I really appreciate people who solder well. My grandfather was a master welder. He tried to teach me to weld... once. I think I'll stick will smaller things. Thanks for watching!
Thanks! I think the words "electronic" and "soldering" can put people off. With a few basic skills, a world of possibilities open up! I appreciate the kind words, thanks again and all the best!
Thanks! Sometimes it’s the simple things that are the biggest mental blocks for me. I’m fundamentally a bit lazy and always want to figure out the technique that is the least fiddly. Thanks for the comment! Cheers!
Twist and solder will provide both a mechanical and... well... soldered connection which is probably stronger than solder or twist alone. For connections that might be stressed, that may be a better option. In the case of LEDs, I find this to be very compact. Unless you're using something like a wire nut, twisting alone can lead to loose connections. I hope it all works for ya and thanks for commenting! Cheers!
Say you wanted to solder a string of 10 LEDs. I know you would just put a resistor on each one like you have shown, then run all the positive and negative wires to each corresponding +/- lead down the string, but it would be great if you had a video on this to see how you yourself would do it. Many thanks for a clear and very well put together instructional video!
Thanks for the comment and suggestion. I generally try to keep things as simple as possible but there is a way to wire more LEDs with fewer resistors. It's a great suggestion for a follow up video! Cheers!
great tutorial the only thing i do different is the heat shrink on the positive lead i shrink first to hold it in place. it could slide down a touch while your putting the larger one on causing an invisible short but other then that great job
Thanks! Great tip! It can really be your best friend... especially when you want to hold irregular shapes or several components on a board. Awesome comment! Cheers!
You bet! I like making these shorter and more focused videos. More complex projects become a real challenge to create. Thanks for the comment and cheers!
Would it be useful to hold the LED by the leg being soldered rather than the LED itself to avoid heat damage to the LED? Or is this something not to be concerned with?
Outstanding question! I think this often gets glossed over. Here's my quick thought (long thoughts to follow). You want to apply just enough heat to just enough area to bring the two surfaces up to a temperature where the solder melts, flows, and sticks. Easy! Now that we have that outta the way, here are some additional noodlings. You're spot on. It's possible to damage components with improper soldering techniques or when the thing you're soldering is just plain challenging. If you have heat sensitive components, your suggestion of clipping the alligator clip to the lead between where you're applying heat and the component you're protecting is a solid technique - you can buy heatsink clips specifically for this purpose. My clips have a silicone sleeve that I would remove if I want to use it to help pull heat away from the LED. There are times where the idea of a heat sink will fight our best efforts. I've experienced this when soldering heavier gauge copper wire or when soldering to circuit boards where the thing I'm soldering is connected to a huge copper ground plane (you'll know it when you experience it!). In those instances, the large amounts of copper seem to pull every bit of heat I apply away from the thing I' trying to solder and I end up with a cold joint. Ideally, we want to heat up a small area quickly and get the solder flowing before the heat spreads to places we'd rather avoid. OK... now that I've rambled a bit... to get to the specifics of your question about soldering resistors to LEDs. My goal is to make the final package as compact as possible so I may not have enough space to get a clip on the lead. The leads on resistors and LEDs are thin. This works in my favor. They come up to temperature quickly and don't hold the heat for long. That allows me to get a good solder joint fast. If I tin (add a bit of solder) to the leads prior to joining them, the final solder can be even faster with less fiddling. I've found resistors to be incredibly heat resistant. They work by converting and dissipating current as heat so it's in their DNA. LEDs can be damaged by excess heat but I don't think I've ever damaged one even when I was doing a terrible soldering job (I usually destroy them with too much current). They're designed to run through commercial soldering processes so they're pretty robust. If you are working with reasonable speed and care, you should be able to solder LEDs without too much special consideration. I did take a quick look at some LED data sheets and the two I looked at said something along the lines of 250C for 3 seconds 3 to 5mm from the base of the LED. That's helpful... sorta... Naturally, things need to be set to the right temperature. Too low on your iron and you're not going to get heat transferring quickly enough. Too hot and you're pumping too much heat too quickly. My soldering iron is currently set for 350C (according to the readout that's probably only semi-accurate) for the tip and solder that I use (fine tip and 0.8mm rosin core 60/40 solder). That would seem too hot for what the LED is supposed to be soldered at but this is all a bit of wizardry with a dash of thermodynamics. It's challenging to find hard numbers on the melting point of solder and the "correct" soldering iron temperature. Even the data sheet on the solder doesn't specify a melting point (that I could find). I think everything is vague because "it depends". When you touch a 350C tip to room temp solder and a heat conductive component, you don't instantly heat everything to 350C. In fact, if your iron is just at the melting point of the solder you're gonna have one heck of a time soldering because everything will wick heat away and it becomes a real struggle to get a good joint. The iron is hotter so you can quickly get a small area up to the temperature where the solder flows and then you immediately remove the heat... precision through brute force! This all means you need to find that sweet spot where the iron you use is quickly and efficiently delivering the right amount of heat to the thing your soldering so the solder you're using works without being so hot you damage things. PHEW! Easy... right! I can't tell you how many rolls of solder I have that I hate because they just don't flow the way I want them to and I've had to crank the iron up to temperatures that seemed a bit too high for my liking. OK... that was a LOT! I hope it helped in some small way. Soldering is really a skill that comes from experience and a bit of experimentation. You're considering the right things and asking the right questions so you're well ahead of the game! All the best!
@@RandomMakingEncounters wow… a proper response… very much appreciated… thank you… i think in my case.. new to soldering potential delicate components… i might err on the side of caution till i get the hang of it. I do have a habit of tinning wires to be soldered which seems to make things quicker when finalising the joint. So one could presume this is also true for legs of components as well?
@@MrSteamDragon indeed. The only caveat would be soldering circuit boards where tinning would prevent the component from fitting through the holes. Happy soldering!
Sometimes, resistors are in a little small plastic black Box with a tarry type of substance in there, are are these little boxes for insulation? Why would you insulate a resistor.?
I’ve never seen that specifically… at least not noticed it. A couple of things come to mind. It may be there to provide some amount of waterproofing to the circuit? Temperature does impact resistance as well. Resistor values will change with temperature change. If precision is needed, it’s possible that some amount of protection keeps things working as expected. The interwebs provided no additional clues.
Thanks! It's a pretty common topic but a lot of folk have very little exposure to soldering and electronics. LEDs are really the best and easiest way to get started... I mean... everything is just a little cooler with an LED! Take care!
Not stupid at all! LEDs are mysterious little things. The best thing to do is use an LED resistor calculator like ledcalculator.net. The broadest answer is you will usually need a resistor. The only time you generally don't see resistors is when people use coin cells with LEDs. This has more to do with how much current (Amps) the battery can deliver than the need to use a resistor. With 3 volts, it's just enough voltage to light an LED but the batteries may dliever too much current to be kind to it. It will be a very low resistor but is needed to deliver the right current. One way to think of these things is a water analogy. Think of electricity as water flowing through a pipe. Voltage is the pressure of the water. More voltage... higher water pressure. With higher water pressures you can do more work. If your batter voltage is too low, there isn't enough "pressure" to get the job done. Amps is the volume of water. Low amps is a straw... high amps... a firehose. Both could have the same pressure but the difference in what's coming out the end is dramatic. A resistor is a pinch in the hose that slows the flow. For your LED, 3 volts may be just enough water pressure to do the work but the two AA batteries could deliver enough volume of water to overwhelm the LED... you need to pinch it just a bit. Sorry for the lengthly response. This is really an oversimplification but I've always found it a helpful analogy when I'm thinking about electricity. All the best with your projects! Cheers!
Soldering is a bit like cooking and the answer is usually... it depends. My iron is currently set to 350C. I have a fairly fine tip on it and am using 0.6mm diameter solder. Your setup will vary so experimentation will help you find the right combination of things. Here are some of my general observations. Lead-free solder requires higher temperatures. Your iron will generally need to be hotter than the melting point of the solder since it needs to transfer heat reasonably quickly. The heavier the tip on the iron, the more thermal mass it has and can deliver more sustained heat to the work. What you're soldering will have a dramatic impact on everything. If you're soldering thin wires, they soak up less heat and soldering is faster and easier. If you're soldering chunky components or things with a lot of copper (battery connectors), they're heat sponges and you're need larger tips, more heat, and even a torch for really big things. I really struggle with soldering heavy gauge copper wire and battery connectors. 460C does seem a bit high and I would probably dial it down to maybe under 400C. It's going to really depend on what you're soldering but things to consider are working with thinner solder and maybe a slightly heavier tip if it doesn't seem like it's transferring enough heat. Also, keep the tip clean - gunk on it can actually act like an insulator. I also start by melting a bit of solder on the tip away from the work before trying to connect the parts... this helps create more area for the heat to transfer. Here's a really good site that covers more on soldering - www.techspray.com/ultimate-guide-to-electronic-soldering All the best with your projects!
At this point, the wires could just go right to a batter pack that holds 4 alkaline batteries. There are holders you can get online that are inexpensive and even have built in switches. Since each LED now has its own resistor, you don't have to worry about any more complicated circuit design.
Thanks for watching! There are no stupid questions. Whenever I'm trying to learn a new skill, I'm always starting from not knowing on a journey to sorta knowing a bit more :) In this application, the resistor limits the amount of electrical current flowing to the LED-too much and the LED will burn out. Resistors come in a bunch of shapes and sizes and the values are measured in Ohms. The bigger the number, the more it limits the amount of current flowing through. To figure out what resistor you need, you can use an online calculator like ledcalc.com. The most important number you'll need to know is how much power you're supplying to the LED. For example, 4 AA batteries would generally be 6 volts-ish (1.5 volts X 4). The rest of the numbers depend a little on the LED but there are little cheat sheets if you click the question marks. There's a LOT of wiggle room with resistors as long as you're using values higher than what the calculator spits out. Using very conservative numbers, you might be able to use a 220 ohm resister for most standard LEDs when using six volts of power. Some LEDs that you buy online come with a few different resistors or some come pre-soldered. Be careful on the pre-soldered because they are often wired for 12 volts and I would generally use between 4.5 and 6 volts for my projects. You "might" be able to get away with no resistor and a couple of batteries (3 volts)... but that isn't always true so resistors should be used to be kind to your LEDs. Hope that helps!!
Generally speaking, you always need a resistor. LEDs will run off of coin cells without a resistor. LEDs usually need at least 3 volts or 2 alkaline batteries to light and that is usually around 3 volts. I have a video in the can that goes into this a bit that I may need to get edited and posted. The online calculators like ledcalc.com are a great tool to help you figure out what you need.
Resistors generally do not have "polarity"... meaning they don't have a preferred way of being inserted into a circuit. If you are wiring one LED to one resistor, it doesn't even matter if you put it on the positive or negative lead of the LED. One component that is pretty common that does have polarity is the electrolytic capacitor (they're cylindrical can-like doodads). They usually have big minus marks on them to show the negative lead. Those will actually be damaged if you wire them incorrectly. I use capacitors to smooth out voltage spikes. Think of them like big empty tanks.... the power flows in and has to fill em up first before releasing the energy in a more controlled way. Hope that helps and thanks for watching!
Hi everyone, I was wondering if someone could help me out; I have one of those LED wall initials you get on Amazon, you can run it on three AA or usb, the latter didn’t hace a switch, which bothered me greatly, so I decided to get a switch and snip off the battery compartment and run the light directly of off usb, immediately I noticed the wall plug was getting rather hot and so was the light, upon reading turns out a resistor was needed since the light ran on 3V and the plug was a 5V, since I’m not an expert, trying to find the proper resistor was quite a chore, but I think I did…so; a 100ohm resistor seems to do the trick, but it might not be so can I exceed that? Like solder a 120ohm or would be overkill? Also is putting heat shrink over the resistor bad, would it make it overheat? I’m sorry if I over explained myself, I just love learning. Awesome video btw, I wish I had a friend with your abilities, I could just sit and learn all day.
I can't give you specifics on your project but gengerally, in practice, resistors only reduce current and not voltage. There are ways to reduce voltage with two resistors using what is called a voltage divider. If your light is really just made up of LEDs, most LEDs can utilize different voltages as long as you don't use too much current. In order to figure out the correct resistor there are online tools like ledcalc.com where you plug in the number and type of LEDs. It also matters if the LEDs are in series or parallel... lots of variables so don't take any of this as direct advice. The calculator will also loosely tell you how much current your circuit will require based on the number of LEDs. With all of that in mind... if your USB power source can't supply enough amps, it will overheat... which is a fire risk. If you provide too much current to the LEDs, they'll just burn up and the whole thing will stop working. I would not add a heat sink. If properly configured, very few things require heat sinking (CPUs... power regulators). Anything that is generating excessive heat is headed towards badness and should be disconnected and fixed. You should always err on the side of a higher resistor with an adequate current rating and a power supply that can handle the load. One final disclaimer... my degree is in fine art and all of this is self taught. I'm not an electrician or electrical engineer so this is mostly learned from a lot of Googling and a lot of fried components. Always be very careful when working with electricity. An old survival trick is starting a fire with a nine volt battery and some steel wool. It doesn't take a lot for things to go wrong.
Absolutely beautiful work and explanation. Kudos!
I really appreciate people who solder well. My grandfather was a master welder. He tried to teach me to weld... once. I think I'll stick will smaller things. Thanks for watching!
@@RandomMakingEncounters indeed a great piece of satisfaction when you can unite earthly elements perfectly!
Love your turials. I will be watching more of them. Thanks!
Thanks! I appreciate it. I really need to make more! I've been really lagging lately. Cheers!
Beautiful work, I love your technique, thanks for sharing
Thanks! I think the words "electronic" and "soldering" can put people off. With a few basic skills, a world of possibilities open up! I appreciate the kind words, thanks again and all the best!
Even though this was a fairly simple task,,i really enjoyed they way you put this vid togeather,,,thankyou for sharing my friend,,thumbs up👍
Thanks! Sometimes it’s the simple things that are the biggest mental blocks for me. I’m fundamentally a bit lazy and always want to figure out the technique that is the least fiddly. Thanks for the comment! Cheers!
Thank you very helpful. I was going to tightly twist the wires but I can see how much cleaner it is side by side. I'll give it a shot.
Thank You.
Twist and solder will provide both a mechanical and... well... soldered connection which is probably stronger than solder or twist alone. For connections that might be stressed, that may be a better option. In the case of LEDs, I find this to be very compact. Unless you're using something like a wire nut, twisting alone can lead to loose connections. I hope it all works for ya and thanks for commenting! Cheers!
Thank you, clear explanation.
You've very welcome. I hope it help with your creative adventures! Cheers!
Say you wanted to solder a string of 10 LEDs. I know you would just put a resistor on each one like you have shown, then run all the positive and negative wires to each corresponding +/- lead down the string, but it would be great if you had a video on this to see how you yourself would do it. Many thanks for a clear and very well put together instructional video!
Thanks for the comment and suggestion. I generally try to keep things as simple as possible but there is a way to wire more LEDs with fewer resistors. It's a great suggestion for a follow up video! Cheers!
great tutorial the only thing i do different is the heat shrink on the positive lead i shrink first to hold it in place. it could slide down a touch while your putting the larger one on causing an invisible short but other then that great job
Good power tip... no pun intended... or maybe it was! Yes! Ya gotta make sure those leads don't touch. Thanks for the helpful comment. Cheers!
Quick tip for holding components while soldering, stick them in Blu-Tack.
Thanks! Great tip! It can really be your best friend... especially when you want to hold irregular shapes or several components on a board. Awesome comment! Cheers!
Great video man!
Thanks for the kind words. I'm happy to hear it's helpful. All the best!
Very helpful video! Thanks for sharing :)
You bet! I like making these shorter and more focused videos. More complex projects become a real challenge to create. Thanks for the comment and cheers!
thanks mate helped me out heaps . needed to know and no bugger would say
Happy to help. LEDs can be complicated or easy. I tend to stick to one resistor to one LED to keep it simple! All the best!
Would it be useful to hold the LED by the leg being soldered rather than the LED itself to avoid heat damage to the LED? Or is this something not to be concerned with?
Outstanding question! I think this often gets glossed over. Here's my quick thought (long thoughts to follow). You want to apply just enough heat to just enough area to bring the two surfaces up to a temperature where the solder melts, flows, and sticks. Easy! Now that we have that outta the way, here are some additional noodlings.
You're spot on. It's possible to damage components with improper soldering techniques or when the thing you're soldering is just plain challenging. If you have heat sensitive components, your suggestion of clipping the alligator clip to the lead between where you're applying heat and the component you're protecting is a solid technique - you can buy heatsink clips specifically for this purpose. My clips have a silicone sleeve that I would remove if I want to use it to help pull heat away from the LED.
There are times where the idea of a heat sink will fight our best efforts. I've experienced this when soldering heavier gauge copper wire or when soldering to circuit boards where the thing I'm soldering is connected to a huge copper ground plane (you'll know it when you experience it!). In those instances, the large amounts of copper seem to pull every bit of heat I apply away from the thing I' trying to solder and I end up with a cold joint. Ideally, we want to heat up a small area quickly and get the solder flowing before the heat spreads to places we'd rather avoid.
OK... now that I've rambled a bit... to get to the specifics of your question about soldering resistors to LEDs. My goal is to make the final package as compact as possible so I may not have enough space to get a clip on the lead. The leads on resistors and LEDs are thin. This works in my favor. They come up to temperature quickly and don't hold the heat for long. That allows me to get a good solder joint fast. If I tin (add a bit of solder) to the leads prior to joining them, the final solder can be even faster with less fiddling. I've found resistors to be incredibly heat resistant. They work by converting and dissipating current as heat so it's in their DNA. LEDs can be damaged by excess heat but I don't think I've ever damaged one even when I was doing a terrible soldering job (I usually destroy them with too much current). They're designed to run through commercial soldering processes so they're pretty robust. If you are working with reasonable speed and care, you should be able to solder LEDs without too much special consideration. I did take a quick look at some LED data sheets and the two I looked at said something along the lines of 250C for 3 seconds 3 to 5mm from the base of the LED. That's helpful... sorta...
Naturally, things need to be set to the right temperature. Too low on your iron and you're not going to get heat transferring quickly enough. Too hot and you're pumping too much heat too quickly. My soldering iron is currently set for 350C (according to the readout that's probably only semi-accurate) for the tip and solder that I use (fine tip and 0.8mm rosin core 60/40 solder). That would seem too hot for what the LED is supposed to be soldered at but this is all a bit of wizardry with a dash of thermodynamics. It's challenging to find hard numbers on the melting point of solder and the "correct" soldering iron temperature. Even the data sheet on the solder doesn't specify a melting point (that I could find). I think everything is vague because "it depends". When you touch a 350C tip to room temp solder and a heat conductive component, you don't instantly heat everything to 350C. In fact, if your iron is just at the melting point of the solder you're gonna have one heck of a time soldering because everything will wick heat away and it becomes a real struggle to get a good joint. The iron is hotter so you can quickly get a small area up to the temperature where the solder flows and then you immediately remove the heat... precision through brute force! This all means you need to find that sweet spot where the iron you use is quickly and efficiently delivering the right amount of heat to the thing your soldering so the solder you're using works without being so hot you damage things. PHEW! Easy... right! I can't tell you how many rolls of solder I have that I hate because they just don't flow the way I want them to and I've had to crank the iron up to temperatures that seemed a bit too high for my liking.
OK... that was a LOT! I hope it helped in some small way. Soldering is really a skill that comes from experience and a bit of experimentation. You're considering the right things and asking the right questions so you're well ahead of the game!
All the best!
@@RandomMakingEncounters wow… a proper response… very much appreciated… thank you… i think in my case.. new to soldering potential delicate components… i might err on the side of caution till i get the hang of it. I do have a habit of tinning wires to be soldered which seems to make things quicker when finalising the joint. So one could presume this is also true for legs of components as well?
@@MrSteamDragon indeed. The only caveat would be soldering circuit boards where tinning would prevent the component from fitting through the holes. Happy soldering!
Great job! 👍 thank you
You are very welcome… sometimes it’s the little things. Cheers!
Sometimes, resistors are in a little small plastic black Box with a tarry type of substance in there, are are these little boxes for insulation? Why would you insulate a resistor.?
I’ve never seen that specifically… at least not noticed it. A couple of things come to mind. It may be there to provide some amount of waterproofing to the circuit? Temperature does impact resistance as well. Resistor values will change with temperature change. If precision is needed, it’s possible that some amount of protection keeps things working as expected. The interwebs provided no additional clues.
Very informative
I appreciate that! More to come.
Well done 👍
Thanks! It's a pretty common topic but a lot of folk have very little exposure to soldering and electronics. LEDs are really the best and easiest way to get started... I mean... everything is just a little cooler with an LED! Take care!
Stupid question: if i use 3volt LEDs and a 3 volt AA battery pack, do I need resistors?
Not stupid at all! LEDs are mysterious little things. The best thing to do is use an LED resistor calculator like ledcalculator.net. The broadest answer is you will usually need a resistor. The only time you generally don't see resistors is when people use coin cells with LEDs. This has more to do with how much current (Amps) the battery can deliver than the need to use a resistor. With 3 volts, it's just enough voltage to light an LED but the batteries may dliever too much current to be kind to it. It will be a very low resistor but is needed to deliver the right current.
One way to think of these things is a water analogy. Think of electricity as water flowing through a pipe. Voltage is the pressure of the water. More voltage... higher water pressure. With higher water pressures you can do more work. If your batter voltage is too low, there isn't enough "pressure" to get the job done. Amps is the volume of water. Low amps is a straw... high amps... a firehose. Both could have the same pressure but the difference in what's coming out the end is dramatic. A resistor is a pinch in the hose that slows the flow. For your LED, 3 volts may be just enough water pressure to do the work but the two AA batteries could deliver enough volume of water to overwhelm the LED... you need to pinch it just a bit. Sorry for the lengthly response. This is really an oversimplification but I've always found it a helpful analogy when I'm thinking about electricity.
All the best with your projects! Cheers!
@@RandomMakingEncounters that helps a lot, thanks!
What temperature you put to solder? I am around 460ºC and I don't know if its to much or low. Thanks!
Soldering is a bit like cooking and the answer is usually... it depends. My iron is currently set to 350C. I have a fairly fine tip on it and am using 0.6mm diameter solder. Your setup will vary so experimentation will help you find the right combination of things. Here are some of my general observations. Lead-free solder requires higher temperatures. Your iron will generally need to be hotter than the melting point of the solder since it needs to transfer heat reasonably quickly. The heavier the tip on the iron, the more thermal mass it has and can deliver more sustained heat to the work. What you're soldering will have a dramatic impact on everything. If you're soldering thin wires, they soak up less heat and soldering is faster and easier. If you're soldering chunky components or things with a lot of copper (battery connectors), they're heat sponges and you're need larger tips, more heat, and even a torch for really big things. I really struggle with soldering heavy gauge copper wire and battery connectors.
460C does seem a bit high and I would probably dial it down to maybe under 400C. It's going to really depend on what you're soldering but things to consider are working with thinner solder and maybe a slightly heavier tip if it doesn't seem like it's transferring enough heat. Also, keep the tip clean - gunk on it can actually act like an insulator. I also start by melting a bit of solder on the tip away from the work before trying to connect the parts... this helps create more area for the heat to transfer.
Here's a really good site that covers more on soldering - www.techspray.com/ultimate-guide-to-electronic-soldering
All the best with your projects!
@@RandomMakingEncounters Thanks so much for your answer!
Now what do you do with those wires?
At this point, the wires could just go right to a batter pack that holds 4 alkaline batteries. There are holders you can get online that are inexpensive and even have built in switches. Since each LED now has its own resistor, you don't have to worry about any more complicated circuit design.
I don’t know anything about electrical stuff so this may be a stupid question but what does the resistor do and is it necessary to add?
And thank you for the video. I did find it informative and I love how you explain things!
Thanks for watching! There are no stupid questions. Whenever I'm trying to learn a new skill, I'm always starting from not knowing on a journey to sorta knowing a bit more :)
In this application, the resistor limits the amount of electrical current flowing to the LED-too much and the LED will burn out. Resistors come in a bunch of shapes and sizes and the values are measured in Ohms. The bigger the number, the more it limits the amount of current flowing through. To figure out what resistor you need, you can use an online calculator like ledcalc.com. The most important number you'll need to know is how much power you're supplying to the LED. For example, 4 AA batteries would generally be 6 volts-ish (1.5 volts X 4). The rest of the numbers depend a little on the LED but there are little cheat sheets if you click the question marks. There's a LOT of wiggle room with resistors as long as you're using values higher than what the calculator spits out. Using very conservative numbers, you might be able to use a 220 ohm resister for most standard LEDs when using six volts of power. Some LEDs that you buy online come with a few different resistors or some come pre-soldered. Be careful on the pre-soldered because they are often wired for 12 volts and I would generally use between 4.5 and 6 volts for my projects. You "might" be able to get away with no resistor and a couple of batteries (3 volts)... but that isn't always true so resistors should be used to be kind to your LEDs. Hope that helps!!
@@RandomMakingEncounters thank you for explaining this! Yes this makes sense.
How do you know if you need a resistor?
Generally speaking, you always need a resistor. LEDs will run off of coin cells without a resistor. LEDs usually need at least 3 volts or 2 alkaline batteries to light and that is usually around 3 volts. I have a video in the can that goes into this a bit that I may need to get edited and posted. The online calculators like ledcalc.com are a great tool to help you figure out what you need.
You’re so kind to answer all my questions.
Does it matter which way round you fit the resistor?
Resistors generally do not have "polarity"... meaning they don't have a preferred way of being inserted into a circuit. If you are wiring one LED to one resistor, it doesn't even matter if you put it on the positive or negative lead of the LED. One component that is pretty common that does have polarity is the electrolytic capacitor (they're cylindrical can-like doodads). They usually have big minus marks on them to show the negative lead. Those will actually be damaged if you wire them incorrectly. I use capacitors to smooth out voltage spikes. Think of them like big empty tanks.... the power flows in and has to fill em up first before releasing the energy in a more controlled way. Hope that helps and thanks for watching!
Hi everyone, I was wondering if someone could help me out; I have one of those LED wall initials you get on Amazon, you can run it on three AA or usb, the latter didn’t hace a switch, which bothered me greatly, so I decided to get a switch and snip off the battery compartment and run the light directly of off usb, immediately I noticed the wall plug was getting rather hot and so was the light, upon reading turns out a resistor was needed since the light ran on 3V and the plug was a 5V, since I’m not an expert, trying to find the proper resistor was quite a chore, but I think I did…so; a 100ohm resistor seems to do the trick, but it might not be so can I exceed that? Like solder a 120ohm or would be overkill?
Also is putting heat shrink over the resistor bad, would it make it overheat?
I’m sorry if I over explained myself, I just love learning.
Awesome video btw, I wish I had a friend with your abilities, I could just sit and learn all day.
I can't give you specifics on your project but gengerally, in practice, resistors only reduce current and not voltage. There are ways to reduce voltage with two resistors using what is called a voltage divider. If your light is really just made up of LEDs, most LEDs can utilize different voltages as long as you don't use too much current. In order to figure out the correct resistor there are online tools like ledcalc.com where you plug in the number and type of LEDs. It also matters if the LEDs are in series or parallel... lots of variables so don't take any of this as direct advice. The calculator will also loosely tell you how much current your circuit will require based on the number of LEDs. With all of that in mind... if your USB power source can't supply enough amps, it will overheat... which is a fire risk. If you provide too much current to the LEDs, they'll just burn up and the whole thing will stop working. I would not add a heat sink. If properly configured, very few things require heat sinking (CPUs... power regulators). Anything that is generating excessive heat is headed towards badness and should be disconnected and fixed. You should always err on the side of a higher resistor with an adequate current rating and a power supply that can handle the load. One final disclaimer... my degree is in fine art and all of this is self taught. I'm not an electrician or electrical engineer so this is mostly learned from a lot of Googling and a lot of fried components. Always be very careful when working with electricity. An old survival trick is starting a fire with a nine volt battery and some steel wool. It doesn't take a lot for things to go wrong.