In this video I will be showing you the dangers of cheap 405nm violet laser pointers and how to modify the current shunt resistor on the 405nm violet laser pointers to make them safe or to use them in your own custom laser pointer build.
They do make really nice CC drivers for projects. They became so much more useful after figuring out how to change the current. I wish I figured this out years ago lol.
I have a 3w 405nm laser and it looks nowhere near as bright as a 200mw 532nm green laser, yet it burns through stuff a lot faster. Then I saw the human eye is more sensitive to green light than any other colour. Science is awesome.
Excellent work dude dispelled some myths and helped protect some seeing balls, as usual OUTSTANDING work you show both the upsides and the downsides and stop us blowing up expensive components you rock! :-)
I try to be as thorough with a topic as I can be, my goal is to help others out and prevent some of the electronic catastrophes I have gone through for others. Thanks for the comment!
That first part about the IR was fantastic thank you. I've been terrified of the IR from the various 532nm lasers I've got/had. I just bought some glass IR filters and was going to put them in my laser pointers but now thinking maybe I'll just stick to being careful instead. PS: Regarding the plastic bag over the laser pointer - I recall seeing a video about thermal cameras which showed that many things, including that specific plastic, is virtually trasnparent to IR. Anyone replicating what you did without the correct eye protection is likely to get a face full of IR laser.
You are correct, many plastics are quite transparent to IR, I did just run a test on the transparency with my 808nm out of focus so it did not burn through the bag, it looks like the black bags are about 90% blocking to 808nm, anything deeper into the IR range would probably start passing through more easily. The white bags with the same material are nearly transparent thought to the point of nearly clear images. Lots of organic dyes like in cotton clothing will also reflect/pass IR light quite well where as synthetic materials tend to absorb it such as felt fabrics. All in all it was about the most practical test for others I could think of concerning most laser pointers for those who don't have a laser power meter.
This is just devious. Fate is being mischievous for our diode tech progress having the "green gap", exactly in the wavelength that is the most brightest to us. And giving us amazing progress in the blue range which is some of the least visible to us. Well I guess thank god it's visible at all. And for mass blindness worldwide not happening yet somehow.
The correct one? As long as the wattage going through your resistor is less than the resistor's power rating you'll be ok. As far as type, for the pointer driver's SMT is the way to go.
@Zenodilodon I thought I seen you use some type of polymer resistor I wasn't aware of at some point. I'm roaring at your reply. I'd say the same thing haha they were the caps you replaced the smd one with. I should've thought before I spoke. My wife's brother I'd the local fluke authorized reseller and he offered me a new 87v for 400 but the design is so old now. Even though they are 800 otherwise Gere in Canada. I'd buy an older digital fluke like that in a heartbeat for my collection. I've been loving brymen. As far as doing digital electronics and repairs mostly. I'm going to get the bm869s soon. Welectron sells them cheap on ebay but if you go to their store you pay way more and have to spend 500 euros before shipping haha I got a brand new siglent sds2202x-e I'm trying to sell and I live in a place where that fluke dealer I told you about is the only place to get meters that aren't from Canadian tire so selling a scope here is impossible. That was a great video by the way. Thanks man
Yep, I put in a pair of white SMD LEDs and resistor behind the screen. I turn the light on and off with a little switch that is on the side of the meter. It's a handy thing to have.
Hi. I want to make a soldering/desoldering aid and i thought a modified laser pointer might be the solution. It might be also interesting for you if you are working with smd components, micro soldering etc. I always have problem removing components with my micro soldering tools. They have very little thermal mass so they loose their heat very quickly. I thought that a modified laser pointer which emits IR light might be a supplemental heat source. Lets say this IR laser pointer can provide 1/3 of the heat needed. Which is not so much heat so it can be done with a very low power laser. I think. What do you think about this? A laser pointer would be powerful enough? Would the reflected IR light can cause problem even though it would be pretty weak? I say an IR laser but perhaps a blue would be better?? I will be happy if you can share your opinions. (I am talking about 80-100 celcuius degrees.(175-210 fahrenheit ))
This isn't very effective, solder reflects IR and it's not a very efficient transfer of heat, it's also hazardous to eyes due to reflections.
4 года назад
@@Zenodilodon I am talking about very small components and very small areas of solder. Most of the area it will heat will be the component itself anyway. So it should heat a 1mm x 1mm square to 80-100 degrees celcius. I guess you did not understand what i was thinking but no problem. Thanks for the reply.
@ IF I was on path to try something, would try a fibre laser for that. It have extremely small exit/beam so it can heat a point i.e. I understand this is waht is needed - to heat a point lightly so you can really up-heat whatever is needed. GL ~~~
@Zenodilodon any idea of the frequency response of the driver circuits? Can you modulate them fast enough to provide useful visible signal transmission to a remote device, say in the MHz frequency range?
DC-DC converter laser drivers have a major cap in modulation because the signal can chop up the DC-DC pulsed and cause spiking. I have run these at .5khz just through turning on and off the power but if you want faster you will need a linear laser driver with op-amps and transistors that can modulate much faster. You can use the LM358/transistor combination and interrupt the op-amp current feedback loop and get some good speed. I would suggest getting a cheap read laser driver and messing with that for Khz and Mhz speed.
Great info :) Do you know if just raising the resistor value will compensate for running this laser ( the boost drive specifically) off a higher voltage, say 5v? My hope would be to still make less bright for sure...
The resistor value changes current. The voltage range for input will depend on your output voltage ( this depends on the load and voltage drop at x current ) If you raise the value of the resistor in this case it can actually work against you. The laser diode runs a little above 5v if I recall correctly, so with a higher value resistor and less current that voltage will drop closer and closer to 5v as you lower the current allowed to the laser diode the voltage will continue to drop. Since the voltage of the output must be higher than the input to regulate properly. Here is the problem in a nut shell. IE LD v 5.7v 100% relative power/Driver input 5V ok! LD v 5.4v 80% relative power/Driver input 5V ok! LD v 5.1v 60% relative power/Driver input 5V questionable LD v 4.8v 30% relative power/Driver input 5V Unstable LD v 4.8v 30% relative power/Driver input 4.2v ok! You can work around this though by also placing a lower value resistor such as 2 ohm in series with the laser diode to raise it's needed voltage at x current, or consider a 3.3v voltage regulator between the 5v source and the driver. Hope this helps.
A lot! Thank you, I may end up running it off a 3.7 li-ion, and just raising the current limiting resistor untill it it feels good, or go with the series resistor. It's for a simple laser projection project, so safety is the big goal, not perfection. I appreciate the reply, cheers!
@@Zenodilodon all good, figured you are busy, but let me know when you get a chance to try and chat again maybe we can do it by voice ,let me know what you think of that argon laser i sent you the info on and id like to get me a hand held or maybe a module lab type green or blue laser perhaps you can point me what is the best places to shop for these things, i was looking at zeus lasers and they seem to have a good reputation ,ive seen a 303 laser that a freind once brought to work and man that thing is very visible even in no fog conditions and cheap too, anyways i was hoping to maybe show you on cam (if i can get it to work) my long distance white light thrower and maybe get you to answer some things on it ,let me know when you free, just go on your gmail and give me a shout on the hangout
How to know how far you can push a LD? With an adjustable driver or supply that has sufficient voltage so to not plateau, is “pfzzt!” the only indication of the limit of a LD?
Laser diodes are always driven in constant current operation because they have a negative temperature coefficient characteristic and are pretty sensitive. If the laser diode is an unknown extracted diode there may be markings on the back or around the rim near the window to indicate what model it is. If not than it's a game of trial and trying to match voltage/current slopes of known diodes of that wavelength to find the closest match. These can be found on datasheets and DTR's Laser Shop also does a great job of listing the information. This can be extremely difficult otherwise if there are no markings. You can identify the color of the laser diode by the color of the output window. The AR will be the inverse of the output color such as blue for red LDs and yellow for blue/violet LDs, IR is often a greenish color. I tend to look up diode datasheets and check their rated current, usually I avoid pushing them to the max current because this can damage or greatly reduce their life expectancy. Never try to voltage regulate because as they warm up they consume more current and can thermally run away. Make sure your PSU had a stable current regulation and voltage above the diodes listed voltage at its rated current. The voltage of course will end up dropping under the load of the LD when regulating current. I hope this wasn't too verbose and helps.
Where the old shunt resistor went. This location is different on different board. For this reason I try to teach what part to look for and the concept behind why changing a part works. Figure it like a video on changing spark plugs. If I clearly show how to change it one one model of car then the video is only good for that model, if I tell you what a spark plug can look like and it's primary function that information can be used on all models. All you are doing is changing the value of the shunt, you have to figure out where that is on your board. Usually the lowest value resistor on one of these drivers.
They can vary from 30-100mw. When pushed up past 70mw they don't last very long at all. 50mw is the upper practical range if you want more then an hour of life before it fails completely or looses a bit of power. The 405nm laser diodes are quite fickle, they can last years or minutes depending on the day of the week they where made it seems. Placing a SMD capacitor of10v 1-5uF helps kill spikes on the diode. If you want a word of wisdom, don't expect to overdrive these, or any laser diode and expect much lifetime. If you want the power get a laser diode with that rating and under drive it a tad under spec, add an additional capacitor like I mentioned and you will have a laser with unquestionable years of service.
if you use 18650 battery does calculation for the same diode change? or let me ask you instead, why did you made calculation using 0.3 volts. is that the voltage you were supplying for the driver, or was it diode working voltage?? noob question but i am confused. as you were using some lithium pack
The lower voltage I use for the resistor calculations come from the voltage that is read across the current shunt resistor. The driver's input range is about 3-5v. The input voltage doesn't effect the resistor voltage in this circuit.
@@Zenodilodon thank you. one more question, is it safe to use this driver modification with 488nm diode? i am asking if there is some safety as reverse polarity protection or that some reverse voltage safety mechanism?? thank you
@@milanmacik6094 You can use this driver for 488nm laser diodes no problem. For reverse protection what I end up doing is to put a little piece of a paper sticky label with a hold cut in the center in the bottom of the laser pointer's battery compartment. This allows the + bump on the battery to make contact through the hole, but the flat - side cannot. These drivers do not have good reverse battery protection and it's better to be safe.
Also, note that if the revision of your 488nm laser diode has a case - pin the laser diode module must be electrically insulated from the laser host as it will be +.
@@Zenodilodon it will be Sharp GH04850B2G, so case pin is not used. So i guess i shoud bend the case pin to + pin?. Correct me if i am wrong. Thank you
@@Zenodilodon Ohh okk thanks for the reply, I just want to make a burning laser for once, but I don't have access to such low resistance resistors, but yea killing the circuit due to overheating is a bad idea too. Thanks tho, learnt a lot about lasers from your videos.
@@origamiworld2014 You can go up to about 500mw max with these drivers but additional cooling is required for the heat sink. You'll also need to get a stronger laser diode as the stock laser is only good for about 70mw at it's peak, after about 60mw or so they don't last very long. You can pick up an M140 A type for about $10 USD and press it into most laser modules. The M140 A type is nominally rated for about 1.2 watt so running it at 500mw will give it a very long life. Low value resistors are uncommon in the 5-1 ohm range in general electronics, usually I see higher ones or those in the sub 200miliohm range on laptop motherboards. This is the reason I had to use the larger ceramics myself for this range, and let me tell ya I have a whole house full of electronic salvage and still nothing in surface mount in the correct value. Glad you are learning a lot, it's why I post content. I want to see people accomplish there goals easier than I did. Burning lasers are cool, but as someone who has messed with at least 100 lasers capable of burning I'll say it gets old pretty fast. There is a lot you can do with lasers even at low powers that continues to astound me whether it's something as simple as laser lumia or more complex like setting up interferometers. Even if you don't currently have a burning laser I would suggest looking into other laser uses as you might find enjoyment still in some of the other uses just as I do. Eventually you will have a burning laser, they are quite common these days in both the pointer market and as part of consumer technology.
Я недавно купил фиолетовый лазер 405 нм. Он светит очень слабо. Сначала он жег тёмные материалы, а потом перестал. Что с ним могло произойти? Светит так же слабо. Сначала как включаю он более менее ярко светит, через несколько секунд становится тусклее. Мерял ток потребления, он падает. Заметил что все детали драйвера очень сильно греются. Рука не терпит. Я понимаю из за нагрева и падает ток и яркость? Поставил медный радиатор на все смд компоненты через термопрокладку, ток падает но не так сильно. Яркость все равно слабая. В чем может быть проблема? Какой компонент вышел из строя?
Ваша проблема либо в том, что лазерный диод частично вышел из строя и потребляет больше тока из-за внутренней неисправности. Другое дело, что это может быть повышающая микросхема или выходной выпрямительный диод. Учитывая, насколько дешевыми могут быть эти указатели, проще купить новый. Многие 405-нм указатели настроены на ток, слишком высокий для диода. Это распространенная проблема.
@@Zenodilodon уже сегодня доломал его. С братом двоюродным, он разбирается в электронике. Сначала думали что конденсатор в схеме., многовато ёмкости было, потом думали что стабилитрон, маловато напряжение пропускал, на лазерный диод шло что то мало не помню сколько. Потом уже поняли что сам лазерный диод подсел. Давали ему до 5 в а он потреблял очень мало тока. В итоге я сам потом решил поэксперементировать. Лазерный диод подключал к аккумулятору 18650 через резистор, сначала 8 ом потом 5 потом 3. В итоге спалил совсем его. Ток максимальный выдерживал 450 мА. А светил кстати так же как и изначально в указке, сначала поярче потом тусклел, видимо из за нагрева. Думал если будет ярко светить соберу в указку чисто на одном резисторе. В итоге так и не понял косяк в лд был или в схеме тоже. Непонятно сколько тока этому лд нужно. Не расстраиваюсь, закажу новую. А так зато поэксперементировал. Ещё непонятно почему у этого лд корпус плюсовой? И задействованы походу все три вывода. Третий датчик освещённости с обратной связью? Когда спалил его полностью поменял полярность и подключил т е минус на массу а плюс на этот датчик как я понимаю лд светит но очень слабо.
@@АндрейЛукошников Вы не можете испортить 405-нм лазерный диод одним 18650. Химия 405-нм лазерного диода требует 5 В или выше для работы, если лазерный диод исправен. Если диод производит много тепла и не светится, он уже был поврежден до подключения к 4,2 В.
@@АндрейЛукошников Правильно, если лазерный диод исправен, он должен быть недостаточно питаемым от батареи. Неисправный лазерный диод 405 нм имеет внутреннее короткое замыкание и нагревается при более низком напряжении. Текущий рейтинг зависит от вашей модели лазерного диода, вам нужно будет посмотреть техническое описание. Я не знаю ваш Лазерный диод, я всегда покупаю новый из проверенных источников, чтобы предотвратить бессмысленные игры в догадки.
At 29:30 you aimed the laser diode at the black battery. NEVER do this! That's like placing a blow torch right under the stand of its own propane tank. Lithium batteries are extremely flammable and will explode with very poisonous smoke if ignited by the laser.
Well, no... sorry A the material surrounding the battery materials is quite reflective or is plastic covered and once the plastic is melted away it's pretty much reflective. Secondly the thermal mass of the batteries is quite high compared to the energy of the laser beam as these levels, you could leave a battery in a 1 watt laser beam no problem, most of the energy is reflected away. Lithium cells exploding, well see 2 things has to happen, first you need enough energy to have the cell heat up and produce gas, most of this being I believe hydrogen fluoride as gas that supports combustion. Which well, given the battery fires I have had over the years I have been doing stuff can't be all to bad. I have taken batteries apart too and well, chemically overall they are pretty safe chemically. I guess that about wraps up that.
If by screw you mean potentiometer then no. Not all laser drivers simply have one to turn for adjusting the current. Many of them have to be set with a change of the shunt resistor. You would know that if you watched the video.
