |  last reply


Do Colleges look at Freshman year?

Do Colleges look at Freshman year? I'm just wondering cause I'm kinda freaking out about my english grade. I'm not sure what I have right now, but last marking period I had an 82%, and right now I've not been doing so hot. It's a weighted class (an "A" is a 5.0, a "B" is a 4.0, etc.). I know a "4.0" is perfect (but I'm starting to look at a "C" here, which is freaking me out), but perfect isn't so great anymore. I'm taking almost all advance/advance honors class (all my classes are weighted, except German 2 and some electronics course). Should I be freaking out?

Topic by guyfrom7up    |  last reply


How To: Create an Android App With Android Studio to Control LED?

In this tutorial here: https://www.instructables.com/id/Android-Bluetooth-Control-LED-Part-2/#step1 it says to "Import the followings packages:" in the DeviceList class. My question is, HOW DO YOU IMPORT these packages? Does it mean to copy and paste somewhere the two code snippets: #1 import android.widget.Button; and #2 import android.widget.ListView; into the DeviceList class, it doesn't say.  While I am new to instructables I do have some background in C#,  C++,  and other languages and I certainly am familiar with the "importing" feature in many programs but I never heard of "importing" directly into code. Can you please help me understand what it means to "import" in the tutorial. Thanks David Lee

Question by dmenefee    |  last reply


Storm 223

Hi guys, i want to build a storm 223, having finally posted my 222. However, i can't think what mode of fire/type of gun/trigger/ammo to use. So i thought i'd let you guys help me :) I am holding a vote; anyone can vote for one of the categories below. everyone only gets one vote, but votes for one of each of the classes. The closing date is Finishedso stop votingClass 1: mode of firingsingle shotsemi auto with (specific) shotsbolt actionmachine gunother (please state)Class 2: type of gunstandard riflesniperassault rifleshotgunpistolpump shotgunslide pistolsawed off shotgunother (please state)Class 3: type of triggerstandard (eg. desert buzzard's trigger)sear systemnew inventionother (please state)none (eg. pull/release or mg)==Class 4: type of ammorodsconnectorscapped rodsrubberbandsother (please state)Class 5: range aspirationlongshortmediumWhen voting, consider the following;i have done a semi auto assault rifle, a sniper rifle, and a semi auto chain driven.this is number 4 for me, the one before the legendary storm 224, so make it good.this is real guys, so make it possibleHappy voting!EDIT: The storm 223 is nearly finished, and i have posted up some pictures below!

Topic by The Jamalam    |  last reply


Homework question - Philippe Petit's knees Answered

#2 Son is doing a short talk at school on Philippe Petit, the Frenchman that tightrope-walked between the Twin Towers. He has plenty of information, except he has found several references to a move Petit did called "knee salutes".  He would like to do one in front of the class, but we can't find an image or description of the move. Anybody know? (Edit: Best Answer chosen by #2 Son)

Question by Kiteman    |  last reply


animations

Here are some animations i made in videeo class this may take a while to download but the first is about 6 MB update 1 full quality version in update 2 i got a friends version of drunk driving yes these are PSA (public service announcments) he said it gets kinda loud but i dont know no low quality ver for this pyro-

Topic by ich bin ein pyro    |  last reply


Come to the TechShop Orlando Community Meet-Up Party Saturday Night (2/23/08)!

Where Do You Make YOUR Instructables? Make Them at TechShop Orlando!If you haven't heard about TechShop yet, TechShop is an open workshop space that provides its members with access to many tools and machines, and a place that they can just hang out and work on their projects. TechShop also offers lots of short, inexpensive classes on all the tools and equipment to members and non-members. Most importantly, TechShop is a full-time community for Makers.TechShop is currently in operation in Menlo Park, California, and is opening 9 locations, including one in Orlando, Florida, this summer. TechShop's founder Jim Newton and TechShop Orlando partner Robin Lopez invite all Orlando area Makers to come to the TechShop Orlando Community Meet-Up Party on Saturday, February 23 from 7 to 10 PM. You'll have the chance to talk about what you want to see at the Orlando TechShop facility, and find out what their plans are during an open Q/A session. Pizza and soft drinks will be provided by TechShop, and there will be a no-host bar.If you can attend, TechShop asks that you RSVP at the TechShop Orlando Web Site at: http://orlando.techshop.ws/rsvp.htmlIf you have friends, relatives or know of clubs or groups that you think would like to know about TechShop Orlando, please invite them to come to this event by forwarding this message to them along with the RSVP link. All Orlando Makers are welcome!TechShop Orlando - http://orlando.techshop.wsCommunity Meet-Up Party Information - http://orlando.techshop.ws/rsvp.htmlTechShop HQœ - http://www.techshop.ws

Topic by TechShop    |  last reply


Trebuchet does not release load

Have built a pallet/ man sized trebuchet in a 4th grade class project. Looks great, swings well, but the tennis ball load is either released before the sling swings up, or not at all (slams against the arm). Have used 2 ropes with a shallow bag. Any suggestions? (Kids were disappointed on Friday)

Question by BobS    |  last reply


Does ClassD amplifier not suitable for 60Hz transformer?

Hi there, My application is in Audio range. I am going to use a Transformer instead of Speaker. A 3- phase power calibration is my intention. Similar to this link, https://us.flukecal.com/products/ele...wer-calibr... My current AMP design might be class AB type. I am thinking how can I move class AB to Class D amplification. A lot of the design effort relates to maintaining linearity and avoiding crossover distortion. 2 amplifiers( current, voltage) output will feed to CT and PT! REQUIRMENTS : 1. The amp input should be plus and minus 7volt AC, 45-65Hz( 1 Hz has been converted to 1024) 2. Amp operating voltage should be more or less 24v. 3. 2 channel signal (not sure PWM) should be use , one for current, one for voltage. 4. Can run current transformer(input 16.5 V/1.5 A) and potential Transformer (input15v/2A). 5. If possible both voltage and current amplification is required in one IC. 6. Both positive and negative half signal should be amplify. For CT, current transformer primary winding has 80turns, 16.5 V/1.5 A, secondary has 20Turns, 4.125v/6A output!For PT, Potential transformer, Primary has 80turns, 15v/2A rating input, secondary has centertap! At secondary 960turns, 360v/0.332 A and 960turns 180v/0.166A output.For the time being lets disscuss issues like, 1. Low frequency and high frequency phase shifts caused by a transformer will occur if the transformer is inside the negative feedback loop (when the output of the transformer provides the negative feedback). Then the amplifier must be compensated for these phase shifts.A transformer causes a phase shift at low frequencies caused by its inductance. 2. A product with a Class-D audio power amplifier (APA) driving an output transformer with inadequate low-frequency performance may shut down when its output is stepped from zero to maximum at the start of a sine cycle. Shutdown is triggered by short circuit protection (SCP), after the first half cycle of the sine output. The root cause is saturation of the transformer core. 3. Class D amplifiers approximate voltage sources, they won't take kindly into a CT load.

Question by Hasan2015  


Spanish or French | Intro to Metalworking or Intro to Engineering and Tech.?

Ok, so it's that time of the year - picking 9th grade courses. I'm signing up for all gifted (higher than honors) academic classes, but am stuck on my electives.To get into universities and colleges in Georgia, I have to take 2 sequential years of either French or Spanish. My mom says Spanish is easier, like I'm sure most people would. I don't really care about speaking fluently in either language; I just need to go to college.What would you say would be the easiest to get through?So, I guess all of y'all know that I aspire to go into the mechanical engineering field. High school is a good place to start out, but I've come upon another bump in the road: Should I go with the metalworking classes, or the engineering (and technology) ones?I've always wanted to be able to weld, and I'm sure that's a major skill when it comes to engineering. Classes that my future school offers include Intro to Metalworking, Arc Welding, GMAW and GTAW (which I won't take), Intro to Milling (which includes using a lathe and a CNC machine), and a sheet metal class. The engineering class covers things like CAD, CAM, CNC, robotics, audio and visual productions, and other technology things.I think the metalworking would be best for me - I'm more of a hands-on person; i.e., I like tangent things, not doing "theoretical" things on a computer, though I know all of the CAD stuff would be very useful.I'd like to take all of it if I could, but that's only possible by going to summer school (which costs $180 per class).Any help would be appreciated!

Topic by Bran    |  last reply


Transformers

Hi There! I have here a transformer from an old UPS (Belkin 550VA), I just wondering if I can use it as a battery charger, my problem is I cannot locate the PCB connected to it. Available information I have here are in one side there are 3 wires Blue, Brown & Red on the other side Black, Red, Brown, yellow, Blue. It is also labeled on the top 080-48172-00 GP 0751 Class B Viking B-2 E210832 Can someone help me with this little project? Thanks in advance! Jayce 

Topic by jayce_sos    |  last reply


Making sum research on robotics ? Answered

Hey i need sum details on my research  i'm not big rich person i'm just a middle class person from a small town  but i'm making some research in robotics. i just need 2 clear sum doubts here.. 1)is it possible to make a jet engine much smaller than a back pack size?? 2)is it possible to make a system work as per our mind reaction like by voice activating?? 3)is there any metal that stands against the military tanker bullet??

Question by vjeeva    |  last reply


HELP please!! with Li Ion battery

1 st question: i have a 7.4v 2200mA li ion battery. my ip camera takes 5v 2amps what color resistor should i use and how many ohms? 2nd quesiton: i have a class 2 battery charger 12 volts 300mA is it good to charge my 7.4v li ion battery?

Question by dwstar79    |  last reply


Controlling multiple Arduino pins in VB or C#? Answered

How do I control different pins of an Arduino via VB or C#. Something simple, for instance; if I created 4 buttons. Button 1 would turn ON pin 13, button 2 would turn OFF pin 13. Button 3 would turn ON pin 12 and button 4 would OFF pin 12. I know that it works via a serial port, but I can only control 1 pin. Simple stuff, but I just can't figure it out. PLEASE HELP!!!!

Question by cmcg182    |  last reply


iTouch not syncing?

*I don't have it with me now, but tomorrow I WILL!* One of the kids in my class has got a problem. Her first iTouch's screen broke (I know how to fix that), but her replacement iPod wont sync with her computer. Could this be because iTunes can't sync with 2 iPod's on its "list"? I just want to know of any fixes so I don't go stumbling along.

Topic by wolf555hound    |  last reply


Market Day Project- Need Help

My AP Economics class is having a "Market Day" in 2 weeks; here are the rules: Limit of $14 total (Can go over by around 5 without anybody noticing) Must make atleast 10 items Person who sells the most items gets a good grade No food/ weapons/ things not appropriate for school If anybody can help me or point me in the right direction, I would greatly appreciate it.

Topic by kargod    |  last reply


Bridging two identical amplifiers to increase the rms output power Answered

Hi, i was wondering  if i can bridge two identical amplifiers, to drive a 4ohms 400w-rms dvc subwoofer, the second problem is what about the power supply, i don't think i can use one 24volt car battery for the two amps so can i use two separate car battery, below is the amp i want to bridge. JBL GX-A3011SI 1200W Class D Mono Car Subwoofer Amplifier. Product Info: Low Distortion Class AB Design Active Low Pass Filter Noise Rejecting Differential Inputs Filter Range 30Hz to 320 Hz Peak Power Output  1200 W 4-Ohm Power Output  200 W RMS x 1, <1% THD+N 2-Ohm Power Output  300 W RMS x 1, <1% THD+N Design Low Distortion Class AB Input Variable Line Level and Speaker Level Signal to Noise Ratio  93dB since the output rms @4-ohms is "200 W RMS" so bridging two of this amps will give me a 400w-rms. Thank you. Regards

Question by Lima79    |  last reply


box that has 4 led lights-(W-G-R-B)with a separate switch to turn each light on/off, and can run on battery power.

I am looking for a led box to build that is approx. 8-12 inches long, that has four separate colors and switches to control each light (white-green-red-yellow), 2-3 inches wide, and about 1-2 inches deep-similar to a drag racing light, but much, much smaller, and can run on battery power...looking to know exactly what parts to buy and where, and detail directions on how to build this box- i am a teacher and want to use this for my classes...thanks!!!

Question by rungdc    |  last reply


Has anyone made a swivel or swing arm out of black pipe fittings??

Ok, so here's the project. I want to make bar stools like the ones in this picture. http://pin.it/jxn4TMz See how there are two stools attached to a single black pipe upright with tees? My idea is to use schedule 40 uprights 1.5" with class 3000 2" socket weld tees. Dimensions look like the 1.5" will slide through the tee and then I'll weld 2" sch 80 for the arms going to the stools. But while clearances are tight inside the tee and upright, any ideas on how to make things swivel smoothly or take up that extra slop? Or any other ideas on how to skin this cat?

Question by chugachpowder    |  last reply


How to make a giant (12'x12' x 9 ' high) inside of a computer for my kids school.

Hi all, I need to figure out how to make a giant inside of a computer for a school project for my kids class.  I can get a 2"x4" frame for the entire space, but need ideas of how to decorate the inside of this giant box.    Any brilliant ideas on how to do this thing on a shoe-string budget? Thank you all for your brilliant ideas.  I am a worker, not creative!

Question by tinkj    |  last reply


How to get started in digital art?

I really want to get into digital art. I have had art classes when I was in grade 7 and 8, but none beyond that. I have uploaded 2 paintings my teacher made me draw ( Starry night looks horrible,  I know). I also uploaded a third picture showing that sort stuff I wish I could make. so, where do I get started? What materials do I need?

Topic by _ZERO_    |  last reply


Steampunked Utensils

I am taking a class for 2 weeks up in Maine (Haystack Mountain School, Boris Bally will be teaching) where we will be will be using the eating ends of spoons, forks and knives to create new utensils with new handles. I would love to steam punk some of my "new" utensils. Over the years I have collected a huge amount of weird stuff that might work so if you suggest it I may actually have it. We will be using cold connections and soldering so anything goes. Any ideas are most appreciated.

Topic by Ninzerbean    |  last reply


WheatStone bridge

Recently i studied the wheatstone bridge in me physics book in class but i could not understand it properly. I asked the teacher about my confusion but he also dont know. i have posted the picture of topic(wheatstone bridge). My question is ;1.Why current I1 is following through point A to D in loop ADBA. 2.Why current I2 is following through point D to C in loop DCBD.My confusion is that why current are following through these two paths. As current always flow through level of a higher potential to a level of lower potential but here it seems opposite.

Topic by DabuHackker    |  last reply


RIR Sensor with ~3ft detection capability?

Question for you sensor experts... I'm looking to do a project that would involve detecting when an item passes through a doorway near ground level (~6 inches above ground level).  Doing a bit of research it looks like a reflective infrared sensor would do the trick ... only issue I have come across is that there seem to be a slew of these sensors with detection capability of about 15mm max and then another class of these (home security grade) that have detection capability for several 10's of feet. Any ideas on a RIR sensor (links appreciated!) that has capability ~2-3 feet?  Another caveat is I'd like to string up multiple of these sensors in a close proximity, each with the sensor observing a 2-3 ft area right in front of it. Thanks! Nick

Topic by NickF73    |  last reply


your thoughts wanted for making usb car charger using an old usb computer port

Its been 20 yrs since my electrical class so I'm a little rusty on it. What I'm wanting to to is make a usb charger for my car using a duel usb port from an old computer each usb port has a separate cable that used to plug into the mother board I'm wanting to use the old usb cables and run a series to parallel circuit 12v power supply cigarette light to a 5v voltage regulator my question is will i need a regulator for each usb port (see picture "B") or just one with 2 positive and 2 negative wires going to each usb wiring connector?(picture "A") please forgive my not to scale horrible drawings

Question by inotnrml    |  last reply


Minecraft Map: BuildBlocks PvP

Hello, recently I made a map called control point and I wanted to do something with the /scoreboard command. So here is the outcome. Team based Simple yet fun 3 different class-each with strengths and weaknesses 2 teams 10 lives to each player Players team and number of lives left displayed Each dead player is teleported to a spectate area Each team can build there base (Withing the regions) If your team uses all the resources your team loses No friendly-fire :D The objectives is to basically kill the other team and be the last one standing

Topic by didexo    |  last reply


DS3231

Arduino: 1.8.4 (Windows 10), Πλακέτα:"Arduino/Genuino Uno" Hello everybody I use Arduino R3 Uno with DS3231 and 1.8 TFT spi 128X160 and this is my first project. #include     #include #include #include #include // Init the DS3231 using the hardware interface DS3231  rtc(SDA, SCL); #define TFT_CS     10 #define TFT_RST    9  #define TFT_DC     8 #define TFT_SCLK 13   #define TFT_MOSI 11   Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS,  TFT_DC, TFT_RST); void setup(void) {   // Setup Serial connection   Serial.begin(115200);     // Initialize the rtc object   rtc.begin();   // You will need to do this in every sketch   tft.initR(INITR_BLACKTAB); // Blank Screen   tft.fillScreen(ST7735_BLACK); // Set background BLACK     // Start writing colored text tft.setTextColor(ST7735_RED);   tft.setTextSize(1);   tft.setCursor(5,10);   delay(1000);  // pause for dramatic effect   tft.print("1.8 TFT with DS3231"); } void loop() {   // Blank Screen   tft.initR(INITR_BLACKTAB);     // Send Day of Week   tft.setTextColor(ST7735_WHITE);   tft.setTextSize(2);   tft.setCursor(10,30);   tft.print(rtc.getDOWStr());     // Send date    tft.setTextColor(ST7735_WHITE);   tft.setTextSize(1);   tft.setCursor(10,50);   tft.print(rtc.getDateStr()); // Send time   tft.setTextColor(ST7735_WHITE);   tft.setTextSize(1);   tft.setCursor(10,70);   tft.println(rtc.getTimeStr());   // Send current temperature   tft.setTextColor(ST7735_YELLOW);   tft.setTextSize(1);   tft.setCursor(30,90);   tft.print("Temperature: ");     tft.setTextColor(ST7735_BLUE);   tft.setTextSize(2);   tft.setCursor(35,120);     tft.print(rtc.getTemp());   tft.println(" C"); } Clicking for compilation illuminates the line 8 DS3231  rtc(SDA, SCL); Software: arduino-1.8.4 windows 10 Libraries: DS3231 1.0.2 Libraries are up-to-date and when I ask to add again library DS3231 adds #include Please help. Where is the error? D:\Τα Ξ­Ξ³Ξ³Ο?αφά ΞΌΞΏΟ…\Arduino\@-NEW_Projects_OCT_2017\1.8TFT_with_DS3231\1.8TFT_with_DS3231.ino:8:21: note: candidates are: In file included from D:\Τα Ξ­Ξ³Ξ³Ο?αφά ΞΌΞΏΟ…\Arduino\@-NEW_Projects_OCT_2017\1.8TFT_with_DS3231\1.8TFT_with_DS3231.ino:4:0: D:\Τα έγγραφά μου\Arduino\libraries\DS3231/DS3231.h:64:3: note: DS3231::DS3231()    DS3231();    ^ D:\Τα έγγραφά μου\Arduino\libraries\DS3231/DS3231.h:64:3: note:   candidate expects 0 arguments, 2 provided D:\Τα έγγραφά μου\Arduino\libraries\DS3231/DS3231.h:60:7: note: constexpr DS3231::DS3231(const DS3231&) class DS3231 {        ^ D:\Τα έγγραφά μου\Arduino\libraries\DS3231/DS3231.h:60:7: note:   candidate expects 1 argument, 2 provided D:\Τα έγγραφά μου\Arduino\libraries\DS3231/DS3231.h:60:7: note: constexpr DS3231::DS3231(DS3231&&) D:\Τα έγγραφά μου\Arduino\libraries\DS3231/DS3231.h:60:7: note:   candidate expects 1 argument, 2 provided D:\Τα Ξ­Ξ³Ξ³Ο?αφά ΞΌΞΏΟ…\Arduino\@-NEW_Projects_OCT_2017\1.8TFT_with_DS3231\1.8TFT_with_DS3231.ino: In function 'void setup()': 1.8TFT_with_DS3231:24: error: 'class DS3231' has no member named 'begin' D:\Τα Ξ­Ξ³Ξ³Ο?αφά ΞΌΞΏΟ…\Arduino\@-NEW_Projects_OCT_2017\1.8TFT_with_DS3231\1.8TFT_with_DS3231.ino: In function 'void loop()': 1.8TFT_with_DS3231:47: error: 'class DS3231' has no member named 'getDOWStr' 1.8TFT_with_DS3231:53: error: 'class DS3231' has no member named 'getDateStr' 1.8TFT_with_DS3231:59: error: 'class DS3231' has no member named 'getTimeStr' 1.8TFT_with_DS3231:71: error: 'class DS3231' has no member named 'getTemp' Χρησιμοποιώντας την βιβλιοθήκη Adafruit-GFX-Library-master στην έκδοση 1.2.2 στον φάκελο: D:\Τα έγγραφά μου\Arduino\libraries\Adafruit-GFX-Library-master Χρησιμοποιώντας την βιβλιοθήκη Adafruit_ST3775 στον φάκελο: D:\Τα έγγραφά μου\Arduino\libraries\Adafruit_ST3775 (legacy) Χρησιμοποιώντας την βιβλιοθήκη SPI στην έκδοση 1.0 στον φάκελο: C:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\SPI Χρησιμοποιώντας την βιβλιοθήκη DS3231 στην έκδοση 1.0.2 στον φάκελο: D:\Τα έγγραφά μου\Arduino\libraries\DS3231 Χρησιμοποιώντας την βιβλιοθήκη Wire στην έκδοση 1.0 στον φάκελο: C:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\Wire exit status 1 no matching function for call to 'DS3231::DS3231(const uint8_t&, const uint8_t&)'

Topic by BillyK11