Julian, you are THE BEST explaining easily how to drive LEDs!! THANK YOU!!! I'm learning a lot with your videos!!

Went through full loud shooting apes in the internet jungle, started being desperately entangled in inextricable intellectual porridge, then sinking stuck in quicksand thought when i saw the regulated Led light....Tarzan julian saved me... Thank you a lot! that's one good tutorial.

I find I am always watching your videos when I am trying to learn. Thanks this is the best high powered LED video out there!

Hi Julian! Your videos are very brief and easy to absorb for any newbies or experts. Thanks and continue with the videos. BTW, those high power LEDs such as 20,30,50 and 100 Watts do come with the Drivers incorporated into the LED itself. So we save on power supplies and drivers but we pay a little bit more on the LEDs. Do put up a video on these new ones please! Bye!

Awesome information! In the process of designing custom shaped turn signals and brake light for my motorcycle. So this helps immensely with the wiring issue.

Outstanding video. I'm a beginner at all this but am currently trying to design a CREE XM-L T6 LED system for my motorbike, so this was exactly what I needed to see. Well done.

thank you very much for that, it is interesting that they have still had to use multiple drivers, but never the less it looks like a great place to start

Thanks - the converter in the video uses the LM2596

You're absolutely right, for prolonged use, the 1W LEDs should also be properly heatsinked, so buying them on the star boards is a good idea. Also I was using them in free air outdoors - if they're in some sort of enclosure, the heat build-up could be quite rapid.

Fantastic Video Julian. Keep up the great work. Nick.

I see many from this manufacturer with a third pot between the other two...what is that for? Duty cycle or something? Is it so you can use the driver as a dimmer or something?

Julian ,best clear explanation , now I understand how it works . thanks pal

Thanks for this video Julian, its just what i needed.

Great video! I like that screwdriver cover for those annoying screw slots. I think I'll start using small alligator clip covers like that.

Very nice job Julian!

Excelent, julian. I do not like to connect leds in parallel, but if they are all the same thats ok.

No problem. In fact if you look through their products, you'll find a 1W LED driver with EN input (for PWM control) for $4.37 which seems pretty reasonable to me. It's got a "Make Offer" thing too, so you could probably get 10 units for quite a bit less than that.

Great video. How can anyone dislike this video.

Awesome explanation. thank you!

I think the 3rd pot is something to do with charging batteries. It alters the point when the fully charged LED comes on. Not completely sure about that though. The unit with the larger coil (with the visible windings) has a higher output current rating.

You skipped the part where you say you set the voltage to 3.3V for the single led setup. Other than that truly great video and explanation. Cheers!

Thanks. Clear & concise.

You can see the mismatch at low current, but wind up the power and it all looks good.

Hi Julian I must say I really enjoy your videos,even ones that I have no interest in, I just enjoy the tech aspects that you explain in detail.I am starting a project in replacing my 4 ft. shop lights.I could buy the new led fixtures but I enjoy the diy aspect Here is what I have in mind, Am planning to use the Epistar LED Emitter: 3W - Output Lumens: 180-210 Lumens - DC Forward Voltage (VF) : 3.0-3.4Vdc - DC Forward Currect (IF) : 700mA - Color Temp: 6000~6500K ( White) - Beam Angle: 120 degrees mounted on a heat sink in parallel 8 leds per fixture for a total of 48 leds. The question I have is I have several old PC power supplies that I would like to use for power.I know that I will probably need voltage/current buck converter to regulate power, will one 300 watt supply work or do you have a better solution as this is my first led project Thanks

Yes, if the LEDs are in series.

Hi Julian, Firstly, may I compliment you on your videos. Of all the electronics videos I have watched to date on KZfaq yours are by far the best. Not only are you extremely clear and concise in you explanation of everything, but equally you ensure that what is important is shown on camera. I am slowly working my way through all you videos as they are a wonderful resource for so many, at all abilities. I am now unfortunately disabled and have been looking for a hobby I can manage from my wheelchair, electronics appears to be the ideal thing but I am very much a beginner. I’m sorry to be cheeky but I wondered if I could ask you for some advice please...my little grandson has a 12v battery powered “sit on” car and although I will not be able to fit everything myself I want to build a LED lighting project that my son in law can fit. I saw a video a while ago that shows the functionality that I would love to achieve and tried contacting the author. Unfortunately he is probably a very busy man and failed to respond. The video link is here: m.kzfaq.info/get/bejne/pqpdfNGT0b-onJ8.html He mentions buck converters which I have investigated, but based on the type of small battery installed in these toys my research thus far seems to indicate think maybe buck/boost (or is it boost/buck) would be more suitable. With my very limited knowledge I have looked everywhere I can think of but cannot find one suitable so was therefore wondering if you could please possibly advise me accordingly as clearly you know this stuff inside out? The criteria that I am aware of appears to show the following considerations... 1. 12v battery Vin (I would guess this would vary as the battery is run down by use) 2. be as efficient as possible to minimise drain on the battery 3. have the ability to set both output voltage and amperage 4. be Arduino controlled so needs some form of “enable” or “switch” control 5. due to possible issues with heat I am guessing that 1w LEDs will be the brightest type I can use, and as his car only has 2 lenses on the front I’m envisaging that the largest circuit will consist of just 2 of these 1W LEDS. I’m guessing you’re a busy man too and although it’s going to take me a long time to figure all this out, simply by knowing which buck/boost converter to use will help more than you know., and based on some of the comments on the video previously mentioned, plus all the other online videos showing similar projects I think you could make a fortune if you designed and sold a schematic and/or circuit diagram for such a project. Sorry to bore you with all this but I’ll keep my fingers crossed you kindly reply. Thanks. Kind regards, John PS. Could you also please possibly list the 3 boards shown in this particular video? Thank you again

Still very helpful information. Thank you!

Useful, thanks. Castor MIEE old school!

For step up you just need a step up converter (boost converter). They look very similar and are similar in price, they are perfect for wiring up a whole horde of LED's in series. You can turn 12v into 33v and run 10 LED's in series. I usually run each LED at around 3.3v, a bit under the 3.5v rating.

You can buy dedicated 1W (or 3W) LED driver modules with an E (enable) connection for PWM control, but I can't think of a way to drive 10 separate LEDs from one driver module if you want individual control over each LED. You'd probably need 10 driver modules.

Yes - that should be OK. Three LEDs in series will need about 10 volts, the buck regulator should be able to supply that from a 12v input, but you'll be near the limit with 2v difference between input and output. 2 rows (or columns depending how you look at it) will require twice the current of a single row - 2x 700mA is 1400mA. This should work.

Hi there, thanks for the video. I don't understand one thing if you don't mind me asking. When you have a voltage regulator, do you setup the voltage to a exact amount like the amps? Like if the Vf of the led is 2.2 you would set for exact 2.2 and also limit the current? Last question. sorry to bother :). What about led drivers? are they a good option?

thanks for the reply, I know there are LED drivers out there that can control an array of LEDs, but i haven't seen anything for 1W LEDs, but thanks for the answer, i was thinking i would probably have to use individual drivers,

Julian, Is constant current driver? If so, is it correct that when you connect the 2 strings of 3 leds in parallel, when one of the 6 leds fails the CC driver puts the same current through the other string of 3 leds which then get twice the intended current so those 3 leds will go pop. Does it follow then that you cannot use a CC driver on LEDS when in parallel, only when in series?

Julian, thank you for your thorough and complete videos. Have you tried, or do you know if it is possible to regulate the intensity of the led’s in this array with an Arduino and mosfet using PWM in between the buck converter and the led’s? Thank you for your time.

i just had a look and they have some really great stuff, i think i will save that seller for later! but as for the drivers, i need them small because i am going to have a 24 grid of LEDs and the drivers can't take up too much room so i was thinking of designing my own based on the PT4115 driver, its very small and looks like it can handle up to 3 watts

Thanks for this post Julian .... where do you get your buck converters from. Mostly Ebay? Some no doubt are better quality than others.

Hi Julian. With 14 volts in the input, can I have 9 volts in output using the kit showed in your vid?. Regards from Italy.

Hello, I have a moped and I'd like to replace the original lightbulbs with LEDs, the alternator is producing 12V AC, first I have to rectify the current to DC but the voltage increase with the RPMs... If I have something like 6-19V at the input of the led driver, it would be ok? Thank you! :)

Hi Julian, I am new to this LED. I am trying to learn. I have some of the small 3W LED which you have shown in your video. I like to use them for a lamp to convert to 12V so I can plug into 110V wall outlet. What kind of voltage current regulator would I need to use to support the LED. I like to use anywhere from 1 to 3 LED for the lamp. Thank you John

great video, very useful, thank you. Would it be possible to tell me the manufacturer and part-number of (a) the switch-mode voltage & current regulator and (b) the 1W LEDs that you used?

Hi Julian! thank you for your videos , why do we need to regulate the driver voltage output if the current is already regulated ? thank you

I'm wondering what would be a good solution for a traffic director like this: 36" Amber Traffic Directional Advisor Strobe Emergency Warning Arrow Stick I don't have a problem using smd parts, but wondering if there's any single-chip drivers, or a driver that would have some circuitry like one of these boards but multiple leads off it that I could switch with a micro and not blow anything up.

Hello, Thank you for the video! Does the output current remain constant throughout the battery's voltage drop (without adjusting)? Thanks!

The accurate power supply control to the led is interesting and the problems caused by the alternator kicking in on a car to charge the battery. In car specific led exchange bulbs do they have any sort of regulation or resistance on board and are they doomed to failure more rapidly than the incandescent filament?

Try searching eBay for "RGBY Quadcolor 4*1Watt LED Built-in Driver Board LED" by Sure Display. It has 4 drivers on one board with PWM control inputs. The LEDs are pre-fitted but could be removed. Sure Display may have other driver boards that would be suitable.

What's the thing you're using to adjust the pot I always find it a pain to use a screwdriver on them

Great video, just what I was after. One thing Im not sure of though is I want to have three LEDs that can be independently switched. Can I put three 1W LEDs in parallel and use a relay to turn some on and off or does it need to be all on or all off on the output?

One question. I want to connect a 3w LED with a 18650 battery. (Yes, I'm going to use heatsink and so on). But I just can't find the proper driver for it in my country and buying it from China takes almost 3 months to get here... So, any idea of what can I use? Thanks!

I'm trying to complete a project but need some additional info. I want to power a 3w rgb led for a project but I was told I may have an issue with the heat that they generate. I want to put it in a headlight housing so space is a factor would I be able to have a heat sink that will work properly in a tiny space and if I used the same board to power the led what could I use to control the color

Julian, where did you acquire the converter, in the video, as I can only find one on eBay but the seller won't ship to the Uk? I assume you got it from China or Uk seller. Thanks

Try a search for "buck converter CC CV". There's one for sale by Bisany and another by Polelu.

nice tutorial

Thanks for the video, I am making a UV resin curing lamp. How come you did not try 4 LED 3 watt lamps in series from the 12v battery? Did you give it a try? The bulbs I got were 3.2 to 3.4 volts

Julian, In the 3s2p arrangement driven at 600ma, should any single LED develop a fault then surely the whole circuit will go faulty as the 600ma will momentarily flow through the branch without the initial faulty LED and overdrive that branch?

Well done

HI, Great video. I have a question, what if you 9 leds in series/ 3 x 3 @ 900mA and one led in one series went out causing that entire 3 led in series to stop work, wont that overpower the other 6 @900mA. Thanks

Both would work.

What LED driver are you using in the video? Cheers

could you tell me the source of the 12 volt regulator to buy? thanks not sure if it was in the description thanks again great videos, most ppl do not have any electricity knowledge

Hello, thanks for the video it's very helpful - but I'm still a little confused about how to regulate my high power LED. I have a CREE XM-L2 U2 LED, which wants 3000ma at 3.5v for maximum power. I have a voltage and current regulator like the one in your video, it can deliver 5A. Do I need to regulate both the current and the voltage into the LED, or just the current?

Hi, I made myself for a spare time hobby a small 3D printed desk lamp, where I'm using a simple joule thief circuit to drive 3 of the 5mm white LEDs in parallel from a single AA battery. I bought a 3W white LED in order to make it brighter. When I connected it instead of 5mm LEDs, it lit a bit dimmer due to voltage drop. Checked with a multimeter: JT provides total of 22V through a diode without load and when I turn on the LED it drops to 2.3V at around 24mA current, I know that max. voltage for this LED is around 4V at higher current. Any ideas what shoud I modify to provide it with sufficient current? Do you maybe have good and simple references for this? Thanks!

Hi, a long shot asking on a video so old, but I have one of these constant current / voltage boards, I set it up for my IR 10W 5-6V 850-1000mA LED as Max 950mA and Max 5.5V, it seems to be getting fed the 950mA but when I do a voltage check on it, it only show 4.5V, any reason this might be?

I would think the same ! I've been advised not to put LEDs in parallel with the same resistor. I would think the same about The DC/DC current limited PSU used in the video ! Especially when you know how behave a diode. But I'm a humble beginner !

Hi Julian another great tutorial, I am about to purchase one of these or similar modules but have noticed sometimes they are a blue board, or a red board. are they same? just different coloured boards? Thanks.... John :)

Informative and well presented. Thanks Much. ...... One day they'll make LED's that self limit the current??

The output still depends on the input though, when the voltage deceases in a battery the buck converter wont be still putting out the same converted voltage, it will lower. And it's the same if the source voltage increased (like your example of the alternator). An LED can have the right current, but if the voltage is far too high the LED will still burn out as voltage times amperage = watt power. So you still run the risk of burning it out, this is precisely why LED's have voltage ratings to start with! You can't just feed them any voltage and make sure that just the current is fine. So if your battery went up to 14.4v and you set the buck converter before at 12.6v battery input to 3.5v output for LED's and 30mA. Then when the battery voltage goes up from the alternator the output will go past 3.5v (most likely past 4v). Which will lead to the LED not consuming it's normal 0.1w, but instead wthin 0.13-0.15w. So while it isn't terrible, usually it will shorten their life significantly to be running 50% more power through them than they are rated for.

is there also an pwm input on this board. incase that I would like to dim the light by microcontroller?

Thanks Julian.

Where did you buy those CC regulators?

where did you get your voltage regulator?

HI This is perfect for me thanks. However, if I want to put a Pot or rheostat type device on this to drop the voltage and therefore dim the LED's - where would I put it? Will the VR try to keep the voltage up if I put it in between VR and battery?

Hi Julian Great videos but the way! I have a few of this exact regulator, could I use it safely as a sub c batterie charger. I need to charge them individually so I have set the voltage to 2.3 volts and the current at 450 mA as they are 5000mA cells. Is that OK? And when they reach capacitie will the converter stop charging? The light is red while charging, will it turn green when they are full? Thx again! Adam

what would you do if you had an array of these LEDs? for example if you had 10 white LEDs and you wanted to PWM each one individually so they could all be at their own brightnesses, would you need a regulator per LED? surely if they were all using the same regulator then the load would change depending on how many were on or off.

So if I wanted to drive 16: 1 watt leds with an arduino, I would need 4 constant current drivers and a transistor to switch each one on from the arduino pins?

At 06:47 where the matrix led are powered that way, will both string of 3 series leds get 300mA each equally ? Or will one series led draw a different amount of current ?

I did a quick search on eBay for "1W red LED" and found some with 655 - 660nm wavelength.

The one I have from banggood has three blue boxes with adjustment screws. Would be nice if they had labels or a link to documentation online.

Hi , if i wanted to use a 12v psu with a current and voltage regulator as in your example but for 3w leds that have a forward voltage of 3.4 and a 700ma current draw. could i run 6 - 2 rows of 3 from one 12v supply? assuming i set the voltage to 12v and the current to 1.4a?

Hi nice video !!!!!!!! Can you please tell me the DC-DC converter IC that you are using?????

due the voltage change on battery so we need driver regulator for the led. What if I change power source with DC adaptor (I assume has steady voltage and current), do we need the regulator anymore? Or it can be done with only use resistor?

So if I use a voltage regulated supply (like out of a PC power supply), then the resistor method is safe?

where did you buy that current and voltage regulator. I can't find it on Ali Express.

A few words of caution, I have recently bought a current and voltage controlled circuit off E-bay, I wanted to push a constant 150 mA of current through 6 luxeon LEDs from a 12 volt DC battery supply, underdriving them by a long way and cooling them with oversized Aluminium heat sinks because I want them to last virtually forever. I carefully set up the circuit to limit current to 150 mA and the voltage was set well within limits. However, I made the fatal mistake of hooking up the power to the circuit and then connecting the LEDs to the circuit. This created a sudden surge and pop went one of the Red Luxeons, not much of a problem normally just replace it, except the LEDs were carefully installed on heat sinks behind tongue and groove wood panelling, the whole episode cost me a days work. Finally, I decided to use a voltage boosting circuit only and run it through an LM317 circuit I built a while back to limit the current, again a big word of WARNING here, avoid the simple ONE resistor only LM317 current limiting circuits, build one with a potential divider as I did. Because I bench tested on breadboard a simple LM317 circuit with a single power resistor and the damn thing allowed an initial surge of around 2 AMPs before settling down to the required current flow. In summing up the whole experience was dreadful and I hope I can save someone similar problems, always hook up the LED side first before powering up, check and check again on a bench test first before you even get to that stage, one more thing I did after this incident is I installed a 100uf 25-volt Tantalum Capacitor across the plus and minus rails to the LEDs, on powering up this effectively causes a momentary short circuit across the LEDs, forming a shock absorber to buffer any current surges. Bear in mind a capacitor across the LED supply rails could make things worse if you were to power up and then connect the LEDs up downstream of the Capacitor. I hope I have helped people avoid the problems I have just had to solve.

Could you use a pc power supply as your power supply. 12v 24a which i'll regulating to 12v 1.4a? I'll be adding a heat sink behind the lm2596. would that help?

Simple n best.sir

Is it possible to drive a 1W led with a 9V battery using the led driver shown at 4:25? Thank you.

If we use for example 6*0.5w resistors (of course with the right total resistance) to power up a 3w led, will it then be sensitive to regulating voltage, f.e between 12v-14v?

Where could I buy the voltage regulator you use to regulate the battery.

Hi, I have current source 900ma box. Input ac 220, output 12v labeled - Led and + Led. My Led 3 w, star Led same as on your video. My question can connect this Led direct as the box labeled which in this case I’m putting 12v on the Led or I should connect a series resistor which can drop the voltage across the Led? Thanks

Dear Julian Great videos you have. what>model Buck>converter is this. The>Current buck converter ? Gr

Hi Julian could you please do a video showing how to run 3W RGB with a pot to control brightness on each channel as there doesnt seem to be anything else out there on this topic

Which module I can Use for drive 12V Led Strip on 12V Battery?The Linear Lm317 have too much Drop Voltage.Thanks for your Videos

Hello Julian i've purchased the same voltage and current regulator to drive 3w leds , i' ve set the voltage to 3.3 v and the current to 700 mA as instructed on the data sheet however the led only drew 200 mA am i doing something wrong or it's just the quality of the leds . it's mounted on an aluminum heat sink and i got an additional heat sink but it did not heat up can you kindly advise ?

I want to use the 3W RGB high power LEDs to light some fiber optic fabric in a costume. I've I'm only using 3.7V Lipo battery how hot will they get. If I put them on HeatSink will it be safe around fabric? Everything I read says those little high power lights get really really hot. Thank you!

Could you please let me know were you got 0.09 from ?? Thanks

Hi, I bought some 1W LED with the star back PCB. Can i run them at their nominal rating without more heatsink and not set them on fire? They shouldn't run more than 5minutes at a time.

how can i find a circuit like this,? voltage and current control

Would it make more sense to run a single 50w led or 3 x 13 3W leds? The 3W leds only need mounting on those 20mm star heatsinks. were as a 50w single led needs a massive heat sink. Would 13 x 3W leds give the same heat output all together as the 50w led? The main problem I have is the heat.

What's the exact name of the regulator. (Ex:lm2317)