# COMMUNITY

### Opposite of a resistor

So a resistor reduces the current, what would increase the "speed" of the current? Is there such thing?

Posted by jaketheman987 8 years ago

### How to identify if the resistor is out of tolerance?

Asked by StephenR39 2 years ago

### resistor parallel

Sir I need 100ohm 3 watt resistor but cannot find it in market, in market I find 100ohm 1watt resistor ,plz tell me how I acquire (100ohm 3 watt resistor) value. can I parallel three 100ohm 1 watt resistor to get my value

Asked by robinhoodxx 3 years ago

### What is the colour code for 4,5&,8 volt Resistor? Answered

Asked by Milin 18 5 years ago

### is it needed to use a resistor in a circuit consisting of a 12 volt motor and a 12volt rechargable battery .

I' making a wheel chair run by a 12 volt rechargable  battery connected to a 12volt motor and also a switch.Is a resistor needed,if needed what resistor should be used?Can I use a variable resistor

Asked by pvamsi 4 years ago

### Why are these resistors marked as such? Answered

Hi, I ordered a kit of assorted resistors (112 types, 10 of each), and it's awesome, however, some resistors are marked weirdly, like 1k8, 2k7, 1m8, 2m2, there's quite a few. What's the meaning of these?

Asked by XOIIO 5 years ago

I'm trying to do the evaporator workaround for the Ford Fusion. Instructions from this page say to use 37kOhm 1/8 watt resistor. No one has this. Can I use other wattage rated resistors such as 47 kOhm 1/2 or 1/4 watt ?

Asked by DaleH48 1 year ago

### how to make a circuit using 4 lED's, 9volts battery, and resistor?

How to make a circuit using 4 lED's, 9volts battery, and resistor? what kind of resistor should I use?

Asked by imatrianidar 2 years ago

### what is a resistor? can some 1 give me a very simple robot to start with ....cause im new to robotics.....?

Asked by arun.fifa 8 years ago

### Resistor for Nano Arduino circuit

I'm trying to work out what resistor to get for the Nano Arduino circuit for this mini fridge build. From the photo it looks like a 5.6K 1%, but I have no idea what wattage? In the circuit diagram it is listed as 4.7K with no other details. www.instructables.com/id/DIY-Portable-Mini-Refrigerator/ Any help would be great!

Asked by KarolinaK19 7 months ago

### What resistor do I need to drop 9 volts to 4.5 or 5?

I need to use a resistor (not a voltage regulator, sorry) to drop 9 volts from a battery down to 4.5 or 5. I am running an attiny85, which is also used to power up to 3 30ma leds. What do I need to use?

Asked by XOIIO 5 years ago

### is this led array right?

+18V + -|>|- -|>|- -|>|- -|>|- -|>|- -/\/\/\- + R = 22 ohms + -|>|- -|>|- -|>|- -|>|- -|>|- -/\/\/\- + R = 22 ohms + -|>|- -|>|- -|>|- -|>|- -|>|- -/\/\/\- + R = 22 ohms + -|>|- -|>|- -|>|- -|>|- -|>|- -/\/\/\- + R = 22 ohms + -|>|- -|>|- -|>|- -|>|- -|>|- -/\/\/\- + R = 22 ohms this lay out has the resistor on the negative side is this right many thanks for helping karl

Asked by kturner6 4 years ago

What resisitor do i need to go from 18Volts to 1Volt?

Asked by michoi 8 years ago

### How much will it take to burn out a 1/8 watt 1 ohm resistor? (and capacitor question)

I love electronics, and pranks, so I want to rig some things to "fail" by releasing smoke, and I figured what better way than resistors? I was wondering though, if I get some 1/8th watt 1 ohm resistors, will I be able to burn them out with the voltage from say, a USB port, or a double a battery or two? I was also wondering, is there anywhere online I can get some electrolytic capacitors, not super tiny ones, but moderate size that are only a couple volts?

Asked by XOIIO 5 years ago

I was just wondering if there is some kind of marking on a resistor that tells you which direction you should read it. I've seen brown bands on the ends of some resistors but not always, so I was just wondering if someone could help me out. Thanks Zealous

Posted by Zealous 9 years ago

### 3V Resistor and LED

What would be a good Ohmed resistor for an LED running on a 3V power source? 3.2-3.4V typ with a 3.8V max.

Posted by Brennn10 8 years ago

### does anyone know the value of the r21 resistor in an xbox360 controller?

Does anyone know the value of the r21 resistor in an xbox360 controller?

Asked by tefftb 9 years ago

### I need a 18 Ohm resistor

Does any one have a 18 Ohm resistor that they could stick in an envelope and send to me because eighteen bucks is a little steep for A resistor. oh ,and radioshack doesn't carry them either :( ~Matt

Posted by iman 9 years ago

### Resistor negetive to positive?

Hey. I'm changing all the LEDs in the switches in the car. All is going well except one switch, there is 1mm distance between a circuit board and the LED. The LEDs are 12v no resistors. I'm using ultrabright red LEDs that need resistors. However, I'm sure I've seen circuits that resistors go on the negative and positive leg before the LED. Would this work or would the LED still blow? Thanks.

Posted by Josho 9 years ago

### Whats the difference between a 1/2w resistor and a 1/4w resistor? Answered

I am in need of a 33ohm 1/4W resistor. The closest I can find is a 33ohm 1/2w resistor. the source voltage is 6v, the leds(2) 2.6V each with a 28 MA current. Is that ok?

Asked by hunter1125 8 years ago

### Hot, Burning Resistor Question

Ok....I have 24 leds in parralel attached to a 9 volt battery - and a 10 ohm resistor - as reccommended by LEDCALC.comLEDCALC.com - but, when i connect the circuit and hold the resistor in my hand, it becomes INCREDIBLY hot. Each led is in parallel, individually. So...is it normal for it to be that hot, or did I do something wrong?

Posted by Joe426 10 years ago

### Resistors

Please help me! I can't seem to understand the values of resistors and how they affect current and voltage. I have a 7.5 volt, 350 milliamp circuit that I would like to limit to 5 volts, and if possible raise the current to 500 milliamps. How could I do it?

Posted by jasper28 10 years ago

### which resistor do I need for my LED?

What resistor is best for my single LED?  I've read that I need 1 Ohm (is that correct?), but I don't understand power watts and tolerance.  Could I get away without using a resistor at all?  Thanks. battery voltage: 3 diode forward voltage: 2.8-3.4 diode forward current: 20mA

Posted by aliasjanedoe 6 years ago

### resistors for leds why?

I know i need resistors for leds, i know how to calculate what i need, etc. etc. but what im wondering about is why. why arent leds like glowing bulbs, what makes the difference in needing the resistor. also, why cant 1 resistor take care for multiple leds at the same time? please, if ur answering my questions, make it understandable english. im not comfortable enough in the world of science to understand that kinda stuff... (otherwise i wouldnt be asking these questions :D )

Asked by godofal 8 years ago

### how many ohms does this resistor have in the led

Posted by dereklevine158 5 years ago

### What resistor should I use to complete the circuit with a 3V battery and 10 LEDs?

I have connected 5 green LEDs and 5 red LEDs with 2 ply conductive thread and I am unsure as to what resistor I should use to complete the circuit (with a 3V battery).

Asked by Protocal7 1 year ago

### 1/8 w resistor for 12v?

Hi, I've been trying to add a LED light for my glove box, since it didn't come with any. I bought one radio shack led with built-in 1/8w 680ohm resistors to see how it was made. I read the 1/8w resistor wouldn't work and it would burn up? Using something like 1/2w would be better. I tested it with a 9v battery and I didn't feel it getting hotter. Maybe just warm? I got some LEDs off ebay many years ago and I have no idea what their specs are. They are 3mm led bulbs. I decided to make my own by using 5 1/8w 150ohms resistors. 150 ohms are the only resistors I have on hand. With the combined resistance of 750 ohms, how much voltage is going to the LED? Will I be fine with just using 4 150 ohms resistors? Will is be dangerous to use the 1/8w resistors? I don't want a fire. Will having more resistors also help spread out the heat among the resistors? I drive 4 hours a day, so the light will only be on for that duration. Thanks

Asked by RoboRay 6 years ago

### Need to know if i can replace a 22 ohm /10% (1.5w ((I think due to size)) resistor with a 22 ohm / 2% 2watt.

The resistor placement is R2 in a Behringer B215D powered PA speaker. The resistor that was in it is smaller round than the replacement piece,but is the same length. The schematic does not state the wattage of the resistor so I'm a little confused. Any help would be greatly appreciated.

Asked by hal.jensen.9 3 years ago

### How do resistor-capacitor circuits work? Answered

I know this is a basic question, but it has bugged me, and is in two parts. The first: Are resistors like reduction valves for electricity? i.e. Do they simply absorb and dissipate excess electricity, or do they restrict its flow, as in making a large capacitor discharge its energy through a resistor to prolong output from the capacitor? Also, do capacitors store electricity until it is full, then release it, or is that only when they fail? Thanks!

### the right resistor?

Hey guys got a question. I want to add an ultra bright LED from my mini mag light to my atx benchtop power supply. The LED ran off 3v (2 AA’s.) The line I want to use is the 3.3v (14 amp) from the atx to power it. What size/power rating resistor should I use?

Posted by jmille38 7 years ago

### LEDs in parallel or series? One or many resistors?t

I want to make an LED strip, and I'm not sure weather to place two strips of copper down the side of the strip and attach the LED's to that, so it's parallel, or just make it series. What is the best? Should I use one resistor or many? (Obviously this only effects parallel) Thanks.

Posted by Josho 10 years ago

### if i put 3 resistors in line with each other does that add the resistance values together? Answered

What i mean is if they are like this in a circuit: > -R1- -R2- -R3- > becuase i need 300kohms, but all i have are multiple 100kohm resistors. if i put them like described above, will that equal 300kohms? if not, what way does?

Asked by zack247 7 years ago

### Only up to four LEDs light up.

I've got loads of LEDs and resistors from eBay and using the resistors, only up to 4 LEDs in serial will light. I can't just use more resistors, as I broke open a mains lighting bulb that uses 20 LEDs to provide lighting. Looking at the printed circuit, they are all soldered in series. If I put + at one side of an LED and - at the other with these resistors I have, it lights, two three and 4 work, but on the 5th, it drops dim, after that it won't light at all. Do I need a different resistor, of is something else wrong. Could someone kindly tell my what resistor I need for 20 5mm White LEDs running off 18v (two 9V batteries), and 9v (one)? Thanks! Josh.

Posted by Josho 9 years ago

### What resistor and method should I use to string 12 led's in parallel from a 5v source?

I'm trying to figure out what resistor I should use to string 12 blue led's in a ring from a 5v source (like this except instead of 8, using 12: http://www.llamma.com/xbox/Mods/xbox_jewel_led_mod.htm). The specs that I have on the packaging of the led's are: MCD 4000~6000 and VF: 3.0v~3.2v. I read 2 different ways to do this, one (the easier way which I was leaning towards) was to use one resistor for the entire parallel series. The other way was to use an individual resistor for each led. What do you recommend. Can I get away with doing it the easy way, and if so, what resistor (ohms, wattage, and tolerance) should I use? Thank you.

Asked by banunoo 8 years ago

### What size resistor do I need?

Hi, I have a Wilson Sleek antenna booster that runs on car battery power, 12VDC and draws 2.5A.  I would like to power it away from the vehicle using a 19.2VDC Craftsman drill battery that measures 21.7VDC at the terminals, fully charged.  What size resistor installed in series with the Sleek will allow it to safely operate from the Craftsman battery?

Asked by plentyblackcoffee 6 years ago

### Homebrew heaters using resistors?

Hello, First time poster! :) I've been reading up on some projects on this site centered around small homebrew heaters. One I came across I want to adapt is using two resistors and usb port power to make a small coffee mug heater. I'm kind of a novice at electronics, but I'd like to know how to design such a heater with safety and functionality in mind. I also want to control this heater via arduino if I can get a prototype together. Some questions I have: Where to get and what kind of resistors for heaters? How do I figure out what resistors to use based on power. e.g. 12v or USB power? What's a good thing to "encase" the resistors with that will withstand heat? I have thought about using radiator repair epoxy. Thanks for any help!

Posted by Sylvester2009 8 years ago

### I have a string of like 20 L.E.D's do i need a resistor?

Asked by nosedive25 9 years ago

### Can I make a 15W+ 1-5Ohm resistor?

I'm making a yard sprayer with a 12V, 5amp pump.  It works great, but I'd like to add in a 2nd, slower speed setting for situations where I want less fluid going through the sprayer.  It needs to a be a simple fast/slow switch, not a variable resistor, since I need the flow rate to be repeatable and consistent.  Ideally, I'd like to make about a 2-ohm resistor, that would need to be able to handle about 15W.  Unfortunately, no local shops have anything like that, and I don't want to wait for an on-line order to get shipped. Is there any way to make a DIY resistor to roughly achieve these characteristics?  (Like I said, the important part is that it will be a consistent resistance value, not a specific resistance value, and not burn up with 2-4 amps going through it..)

Posted by SvdSinner 5 years ago

### How can you tell or measure how many watts a resistor can handle.? Answered

Let's say I salvage a few resistors from an old electronic, how can I tell if it's a 1/8 watt or 1/4 watt etc? I have a multimeter if need be.

Asked by surlistyc 7 years ago

### Bleeder Resistors and momentary load switching on EL wire

Okay so I have a CL-ELI IPTC 9V to 3Khz inverter from Coolight.com that I want to use to power some wire with momentary(like less than 2sec) load changes. I could wire in a power switch between battery and inverter to turn off, switch loads, turn on, but a friend recommended using a bleeder resistor wired across the inverter leads on the 3Khz side before taking them out to the load, allowing me to simply quickly switch loads without frying the inverter. Good idea, bad idea? If its a good one what Ohm resistor should I be using?

Asked by -Kai- 7 years ago

### What type of resistor?

Can anyone help me I'm not very good with electrics but I would like to know how to find out what type of resistor I would need to run power from my ps3 power supply to the fan... If I wire it straight it's running way to fast and would like to set it to a lower speed. I have used a 220k potentiometer in the past but dont want to have to adjust it plus they are to bulky is heir a certain kind I should b looking at??

Asked by s3xo turbo 5 years ago

### Resistor values for common anode RGB LED? Answered

Hi,  I have 10w RGB common anode LEDs. Forward Voltage is R:6-8v, G:9-12v, B:9-11v. Forward current is 300ma.  I calculate resistor values as R:15ohms, G:1Ohm, B:3.9Ohms.  This is based on max Forward Voltage.  I was told I wouldn't need resistors but clearly that is not the case as in one of the LEDs the red has failed.  Is it as simple as putting the correct value resitor between each cathode and supply?  Also, if I were to increase the resisors to lower the voltage a little (i.e. R:7v=18Ohm,  G:11v=3.9Ohm B:10v=6.8Ohm) would that help keep the heat down? Many thanks,

Asked by Summerly 5 years ago

### How do I create switch on&off LED light?

HI, just wondering how to mix this all up and get a Switch/Resistor LED Light to put on my helmet

Asked by BrociliTree123 5 years ago

### why does an led have to be given a resistor before it Answered

If a device draws only its required amount of current from a supply,. then why does an led have to be given a resistor before it? wont it just take 20 mA from a 3 volt 5 amp power supply? i checked many instrctables for it but couldnt find a proper explanation for my answer so i thought of asking it.. and people say that led should not be directly connected to any supply as it may blow or get damaged or burn.. but i have done that many times and also had made a torch for my uncle using two white leds of 3.5v( not sure but they are big) and used a 9 v battery without any resistor...it lasted till the battery drained but never blasted... and yes its in series.. and thanks in advance for answering me.. and sorry for bad image quality..used my phone

Asked by hussainb 8 years ago

### Help with voltage/resistor

Hello.  I bought some Christmas LED replacement bulbs but they have no specs with them.  I decided to wire one up.   I figured I would go with 1 . 5 volts at 7 1/2 mA.   Using a 9 volt battery, I have a 1K ohm resistor.   9 - 1.5 = 7/ .0075.  My problem is, when I put my meter on it, the one side of the resistor is showing 9 volts, correct, but the other side is showing 3.5 volts.   Shouldn't it only be reading 1.5 volts?  What is wrong?  *I've had the LED lit up for over 25 minutes so far and it hasnt burned out yet. Thank You. EDIT:   I just added  a 10K resistor, so now I have 11K (in series), yet I am still getting a reading of 3.5 volts.   I'm missing something here. lol   I'm also getting a reading of about 9mA with 1K and 11K ohms.   I'm lost.

Posted by pennsteve 8 years ago

### What size resistor should I use to shorten a string of Christmas lights?

I need to shorten a string of christmas lights from 20 lights to 3 lights. The unaltered string ratings are  120volt,  .08 amps. The bulbs/lamps are 6volt and .48 watts each.   It is interesting to me that 20 lights x 6volts = 120volts. I'm sure that is not by coincidence but I'm not an engineer so I don't know how to use that information. I need to know what size resistor I need to use.  This is way to confusing for me to follow. If someone can help me out with a simple formula I would appreciate it as I need to work with lights strings of many different lengths.  Please try and put your answer into laymens terms. Thanks

Asked by nobill11 7 years ago

### Variable resistor problem..

Http://img86.imageshack.us/my.php?image=picture433pb4.jpgI ripped this out of a car audio system, i don't know the input volts, or whats what. I use to have it connected to a 3V battery to change a LED from 0 to 3V. Well, i pulled it out, wires gone. resolder wires as you can see. problem: WHAT IS WHAT?! All i know by the labels is it says RED on the lowest rail. the rest, dont know. If someone can please help me id love that. It switches on/off as well as changes volts. so i need 4 wires connected.

Posted by Killa-X 10 years ago

### Can we use variable resistor as a normal resistor? Answered

Like i want 4.7kohm constant can i do that som how

Asked by TheGreatResistor 2 years ago

### What resistor(s) would I use for this LED?

What resistor(s) would I use for this (http://mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtJ8nYvfCigMnhPGGOZPOa2uZUDzR6R8VM%3d) UV LED? I'll be using 3 of them in a row with a 9v power supply, would I wire it to be battery - resistor - UV LED - resistor - UV LED - resistor - UV LED - battery? Or something like battery - resistor - UV LED - UV LED - UV LED - battery?Thanks!

Asked by sciguy77 8 years ago

### resistor color code situation

I have a resistor wich the color makes no sens. its brown gold orange orange black (or the other way around), i cant mesure it for some reason. can anyone help me?

Asked by pbergeronronronron 6 years ago