Ah! For a moment I was that young boy, playing with batteries and lamps ...yes I had no LEDs , they existed only in the lab. I would learn ohms law early on, in school I would find the proper shop class, I knew it by the satellite which hung over the teachers desk, built by high school seniors it boasted all they had learned. I smile thinking of what might be built into it today.... then it has been 60 plus years. From ohms law to circuit analysis, old man Bennett taught us well. Yes we could repair that radio or TV, we constructed telsa coils, and experimented with high frequency and voltage. Well I reminisce far afield , but thanks for the memories. Years latter I would share Bennett's teachings, giving several a step up, on their way to becoming engineers , closing the circle. Take care.
WOW!! I GET IT!! Great demo and presentation!! I have been searching and Googling all week on 'How to light a simple basic LED' as a beginner. I have seen numerous 'attempts' on TH-cam as far as explaining the fundamentals. Most presenters would flaunt their technical 'expertise' with no idea of who their audience is on the other side of the screen. Kudos and continued success. Mike Y. Chicagoland
Crystal clear. I recommend this for young children eager to learn electronics basics but also for inquisitive adults wishing the same 🙂 Thank you for another useful tutorial.
Hello, thank you for the explanation on how to calculate the resistor needed when you want to connect an LED, I don't know much about electronics, I only do small DIY jobs on low voltage and I admit that I always have trouble knowing what resistor I should put for each LED, I'm keeping this video in my dedicated playlist because I know that by tomorrow I'll have forgotten how it's calculated and being able to find it again will allow me to come back to it in the future and find this calculation again, which will prevent me from burning out LEDs because I didn't put a resistor in. 👍😉
I am trying to learn this. I want to add LEDs to my action figures & models. But for some reason, this gives me a ridiculous amount of anxiety. I don't know why but it does.
This is very helpful! i'm trying to make a replica of a relay panel so this is the perfect explanation. I can't wait to try it out for myself! thanks a lot!
AWESOME video, Thanks for sharing! I've been struggling with this when I do lighting projects. I've suffered LOTS of blown LED's from not knowing how to properly calculate the right resistors!
Great video! I was looking for some help on how to hook up the leds for my fpv drone! Your videos are a huge help for me, I honestly don't know where I would be without your videos, everytime I have a question, or am unsure about something on my quad, your videos always come to the rescue! I built my first racing quad (infact my first quad ever that I built) and it flies a dream! I couldn't have done it without your videos to help me, I probably would have fried my fc by now without them😂. Happy flying!
Forget about the resistor - it’s a red herring. The concept you need to focus on is Kirchhoff’s current law and Kirchhoff’s voltage law. In simpler terms: When two components are in series, the currents through them are the same, while the voltages across them add up. When two components are in parallel, the voltages across them are the same, while the currents through them add up. And the reason behind the above general laws is to do with the physics of electricity, i.e. that current is flow of charge per unit time, while voltage is potential energy per unit charge. Ohms law will keep you on track.
Fantastic video Lee! I really enjoyed it. It is a good refresher to learn this stuff again. Electronics is so fun to mess with. Thanks for showing us this.
Do you think you could make a video on what value of a resistor do I need to mod a standard size RC servo to move more than its standard deflection? Application: To see if we could use a cheap and cheerful standard size servo or a 9gm servo for FPV to get more panning. Absolutely loved this video, great going. Thanks.
Nice video as always. I actually needed a more complex wiring diagram for example how can we connect multiple leds, let say 18 leds in a strip with a 12v battery. I don't really understand if we put more than 1 resistor how actually it works and how to calculate voltage drop etc. I was told to divide 18 leds into 3 parts of 6 leds each. The leds require 2.2 volt to light up brighter. So if I need to light them together I will need 6.6volts right?! So 12.4-6.6=5.8v/0.02= 290 ohm. So should I put a 290ohm to the beginning of the strip? Can I put 3 resistors on each part or the first solution is better?
Current dictates brightness, not extra voltage. If your leds need 2.2v then you can only get 5 in series on 12v. You'll need 3 strings of 5 and the last string of 3 wired in parallel. Each with an appropriate resistor. Best of luck
I’m still a little confused on which resistor I would need, if I was to wire up 2x 12V Single LED’s to a 9V battery would I need multiple Resistors and if so how many ohms would that be? Any help would be great. Thank You
If you want COB then check out the MenaceRC COB LED products - very easy and safe to use in the hobby. Else you can use the same maths used in the video for a COB LED. You need to find the current and voltage it needs and you can use the same method! Best of luck
@@Painless360 Thanks again 😊 I’ve been playing around with them lately - fantastic, cheap too! I have some circular COBs - super bright. They’re about 1 inch diameter and wafer thin, about 1.7mm 😳 The Cree LEDs are also impressive but with both, I’ve blown a couple lol. Been scratching my head about unmarked voltages & whether they need resistors etc 👍🏻
The ones that I've seen run on something like 3.1v and need 300-700mA (0.3 - 0.7 Amps) so you need to fined the specs of the ones you have and you can figure out the resistance value. Watch for the smaller resisters getting warm. As you need them to dissipate more power they need to have a higher watt rating..
Mahalo for the amazing explanation. I wonder if you can tell me if I can do something kind of similar. On my pc motherboard there is pins to connect a led to indicate that the pc is powered on, I was hoping to learn how to connect multiple leds to the motherboard pin?
It depends on how those connections on the motherboard are setup and the voltage and current they provide. If it is more than about 3V, then you will need a resistor as shown. It is is around 5v, I'd wire a couple of LEDs in parallel and if it is something like 12v, then you can have a couple of LEDs in series..
Hi! Thanks for the video. I’m trying to add some lights to a diorama. I’d like to run a total of 4 3-6v LEDS (all have internal resistors) and 3.7v motion sensor. I have a 6v battery pack. Will they all run? Looking at your content I’m assuming they will but maybe not as brightly as they should?
I have some 5mm LEDs in a midi controller that only will light when tapped. They no longer stay lit on their own. Are they known to die over time like this?
Any info on a switch to switch between different modes?? I’m deconstructing a battery lamp and just want one mode then off - trying to figure out what I need to do to make this happen??
I have question. I took Christmas lights with 10leds that powered by 2 x 1.5v aa battery. Added 30 more same leds, changed battery for rechargeable 3.7 1800mah and now it's bright first half hour then few ours it darker. Then it's goes even more darker and staying like that for bout 6-8h I did remove that resistor tho as dont know what 3.7v do to it. My question is how can I stabilise light so battery discharging gradually instead being bright for short time and dimm for long time?
The lights are dimming as the battery discharges. I'd use a battery with a higher voltage so you can connect them in series and reduce the current used... best of luck
@Painless360 thank you. But problem is I used this light for 3d printed eiffel tower model so I won't able to pull them out and put in series. It is make sense that they go dimmer because of battery. I want to know how to make stable discharge. E.g now after fully charge the power works like that: 100% - 30min. 50%- 1.5h. 25%- 6-8h till fully dead. Is there any way of making for example: 100- 1h 75-1h 50- 1h 25- 1h?
I see that the red and blue LEDs seem a little too bright and can’t see the colour. What could be done to improve it? I’m curious cos Iv recently got bk into RC cars and im going to be showing my son (10) how it’s done. Tia
So you could put 5 in series at 9v with no resistor? Then power supply amperage divided by .1 = the number of parallel circuits you could add?? Great vid!
I cold not grasp how the 1st led seems to get hit with the total voltage first, say 3 led's, only way I can understand that is that because it's series they all act as one, one bucket that fills evenly at once
I realized that the more LEDs you connect in a circuit, the lower the brightness of the first 2 LEDs on that last example. Is it because of the voltage of the battery and how much energy is being "filtered from the resistor?
In the beginning of electronics it was thought the flow was positive to negative (Thus the backward shape of the diode symbol on a schematic). As electronics progressed it was discovered electrons actually flow from negative to positive. Shouldn't the voltage modifier (usually a filtered circuit) be before the load on the negative side instead of at the end of the logical circuit?
The resistor can be on either side - it's independent of current direction. And since electons are negative, charge still moves positive to negative. If you give someone debt, the flow of money of from them to you!
Ok, now I need resistors... I have three different size LED lights, I have several AA Battey packs, extra low voltage parallel 22AWG wire, two diffrent types of small switches. Ok, now track down the resistors. Hold my non Anhauserbush beer.
(edited) Dumb thing, but, I noticed that for these LEDS there’s a pattern to the resistor amount. You’ll need to know what resistor number for a single LED tho SO 1 LED - 360 2 LED - 270 3 LED - 180 4 LED - 90 5 LED - no resistor They’re all a multiple of 9/90. For every new light, go backwards in the 9/90’s times table and you’ll get your resistor
Heavily edited, sorry @@Painless360 The 9 volt battery from the video. It’s only based on what I saw here. I don’t know much, Imma update my comment to be an observation instead of rule. The thought only applies to these specific LEDS and their configurations. I don’t have enough experience yet to make a legit rule of thumb… The volt supply made me think though, since it’s a 9 volt, you need 360, (haven’t done math yet, it’s a theory) if you wanted to do a 12 volt battery, a single bulb would need 480(I THINK???)? *If* that’s the case, you’d go backwards by 12/120. My hypothesis is: x=volt battery. x*40=resistor for 1. For multiple bulbs: y: amount of bulbs *AFTER* THE FIRST BULB. (X*40)-[y*(x*40)]=new resistor number. Meaning: 1-480 2-360 3-240, etc
The maths needed is pretty easy trying to avoid that basic maths may cause some to miss the essential point (that it is related to the voltage supply being used) and get into trouble... Happy flying!
Ah! For a moment I was that young boy, playing with batteries and lamps ...yes I had no LEDs , they existed only in the lab. I would learn ohms law early on, in school I would find the proper shop class, I knew it by the satellite which hung over the teachers desk, built by high school seniors it boasted all they had learned. I smile thinking of what might be built into it today.... then it has been 60 plus years. From ohms law to circuit analysis, old man Bennett taught us well. Yes we could repair that radio or TV, we constructed telsa coils, and experimented with high frequency and voltage. Well I reminisce far afield , but thanks for the memories. Years latter I would share Bennett's teachings, giving several a step up, on their way to becoming engineers , closing the circle. Take care.
WOW!! I GET IT!!
Great demo and presentation!!
I have been searching and Googling all week on 'How to light a simple basic
LED' as a beginner.
I have seen numerous 'attempts' on TH-cam as far as explaining the fundamentals.
Most presenters would flaunt their technical 'expertise' with no idea of who their
audience is on the other side of the screen.
Kudos and continued success.
Mike Y.
Chicagoland
Crystal clear. I recommend this for young children eager to learn electronics basics but also for inquisitive adults wishing the same 🙂 Thank you for another useful tutorial.
Hello, thank you for the explanation on how to calculate the resistor needed when you want to connect an LED, I don't know much about electronics, I only do small DIY jobs on low voltage and I admit that I always have trouble knowing what resistor I should put for each LED, I'm keeping this video in my dedicated playlist because I know that by tomorrow I'll have forgotten how it's calculated and being able to find it again will allow me to come back to it in the future and find this calculation again, which will prevent me from burning out LEDs because I didn't put a resistor in. 👍😉
I am trying to learn this. I want to add LEDs to my action figures & models. But for some reason, this gives me a ridiculous amount of anxiety. I don't know why but it does.
Once you see the light peace will come over you
Me also
You are not alone
It's like a big mystery lol
I feel the same!
Wow, you gives very simple calculation to wire up led in quad, wing , before this we burn many led due to wrong register value calculation. Thanks....
Many thanks for the clear simple demonstration. Im a novice at this but will now give it a go for my minimum houses.
This is very helpful! i'm trying to make a replica of a relay panel so this is the perfect explanation. I can't wait to try it out for myself! thanks a lot!
Very good video and I like that you go into explaining why instead of just telling us how if that makes sense lol
AWESOME video, Thanks for sharing! I've been struggling with this when I do lighting projects. I've suffered LOTS of blown LED's from not knowing how to properly calculate the right resistors!
Great video! I was looking for some help on how to hook up the leds for my fpv drone! Your videos are a huge help for me, I honestly don't know where I would be without your videos, everytime I have a question, or am unsure about something on my quad, your videos always come to the rescue! I built my first racing quad (infact my first quad ever that I built) and it flies a dream! I couldn't have done it without your videos to help me, I probably would have fried my fc by now without them😂. Happy flying!
This is a perfect Teacher TU MR.painless
Excellent video, thank you, its clear and well explained, electronics perplex me at times but this has helped me a great deal for my project!
Forget about the resistor - it’s a red herring.
The concept you need to focus on is Kirchhoff’s current law and Kirchhoff’s voltage law.
In simpler terms:
When two components are in series, the currents through them are the same, while the voltages across them add up.
When two components are in parallel, the voltages across them are the same, while the currents through them add up.
And the reason behind the above general laws is to do with the physics of electricity, i.e. that current is flow of charge per unit time, while voltage is potential energy per unit charge.
Ohms law will keep you on track.
I learned something new today! Thanks. Back to building my RC...
that's filled a gap in my knowledge cheers Lee stay safe.
great explanation, so if we have 6 LEDs, no need for resister ?
I always add one for safety... best of luck
Extraordinarily clear. I am now a genius. Much thanks, and happy flying.
Fantastic video Lee! I really enjoyed it. It is a good refresher to learn this stuff again. Electronics is so fun to mess with. Thanks for showing us this.
Awesome! Great explanation/demonstration! Thank you so much!
Do you think you could make a video on what value of a resistor do I need to mod a standard size RC servo to move more than its standard deflection?
Application: To see if we could use a cheap and cheerful standard size servo or a 9gm servo for FPV to get more panning.
Absolutely loved this video, great going.
Thanks.
It wouldn't work like that. The rotation is a servo is measured internally using a variable resistor mounted to the output shaft... happy birthday
Excellent information and very well explained. I will try to use this video to teach my boys some common knowledge of life and electronics. 👍👍😎✌👊
Is it not best practice to use a resistor on each LED in parrell to prevent circuit failure if one LED fails.
That isn't needed, wiring LEDs in series is a very standard way that efficiently uses the current and LEDs last for a very long time.. Happy flying!
That would be a good idea in a safety-critical application, but waste too much power in most applications.
Excellent tutorial, enjoyed it.
Nice video as always. I actually needed a more complex wiring diagram for example how can we connect multiple leds, let say 18 leds in a strip with a 12v battery. I don't really understand if we put more than 1 resistor how actually it works and how to calculate voltage drop etc. I was told to divide 18 leds into 3 parts of 6 leds each. The leds require 2.2 volt to light up brighter. So if I need to light them together I will need 6.6volts right?! So 12.4-6.6=5.8v/0.02= 290 ohm. So should I put a 290ohm to the beginning of the strip? Can I put 3 resistors on each part or the first solution is better?
Current dictates brightness, not extra voltage.
If your leds need 2.2v then you can only get 5 in series on 12v.
You'll need 3 strings of 5 and the last string of 3 wired in parallel. Each with an appropriate resistor.
Best of luck
th-cam.com/video/m__1HsZ1eN0/w-d-xo.html :D
I’m still a little confused on which resistor I would need, if I was to wire up 2x 12V Single LED’s to a 9V battery would I need multiple Resistors and if so how many ohms would that be? Any help would be great. Thank You
im just 9 years old btw but im motivated for these
Who asked
Not u@@ta.shchaudhary
Thank you so much for this knowledge
if the voltage (of the LEDs) adds up close to the battery's 9V, a resistor can be avoided to prevent energy loss?
I'd always use a resistor to limit the current... Best of luck
Great video thanks! 👍🏻 Any chance you can do something similar with COB & Cree LEDs ?
If you want COB then check out the MenaceRC COB LED products - very easy and safe to use in the hobby. Else you can use the same maths used in the video for a COB LED. You need to find the current and voltage it needs and you can use the same method! Best of luck
@@Painless360 Thanks again 😊 I’ve been playing around with them lately - fantastic, cheap too!
I have some circular COBs - super bright. They’re about 1 inch diameter and wafer thin, about 1.7mm 😳
The Cree LEDs are also impressive but with both, I’ve blown a couple lol.
Been scratching my head about unmarked voltages & whether they need resistors etc 👍🏻
The ones that I've seen run on something like 3.1v and need 300-700mA (0.3 - 0.7 Amps) so you need to fined the specs of the ones you have and you can figure out the resistance value. Watch for the smaller resisters getting warm. As you need them to dissipate more power they need to have a higher watt rating..
@@Painless360 okay thanks 👍🏻👍🏻👍🏻👍🏻
Mahalo for the amazing explanation. I wonder if you can tell me if I can do something kind of similar. On my pc motherboard there is pins to connect a led to indicate that the pc is powered on, I was hoping to learn how to connect multiple leds to the motherboard pin?
It depends on how those connections on the motherboard are setup and the voltage and current they provide. If it is more than about 3V, then you will need a resistor as shown. It is is around 5v, I'd wire a couple of LEDs in parallel and if it is something like 12v, then you can have a couple of LEDs in series..
How did you find out the current the LED needs? Coz I need to know the current in order to know the resistance
In the specs for the LED. Milliamps needed for full brightness are stated, but 20mA is a safe bet if you don't know... Happy flying
Hi! Thanks for the video. I’m trying to add some lights to a diorama. I’d like to run a total of 4 3-6v LEDS (all have internal resistors) and 3.7v motion sensor. I have a 6v battery pack. Will they all run? Looking at your content I’m assuming they will but maybe not as brightly as they should?
I'd test them with two in series and see how that works first. If they are too dim then connect all of them in parrallel... Best of luck
What direction do you put the resistor on?
Doesn't matter.. happy flying
@@Painless360 thank you for your helpful videos
I have some 5mm LEDs in a midi controller that only will light when tapped. They no longer stay lit on their own. Are they known to die over time like this?
Sounds like a broken connection to me... Best of luck
Can you use resistors larger than what you need?
Yes, but the LED will be a little less bright... best of luck
having a LED config. of around 9V with a 9V battery and a Zenner diode in parallel can act as a regulator and thus avoid using a resistor?
Give it a go... Best of luck
can i cut the lead if it is too long? sorry if thats a stupid question
Yes you can. Best of luck!
Any info on a switch to switch between different modes?? I’m deconstructing a battery lamp and just want one mode then off - trying to figure out what I need to do to make this happen??
Sounds like a simple switch to me if you only need off and on... Best of luck
its interesting Flashlight makes have not upgraded to tooling for the plastic molds, they just put a led in and put in an AA C cell adapter
I have question. I took Christmas lights with 10leds that powered by 2 x 1.5v aa battery. Added 30 more same leds, changed battery for rechargeable 3.7 1800mah and now it's bright first half hour then few ours it darker. Then it's goes even more darker and staying like that for bout 6-8h I did remove that resistor tho as dont know what 3.7v do to it. My question is how can I stabilise light so battery discharging gradually instead being bright for short time and dimm for long time?
The lights are dimming as the battery discharges. I'd use a battery with a higher voltage so you can connect them in series and reduce the current used... best of luck
@Painless360 thank you. But problem is I used this light for 3d printed eiffel tower model so I won't able to pull them out and put in series. It is make sense that they go dimmer because of battery. I want to know how to make stable discharge. E.g now after fully charge the power works like that: 100% - 30min. 50%- 1.5h. 25%- 6-8h till fully dead. Is there any way of making for example: 100- 1h 75-1h 50- 1h 25- 1h?
th-cam.com/video/m__1HsZ1eN0/w-d-xo.html :D
is that make sense to use voltage divider on led wiring
I see that the red and blue LEDs seem a little too bright and can’t see the colour.
What could be done to improve it?
I’m curious cos Iv recently got bk into RC cars and im going to be showing my son (10) how it’s done. Tia
Using a resistor with a higher value will cause the led to be dimmer.. Happy flying
Nicely done video 👍🏻
So you could put 5 in series at 9v with no resistor? Then power supply amperage divided by .1 = the number of parallel circuits you could add??
Great vid!
that was also my question while watching
Hi painless 360 I have a question about Inav. Can I use Inav with Spektrum transmitters and receivers?
Yes, you can. Most modem flight controllers need to SBUS input though so you will need a reciever that has that.. Best of luck
thank you sir very well explained!!!!! I am new to this kind of stuff it is very interesting.
Nice with the physics as well!!
So say I want to do a line of 12 would i need 2 x12v battery's and what would the resistor need to be many thanks 👍
What would you calculate it needs to be using the way shown in the video?
I'm just learning this.. where do get the 20 milliamps from
The specs from the LEDs. It is a common current value to light an LED at, or around, full brightness... Happy flying
Excellent video 😍🙏👍
Will a 9v battery power 7 led’s and what size resistor please
What's would your guess be after watching the video?
great video. hope you can make e 2 way ON and OFF switch for lipo please
Not sure what you mean - can you elaborate?
Amazing job
The voltage drop I understand but how do we know the amperage wont be exceeding 20 mAh
Ohms law ... Happy flying
@@Painless360 Oh yeah, amperage was included in the calculations. Thanks man
So if I have a 1.5 v battery I wouldn't need a resistor do I?
Many who don't understand how to do this use button cells to power leds directly without issue.. Happy flying
sure but the LED will not turn on
Great video thanks Lee cheers🙏
I cold not grasp how the 1st led seems to get hit with the total voltage first, say 3 led's, only way I can understand that is that because it's series they all act as one, one bucket that fills evenly at once
It doesn't work like that. It is a little counter intuitive, I admit! Happy flying!
Are their any orange ones.
You can get them in pretty much any colour. I use flickering orange leds in some of my hone made Halloween decorations... Happy flying
@@Painless360 I'm building a tall pumpkin man for Halloween and I'm looking for cool orange lights.
hi what aboyt 3 flashing led red blue yellow i series? the same formula
Yes but watch out for flashing LEDs, using them in series can make some odd things happen.. Best of luck!
Hi . Ok I had to actually get the old old school books out ! The video is really good.
Why cant you hook up positive to positive, and the negative to the negative to the battery?
It needs to be in a loop, a circle , a circuit
I realized that the more LEDs you connect in a circuit, the lower the brightness of the first 2 LEDs on that last example. Is it because of the voltage of the battery and how much energy is being "filtered from the resistor?
You need to calculate the right resistor value for the LEDs you have in series... best of luck!
Really helpful for an absolute beginner (Yup that's me!)
Very goog info thanks
In the beginning of electronics it was thought the flow was positive to negative (Thus the backward shape of the diode symbol on a schematic). As electronics progressed it was discovered electrons actually flow from negative to positive. Shouldn't the voltage modifier (usually a filtered circuit) be before the load on the negative side instead of at the end of the logical circuit?
The convention for current in diagrams and design is from positive to negative. Don't let the actual electron flow confuse you.. Happy flying
The resistor can be on either side - it's independent of current direction. And since electons are negative, charge still moves positive to negative. If you give someone debt, the flow of money of from them to you!
So 5 led needs no resistor
Depends on the voltage, see link in the description... Happy flying
@Painless360 I meant for 9v lol, nice tutorial by the way I read electronics for dummies but this video made sense a lot easier
thnx for sharing
Ok, now I need resistors... I have three different size LED lights, I have several AA Battey packs, extra low voltage parallel 22AWG wire, two diffrent types of small switches. Ok, now track down the resistors. Hold my non Anhauserbush beer.
Buy the led light with the resistors already attached! So much easier.
I want to put one of these led lights in a paper building. Do I have to worry about fire?
Hey Lee, I commented a few minutes earlier... But the comment disappeared. 😕
No idea where it went.. I've not seen it. Happy flying!
aren't LEDs meant to be super efficient? how is it that a whole 9v battery wouldn't be able to power 5 little LED lights?
They are super efficient compared with filament lamps. Wire in parrallel as well as series to light lots. See my video on it.
Nice! I just put Switchable LED's on the back of my EDF powered AR 900 Wing 😎🤙 Video of maiden is up on my page
(edited) Dumb thing, but, I noticed that for these LEDS there’s a pattern to the resistor amount. You’ll need to know what resistor number for a single LED tho
SO
1 LED - 360
2 LED - 270
3 LED - 180
4 LED - 90
5 LED - no resistor
They’re all a multiple of 9/90. For every new light, go backwards in the 9/90’s times table and you’ll get your resistor
Nice idea but what supply voltage does that 'rule of thumb' work on?
Heavily edited, sorry
@@Painless360
The 9 volt battery from the video. It’s only based on what I saw here. I don’t know much, Imma update my comment to be an observation instead of rule.
The thought only applies to these specific LEDS and their configurations. I don’t have enough experience yet to make a legit rule of thumb…
The volt supply made me think though, since it’s a 9 volt, you need 360, (haven’t done math yet, it’s a theory) if you wanted to do a 12 volt battery, a single bulb would need 480(I THINK???)? *If* that’s the case, you’d go backwards by 12/120. My hypothesis is: x=volt battery. x*40=resistor for 1. For multiple bulbs: y: amount of bulbs *AFTER* THE FIRST BULB. (X*40)-[y*(x*40)]=new resistor number. Meaning:
1-480
2-360
3-240, etc
The maths needed is pretty easy trying to avoid that basic maths may cause some to miss the essential point (that it is related to the voltage supply being used) and get into trouble... Happy flying!
To many numbers 🥴
Welcome to the world of electronics where maths is a requirement.. Happy flying
Too