DON'T make an LED flashlight like this

[@camforman]

Great video. Im an electrical engineer and regularly see these things in commercial products. Leds are regularly connected in parallel with no balasting resistor and connected to a voltage source. While it does work but not for long and rejected peices because the LEDs came from mixed lots must really hurt their yeild.

[@TheUnknownCatWarrior]

Some bottlenecks: 1. The LED needs more heatsink. 2. You should use a switch mode regulator instead of an analog regulator.

[@MrHerhor67]

Yeah, SMPS with CV and CC modes. Or maybe even power limit, but that's more difficult to implement.

[@threeMetreJim]

It may not be too inefficient using an analogue regulator as the battery voltage and LED forward voltage are not too far apart - worst case full battery (4.2V), about 210mW dissipation in the regulator (assuming 3.5V LED voltage drop and 300mA forward current), becoming less as the battery discharges. 20% waste at full charge and becoming lower, comparable to a simple switching regulator. Heatsinking would probably need to be improved if the LED is in an enclosure.

[@chiwel]

thanks god, for this person made this video, i just bought some broken led for a dollar, so i want to change it, but what i know some video doesn't check how broke led without proper module. And I want to ask something what module for; strip cob led 5w(4 piece) with 3 battery? I use brand new laptop cells because I have. And thanks 🙏 for the answer.

[@albertogregory9678]

Depends on the COB led forward voltage

[@edic2619]

Great video. Very easy to understand. Thanks.

[@goury]

I sincerely thank you for this educational material. It was very useful and educative.

[@X4R2]

Great video, thank you! I got a high power LED a while ago, and now I have a project to try it in! I'm curious, I've heard the light intensity of LEDs is usually modulated by flashing them at a high frequency (like PWM?) since they don't function below a certain voltage. How dim can the LED get with current limiting?

[@LeftyMaker]

Yes, you can use PWM to control the brightness of the LED. The datasheet for the chip in the driver says it supports it by feeding the PWM signal into the enable pin. They can get very dim with current limiting too, but the brightness is more difficult to control.

[@HammadAMansoori]

This is the information I was searching for a long time. Thanks brother👍

[@Dark_Matter2]

LEDs glued to wood is insane decision. Btw good video I will use those PCBs in future projects

[@LasershowLab]

Thanks for video might help me using the idea as guide and can be applied to my DIY handheld laser pointer.☝️👍👍

[@glowytheglowbug]

a single resistor also helps to stop drawing max current (since its a diode not a bulb it draws as much current as it can)

[@bertram-raven]

Doing it the right way = 4600 views. Total Nonsense = 4,000,000 views. Welcome to the internet.

[@ironflav]

Hello, can you tell me what is the right way to do it please ?

[@Techno0070]

Very good information sir❤

[@Kaloyan-trains]

Супер, но този LED Driver има ли го някъде в България?

[@LeftyMaker]

Не го виждам в Елимекс и др. Може би не

[@chaBUDZ]

Thank you for making the video

[@Jan-iq8ep]

Dobrý den, zda se mi to nebo podle vašeho přízvuku jste Čech? :)

[@barrybrevik9178]

I am late to this video, but maybe you will see this anyway. I like your design, and I want to try the same thing. I have some LEDs that look exactly the same as yours, but they are 3 watts. I want the extra brightness, so can I make some small change to drive 3 watt LEDs?

[@LeftyMaker]

Sure, but you will have to use a different driver to get full power. This one gets only to about 2W from a single battery

[@hobomaster6237]

Good Debunk vid , nice

[@acche-rc]

What's a pull down resistor?

[@TheSimoc]

It is a resistor that pulls the voltage down to ground potential on that pin when the switch is open. Otherwise, if left floating, the high-impedance sensitive enable input could get randomly activated by induced, leaking etc. voltages.

[@LeftyMaker]

Yup. Without it, the LED may (and did, in my case) start flickering when it's supposed to be off. The opposite is a pull-up resistor.

[@Sylvan_dB]

To add a bit to the prior answers, sometimes the power and ground connections are referred to as "rails." There is always a higher voltage rail and a lower voltage rail, even if that lower voltage is the common or reference rail. In a simple circuit like this, the higher rail is the battery positive and the lower rail is the battery negative. (More complex circuits can have multiple rails at different voltages.) A "pull down" resistor connects between a point and a lower rail, pulling that point down toward the lower rail. A "pull up" resistor connects between a point and a higher rail, pulling that point up toward the higher rail. If you connect equal value pull down and pull up resistors to the same point, that point will be centered at a voltage mid-way between the two rails. If one of the resistors has a lower value, it will "pull harder" toward that rail and the voltage of the point will be closer to that rail. The voltage of the point can be calculated using ohms law (amps = volts / ohms) multiple times with the total resistance to find the current, and individual resistance values to find the voltages across each resistor.

[@ManuKumar-yr4jw]

LeftyMarker in the another video you shown in this video has leds connected in parallel so they will waste a ton of amps and power so the first led will share the amps and power to the second one and it repeats like that so there will not be high amount of power and amps to burn down the led and 8 of them in parallel will form 8watt so there won't be enough power and amps to burn down the leds

[@Sentinel-1]

02:43 One small correction: the current is limited by the total resistance of the wiring and the internal resistance of the battery. In the case of dividing the current into 8 high-power LEDs, this may be enough to limit the current to an acceptable level (although this is still a mistake from a circuit design and engineering point of view).

[@Sentinel-1]

Oh, nevermind. You've mentioned it later @ 04:30. 👍🏻

[@kamui30]

Can we set this up with multiple configuration like low mid max output for the light?

[@sshutupurface8345]

Im using a LM2596 off temu its set at 3.1v and no resistor I run 3 x 3w LED's in paralell 3.1v x 0.7A = 2.17W per led total 2.1A medium heat with heat sink

[@ashkananisi5181]

what is efficiency of CN5711?

[@EduardoFernandes-yw6jj]

I made a flashlight following that schematic and worked well, but one day stopped to work. I thought that something burned, like the LED or the LED driver, because I tested with a multimeter and the voltage was OK in the TP4056 and going at the LED driver VIN, but there's no voltage at the LED pin of the driver. So I tested the LED, putting 3V in the LED and GND pins of the driver using my adjustable voltage powersupply and the LED turns on, and after that the LED driver worked again like there's no problem before. What could have happened? It's good to know that nothing burned but can be a problem if that happens sometimes, because I need to dismantle the flashlight and inject 3V in the LED again.

[@LeftyMaker]

Weird. Never happened to me before. I wonder if it is the driver shutting down for some reason. Could it be overheating? Does it turn off after prolonged use? Or could it be a poor connection to the enabling pin?

[@EduardoFernandes-yw6jj]

@@LeftyMaker well, I don't know. After the "resurrection", it's working fine again. I'm trying to use as much as I can to see if the problem happens again. The first time it occurred after few minutes turned on, but I'm testing now for more than 15 minutes and still working, and there's nothing overheating. I hope this don't happen again, I only commented here to know if this is something that could happen.

[@LeftyMaker]

Nope, that's not typical. I've had it on for close to an hour without issues. But if it does happen, I don't have any guesses what could be causing it.

[@firmanmna5154]

Thanks for the info. I once made a flashlight with 4 hpl leds and added a heatsink. I connected a 4.2v battery directly to the led. And the led got very hot even though I added a heatsink And it only lights up for 10 minutes with a 2000mah battery. Now the battery has dropped And also the LED😅

[@LeftyMaker]

yup, sounds like you overloaded them. They either burn out or get dimmer when you put more current through them than you should.

[@alexvas603]

could you please check CE disabled driver current? in specs CN5711 1 milliAmp. to much for emty battery...

[@LeftyMaker]

yeah, I got 3.2 microamps. Maybe you mistook uA for mA?

[@araird5899]

hello i want to do the same but in a helmet for bike who can i do dess plz?

[@LeftyMaker]

I would recommend buying an actual bike light. It would have proper lenses and reflectors for the LEDs, so it will provide better illumination

[@yanipro3978]

Супер си брат

[@ardawanx]

nice, but the original video showed multiple LEDs while you demonstrated a single LED.

[@LeftyMaker]

For multiple LEDs you can use multiple drivers in parallel. With a higher supply voltage you can run LEDs in series, but not with this driver. I will soon make a video about a different driver that can run long strings of LEDs

[@threeMetreJim]

The builder of that flashlight will get a nasty surprise if it's dropped and the cell is damaged. I deliberately damaged one that size to see the effect (outside in the open of course!) and it went up like a smoke bomb before bursting into flames. There are too many dodgy and incorrect videos like that, but there is little regard for safety in the places the videos originate.