A Comprehensive Guide to Understanding Laser Diode Drivers
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- Опубліковано 20 вер 2024
- Have you ever wondered what terms like TTL and Analog mean? Do you want to understand the differences between Linear and DC to DC converter based Laser diode drivers as well as their pros and cons? Look no further because in this video I run through why Lasers need drivers, the circuit theory and architecture of Laser diode drivers and how to get the best performance possible without risk of damage to your Laser diode.
This is not a Laser driver recommendation video! Do not ask me to recommend a driver as I make/modify my own. This is a video to teach you how to evaluate a driver with your own brain. If you ask I WILL recommend a high end driver with top notch product support and not a low price budget driver.
For more supporting information.
How to adjust constant current by modifying the current shunt resistor
Shunt Mod video
• Shunt Mod & The Danger...
How to modify Linear Laser pointer drivers with fixed resistors and more information about using drivers in general.
CD/DVD Laser Video
• Bare&Basic CD and DVD ...
How Noisy can DC to DC converters be?
Testing Drivers from Giannis
• Testing Laser drivers ...
Support the channel!
www.paypal.com...
without this i would have never freaking ever been able to build my own driver for a osram laser array, some of the most helpful and informative content i have seen in a long long while
The video ive been searching years for!
(Vs)Heavy basic introduction non stop...
then steady (Ir) Laser driver topology knowlege drops constant!
Great Education!
Every time I watch your videos, I learn a ton more. You really are a youtube treasure and these tutorials are the cream of the crop for us engineers doing real work in the photonics industry. Big thumbs up from me!
I'm super happy to see a new video on this channel. Laser diode drivers are a subject on which my knowledge is scantily clad at best. It's bedtime right now, but I just saw this in my feed, so I'm bingeing first thing tomorrow morning. Thanks, Mr. Z!
Your knowledge is about to be Daedric armor clad :P
Its no doubt you certainly know your stuff,this is the best video ive EVER seen that breaks all this down and very effectively uses the time given to make fluent sense of it all.
Man, you are amazing! I wish more people would know how fun lasers can be behind the curtains
I'm really happy I found this channel. It's tough to find info that's so well explained
Glad you enjoy the content. I try to post up information in the hopes of empowering people and giving them a better start in working with laser than I had.
Worked on one of the first SSDP green lasers in the early 90's. We used constant current only, because using the built in photo-diode for power control may well overdrive the pump diode and kill it. We characterized our diodes using an adjustable power supply and a series resistor to gradually raise voltage from the point where the diode acts as a regular LED, until the lasing threshold. Monitoring current, actual output power and temp as we went. We ran our diodes well below maximums and always used ESD protection. Something I've not seen in many videos, and even a small ESD can drastically reduce the diode life.
Perfect. This was honestly exactly the puzzle piece I have been looking for, since I discovered your channel only two days ago! Sitting in my covid room and evaluating a new hobby:)
Made it half way through the video so far and I’m looking forward to the rest later. Very informative and comprehensive!
Glad you found this piece useful! Welcome to the hobby, soon it will become a life style.
Thanks 😊
Wow! A free lecture!
Awesome content MrZ i'll be chopping back and forth for nuggets of genius then! the whole ball of wax in fact!
YESSS I've been waiting for this!! Awesome content.
Strap in, you're going to learn useful stuff in this one!
Ironically the old Energizer boost drivers for charging phones up worked awsome for driving 1w blue laser diodes on 3 to 4.5V from any source of 1A or better. they also could be amplatude or pwm modulated by tapping one transistor and adding a mosfet ❤
Dude. DUDE. You’re cool! So I have this old HP 410b vacuum tube voltmeter, which is basically a differential amplifier made out of vacuum tubes. To measure AC voltage, there is a tiny vacuum tube in the AC probe itself, to convert the ac voltage to half rectified dc voltage before it is fed into the differential amplifier in the voltmeter box. This tiny vacuum tube in the probe can measure up to RF frequencies, and is a special little tube that requires a filament at a constant temperature.
In the VTVM itself, there is a component called a ballast tube, which is nothing more than a vacuum tube shaped device that has a tungsten filament in it. It is very expensive to replace. This ballast tube is there to regulate the probe vacuum tube filament so it is at a constant temperature.
All along, I thought, “what a lazy design from HP engineers back in the day, using a lightbulb as a resistive element to regulate filament current.”
But after watching this video of yours, it makes perfect sense why they are using a “lightbulb” to regulate current. In fact, it is absolutely brilliant! Sorry for the long comment, but that design element bothered me for years on that HP VTVM. Until I saw this, I then realized it’s a brilliant design from those old school HP engineers!
And this video has nothing to do with vacuum tube voltmeters to begin with lol
Ah the humble resistor, there's a lot to be said for it! And calling that lovely lightbox panel a white board, criminal! 🤣 It would be interesting to see the sort of lifespans of various lasers with all of these different methods, something I was hoping to see would be a super cooled laser, but I understand that can change the colour output it produces
The resistor got its own dedicated and expanded upon video on one of the good engineering channels are on UA-cam. Just in the last few days I believe. Covering everything resistors, barristers, ldr's, and everything in between
@@hullinstruments right?
I am somewhat confused by why you would use an lm 317 and a feedback control system with a current shunt resistor.
Doesn't the lm317 have its own reference voltage and manages to compare it to the output voltage all own it's own if configured as a constant current source? Where would be the need of a feedback voltage and how could it even be used to further increase the "constantness" of the current the lm317 provides?
Grazie mille e buon anno!!!!
Yeah, the just came in today. My deep electronics skills are rusty, so I humbly ask you for your advice. I've got 2 of the worst driver ever. Can I maybe use them as a variable power supply in front of a real driver? Hate to waste $20. And while I might have your attention, where do I get cheep mounting hardware? For dicrotic mirrors and diodes and such. I've got some Dicrotic mirrors already. And I'm gathering that regular mirrors are not going to work the same as lase mirrors. I'm on fixed income, so I'm a hunter gatherer at this point. All help is greatly appreciated.
Thank you laser god.
Yeah you can use them as variable power supplies and run a laser driver off those. They do make handy little power supplies and I use them for that purpose all the time. Laser diodes are really fickle, they are one of the few devices left that are typically calibrated by hand on specific power supplies.
I consider them fickle, and still blow them up.
I got an odd question, I understand the cheeper units are not loaded with the safety features of your units, but I'm a fixed income kinda situation and was wondering if you might give some of us with the crappy equipment some videos too. I'm kinda smart, but I'm still having a devil of a time getting the Red beams beautiful. I know, multi mode. But I've got no idea how I would get a smaller MW bank of lasers in my possession without robbing a bank. I'm new on lenses, but I'm hoping that the right one might help. Got some units with steppers, but I got a good deal on some with decent galvos. 500mw upgraded to 3w. Works great, red beam sucks. Vertical or horizontal but not both. I've tried defocusing the other beams, I'm thinking about prisms, You are the accessible laser god on earth right now. Nobody else is either as capable or willing to let us neanderthals pittle with light in a cave, I don't know.
Your our savior, or I just have cheep stuff and I gotta deal with it. I've got a couple of coated glass collimator lenses for red, on the way, we'll see.
Thanks for everything, your my hero.
@@adamdavis5961 You can try to collimate the beam using a 3 cylindrical lens configuration like done in the OPT lasers. This gives pretty decent results compared to a single/compound spherical lens. Since the lens placement is done by adhesion you are most likely going to want to place the lenses with UV cure resin so you can set the lenses perfectly and then cure the resin.
Look for " Red Laser Beam Corrective Cylindrical Mirro/For High Power 635nm-680nm laser " on eBay
Thanks for the compliment, I hope to bring coherent photons to mankind for as long as I can!
The heated LED lights up more strongly because the wavelength of the emitted light increased very little through heating and the ignition voltage decreased very little, so that the other LED was left without the optimal voltage at the terminals.
The association of LED-s with resistors with a negative temperature coefficient is not very good, there are situation when the power decreases by heating such a resistor.
Thanks man appreciate it
Very instructive video. You should be proud of yourself
Epic brain dump, Zen! My cranium is overflowing. This not only answers my questions, but also many of which I never even thought of asking. No doubt, more will come after digesting this.
Thanks! I needed this food for thought. BR 😎
Oh it's another thorough dump for sure. I tired to think of as many questions/gotcha scenarios I could from both experience and the community. Glad you enjoyed!
Is it possible to control pulse or blinking speed of the laser using 555 timer method, followed by transistor or mosfet and then goes to constant current driver(lm317t or lm338t constant current laser driver diy) or either buck or boost laser drive like from some sonic devastator schematic especially for controlling sound pulse or sweep on the left side of the schematic but instead of using ultrasonic transducers as an output it uses laser diode of any kind whether its non burning or burning ones? Planning to build that for emergency or survival purpose like for making SOS signal as well as fire starter for camp fire but not brave enough to hook up those on my precious laser diode(one is 488nm cyan and other one is 445nm-450nm blue) fearing that it will immediately destroy those 2 diodes and getting those 2 replacement is expensive especially the high powered blue ones.
Hmm, a laser guy with damaged pixels on his camera? Wonder why?
I am holding a Buck laser driver in my hand salvaged from a 450nm laserland pen. It is buck because I see many small components and used two AAA batteries to run and it also will not light up my LEDs I wired together even with 2 AAs if that mattered
There is usually a max voltage lockout depending on the chip so the output caps don't blow and it doesn't simply freewheel. Someone had a damaged laser driver that drove up to like 200V which had lost this lockout. You can see what that voltage is by running the driver unloaded.
@@Zenodilodon 0.800V! Before the driver immediately started to warm up and drop the volts dramatically. Also my fingers drive 0.200V :D
*(Whoops this is a cheap ebay dpss 532 driver) Im doing my 450 driver after
bare with me because this is the 2nd reading Ive had on my multimeter. Which is a cheap manual knob 200mA limit: the option I chose was the V---(-) and not the V~
The technical meaning is beyond me I dont know all the numbers behind the LED, it must be a ball park based on its natural design. When I ignored the laser driver and lit the diode its one of those blinding ones and not the glass cylinder ones like you said
@@Zenodilodon ok turns out I tore open the negative connection on my blue laser driver and its broken. Oops, The other one! Has a .9mA reading from my AA, and with some rigging to get my AAAs to run in it read .8mA. After looking at a 1W 808nm diode data sheet saying the limit is .8mA which is consistent with my readings!
Thru this I learned that the laser diodes will ask for the current needed for itself which the driver does not govern shown by what I just saw. A driver getting too warmer quickly from .9mA
Now I know how to read mA from drivers!! :D which ill use for building my own. As well as knowing that cheap ebay drivers or only good for under driven diodes or Else
oh yeah i learned that from ur other driver testing video with your "ohio" driver. I forgot this is still in one comment section
@@nuguns3766 No, the laser drivers are designed to govern current. The boost most drivers can still get pretty warm without a load since they are still boosting the voltage a bit high. There is a trade off. Say the driver is 1W package dissipation. That's say 200mA at 5V, but when you get to 20v that number drops to only 50mA, you could also be stressing the high side caps and that will put a load on the chip. Laser diodes and typically LEDs should never be allowed to govern their own current. Their compulsive little buggers with an insatiable appetite,
@@nuguns3766 Also, how are you testing voltages? The readings with sub 1V, where is any of that coming from?
@15:10 the smoke particles seem to be attracted by the laser diode, I don't see particles going the other way.
It could be the airflow in the room, probably the power supply fan.
Good morning sir!
I have to use laser diodes for a maximum use of 2 or three seconds, always at the manufacturer's reference voltage. My question is this: can I avoid using drivers for such lasers used only for a few seconds without them being damaged or do I have to use drivers together with them??
It's always best to use a proper CC driver. They can be pretty cheap, lower than a replacement diode in price in many cases.
where could i buy that buck pcb with battery? thanks
Fuckin' A; thanks man!
9:45
Am I missing some thing?
@@Zenodilodon no sorry, i was watching this on a pc with very bad Bluetooth, which is why i actually got the Audio from my phone, which was connected to the Bluetooth headset.
So so synch up the audio from the phone with video from the pc again after i had to pause to try and understand something, I left a timestamp which i could click both on the phone and the pc at the same time xD
@@zwischendurundmoll3968 Ah, I bought up the video and had it muted. I was watching my hand shake around and all I could think was " Man, neuropathy and caffeine are a terrible mix " lol
Nice1
Laser bug! ;)
Can you design/build me a driver for me for the NUBM37 125w diode array? I can pay for your services. I have a handful of CC drivers that can easily power this diode, however I need a more compact driver that’s more suited for this specific diode.
I would consider it, but that seems like it would be part of a very dangerous portable device.
I love the comments of people who seem to have seen a two hour video in the first 28 minutes it's been online 🤣
They watch it in the hidden 4x playback speed. Shhhhhh
@@Zenodilodon 😅 and there's me using the old fashioned method!
@@phonotical Hooray for CRTs!
@@Zenodilodon haha can you imagine, a crt phone 😂
In an older comment of yours I saw that you asked Zenodilodon what an electron is. The question is fantastically good, but it was not addressed where it should and to whom it should. In an e-mail, Zenodilodon told me that he is not a physicist, but a laser repairman !
Hello, i know this comment will take a decent amount of time becayse it is about those plasma pens you build a while ago. While looking through the parts i would need, i came up with a few questions you could probebly help me with: Where could i fund some 4 uF capacitors for the build, coukld i use ceramic capacitors instead, if i was to use IRF740 mosfets would they even work, what type of inductor would i need if i was to use those mosfets, and what type of laptop could i find that CCFL transformer in, do comanys still make that type of laptop.
Mouser/Digikey
Ceramics work just fine
Use a fast Mosfet with pretty low on state resistance. Short answer most Mosfets will work.
The inductor is part of the oscillator and needs to be tuned to your transformer/capacitors.
CCFL inverters are still made, ebay has generic ones I think.
Honest answer, the plasma pens are complicated, if you are asking these types of questions you probably need to tackle something easier to understand more ZVS stuff. I have a video on this.
@@Zenodilodon Thank you! I have 3 more questions, one what inductor would i have to use if i used 4 different 4 uF capacitors and would the SGE2685-1 transformer work if i wound the primary coil the same as your tutorial and what voltage would tghe capacitors have to be? thank you in advace
@@JotticunChapter2 The plasma pens where something we made just by picking random parts and throwing things together until good performance was achieved. This is how it's always been with the plasma pens. I can't just give you values. These are close to art in that aspect, each unique and hard to replicate.
@@Zenodilodon thank you. I am just a kid looking for something to do, and when i saw that tutorial i knew that i had to make one and now i think i can. You have helped me alot and(if you let me) i could post a video of mine
@@JotticunChapter2 Let you? This is a public platform, I have no right to tell you what to do/not do. Go right on ahead!
Apologies if I am being vague, or not as helpful as you wish. This is one of those experience things. Having made a few, along with JP making some we have found that these are both very difficult to make and all with unique personality and parts. These came about because JP and I where always trying to out do the performance of each other. JP, and myself have 20+ years of messing with stuff and these where made to push our free thinking skill levels. Everything is on the boarder of failing. The batteries die fast, The transformers like to burn up, the mosfets are known to get hot enough to de-solder in seconds and so on. These are not novice/beginner projects, that is reflected on how few of these have been made by us and replicated by others. The best advice is to play with parts and practice. Once you get a good genuine feel for a good working balance then get a tube that is in line with your assembly skills. Don't force any sort of expectations, chances are it's going to take a while to get them. Enjoy the true science of experimenting and learning. Remember, you can watch martial arts videos all day, but only practice will allow you to actually do it yourself. This is no different.
Very useful video
1:10:00
Well, uh, I just bought 2 of those drivers you said not to use, did I miss the fix for them? Or should I just make room in my butt?
There really isn't a good fix for the bad drivers. With that said I would suggest looking into lubricants lol
As an emergency room doctor, you would be surprised at what comes in, or rather, out.
If you talk like your mouth is full your smart lol
9:45