resistor Q

I'm building an LED circuit and I have the right ohm but the W is 1/2 when 1/4 was calculated out?

Posted by mrshow555 11 years ago  |  last reply 11 years ago

Identify this tool

What is it for?

Asked by Ccross274 3 months ago


Health tips

Posted by joyborro 6 years ago

HELP ME ::: want to interface ps/2 mouse using uno to pc

Hi friends, i am new to arduino board. Trying to make a arduino uno based PS/2 mouse by using ps2dev.h... From the example from that the mouse move diagonally only. how to set that in other direction left,right,top,bottom.. // move the mouse diagonally     delta_x = 1;     delta_y = 1;     write_packet() Anyone guide me, how to move right or left or up or down...plz help me #include "ps2dev.h" PS2dev mouse(3,2); // 2 data 3clock char buttons[3] = {0,0,0}; int delta_x = 0; int delta_y = 0; //we start off not enabled int enabled =0; //ack a host command void ack() {   while(mouse.write(0xFA)); } void write_packet() {   char overflowx =0;   char overflowy =0;   char data[3];   int x,y;     if (delta_x > 255) {     overflowx =1;     x=255;   }   if (delta_x < -255) {     overflowx = 1;     x=-255;   }    if (delta_y > 255) {     overflowy =1;     y=255;   }   if (delta_y < -255) {     overflowy = 1;     y=-255;   }     data[0] = ((overflowy & 1) << 7) |     ( (overflowx & 1) << 6) |     ( (((delta_y &0x100)>>8) & 1) << 5) |     ( ( ((delta_x &0x100)>>8)& 1) << 4) |     ( ( 1) << 3) |     ( ( buttons[1] & 1) << 2) |     ( ( buttons[2] & 1) << 1) |     ( ( buttons[0] & 1) << 0) ;       data[1] = delta_x & 0xff;   data[2] = delta_y & 0xff;     mouse.write(data[0]);   mouse.write(data[1]);   mouse.write(data[2]);   delta_x = 0;   delta_y = 0; } int mousecommand(int command) {   unsigned char val;   //This implements enough mouse commands to get by, most of them are   //just acked without really doing anything   switch (command) {   case 0xFF: //reset     ack();     //the while loop lets us wait for the host to be ready     while(mouse.write(0xAA)!=0);      while(mouse.write(0x00)!=0);       break;   case 0xFE: //resend     ack();     break;   case 0xF6: //set defaults     //enter stream mode       ack();     break;   case 0xF5:  //disable data reporting     //FM     ack();     break;   case 0xF4: //enable data reporting     //FM     enabled = 1;     ack();     break;   case 0xF3: //set sample rate     ack();;); // for now drop the new rate on the floor     //      Serial.println(val,HEX);     ack();     break;   case 0xF2: //get device id     ack();     mouse.write(00);     break;   case 0xF0: //set remote mode     ack();      break;   case 0xEE: //set wrap mode     ack();     break;   case 0xEC: //reset wrap mode     ack();     break;   case 0xEB: //read data     ack();     write_packet();     break;   case 0xEA: //set stream mode     ack();     break;   case 0xE9: //status request     ack();     //      send_status();     break;   case 0xE8: //set resolution     ack();;);     //    Serial.println(val,HEX);     ack();     break;   case 0xE7: //set scaling 2:1     ack();     break;   case 0xE6: //set scaling 1:1     ack();     break;   }   } int xcenter ; int ycenter; int xsum = 0; int ysum = 0; void setup() {   unsigned char val;   // send the mouse start up   while(mouse.write(0xAA)!=0);    while(mouse.write(0x00)!=0); } void loop() {   unsigned char  c;   if( (digitalRead(3)==LOW) || (digitalRead(2) == LOW)) {     while(;)) ;     mousecommand(c);   } if (enabled) {     // move the mouse diagonally     delta_x = 1;     delta_y = 1;     write_packet()    }   delay(50); }

Asked by melwin.a3 6 years ago  |  last reply 6 years ago

Hi I want to ask a question about my graduation project in universty.I desing electronic metronome?

.I use 8 led and it will count 1-2-3-4-5-6-7-8-7-6-5-4-3-2-1-2-3... ıt goes like this but when I desing it,it count 1-2-1-2-3-4-5-6-7-8-1-2-1-2-3-4-5-6-7-8... like this.I use r-555(timer),4510 up/down counter,74ls138.And it will tempo adaggio,moderato,andante,allegro.I mean ıt should give 4 italian tempo .Thanks for helping....?

Asked by eraygau 7 years ago  |  last reply 7 years ago

Is there a way to use cymbals on a rockband 1 drumset?

I just got rockband 3 and wanted to know if there is a way to install jacks in my drum set so it can use the rockband 3 cymbals for pro mode.

Asked by esahcb 7 years ago

What can I make

I have about 40 wood blocks, 3 1/2" x 2 1/2" x 2 1/2".  I don't know what to do with them.  Don't want to send to recycle.  Not really sure if they are recyclable.  I'll attach a photo.  

Posted by carolb4 3 years ago  |  last reply 3 years ago

How do you raise the current from 1 amp to 2 amps without changing the voltage?

How do you raise the current from 1 amp to 2 amps without changing the voltage

Asked by DELETED_MakerNinja 3 years ago  |  last reply 3 years ago

Woohoo! Over 1 Million views...

In the last day or so,my viewcount meter kicked over 1 million views.  And now we would like to thank our gracious sponsors at Autodesk for which this would not have been possible without their kind support and generosity .

Posted by caitlinsdad 5 years ago  |  last reply 3 years ago

resistors and watts

I know how to use ohms law to calculate what size resistor I need but what I really need to know is how to tell/calculate what watt rating I need to use whether it be 1/4, 1/2, 1/8, 1,10 and so on.

Posted by pattyshaw 6 years ago  |  last reply 6 years ago

My instructable has 0 View for about 1 day ! ?

Hi, I know this is a common error but what is the solution ?? 

Asked by ram mere 4 years ago  |  last reply 4 years ago

Are there any planes that use both pusher and puller propellers at the same time?

Would look like 1 in the front and 1 in the back.

Asked by zjharva 9 years ago  |  last reply 9 years ago

sawing 1 1/4&quot; EMT?

Hi everyone, I have found a local store close to my home that will sell me electrical metal tubing, but they will not cut it (they only sell it in 10'-long tubes). They have told me that they have a hacksaw in the back I can use to do it myself, but since I am just kid I thought they might be kidding me. Is it feasible to cut 1 1/4" electric metal tubing with a hack saw? The tubing looks pretty thick to me and I would need to make three different cuts. Thank you for any advice, James

Posted by james.kirin 9 years ago  |  last reply 9 years ago

Controlling motors with my Arduino

Hello, i received an arduino (duemilanove) as a gift for christmas so im still kind of a n00b, i was wondering if it was possible to control motors directly from the arduino for an upcoming project? i would buy a motorshield but im not sure if its compatible with the duemilanove and if i do buy it i wont be able to get it until around easter I need to run two-three motors in bursts repeatedly (ex. Motor 1 for 1 sec Motor 2 for 1 sec motor 1 for 1 sec...................... you get the gist of it) Thanks in advance, Firezone 

Posted by firezone 9 years ago  |  last reply 9 years ago

small solar panel with 1 AA battery?

I need a small solar panel to put on top of a tiki pole so I can have its eyes light up. It has one in it but has quit working trying to find one to replace it . It is approx. 2 1/2 in by 2 1/2 in do you carry such a thing or know where I might purchase one. Thank you for your help in advance Anne Domes

Asked by 9 years ago  |  last reply 9 years ago

Logic gate help

I'm attempting to build an binary calculator out of an old iphone box using LED's and such and have a wiring system set up but i need to know how to make/buy some form of "if then else" gate (i.e. if A=1 then B=1 else C=1 and if A=0 then B=0 and C=1). I would love to know if there is some kind of way to do this using transistor logic but anything that works as an "if then else" gate is welcome.

Posted by cdarcy 9 years ago  |  last reply 8 years ago


Hi all,  I got two 3-way-speakers (8ohm) from my uncle, but I don't have an amplifier. I wanted to use these speakers as audio-monitors for my pc. Is it possible to make an (easy) amplifier-circuit for this use? And do I need one or two circuits (1 circuit-1 speaker / 1 circuit-2 speakers)? Thanks for helping me out! Arnout PS: Sorry if my english isn't that good - I'm from Belgium ;)

Posted by arnoutdejans 6 years ago  |  last reply 6 years ago

Pro membership

Hello everybody... I have purchased pro accaunt, I mean that I have bought 1 month membership for under 2 dollars (sorry for my english) but in my new accaunt there I can see that I have purchased for 1 year?? So I have paid 20+ dollars? How is that possible? I have clicked on 1 month membership for under 2 dollars why do I have to pay for 20+ dollars? Thank you

Posted by kordy 8 years ago  |  last reply 8 years ago

Blu ray movies in 7:1 Audio?

I just got a 7:1 Receiver, and can't find any movies in 7:1. I looked up on google, but would prefer some real answers from people who have actually seen it for themselves, as opposed to just looking it up on websites such as Thanks, BB

Asked by Bartboy 9 years ago  |  last reply 8 years ago

USB connector 2-in- 1

Hi, Is there anyway to charge battery through USB connector as well get output volts from the same port ? any 2-in-1 type adapter or hack available.  They should be able to work through external charger . Any time of solution would be help full. Thanks,

Posted by RichiV 4 years ago  |  last reply 4 years ago

2 + and - out puts into 1 speaker what would happen?

If i took the   end of my headset speaker and the - end and took the   and - ends of something else like some headphones and hooked them to 1 speaker would they mix into one sound or turn in to a scrachy sound that makes no sence?

Asked by dupuis237 8 years ago  |  last reply 8 years ago

Anybody got a fix for a DS slot-1 latch problem? Answered

My sisters DS slot-1 wont keep the games in. I think the latch is broken. Do i have to replace it for her, like un-solder it and re-solder a new one, or is there a simpler fix?

Asked by Redfox888888 9 years ago  |  last reply 9 years ago

An unrated ible has a 1* overall rating?

Link to instructable: The ible has a 1* rating, and no ratings beforehand.  What is going on here?  I have never seen this before. I'm running latest version of firefox on Vista.

Posted by DJ Radio 8 years ago  |  last reply 8 years ago

Shape shifters?

Has anybody ever solved a square-1 or other shape shifting puzzles? I am considering making a Square-1 tutorial, but was wondering how many people knew they existed or had them. - is a wikepedia description

Posted by Does Not Compute 9 years ago  |  last reply 9 years ago

Suggestions for upcoming 1-week speed contests?

We're going to be running more of these 1-week speed contests. So far we've done DIY wallets, fridge magnets, and office supplies; what would you like to see next? List your suggestions here, and argue pros and cons. We're listening!

Posted by canida 11 years ago  |  last reply 3 years ago

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!?

Asked by kolf3500 7 years ago  |  last reply 7 years ago

scale modeling papercraft?

I do scale models, and I was wondering; are there any places where you can download free papercraft things like buildings, army vehicles, ships, etc. for free that are in the equivelant scale of most models, suck as 1/48, 1/72, 1/35?

Asked by the poodleo 7 years ago  |  last reply 7 years ago

is there anywhere that sells a keyboard or a keyboard key with the ubuntu logo instead of windows??

Is there one because i want 1 windows key and 1 ubuntu key

Asked by GASSYPOOTS 6 years ago

looking for plans on building 1 to 5 gal. wooden kegs?

Looking for functional and decorative plans for making wood kegs.

Asked by du1200 9 years ago  |  last reply 9 years ago


This is a talk about zombies

Posted by josefu0 10 years ago  |  last reply 7 years ago

Inateck Contest For Giveaways : Grab the chance in the last week !!

Just want to share with you this contest activity. Inateck launched this activity as a reward  for fans’ support and participation. They totally listed 5 free newly-launched products as the following : Prizes: 1. 1 X Inateck HB5001 4-Port USB 3.0 + 1-Port Charging Hub 2. 1 X Inateck KT4004 4-Port USB 3.0 PCI-E Express Card For MAC Pro 3. 1 X Inateck FE2003 USB 3.0 Superspeed HDD External Enclosure 4. 1 X Inateck FD1003 USB 3.0 HDD Docking Station 5. 1 X Inateck Kindle Paperwhite Cover Ends on 08/04/2014 11:00 am CEST (Tue.) Terms and rules please refer to this link : Wish to be a luck guy with you !

Posted by andersonlono 4 years ago

How about a teeny tiny power supply??

I've seen some pretty good power supply projects on here. Here's a challenge: Make a 5 to 12 volt power supply that can fit into a 1 cubic inch space, of any dimensions, i.e. 1"x 1" x 1" or 1/2" x 2" x 1", etc, including any enclosure. It must put out at least 300ma sustained and must have a fairly smooth voltage regulation for use with other electronics (of course). It must have clear schematics without the use of special programs to view, i.e. it shouldn't be in an eagle format or rather can be viewed with paint, or any of the other picture viewers. It must be powered from the mains and NOT use a microcontroller or any custom chips. The smaller it is, the better, and less than 1 cubic inch is excellent. I've seen real genius on here. Is this genius ready to try this?

Posted by Pazzerz 10 years ago  |  last reply 10 years ago

How to power multiple servos with an external power source?

I need to power the following servos (with the following quantities): 1 x HS-422 Servo Motor, 2 x HS-645MG Servo Motor, 1 x HS-755HB Giant Scale Servo Motor, 1 x HS-805BB Giant Scale Servo Motor, 1 x HS-485HB Servo Motor. I have an arduino uno controlling them but am powering them off of 1 6v 2800mAh NiMH battery (I have 2 at my disposal though). I am using the power strip on the side of my breadboard. I connected all my servos and battery to the same power strip. My servos seem to be going crazy when I have more than 1 connected (they don't listen to the input and just keep going from 1-180 degrees). I have attached the layout below.

Asked by Science102 2 years ago  |  last reply 1 year ago

XBOX 1 Headset Guts Inside an Old Turtle Beach Mic/Headphone

Hi, I have never posted here before, so if this is in the wrong place please let me know and I will move it. I have seen some guides on getting Turtle Beach headphones to work with the XBOX 1 chat adapter thingie. However, what I want to do is that I want to essentially replace the shell of the XBOX 1 chat headset with my old turtle beach headset shell - I just want the chat in one ear and the mic to work. Is that possible?

Posted by wags2284 5 years ago

Ibler ranks? (Idea for Instructables Update)

So, one day I was thinking during school. And, I came up with an idea. What if you had a rank on how active you are in Instructables? Like for example, I came up with rankings from 1 to 3 which should be up to 10 1: Infant - 0 Instructables, 20 comments 2: Toddler - 1 Instructable, 70 comments 3: Pre - k - 1 - 3 Instructables, 120 comments etc. I was wondering, what do you think of this idea?

Posted by Flumpkins 9 years ago  |  last reply 9 years ago

How do i make a 1 amp boost converter that converts between 3-5v to 5v?

Hey, so  have been buying pre built boost converters but i wanted to build my own, my question is, how can i make a step up boost coverer circuit that takes between 3 and 5 volts and converts it to 5 volts at 1 amp. In you answer could you explain what each part does? Thank you!!!

Asked by jbdawinna 4 years ago  |  last reply 4 years ago

Propan-1-ol vs Propan-2-ol as laser lens-cleaning solvents? [Answered elsewhere]

I was going to buy some propan-2-ol (isopropyl alcohol) to clean my laser cutter lenses. Before I went and bought some, I found a small bottle of propan-1-ol (so, I'm a hoarder!). I know they have different structures, and slightly different chemistries, but I can't find anything about their comparative properties as cleaning solvents. Will the 1-ol do the job of cleaning laser-gunk off lenses and mirrors, will it do nothing, or will it damage them? I'd rather gather your wisdom before I risk having to buy new optics...

Asked by Kiteman 2 years ago  |  last reply 2 years ago

Can someone please build a knex DSR-1 Sniper Rifle that shoots blue or yellow rods? ?

It's one of the coolest looking snipers in my opinion, and I'm currently working on one myself. I just want to see other designs so that I can perfect mine. PLEASE! :D?

Asked by knexsniper1 5 years ago  |  last reply 5 years ago

What is the BEST web hosting company? Answered

Is good. Is IX good? I do not want GO DADDY or 1&1 please

Asked by robots199 9 years ago  |  last reply 9 years ago

Can I get a 5 1/4 floppy disc drive to work under Windows XP?

I have a 5 1/4 which appears to be OK, I think I configured it through BIOS and Windows seemed to pick it up, but it wouldn't recognise it past that. I think that XP just doesn't handle this obsolete format, but I don't know. And if you're wondering: "because it's something I want to do" L

Asked by lemonie 9 years ago  |  last reply 9 years ago

Altoids Tin 1/8" Stereo Mixer using a 3.5mm 4 pole conductor (mic + audio)?

Hey have been thinking on how to modify to accept a 3.5mm 4 pole conductor as the output while splitting the mic to the inputs. This is going to be something like the Iphone ear buds with built in mic. I just got a pair of amplified 4 pole headphones with mic that I want to use for everything.  Here is my wish list:   3 - 4 pole Audio in (iphone, macbook, ...) 1 - 3 pole Audio in from computer 1 - Mic in from computer 1 - RJ10 (so I can use my headset with my cisco phone) The audio mixing is basically the same as Rich's write up. But im not sure if I can just split the mic to everything. If I am sacrificing mic volume by splitting to every input I could limit it to the CPU mic and the RJ10.. the ones i really want. Please let me know any ideas or advice you have. Here is my purposed schematic:

Asked by V4zra 6 years ago  |  last reply 3 years ago

1 Year membership trade of!

I am willing to trade my 1 Year Pro of for a 15$ ebay gift certificate/card. You don't need to ship me the card or anything but all you need to do is just send me the code for the 15$ ebay gift card by messaging me right here on instructables, and after you have sent me the code I will immidietly send you the 1 Year Pro by messaging you the code as well! And yes this 1 Year Pro is for If you have some other amount of an ebay gift card and not 15$, then just message me telling me how much amount worth code you have and if I think yeah then I ask you to send me the code and then I send you the code!

Posted by vishalapr 7 years ago  |  last reply 6 years ago

what is the cheapest way to make this?

What is the cheapest way to make a bicycle kart? see me and my mom are very poor "kinda" the money is tight here and i would like to make something cool like this but heres what i have to make one this is ALL i have i dont have anything else meaning this is all the parts and tools i have 1 ten speed mountain bike,1 weed eater "working",2 planks of wood "the legenth of my arm,1 pair of screwdrivers.gasoline "for the engine to run",1 spare bicycle tire,1 spare and rusty bicycle chain,wire plyers,1 hammer,i only have 10 dollars and no im not allowed to get a soldering iron/gun so if theres anything that you know of on how to make this please let me know.

Asked by wizard744 9 years ago  |  last reply 4 years ago

how do i stop an energy sword from blowing up and be able to use it in halo 1?

I have always wanted to use an energy sword in halo1 but it keeps blowing up so I modded it and it does not blow up then i made it pickable but i cannot attack.

Asked by chua_erei 8 years ago  |  last reply 6 years ago

Installing lights in 1/18 scale Diecast Car, need blinkers and four way flashers help..

Im old.. ok?! so dont make too much fun of me,,, but, Im getting a handle on LEDs and their simplicity.. Very cool What I am attempting to do, is to put a full set of lights into a 1/18 scale diecast car. Setting up a basic light setup for the head and tail lights is under control, but where I need help is with blinkers! I need a simple and small setup, so i can activate the right or left blinkers on the toy. As an added bonus, it would be nice to be able to turn on (separately)  all four as if they were hazard lights. Running either 3mm at each of the four corners, or possibly using Fiber optics and  one LED per side... Any and all help appreciated!

Asked by vwluvrs 7 years ago

How can I convert 9 volts DC to 1 millivolt DC?

I need to be able to convert 9 volts to 1 millivolt. Is there a schematic/circuit that can do this? If so, could you please provide one or details on how to make one? Thank you!!!

Asked by vak52 3 years ago  |  last reply 3 years ago