Extractions&Ire - 2022-05-15
A modern light-source for a modern man (who doesn't really know how electronics work), what could possibly go wrong? We need the UV for our cubane ok. Twitter: https://twitter.com/Explosions_Fire Subreddit: https://www.reddit.com/r/ExplosionsAndFire/ Join the Discord!! https://discord.gg/VR6Fz9g Patreon: https://www.patreon.com/ExplosionsandFire Music: from the Aphex Twin soundcloud dump. Sorry once again to people who have sent me cool music, I am too short of time and it sucks. Track name: 22 Pearls References for the whole cubane synthesis: 1997 Lab scale paper: https://www.researchgate.net/publication/244572672_Dimethyl_Cubane-14-dicarboxylate_A_Practical_Laboratory_Scale_Synthesis 2013 Pilot Scale: https://pubs.acs.org/doi/abs/10.1021/op400181g "Cubane Derivatives for Propellant Applications" 1989 https://apps.dtic.mil/sti/pdfs/ADA210368.pdf
I like how other people give genuine chemistry advice in the comments and I'm just sitting here laughing at the funny science man and his magic cubes
As far as I’m concerned this man is the missing link between occult alchemists and actual modern scientists
Wait this is not an occult alchemy channel?
Yeah not gonna lie I know nothing about Chem, I'm just gear for funny Aussie chemist hijinks
Can't help much tbh. This guy is getting his PHD while I'm still doing A levels
Me too I must admit
In addition to the usual explosive chemicals in dirty glassware, my favorite Australian meth-lab has expanded into mixing electricity and ionizing radiation. I'm feeling spoiled today!
I feel like the Dark Age of Technology is just months away now.
and all in milo tin too
@Raven Coldheart Could you imagine if he started programming too?
"You're not gonna illuminate a room full of people with UVC, that would be bad."
-Big Clive has joined the chat
A crossover I need right now
It immediately brought up memories of that art installation that was pretty much made out of flourescent UVC tubes that made a lot of people sick. I think that was the one featured on Big Clive...
@OOZ662 He did indeed discuss an event that was supposed to have had UVA tubes but somehow got UVC ones instead. Everyone at the event got sunburned eyes.
@Michael Hall the phrase sunburned eyes is distressing.
@Andrew Greenwood I've had it a couple of times from beach trips. Feels a lot like pink eye, both have a feeling of sand in your eye and dryness. Another term for sun burnt eyes is snow blindness
Speaking as an electrical engineer, this episode is painful.
But entertaining, in a "monkeys playing with power tools" kind of black comedy way.
Speaking as an electronics tech, yeah.. this hurt to watch. But he's learning. Baby's first diode :'-)
I expected nothing less, and I am sorry
@Extractions&Ire your wallet is the one that will suffer the most. Letting the magic smoke out of IC components is painful.
@Laird Cummings and the reaction will suffer too. The overdriven and overheated LEDs will make a very different light with much higher wavelength.
Being an electrician, I think I finally understand how a chemist must feel watching your videos, lmao.
You playing it fast and loose never gave me anxiety before but holy fuck.
Makes me laugh thinking about previous videos where things went awry.
"I figured it would just take the voltage it needs but apparently not"
the chemistry videos have always given me anxiety, this is another level
I think the difference is that he more or less knows what he's doing in regards to chemistry
when the current spiked to 2 amps i actually yelled at my computer
finally relatable to our crowd
“I keep getting hung up on this 40 mA. An amp should be fine.” Me an electrical engineer screaming: “No it’s 40 mA!!!”
"This bushing requires a 12mm pin. 17mm should be just fine... More is better, right?"
Me, a physicist who's seen her fair share of components go pop when I've accidentally fried them: grabs popcorn
Me, not an electrical engineer but just an electrician: "No it's 40mA!!"
@Douglas Boyle me as softwar engineer NO ITS 40mA
Watching a Chemist work a lab bench power supply to power LEDs will go right into the stash of material if I ever get to hold a lecture about basic electrical engineering. BEAUTYFULL !
Can't wait for a Styropyro collab and UV-C lasers for the Cubane series.
Oops no more reagents! Vapourized by the 60000000W laser they designed together.
Whoever gave you that advice on twitter regarding the LEDs "drawing as much current as they need" is very misinformed. That is true for constant voltage loads, but completely wrong for constant current loads like these unregulated LEDs. The current-voltage curve on any diode is exponential. That is why the current should be limited to 40mA and then the voltage will correct itself to whatever it needs to be. After the threshold voltage is passed, tiny increases in voltage will lead to huge increases in current, which often leads to the deaths of LEDs. Great vid, looking forward to new instalments.
Cascade over-current failure is always an option...
Yea this is correct. Constant current is also important because the resistence is dependent on the temperature. When it heats up, the resistence drops, it draws more current (assuming a constant voltage), thus heating up more etc.
@O range et voila, regenerative feedback loop, and soon the magic smoke escapes.
@Laird Cummings Creating DEDs.
Dark Emitting Diodes.
@Jimmy B le ded
00:00 Intro
00:59 LED history
02:41 UV LEDs
05:01 AliExpress haul - LEDs
06:52 Power
07:45 bench power supply test
09:00 Ebay haul - driver & timer
10:43 Heat sinks
12:13 Unexpected explosion
12:59 now we've got one
13:37 Driver - earth?
14:05 oop sparks
14:28 officially cooked
15:40 Timer relais
16:13 highlighter demo
16:36 Reaction chamber setup
18:00 Outro
If it says 40mA it's 40mA, man. Blasting amps through those LEDs will kill them very quickly. I'm impressed that they even hold up that long. Also: you're not supposed to see the LED's when they're on. They don't create visible light at normal operation AT ALL !!!!! What you're seeing is the death scream of an LED. Similar to normal LEDs which will always glow red shortly before they die, even if they're green LEDs. I would not be surprised, if the LEDs don't generate any useful (for you) UV radiation at that state.
Also, also: UV-C should not make paper fluoresce that strong. Overdriving the LEDs could cause them to drift into longer wavelengths.
absolutely this!
That was brutal to watch. It would have taken just one google search to learn how to drive LEDs. If you can do advanced organic chemistry you can definitely do basic electronics.
Edit: get a resistor: R = ( (Your laptop PSU 19V) - (led voltage 13V) ) / (LED current 0.04A) = 150 Ohm
Original: To not just be "Mr. You're Doing It Wrong". Do the following: take your power supply, set it 13V, turn the current knobs all the way left (voltage should drop to zero-ish, that's fine). Then short the output (or see note below). Turn the "fine" knob of the current settings so that the current meter shows 40mA (which is crazy hard with that meter, sorry). Remove the short from the output. The voltage should pop back to 13V. Then never ever touch those knobs. To be save(er), connect the LEDs to the already switched on PSU. The cheapish ones tend to overshoot the output voltage at power on.
note: instead of shorting the output, use your multimeter in current mode. That even helps with getting the 40mA right.
Yeah one thing that confused me was the lack of drivers available at such low currents?? Like I can’t seem to buy anything off the shelf at 40 mA? And then when I tried with the bench top supply, it seemed fine at 1amp, but I guess that was wrong oops.
@Extractions&Ire Because at low currents a simple resistor will replace the driver :)
Wow! I'm thoroughly impressed those UVB LEDs can survive running at 22x their rated current without dying within 60 seconds, they've certainly come along way from being super sensitive to the slightest abuse. Either that or they've sold you some 1,000 mA 365 nm UVA LEDs... A lot of UVB & UVC LEDs on Aliexpress are actually UVA 365 nm LEDs, might be worth checking they're genuine with the price of that listing being so low.
But oh god your electronics and like my chemistry, I really doubt those poor LEDs are going to survive the several hours for the reaction. I wouldn't be surprised if you're driving them so hard the internal protection zeners are clamping the voltage which is just wasting power as heat. Pretty sure even if you run them at their 40 mA you'll still get more optical power out than those previous lamps. Also DONT put the timer on the LED driver output, you should always have the LED connected constantly otherwise the unclamped output capacitance can pop those LEDs at turn on like you so very well demonstrated on the first victim. Also you can ignore the earth, the LED driver is an ungrounded isolated design.
I recommend you abandon the on-off relay timer contraption (the switch on characteristic might also lead to sudden LED death syndrome) and instead just use the bench power supply and to limit the current you can use some resistors, super easy and makes it easier to adjust. You can probably safely shove 50 or 60 mA though them for a 100 hours without them dying.
Happy to provide further guidance or calculations, you can reach me here in a reply, on Twitter or Patreon.
Yes, properly driven LEDs do not need time offs.
well you gotta give those LEDs credits for surviving that kind of abuse
I recall losing an LED to my lab PSU during some low current tests, even with 10mA current limiting and the supply voltage matching the LED!
Was probably an inductive event, because when the leads shorted there was a spark as the output capacitor dumped it's load - likely the inductive spike that followed punched through the LED; halving it's brightness...
GsaUce Rug Don't know - when flying blind I assume 20mA max current, as it's most typical...
Have seen filament style LEDs lose their shiz on 10mA - but those are their own story...
So half of the "rated" current is my standard procedure...
Everyone seems to have the led wiring under control.
I'm just going to note that steel has pretty poor reflectivity in uv ranges.
A Teflon reaction vessel will capture more of the bounce light.
I physically flinched seeing the amp meter jump up to over an amp on that power supply. Those poor LEDs! I hope they've survived long enough for you to get some kind of synthesis going
Local Australian mad chemist decides he doesn't get enough UV on a daily basis already.
3:52 - fun or not so fun anecdote: one or two years ago in the nearby uni they used UV lamps to disinfect room after lectures. Staff forgot to turn off the lamp for a lecture and students got severe burns. Surprisingly the students were blamed because they didn't notify the staff during the lecture (even though burns show up some time after the exposure).
Of course the students got blamed, because if the Uni admitted the blame, they'd be liable for any and all damages incurred due to the exposure. (Immediate medical costs, and long term ones as well.)
@The Keeper yup, they didn't help them at all, even worse they still required presence on the lectures even though some of the students had to be hospitalised
GsaUce Rug look up Silesian Medical University in Poland, that's a case from 2021 I think. The staff there is notorious for mobbing and other such practices. I don't really know what happened later as I didn't follow the case.
"surprisingly"
I would reach out to Big Clive for technical electronics, especially lighting. He usually does Collab's with stem people.
I was thinking exactly the same thing! I've been watching a lot of his videos and this seems exactly up his alley!
YES! I was thinking he needed an explosion containment pie tin nearby
Fourth vote for Clive
Yeah, you'll want to use the timer to cut power to the driver. The driver has a voltage range and a current rating, and will provide whatever voltage it can within that range to make that current flow. So if you open a switch in its output line, it will instantly swing to it's maximum voltage, trying to overcome the new infinite resistance of the open switch.
and that's exactly what's fried the first LEDs
No need for timers at all. Just properly drive the LEDs and they wont overheat.
You're toasting them. It's actually quite surprising that they don't burn off. In most things in electronics you get voltage specification, so you have motor that needs 12v, you give it, and it draws what it needs. LEDs are different because they have specified current, 40mA for this in the video. That is because, as you could see, at 11.5V they drawing almost nothing at 11.55V 40mA (440mW), and at 11.6V 1A (12W) dying out of heat, and when they heat up, this ideal 11.55V is changing, so exponential dependence with some temperature drift.
What you need is constant current supply, and you had one from the beginning of the video, just use those knobs on the left side, regulate roughly 40mA while shorting supply, and you have ideal supply for the LEDs. (V have to be also high enough, but it will never be too high with so small A). Now when you give them 40mA they will draw how much voltage they need.
The supply that you bought is also a constant current, but in terms of voltage (what was presented for single one, for 2 and 3 in series it's ok), and also in terms of current (800mA, is little bit more than 40mA), it's too powerful.
Yes thats the way to go
I'm a PhD student doing research on UV LED growth and I just want to say that the main challenge of high efficiency UV LEDs right now is partly due to light extraction (i.e. using UV transparent packaging), but mostly due to the difficulties in growing high quality AlGaN p-n junctions and quantum wells. P-type doped AlGaN is extremely challenging, as the acceptor state of the Mg dopant is deeper in the band gap than with p-GaN and thus getting sufficient amounts of holes in the material is extremely challenging, especially at higher Al compositions. Surface roughness is also a major issue, as we need very good interfaces in order to get good heterostructures for AlGaN quantum wells and quantum barriers. There is also the issue of defects in the material and how to get rid of them, as they result in nonradiative recombination. You kind of just missed the point on my entire PhD's work by saying that light extraction is the sole issue lol.
The major reason it's took so long for progress in UV is mostly due to the fact that research in AlGaN growth is extremely costly. Each growth I do is hundreds if not ~$1000 in materials and consumables (and I do maybe 4 growths every day). This is why there are only very few research groups actively pursuing UV growth and it's mostly companies that are doing the research.
To be fair, no one outside of a person working on UV LED growth would know any of this. Even reading this is extremely difficult because of the large amount of context required for every part of the process.
(I personally don't understand about 1/2 of this what with p-n junctions and quantum wells. Its just magic words from a magic man)
I couldn’t agree more. Or less. It just sounds like brilliant word salad to me.
Thanks for understanding this for me!
@Giggabiite If you just replace the words “quantum (anything)” with “weird stuff” then it’s a little easier.
Also wanted to say exactly that! Btw whats up with these quantum waves, aigan(or something like that) and p-thingys?
LEDs basically entirely block current until the operating voltage, then from there they have very little resistance. You want a big resistor in series and then the LED will be polite and take what it needs
Yes that would be fine. Big resistor means roughly 300 ohms here to drop 12 V at 40 mA, that way half the power is dissipated in resistor and half in LED.
This is the best explanation I've ever seen of how LEDs work.
Kind of? If you put a big resistor in there it's going to limit how much the LED can politely take. Throwing in a 150ohm res will let the LED draw ~45mA. Putting in a 300ohm resistor will drop that by half and the LED will only draw 23mA and will be a lot dimmer.
☝️☝️☝️☝️This. I've never used UV LEDs, but if they're anything like regular LEDs, you always put a resistor in the circuit with them, that's how you keep them from blowing up.
Google "LED resistor calculation". Based on the voltage of the power supply and the rated current of the LED, you can work out what size resistor you need.
you want a constant current source, which delivers 40mA
I admire your tenacity to expand beyond your comfort zone. To admit you are underprepared in a field, yet willing to dive in, make mistakes, learn from them, and learn the correct action are the hallmarks of a great scientist.
Whatever uni you went to, I'm sure they're proud to count you amongst their alumni. Good on ya, mate!
Sincerely: a fellow chem PhD student in the USA.
8:14 Resistor. You need a resistor. Diodes of any sort have an exponential current versus voltage curve. Adding a resistor makes it much easier to control the current.
8:47 No, the 40mA number is very important. That power supply has a current limit8ng knob. Use it.
Nail curing lamps might be a good alternative. My lab uses them for most of our photoreactions under UV light. They're like ten bucks off of amazon. They usually have around 5 mW/cm^2 and a lambda max around 365 nm
Can confirm, am in the same lab and used the same lamps successfully.
They seem just too long a wavelength though, which is a shame because yes they are really quite cheap and available. We need shorter than 350 nm
@Extractions&Ire this is probably insane but if you do it and get away with it youd be a legend
But did you consider cooling the LED enough to decrease the wavelength
The wavelength difference isnt big enough for this to be completely infeasible (I think) but hey it will be insane if you do it and sounds very doable if you have some kind of temperature buffer
This video has to be one of the best advertisement for the company that manufactured these leds: pumping 1A inside a 40mA rated LED without instantly frying it is quite a feat, plus they are UVC or UVB which have been notorious for being fragile !
Looking at the specs of your LEDs I'm also somewhat suspicious about the announced output. Typical efficiency for LEDs in that range tends to be below 4%, and yours have about 8% efficiency based on the nominal output/(nomimal voltage*amps) . My guess would be that the nominal output is exagerated but the only way to check that is with an optical power meter.
best advertisement that they sold him the wrong product?
I'm screaming at the screen like a grandfather. "I'm getting too caught up with this 40mA, 900mA should be fine". TBH, constant current regime is always a bit hard to grasp for outsiders, and the threshold voltage marking feels like we could use the given voltage to control them.
Pretty sure he could run 22 stars on 900mA
@RaunienTheFirst you run LEDs in series not in parallel....
Meaning that you give the string voltage until 40mA flow then you stop at whatever voltage that Happens to be!!!
Edit: spelling
8:49 Watching and this kept tickling the back of my "danger, will robinson!" instincts.... why are you operating an unprotected PCB on top of a flexible conductive surface (foil)? I literally can't think of an easier way to have an unpredictably timed catastrophic short circuit...
Those aluminum substrate PCBs are conductive anyway. It's also made my heart skip a beat when I saw the aluminium foil, but it's not an issue with LED modules (the lack of proper heat dissipation is, though).
Hey, I feel your pain man. Trying to do electronics with almost zero experience is basically impossible because you don’t know what knowledge you are missing. My suggestion is to ask for a circuit design or even someone to build the circuit for you. Best of luck man!
To be fair, I think it would be about the same to try to jump into chemistry without any background -- especially considering all the varied naming conventions for things.
E&F x Medhi collab
@Black Roberts OMG he should see if Electroboom would do a crossover yes! Good thinking! i would pay to see that!
basically, an LED acts like an open circuit until you hit a voltage threshold, the forward voltage. Then it behaves like a constant voltage source (with a small internal resistance) with a voltage equal to its forward voltage. So any voltage greater than its forward voltage would cause it to draw huge current (obviously a real LED has a tiny internal resistance blah blah). Thus you need to add a series resistor to limit the current. Say you need 40mA of current to drive the LEDs and the LEDs have a forward voltage of 6V, and you want to power it from 12V, you will need a resistor that drops (12V - 6V) = 6V while passing 40mA, which is (12V-6V)/(0.04A) = 150ohms. I hope this makes sense!
This.
Doing the math will save you so many headaches down the line, and there is a lot of reference out there to consume. I'm sure that Will or Backyard Scientist could help.
You don’t need a current limiting resistor if you use a constant current supply. That said, a string of 40 mA LEDs requires a 40 mA constant current supply (LED driver), not a 500 mA one. What I don’t get is why he isn’t using that bench power supply in CC mode instead of ordering stuff online…
@Jonathan Massacesi it's not clear to me that his power supply has a constant current mode. It looks old enough to be of a vintage were CC mode was only in high end models.
Right when I was about to start being productive. Can't say no to a new cubane episode
i love how everyone gets distracted by him overdriving the leds but noone is mentioning that he is literally doing all of this on a piece of aluminum foil
I was so confused to why.. It's useless as a heat sink because it's so thin and it's pointless to have a reflector behind the leds. If it was meant to compensate for not connecting the ground wire to the Aliexpress power supply to reduce the risk of electrocuting himself it achieves the opposite.
@Björn not only that, its an esd hazard, espeically with expensive new gens parts like those leds ^^
im guessing cause hes doing all of this on his chemistry bench
I think I figured it out! It's a diy anti-static mat! PSA: the purpose of an anti-static mat is to prevent electrons from stampeding to ground through sensitive electronics and works by providing a slow path to ground for high energy (thousands of volt) electrons. Aluminum foil provides a low resistance path for any electrons to go wherever they feel like so it's not the best choice.
@Contomo Haha, I saw your reply after I posted mine! :)
@Björn this one is more a static mat then :P aluminum would oppose a lot of capacitance unless grounded, i doubt he grounded it
Lots of people say its painful to watch, but as someone that doesn't know much about electronics myself (or any of the other mistakes done), the journey tend to be the most enjoyable part of these series. Keep it up Tom!
Original Cubane ran 64-bit. Make sure you're using 64-bit chemistry not 32-bit
He's still using analog chemistry
Obviously, 64 is a cube and 32 isn't.
Firstly, congrats for 'giving it a go'.
Having said that, I suggest you grab another full set of UV LEDs as I suspect those ones will be pretty screwed (you've thrown over 2000% of their rated current through them)
As others have already said in their responses, 40mA MEANS 40mA and anything more starts 'frying' them.
Your benchtop power supply is not accurate enough on its current setting
It's pretty simple to create a constant current circuit - 2 * transistors and 2 * resistors, but the suggested LM317 style is even easier. 1 * LM317 and 1 * 33 ohm resistor will give you 37.8mA. The power supply can be any voltage between about 15V and 40V so your 19V laptop supply will be fine.
LEDs are most likely failure cause is overheating. Not the temp of the heatsink, but the temp of the tiny silicon die itself.
The hotter they are, the more current they will consume so it's a BAD idea to run them in parallel - due to manufacturing tolerances, one will consume a TINY bit more current than the others in parallel. This will make that one a little hotter, so it will consume even MORE current -> RUD (RAPID UNSCHEDULED DISASS$EMBLY!)
You CAN safely place LED in series (but you'd need to increase the voltage of the power supply accordingly)
The MOST 'finicky' LEDs IMO are LASER LEDs. These will 'let out the magic smoke' if you even THINK about over driving them! (e.g. the cheap red ones you can buy from Jaycar will die in less than a millisecond if they're over driven by only 2mA! Don't ask me how I know <<<Sigh>>>). From what I know, the LASER LEDs die by burning the mirrors at each end of the cavity LONG before the die itself is fried.
The LEAST 'finicky' LEDs IMO are the infrared LEDs like those found in your TV remote. These are normally rated around 50mA or so, but are often driven at over 1000mA (1A) to make them 'bright' enough for your TV to sense. The key is that they're pulsed off/on rather than CW (Constant Wave) so they don't get enough TIME to overheat and die.
In your UV case, you're MOSTLY looking at CW operation. (Pulsing LEDs involves timescales of microseconds to millseconds while you're talking about multiple seconds!)
In short, do a simply google search on "LM317 constant current" and run with that
I've forgotten how many times I've rewatched this series whilst waiting for the next episode
Just limit the current at 40 mA and set the voltage above the drop off. You can measure the drop off voltage with a simple multimiter in the diode setting.
To be clear, a lot of bench power supplies can do this, but not all. If yours does, it will automatically reduce voltage until it is pushing no more than 40ma (or whatever you set the amp limit to), so even if you set the voltage to something absurdly high it'll be safe. The power supply will use whichever limit is lower, though, voltage or amps.
@George Dorn Isn't being able to regulate both voltage and current the whole point of bench top power supplies like that one?
@Jul That one can, but some don't have CC regulation. Even in the case of some of the ones that have CC regulation, it's often difficult to actually get it dialed in to anything specific. The behavior of the pot at the end of its stroke and the tiny knob can easily make it difficult to set a current limit like 40mA on a supply where the scale maxes out at 5 or 10 A.
Yeah you need to short the output through a multimeter’s current input and then fiddle with the current limit knob until the multimeter reads 40 mA. Can’t rely on the shitty built-in analog meter.
the multimeater might not be able to pick up a forward voltage as big as 12V
This is fun to watch as an analytical chemist with a focus on instrumentation. Good job figuring things out! Your channel has a great sense of humor and humility
That power supply you have looks like it does constant current, you can (with the LED disconnected) turn the voltage to about 15 volts, then turn the current knob down until the voltage drops. After that you can hook up the LED and turn the current knob up until the desired current. this way the LED can run at as high or as low of a voltage as it wants (largely dictated by LED temperature) and the LED current is controlled by the power supply.
It feels like eye sand for a couple days when you get UV exposure, also sun burns. Aluminum reflects and glass absorbs pretty well. Made some UV cabinets for 2020 and cooked me and my lab mate a bit.
"You can't pump 30 amps through it and expect it to be fine"
I'm stealing this quote
I watch chemistry videos because I'm an electronics guy and chemistry is my weak area. So when I watch you do a multi-stage synthesis, I am in awe of your abilities. .... Having watched you attempt electronics.... Yeah, you're as much as a fuckwit at that as I am at chemistry... I feel so much better now. :D
I'd recommend putting a cooling fan over the top of the can as well. Keeping my fingers crossed there'll be some positive results on the [2+2] step soon!
I think there are people who make DIY constant current supplies for driving laser diodes, so you might be able to make one of those with a low enough current. The 900 mA going through those LEDs is really spooky if they're actually specked for 40 mA; I'm kinda surprised they didn't yeet themselves when you had them on the bench top. even if they don't break for electronic reasons, this will make them heat up a lot faster
Can’t get enough of this channel, I hope you can keep it up!
Keep up the effort! Chromium coated (which seems to be the case here) is actually quite an optimal (low cost) choice for this range of wavelenght but keep in mind that very small oil film can absorb it quite well so try to clean the can with acetone before use (and close it during use of course)
My favorite series, I always get so excited when I see one of these up
I like that this series is so long that the host and equipment is visibly aging during it. I dont even know wtf cubane is but I'm invested now. also as someone who works with electronics but sucks at chemistry its reassuring to see someone afflicted with the reverse :') cheers for the brilliant videos, funny and info rich, hard to pull off.
A lot of people are already talking about other issues, so I'll throw my electrical knowledge at another thing you mentioned:
If you don't want to burn up a bunch of expensive components it's relatively inexpensive to get circuit breakers to put in your test circuit when you set the whole thing up for the first time. it helps ease the worry of frying something you don't want to replace and also helps minimize the risk of a fire, arcs or bad results. The basics are:
-get the right size, the rated current of your breaker should be ~120% of the load listed (take the mA and multiply by 1.2x, that's about the right size).
-don't mix AC and DC, breakers are one or the other just buy the one that matches where you're putting it (You can probably ask any of the electrical people in the discord or something if you're unsure)
-wire the circuit up with the breaker open (not passing current) and in a way so that the breaker opening again will stop all current
This way you can close the breaker once the whole circuit is made, be less at risk of shocks and arcs when doing so and if it's sized right and you're a little lucky it should save your expensive components. Better safety for your parts, and more importantly better safety for the user!
when's the last time you've seen a 50mA "circuit breaker"? maybe you could use a very small fuse, but even then, the exponential runaway behavior of LEDs will probably kill it before the fuse can even warm up. fuses and breakers can protect against thermal damage where it's ok if it takes a few milliseconds to kick in since the component will have barely heated up. but they certainly can't protect a semiconductor device from electrical breakdown, we're talking microseconds or nanoseconds then!
remember, the magic smoke is often just a symptom, the device fails first, then a high-current failure mode causes the heat and lets out the smoke. a breaker will stop the smoke but not necessarily the failure
I don't think they make circuit breakers below like 10 amps. Although they certainly do make small *fuses*.
@Alex C I think they make smaller (down to a few amps) breakers for individual appliances and stuff, but regardless that's still way too high so your point still stands.
His PSU comes with a current limit. He just never ever used it.
I have nothing to say except CUBE, and that this episode reminds me of how when you badly overdrive a red LED it will try becoming green before exploding
Extractions&Ire - 2022-05-15
I think this video is a good demonstration of the difference between science and engineering
Paul Hughes - 2022-05-15
I'll teach you hobbyist level electricity if you teach me hobbyist level chem
Paul Hughes - 2022-05-15
I work IT night shift so time diff don't matter
Paul Hughes - 2022-05-15
Depending on heat output thermal glue MIGHT be appropriate, as it also provides binding to the LED backing. However it is much less conductive than a paste or liquid metal.
Tomás Ochoa - 2022-05-15
And you are doing neither
Spy - 2022-05-15
Did you not want to ask William Osman for a second opinion to save the potential $60 of LEDs?