How to choose the right Resistor
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- Опубліковано 9 лип 2016
- Watch this video to find out how to choose the right resistor and how resistors can set on fire if the right one wasn't chosen.
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Every little helps :) - Наука та технологія
"keep your eyes on the resistor"
*Resistor goes up in flames*
Me: "Dang! Almost missed it!"
hahaha even tossed it into slo-mo. Better not miss it!
This video is five years old but it's still GOLD. Thank you!
Are you a time traveler it was 4 years old
@@franklinguzman7668 So let's say at the time I posted this comment I was wrong about the date. I don't actually know nor do I feel like checking if I am wrong but I would like to point out how you could've made a sarcastically rude comment but you didn't. Instead of coming off as condescending you specifically chose to transform it into a lighthearted joke. I seriously respect that and wish there were more people like you in the world. Thank you.
@@kinglukethe7th524 bro💀💀
😂😂😂@@kinglukethe7th524
I have learned in hard way.. :/ I have just bought my potentionmeter (just one piece) for my project and I was happy that I calculated everything but I forgot to check how many watts it can take and of course started almost burning! I switched off immidiatelly thw hole circuit and it works so maybe it was just the last moment to do this before it broke down!
Thanks for this. One of the few videos talking about watts. It's breaking my brain about whether every resistor I've ever used has been wrong, but hopefully I'll avoid some overheating in the future.
very useful, informative video, just what I needed, thank you
Little resister is suited for 3 to 4.5v batteries with at least 5amp or less depending on the device used aswell
hello, i am learning about this subject currently. I was wondering if you put several of those in 'series' would the same burnout happen?
No because the resistance would increase by said value
The resistance in series is r1+r2+r3...etc= total resistance
why being dead sir it's nice channel Thank you for the resistance knowledge although i didn't look properly in my classes when this had been tought just don't die
I liked the magic trick at the beginning. Hehe. :) Thanks for the nice educational video.
Cheers for the Video clip! Excuse me for chiming in, I would love your opinion. Have you thought about - Runayslarn Survival Manifestation (Have a quick look on google cant remember the place now)? It is a good one of a kind guide for discovering how to repair your electronic items minus the headache. Ive heard some amazing things about it and my mate finally got great results with it.
What size resistor do I need if I’m hooking it to chime for a ring pro?
Very useful thank you
*With a lot of D.C. electronics, such as audio preamps, 1/8 watt is often perfectly suitable, but they are unpleasant to work with even if you are assembling a PCB.* Just something for folks to think about.*
On the other hand, when you're ordering 50,100 or even 1000, the price difference really does add up quickly when purchasing a large variety of values.
*I tend to order large quantities collectively of multiple values, and the 1/8 are sometimes very tempting but since I am still building on perfboard for now until I get to manufacturing my own PCB's, I have some 1/8 watt and greatly dislike them.*
Even on a PCB, I would dislike them but I suppose use them if they are perfectly adequate. *This also goes the other way because I don't like working with 1 watt unless I have to.*
Hey, firstly thank you for your informative videos. I am a newbie in electronics. I learned a lot from your videos but I have a question. If these are 1/4W resistors, why they dont blow up when using them with a led and a 9v battery? Sorry for the grammar, I am Portuguese. And a merry christmas
+BarbasBandas 666 because the current through the circuit is low enough that the power does not exceed 0.25W
oh... thats right.... thanks
@@barbasbandas6665 :D
Very simply explained in a crisp and short manner !! Thanx
I have a 28 watt LED strip that needs to be connected to a power supply of 12v, it works perfect with just 12v and no resistor, but all I want to do is dim it just a bit.. current going through, being used is around 2.3 amps, so if I get 5 ohm resistor? 12÷5= 2.4 amps, I'm not sure if that's good, or maybe I should get a? Idk I really think gonna start burning a few resistors till I get it right.. 😟😅
Howdy, Brother! What resistor should I use if I have a yellow 10mm LED Emitting Diode (1.8-2.2V) powered by two AA Batteries (on/off switch in the loop)? Will 47 ohms work? I'm not even sure if I asked the question properly . Thanks for any assistance.
what happen if you put 10 of the 15ohm in parallel? what is the watt capability now? and what is the watt being dissipated? probably the current is smaller in each but the voltage the same. Is having 10 in parallel means the total wattage capability adds up like 0.25*10=2.5 Watt now? if you have 1.5watt dissipated it should be fine hypothetically?
the formula for calculating the combined resistance of parallel loads is 1/x = 1/R1 + 1/R2 + ...
how could you know what power rating the resistor is ? a lot of chinese ones don't have any specification aside from the resistance value.
in this case youcan use many resistors of 1 watt in parallel , maybe 10 to support 10 watts , or 40 small resistors in parallel
Can you help me as new to electronics can I use a mfr instead of a cfr in a hf attenuator if not why can’t find much information on this
Very clear and I got a question, what if you use a 12v 1.5W solar charger linked to a 3.7v 3800mah lithium ion rechargeable battery and you got two pink 12v LEDs, what resistor do you need if they're in series or parallel please? there's a switch in this circuit too to only use the LEDs when it goes dark.
Can you try and explain as simple as you can please, I'm a beginner at best at all this.
You're linking a 12V charger to a 3.7v Lithium cell? Stop right there, unless you want an explosion. If you can give me a better idea of what you're trying to achieve, I will try and advise a little.
Yeah, I'll try and explain the circuit, at the start there's a 12v solar charger / panel(about the size of a smaller "smart" phone) 1.5w, then I was thinking of putting the 3.7v battery, then the switch, then the two pink 12v, 20ma LEDs so in the daylight, the solar charger would charge the little battery and at night it would have stored enough to power in the day to switch them on. I'm guessing that's dangerous by your reply.
Would it be better to have a 3.5v solar charger and use 3v LEDs instead? and do I need any resistors or diodes in a circuit like this? and what's best for this sort of circuit, series or parallel?
a 3.5V solar charger will not supply the voltage required to charge the lithium cells. since lithium cells at full charge are 4.2V. You can use the 12V solar charger, but will need to use a step-down regulator circuit that will at minimum regulate the voltage to 4.2V. A more advance and battery specific step-down regulator will operate at current mode regulation to supply 1-2A to the cells whilst monitoring the battery voltage, then switching to voltage-mode regulation to trickle charge the battery to 4.2V, thus ensuring a safe charge. As you can see, charging lithium cells safely is quite a complex process and is not as simple as connecting it straight to a voltage source.
thank you i was doing this mistake
This was great, thanks, been searching for "how do you find the voltage drop across a single resistor?" for a while now, and I think this has helped. You ever tried - Henucas Panrooklyn Equalizer - (just google it )?
It is an awesome exclusive product for discovering how to repair electronic devices like a pro minus the hard work. Ive heard some interesting things about it and my friend got excellent results with it.
do you always want to use to lowest possible resistor? is it a sound thing?
I have a receiver with DVD player that has a bad resistor. I know the ohms by reading the bands but how do i get the others numbers so I can buy the correct resistor watts? Pls help me.
Try it or look at similar electronics
I connected resistor to a charger (which gives 0.5A output), but when we calculate current through the resistor i.e v=ir gives 1.1A and power 12.1w is it correct r no.
Resistor:-Brown, Black, Black, Gold.
But still- what does the resistor do? We know it causes resistance but how is it used? Watched 4 videos and still don't know how to take 12vdc down to 9vdc using a resistor. What does the 10k actually mean?
I understand the concept of this, but you were using a resister that is for a single current flow. You were putting the battery positive to one side and the negative to the other. By doing this you were creating a hot spot by the + and - completing the circuit. Of course it would catch fire.
If this 15 Ohm resistor would be more than 10 Watt (big size resistor) it would handle that completed circuit and would be able to dissipate the generated heat without damaging itself.
Clearly you don't understand the concept.
Ok you've had half a decade, have you learnt more since then? 😂
But also new players, need to be aware to ALWAYS measure your voltage source first. For anything running off a Car battery, don't calculate it at 12V. The voltage across a car battery can be as high as 14.8 when engine is running. I once chose resistors to run interior LEDs. The first time I dd this, I calculated the voltage source to be 12V. This worked out that my resistor choice was too low meaning the current being allowed to flow through the LEDs was a few over the limit of the LED... and all the LEDS eventually blew / burnt out one by one over a few weeks.
You let the magic smoke out. Yeeeaaah 😊😊
hi ,
I just wonder why the resistor gets burn if the mechanism is in compliance with ohm law. I mean V/I is constant. Therefore when we increase the voltage, the system is supposed to react that change by an increasing amount of current so that V/I will not change. but instead it burns out. can anyone tell me the reason please
V/I is constant provided that V and I are not too big. That is, Ohm's law is only valid for a given range of potential and current, depending on what the resistor can accommodate. A resistor with a greater wattage rating will allow V/I to be constant over a greater range of values, but any resistor can be burned out if V and I get to be too much bigger than what it is rated for.
What resistor do you need if I connect a 3V battery ( 2x 1.5V battery) to a 4 ohm 3 watts speaker and Green LED that has 1.5 V and 0.01 AMP
You need to list the rest of your specs before you'll get a solid answer.
1. What are the power characteristics of your speaker?
2. What are the power characteristics of your circuit?
3. What are you trying to accomplish?
Start by listing these and I'll see if I can jump in to lend a hand.
@@percivul1786 it appears he/she wanted to make a speaker thingy with above specification but got stuck by the difference in current between the speaker and the LED (I guess we will have to use parallel circuit, but idk).
1. Given the characteristic is whatever you like, how would you approach this ?
2. What did you mean by circuit characteristic ?
I'm absolute noob and want to know too.
So, why then, when I connected 10K 0.25W resistor to the 12V battery it got hot enough to burn my finger? According to the calculations: 12v/10000 Ohms = 0.006Amps; And then 0.006A*12V = 0.072Watts. While resistor tested was 0.25W - way more then 0.072Watts required. Why is it getting melting hot?
Can I use a 5w instead of a 2w with the same ohms?
Depending on how much voltage and amperage you are passing
If Voltage times (amperage divided by the resistence) is more than 2 and less than 5
Then yes
Can someone help!!!!! What's the difference between 330k and a 330ohm resister?? Very new to all this
330k = 330,000 ohms
Excellent Video clip! Excuse me for chiming in, I would appreciate your opinion. Have you ever tried - Runayslarn Survival Manifestation (google it)? It is a smashing one of a kind guide for discovering how to repair your electronic items without the normal expense. Ive heard some incredible things about it and my best friend Jordan after a lifetime of fighting got astronomical success with it.
if you are salvaging some resistors from old electronics how can you know how much is the maximum rated power for such a resistor or electronic component ?
I think you find the color bands on the resistor and look up a spreadsheet online to match the color rating to the one you have
you can't
@@mikebolton2388 as far as I understand, the color bands on a resistor only indicates the resistance of one. So how could you find it's power rating ?
But how do you know the wattage of a given resistor? Where do you look it up? The color code on the resistor only tells its resistance and tolerance, not wattage.
yes!
@@northDSX what do you mean by 'yes' gaddangit. I'm trying to look this up this for days and still clueless
If you could help me I have a mission for you. 😊.. I have big hilti machine . The component I need seems to be the resistor .. looks like the resistor shirt was made out of porculan and it is about 5 to 6 centimeters long cylindrical shape. The porculan broke and i dont have any information on what strenght and resistance it was. How do I find the right resistor? Inside the resistor actually the resistor itself looks like a spring 15 centimeters long folded in 4 rows so it fits the cylinder... what do I do ?
you need to piece the shell back together and look at the color bands to identify the ohms of resistance. Google the color band chart for resistors. Pay attention to the physical size to approximate the wattage.
So I need to make a resistor based circuit for heating... Say up to 45-50℃ powered by 5v adapter/charger. So what value for resistors would you recommend,?
What are your power characteristics? What's your volts in, amps in, etc? It's easy to work out the math but simply saying you have a 5v adapter only give you 1/3 of the equation. How many amps does your adapter output?
@@percivul1786 @sir Bink, sorry for the delay in responding as I didn't receive notification for your reply.
I'm trying to use USB charger, generally rated at 1Amp output. Thank for responding.
@@robbin2685 Ok, so let's look at the math here. Principle one is the power you're using. You have 5V x 1A. Understand that it's rare for a power brick or wall wart to give you those exact characteristics, but for the sake of argument, let's just say it does indeed give you 5V and 1A. This means that you're going to get 5 watts of power (V*I=W). So, you'll be running about 5 watts through your resistor circuit and if it's just one resistor, you could easily cook it unless it's rated for that level of wattage.
So, that said, what all is going into your circuit? Are you using a micro controller or just a passive network? Do you have coils to run your current through? What is the end goal of your project?
@@percivul1786 it's just the passive... Precisely resistors connected to 5v USB charger. And the purpose is simply to generate heat (40-50℃) is good enough. I don't want to fry the resistors. The heat produced is to heat up the thick paper sheet soaked with essential oil which eventually will be used to evaporate essential oil (8-10drops) to disperse the fragrance.
@@robbin2685 I see. Ok, so the thing that jumps to my mind is that while you can use resistors to create a heat source, this is woefully inefficient. The primary reason being that what you really want is temp control. So, running 5 watts through a 10 watt rated resistor will get you a nice and warm resistor, but you have to consider the surface area you're working with. So, while I personally would use a different approach (coil bed or something similar), I'll still give you the breakdown here.
So, here's what you could do. First, measure your wall wart to see what it truly puts out in terms of power. Run your calculations and match a resistor to the wattage by a factor of two (safety over things that smell good). So, as an example:
Your wall wart puts out roughly 4.89V and the most current you can get is roughly .45A or, 450 mAh. IF this was what you got, you'd simply run your wattage calculation. 4.89*.45=2.2 Watts. Very little wattage. So, what you'd do is get a 4.9 ohm resistor rated at 5-10 watts. Power would run from the wall wart, through the resistor and back to the wart. The resistor will allow up to 1A through it BUT your wart is probably going to only output half, or less than that. So, you'd generate 2.2 watts of heat in the resistor, which would get vented out through it's shell (or housing if you get a larger one). Either way, we're still only talking about 2 watts AND it's going to be on a very small surface area. That said, it COULD work but I strongly suspect you will get very poor results using that approach simply because you also have to factor in things like surface area of the target, ambient temp in the room, etc... All of those factors will likely cause you to slightly warm the paper but not much else as the heat tries to dissipate on it's surface.
Our of curiosity, are you stuck with oiled paper or could you perhaps "improve" the design a bit? If you have flexibility, there's much more effective ways to do what you're trying to do here.
Great video? So, why introduce watts when you want the resistor rating in ohms?
Excellent Video clip! Apologies for chiming in, I would appreciate your opinion. Have you heard the talk about - Qanayce Wiyulian Equalizer (Have a quick look on google can't remember the place now)? It is a smashing one off guide for unveiling the technique to repair your electronic items minus the headache. Ive heard some incredible things about it and my work buddy got great results with it.
To tell you how much heat/power it can withstand before it blows up
Sorry, but: Four 15-Ohm-resistors in parallel are still 15 Ohms?!? No way! Since when?
What do you think about 3.25 Ohms instead? Could this be?
Nice catch! You Sir, are a saviour. I should stick to a script ;) thanks for pointing out the mistake, will have to correct this with annotations, or simply remake the video!
Trimmed out with YT Editor, edit will be live shortly!
I looked away... what happened. Shoulda kept my eyes on the resistor.
I still don’t know how to choose the right resistor.
You could cut to the chase with your power calculation and just do V^2/R
He's obviously trying to lay out the steps of the process for people like me who are completely new to the concept.
I want to see the 1W one blow up.
Come on !
>
So this is what happend to my brweyn
Why wouldn't you just use a gigantic resistor for everything & be done with doing any further math & taking any crazy chances?
U showed us a problem but no solutions.
Not my favorite kind of algebra
Sorry but i can't watch a video with a shakey hand and auto focus lense, your giving me a headache
I didn't even notice that it was shaking
Then watch something else
@@megamer2340 yeah i've gone bad to struggling with pdf's, as much as love learning new things this vid hasn't helped much. maybe if i strip the audio from it.......