Resistors actually emit light all the time, the problem is we can't see it because it's around 6000nm in wavelenght. But you're right - visible light is usually a one time event.
roomy's toothbrush toilet cleaner cattle corn car fuel condoms rifle protectors crazy glue wound sealer microwave oven hair drier Lol, maybe not the last one but I liked this video.
Nope because a) all diodes are light absorbing (so there is no reason to distinguish that property of them by a different name for the particular ones used in a solar panel) b) the diodes are only a component of the *panel* hence we name the entire *panel* according to what it does so a *solar* **panel**
I had a long career as a circuit designer, and several times, with high gain circuits, with diodes, I had to take the light sensitivity of the diodes into account.
@@mrwess1927 Any opamp circuits with high gain can be affected by diodes connected to the inputs. I think an audio preamp with a pair of clamp diodes (glass encased 1N4148) across the inputs, for static protection picked up a hum from room lighting. and a high gain DC amplifier (for a seismograph) connected up as an absolute value circuit, had offset problems, if operated in the light. In both cases, either switching to a black epoxy cased diode, or using a black plastic transistor as the diode, cured the interference.
I also learned Electronics in the late 70s and 80s. I'm not sure what type of diode they use in solar panels. But I always thought they were made up primarily from what we knew as LCDs light-collecting diodes versus LEDs light emitting diodes.
I first had that eureka moment when I was sat playing with an LED and was reminded of the 'equal and opposite reaction' law. I thought if LEDs emitted light when a voltage was passed through them, would they create a voltage if light was shone at them. To my amazement this was true as I also connected a volt meter across an LED and shone a bright light at it. It was a few years ago when I did this, and now I have discovered this video and it has made me smile! Thank you! True scientific discovery and learning :)
I saw a video by a professor who researches solar cells. He talked about how LEDs get some amount of their energy from the heat of the crystal lattice. He said if you could get the efficiency of the LED high enough (80ish percent of electrical power into light) they would actually act as refrigerators rejecting heat as entropy in the light emitted. He talked about putting such a super LED across the vacuum of a Dewar flask from a high efficiency PV cell to make a heat pump from the inner wall to the outer wall. All this is pretty well known by people who study PV cells and LEDs, but I had no idea and find it super interesting.
Wait. Are you saying that LEDs at a high enough efficiency can actively absorb heat in molecules and emit it away as visible light? So is it theoretically possible to pump heat away out of a spacecraft in vacuum just by shining a spotlight with this super LED in a direction?
@@BrokenLifeCycle yep. It has been demonstrated in laboratory settings but isn't practical at the moment. It's infrared light not visible light though. www.wired.co.uk/article/230-percent-efficient-leds
@@sunmoon1234 Peltier modules are certainly semiconductors that act as heat pumps. But they don't turn the heat into light, they work on a different principle.
So why don't they just plug in solar panels so they light up and power themselves? I can't believe I'm the only person to think of this. Engineers with their fancy degrees pfft
I've seen someone that was determined enough to make their own semiconductors, and I have to agree. What a crazy process. And she was just about capable of making transistors... Maybe at a stretch an integrated circuit consisting of about 3 components. When you see it as small-scale improvised production it still looks nuts, but not quite as crazy as the real methods. And of course this improvised stuff was using commercially available wafers, which are really difficult to produce in their own right...
I’m sorry but solar panels emits Infrared which is invisible to human’s eyes, also power generated from OLED is not enough to charge your phone as it is so low it turns into useless heat when charging.
The first observation of the led dates to 1907 when Henry Joseph Round noticed for the first time that when a potential of 10 volts was applied to a carborundum crystal, it emitted yellowish light.
hey Steve, I'm studying electronics and I gotta say, pretty well made video! if you want to look at other "reversable" electromechanics stuff here's a few examples: Peltier-/Seebeck-Effect (voltage creates temperature differential, but temperature differential also creates voltage), Piezo-Effect (voltage -> crystal lattice deforms, crystal lattice deforms -> voltage), or coupled inductors (current in one coil -> voltage in the other, but also it affects itself. pretty weird.)
Also some motors and dynamos. I was very happy when I found out you can wire two Lego Mindstorms motors together and control one directly by turning the other.
IceMetalPunk Actually, that’s not really the piezoelectric effect at play, it’s EM induction on the speaker and something more complicated (that has to do with capacitance) on the microphone.
There is no single correct answer to this. There are many different techniques to build a microphone. You can use a magnet attached to a membrane. This membrane is vibrating when you speak on it and the magnet induces a current in a coil. Other microphones use a capacitor with one electrode being a charged isolator (electret). The electret electrode is attached to a membrane similarly as in the previous example. The sound waves make the membrane move again which causes the distance between the electrodes to change. This movement causes a change in capacitance and eventually a change in voltage across the capacitor. Microphones which use the piezoelectric effect exist, but they have a rather bad sound quality. But they are mechanically sturdy which makes (or made) them useful for some applications.
This reminds me that the earlier Raspberry2 B models had a single diode that caused the computer to reset when a sufficiently powerful light hit the board. For example, a photo flash... this is why those earlier models were called "camera shy". Fun stuff.
It wasn't a diode, it was the power IC (component no. U16), which was a WL-CSP chip. Basically an integrated circuit without any packaging, attached directly to the board. Still caused by the photoelectric effect, so the principle is the same, but it wasn't a diode.
In case anyone's wondering, the term that encompasses both microphones and speakers is "transducer", or a device which converts between acoustic information and an electrical signal
And unlike diodes or speakers/microphones, electric motors are actually quite often used as generators as part of their normal operation. Eg. regenerative braking in electric vehicles (cars, trains) or pumped-storage hydroelectric power plant. They can be designed in such a way they're effective at both.
That's interesting considering you commented this 3 minutes after this 5 minute video was uploaded. And every other science video I've watched today. Hmmm...
This video gave me the idea to test old film camera shutter speeds for servicing them. I made a really simple device which is just an LED soldered to an input jack connected to an audio interface to my PC and then on the other side of the camera shutter I put a laser pointer pointing to where the LED would be on through the shutter, shoot the camera while recording the "audio" signal and then see the audio clip to check the interval. And it works perfectly :)
Well, technically the speaker used as a microphone also produces a voltage across it. What you mean is an amplifier connected to a speaker all powered by an LED.
The reversibility of PN junction is a classical well known into engineering labs. I remember as a young experimenting with the germanium OC71 transistors, some manufacturers used a glass case painted with black varnish. By removing some varnish from the top of the transistor with a razor blade, the OC71 behaved just like a phototransistor. I built an electronic rooster, a control system for model railways, an RPM counter and a motorised gate control, all with scraped transistors. Thank you for the inspiring video; the electronic as an hobby has disappeared almost completely (especially the analog parts, which are erroneously considered obsolete), so a video like your is able to recall the spirit and the curiosity of experimental electronics, which appears nowhere along the Internet. Regards, Anthony
Great video! I remember using my cheap on-ear headphones as a microphone when I was a young teen in the late 90s! I always found that whole idea cool :)
Light Emitting Solar Panels! Amazing. Seriously, I always wondered how you know if the solar panels on cheap garden solar LED lights are good or not, without testing and benchmarks and stuff. This is a super easy way to test them. This could probably even be done "in the field" which is while you're at the shop, so you pick out only the good ones.
Does that mean that a led panel with lots of led under the sun (like those on road signs) are constantly sending a reasonable amount of power when off?
The problem with your statement is the word “reasonable”. LEDs are optimized to emit light, and that makes them poor solar cells. Solar cells are optimized to generate electricity, and that makes them poor LEDs.
except the display heats up pretty signifigcantly by absorbing all the light heat degrades overall lifetime of any electronics, but especially for the battery :/ I had my phone shutting off due to overheating (on a relatively hot day, mind you) after I left it in the sun for a while
One thing I noticed about solar cells is that covering them from one side, even just a little bit, caused the voltage to drop dramatically, but covering from either adjacent side, even a lot, doesn't lead to as much voltage drop.
@@jamesdeegan7365 screw you guys because of you not just did my Phone not charge but i wrecked it and my microwave and my phone now i have to buy a new one Screw you Nah im just kidding
I worked in a Solar Panel Factory for some time and we used the exact Infrared method shown here to diagnose faults and cracks before we sent them out the door! The crazy thing is that I didn't understand how it worked until I watched this video nearly ten years later!
I do this every day at work - load up a module into the (pitch black) EL chamber and run a current through it, and use a camera with special aperture and exposure/ISO settings to capture the pattern and check for any cracks. They become very obvious under these conditions. Oddly enough, some of the extremely cracked modules sometime still produce an OK amount of power. Depends on how the damage happens. If you have solar panels, clean any leaves that fall on them. If they shade the exact percentage of a cell needed to cause a 'kink' in the electrical flow, heat builds up and it can literally catch fire. We do a test called the "hot spot" test that puts various sizes of square tape over a section to find the magical % of a cell that causes the "kink" so the manufacturer can put it in their specs/manual.
Hey there, my father (village mayor) has issues with a company providing public illumination powered by solar panels. We would like to apply this method to check if are some panels faulty. Could you give more practical insight? How much current and what voltage is needed and is a laptop camera or front facing Iphone camera (lacking UV filter) sufficient? We tested both cameras on a TV remote and they worked just fine. Thanks
@@josefhula9811 While I am a somewhat knowledgable tech when it comes to solar panels, my expertise ends at testing and identifying problems. I can tell you a good resource: ua-cam.com/video/8huUsh9eu8U/v-deo.html At around 7:20 ish he starts explaining what is needed to capture an Electroluminescence (EL) image. This video shows how to use a multimeter to measure volts and amps, which you can compare with the info sheet on the back of the solar panel. ua-cam.com/video/eh6hzMb69gY/v-deo.html I haven't had the opportunity to vet everything from these videos, but they seem like a good starting point. Sorry I can't be of more help.
One of the best physics demonstrations I’ve seen was when Mr. O’Neil put a wire coil between two plastic cups, strung them to an led, and played music through them by shining a laser he had hooked up to his ipod on it.
Well, you still call it infrared “light”, so yes, IREDs (including those designed for that, like those in a remote controller and solar panels) are also LEDs.
So basically, solar panels , when connected to a voltage source, emit light but we can't see it because they do this in the infrared region and not in visible wavelengths. Good! Thank you.
Manan Varma No, it's just heated up absorber that emits light and wears off in process. After few minutes of that solar panel loses effectiveness and dependig on type and absorber it could completely stop working
@@Phantom-el6oe No, it's not true, and that is not how diodes generate light! If you had a GaAs or a direct gap semiconductor panel, it would glow, once you apply voltage bigger than the bandgap. But it would not emit IR. In the case of Si diodes, they will not emit light because they are indirect bandgap semiconductors.
Thank you so much Steve! A college asked me for a tachometer today to measure fan speed. We don't have one, but thanks to you i now know led's are solar panels. With a scope and flashlight I made the day :D
Is there a link between the frequency of light emitted by a diode and how it would absorb light? That is, for example, do solar panels absorb near-IR better than other frequencies when they emit near-IR?
This is related to resonance. My hypothesis is that if a solar panel is "tuned" (like a string instrument) to resonate at a specific frequency or wavelength, it should be very efficient at absorbing it AND emitting it. However, ultraviolet light has *A LOT* more energy than infrared, and more than visible spectrum. This is why the sun is used as source, because it generates more energy without the need for "tuning". Quantum Dots have the special ability to be "tuned" (only at build time), so if you make a QD solar panel with a lot of QDs tuned to multiple frequencies (specially UV) you get A LOT more energy than traditional panels!
Her: "Did you put the Christmas lights up?" Me: *looks at solar panels* "Get a camera." (I am so lazy) Her: (He's so intelligent) Me: *Buys Steve a drink*
No it can't, a motor with a commutator acts as a dynamo ie it has a DC output. If you put a DC voltage across and alternator* it will just twitch and not rotate. Some types of washing machine pump motor will act as an alternator. * I mean a basic alternator, not an alternator with a rectifier &/or regulator built in.
Yeah, though you'd need multiple LEDs to power the one LED to a good enough standard That is if you're not artificially powering the LEDs, but then again you'd probably need quite a few LEDs
Yes but you generally need to have a lot of light shining on the first LED and the second must have a lower voltage drop. done it shining a blue LED onto a green GaAsP led and using the voltage generated to light a hyperbright red LED. You generally will have to shield the blue LED and the green one, as otherwise the light from the red is nearly invisible in the glare, the efficiency overall is so low. You also have to couple the blue and green together well, so flat top ones are best with some tubing joining them.
I feel like I've lost all curiosity at work. how do I fix this? Is it because my work and hobbies overlap too much? I used to do so much experimentation at home. now I can't bear to look at technical things in my spare time. I know I haven't lost my interest because I get excited whenever I see videos like this.
I go through the same thing. If I'm too concentrated on work or am deeply engaged in something, I don't feel like working more at home. When I am bored at work, I can't wait to come home to my projects
puffin juice it sounds like burnout to me! It happens to everyone, your best bet would be to separate your job from your hobby as much as possible. That’s not to say they cannot be the same type of work, it’s just having them be different helps keep things interesting. If you are working on one type of electronics at work do something else at home.
Film scene idea, geeky hero jury rigs a blinking infrared beacon on the roof of a bad guy building by feeding a voltage into the solar panels that their backup can spot on night vision.
One thing that should have been mentioned is that the various corresponding combos (speaker microphone, etc) differ in that they are engineered for optimal performance in one way or another. A large diaphragm works better for emitting sound efficiently over a small spectrum, while smaller diaphragms work better for absorbing sound across a wide spectrum. A lens for a camera is larger so it can collect more photons over a greater physical area, while a lens used for a flashlight that emits light can use a much smaller lens since the light source is concentrated. So while many things can work both ways, it will work very poorly in the reverse manner it was not designed for.
2:04 yes you can call it an LED even if it emits IR. Any diode that emits any wavelength of the electromagnetic spectrum is an LED. Look out for those gamma emissions though OUCH!
I wouldn't worry too much about gamma rays. Most PN junctions are monochromatic. They emit in a very narrow spectrum. If you can't see the light, because it's outside of the visible spectrum, you might just want to check. (I was going to say: "Look into it", but that might be a bad idea!)🤣😁😝
The semiconductor bandgap (1-10eV) limits the photons energy, so you will never get gamma photons (100keV) . The only way to get gamma or X-ray if you put millions of amperes in the diode and it explodes very violently, resulting in lots of UV photons, some X-ray photons, and maybe some gamma photons from excited nuclei.
@@neurhlp Is that what they call a gamma ray burst?🤣😁😝 As far as sending and receiving at the same time, to illuminate, you have to apply enough voltage to forward bias the diode junction. If the LED is exposed to light, than if the voltage is reduced below forward bias, there will still be voltage across the terminals. You just need to load the diode, so it stays just below junction voltage, to get maximum energy back out of it. As far as efficiency, it's actually quite high, considering the very small area of the LED Vs a solar cell. A screen has millions of them, giving them the surface area of a solar panel, and producing close to similar efficiency. The only thing that makes the idea impractical for now, is that each pixel, represented by each LED element, needs a push-pull pulse width modulator, with an inductor. The magnetics would be very difficult to scale down that many into something the size of a lap-top, let alone a smart phone. in theory it can be done, but not practical for now.
No. While all LEDs do exhibit the photovoltaic effect, to some degree, they are not at all optimized for this purpose and as such are extremely inefficient.
I vaguely remember seeing a write up of a display that exploited this principal. It was interlaced, and the currently dark diodes we're used to measure reflected light from the line that was currently active.
Ever heard anything about the difference between Direct- an Indirect-Semiconductors?! Propably not! In fact it's quite difficult to get any kind of 'effective' electroluminescense from Silicon, regardless of other 'tricks' like doping, structuring,..and regardless of the desired wavelength!
2:46 how did you filter out the visible light?? Did you place some other type of physical filter into the camera, or was there some post processing involved? I'd love to know so I can use such a cool look for projects of my own
I made a talk box with one back in the 90s using an SM57 mounted on a stand with a cheap Radioshack 1/8" jack mic nearby wired as an external speaker to a guitar amp. Then I'd just mouth the words with the mic-speaker blaring away into my cheeks and presto - talking guitar.
Dear Steve thank You! You've just opened a window as when i understood microphones and speaker are two ways of the same principle with Sound frequencies. Now You added Light frequencies!!! 😎🙏🏻🙏🏻
You seem surprised that only 20% of employees at a gigantic profit-worshiping corporation describe themselves as "curious." As a former R&D engineer at another equally profit-obsessed gigantic corporation, I can tell you what impacts curiosity: it's the profit worship. Because the corporations themselves are constructed as artificial legal entities with the _explicit purpose of generating wealth for shareholders at the expense of everyone else_ , that's exactly the way their leadership are chosen to behave. Layoff employees? Sure, if it'll "increase value for shareholders." What if those employees suffer the worst effects of poverty after the layoff? Not the corporation's problem. That's #HowCapitalismWorks, Steve. What if the corporation can make extra profit by lobbying the government to go to war? Could the executives ever be that inhumane? You know the answer. I left that giant evil corporation when the evil no longer seemed worth the (substantial flow of) blood money they compensated me with. Now my innovations are limited to the things I can do without the resources of a giant corporation; but at least none of my new work contributes to murdering Yemeni, Syrian or Venezuelan children, unlike the ongoing work of my former colleagues. The answer is simple: replace profit-motive by service-motive. Instead of allowing "shareholders" to elect leaders, The People can elect them. Instead of firing leaders who don't make enough short-term profit, we fire the leaders whose decisions are bad for everyone, even when that means profits aren't maximized. (If that seems counterproductive, it's because you personally value profit over people.) Nearly everyone can keep doing the same jobs, but simply by replacing profit motive with service motive, we could dramatically change the way human resources are employed, and shift the primary benefit away from a tiny fraction of the wealthiest to the whole of the population. Should we lay off those employees? Instead of considering profit delivered to a few already wealthy executives, we'd consider instead the impact on the community. The layoffs would reduce productivity for obvious reasons, so unless there's something else for all those employees to start doing, maybe the factory keeps running instead. Or, if the productivity is no longer needed--maybe those employees used to process crude oil, and maybe we'd rather build solar panels--then maybe the factory shuts down, and all those employees get some free time to be creative, surviving on Universal Basic Income, while the factory is retooled for building solar panels.
I will suggest that the 'idea' of a corporation - an entity that is a 'legal person' (via the citizen's united ruling by the SCOTUS), and which cannot be harmed in any way, nor jailed, yet in many ways has More 'rights' than a living human being, and whose 'god' is Money, IS the definition of the 'anti-christ'. Simply my 'theory', FWIW.
"unless there's something else for all those employees to start doing, maybe the factory keeps running instead." Laid off employees can find new jobs that are more productive. Think about the internet you are using, for example. Before internet, we communicated with phones. As internet gradually replaced phones, phone industry needed less and less people. Theses people can work on more productive areas, such as internet, instead of wasting their time doing useless "work" that no one needs.
Using an infrared camera to check for defects in solar panels is literally my job lol!!! I use a machine called an EL (electroluminescence) to check for cracks. Thanks for teaching me more about this!
Resistors can also emit light but only once
They also emit smoke for quite a long time before starting to become light emitters.
@@SeanBZA pretty unique design!
@@SeanBZA All computers run on smoke, thats why when the smoke comes out they stop working.
@@SeanBZA Every machine is a smoke machine if you operate it wrong enough
Resistors actually emit light all the time, the problem is we can't see it because it's around 6000nm in wavelenght.
But you're right - visible light is usually a one time event.
1. electric motor generator
2. mic speaker piezo
3. solar panel diode led
galvanic cell Electrolytic cell
Beer Hangover Hair of the dog...
Now I'll waiting for the next generation of phones to have a solar panel screen charging button
roomy's toothbrush toilet cleaner
cattle corn car fuel
condoms rifle protectors
crazy glue wound sealer
microwave oven hair drier
Lol, maybe not the last one but I liked this video.
ceramic microphone ceramic capacitor buzzing ceramic caps
Diodes are not necessarily LEDs. Depends on the band structure, e.g. silicon makes solar cels and diodes but will never electrically emit light.
So, should we call solar panels Light Absorbing Diodes (or LADs) instead? I think so.
or LSD : Light swallowing diodes. Sounds better to me.
Smart LAD
Funny Tad
lad lol
Nope because a) all diodes are light absorbing (so there is no reason to distinguish that property of them by a different name for the particular ones used in a solar panel) b) the diodes are only a component of the *panel* hence we name the entire *panel* according to what it does so a *solar* **panel**
'You can use a speaker as a microphone.'
Hello, CIA.
Hello CIA my old friend...
*NSA joined the chat*
LEDs can also act like a pixel from a camera 😉
If you take a microphone apart, and a pair of head phones, you will find the diaphragms look very similar.
Vincent Robinette depends on the mic. Dynamic microphones are closest to speakers
I had a long career as a circuit designer, and several times, with high gain circuits, with diodes, I had to take the light sensitivity of the diodes into account.
Neat!
Care to share what you know?
@@mrwess1927 Any opamp circuits with high gain can be affected by diodes connected to the inputs. I think an audio preamp with a pair of clamp diodes (glass encased 1N4148) across the inputs, for static protection picked up a hum from room lighting. and a high gain DC amplifier (for a seismograph) connected up as an absolute value circuit, had offset problems, if operated in the light. In both cases, either switching to a black epoxy cased diode, or using a black plastic transistor as the diode, cured the interference.
That’s interesting, a lot can be learned from experience.
Aren't they usually encased in non-transparent mold?
I have forgotten so much of my electronic knowledge from the late 80's ...seeing this video makes me want to learn everything again.. Ty
I also learned Electronics in the late 70s and 80s. I'm not sure what type of diode they use in solar panels. But I always thought they were made up primarily from what we knew as LCDs light-collecting diodes versus LEDs light emitting diodes.
I first had that eureka moment when I was sat playing with an LED and was reminded of the 'equal and opposite reaction' law. I thought if LEDs emitted light when a voltage was passed through them, would they create a voltage if light was shone at them. To my amazement this was true as I also connected a volt meter across an LED and shone a bright light at it. It was a few years ago when I did this, and now I have discovered this video and it has made me smile! Thank you! True scientific discovery and learning :)
That feeling must be amazing
So if I push my car the tank will fill with gasoline?
@@stargazer7644 🤣🤣🤣 I wish 😛😂😂
yea now hook a load up to an oven burner and see if it powers your device by pulling heat out of the air
@@stargazer7644 and if someone pushes you..
I saw a video by a professor who researches solar cells. He talked about how LEDs get some amount of their energy from the heat of the crystal lattice. He said if you could get the efficiency of the LED high enough (80ish percent of electrical power into light) they would actually act as refrigerators rejecting heat as entropy in the light emitted. He talked about putting such a super LED across the vacuum of a Dewar flask from a high efficiency PV cell to make a heat pump from the inner wall to the outer wall. All this is pretty well known by people who study PV cells and LEDs, but I had no idea and find it super interesting.
I imagine a massive bank of these super LED's would make for a nice cooling system for a spaceship.
Wait. Are you saying that LEDs at a high enough efficiency can actively absorb heat in molecules and emit it away as visible light? So is it theoretically possible to pump heat away out of a spacecraft in vacuum just by shining a spotlight with this super LED in a direction?
@@BrokenLifeCycle yep. It has been demonstrated in laboratory settings but isn't practical at the moment. It's infrared light not visible light though. www.wired.co.uk/article/230-percent-efficient-leds
Man, thanks for sharing thats so cool to know...
@@sunmoon1234 Peltier modules are certainly semiconductors that act as heat pumps. But they don't turn the heat into light, they work on a different principle.
I spent over 35 years of my life in electronics; how did I not know this until now? Thanks for another eye-opening, insightful video!
The energy companies would lose money probably
Maybe you worked in the warehouse?
@@DakCuh No this way is not efficient i think, all diodes contains this property but I think there is a reason we don't really use them like this.
So why don't they just plug in solar panels so they light up and power themselves? I can't believe I'm the only person to think of this. Engineers with their fancy degrees pfft
Bloody medics.
STOOPID IT DONT WORK THAT WAY
@@drewadkins4099 hey man good luck in the Wooshlands
@@SteveMould Hey! The medics our thing (biomeds/nurses) to lay into
Entropy
I love how you get right to the point and explain it in a way everyone can understand
“Diodes are really simple electrical components “... my electronics textbook thoroughly disagrees...
The Shockley equation is quite simple ;)
I've seen someone that was determined enough to make their own semiconductors, and I have to agree.
What a crazy process.
And she was just about capable of making transistors...
Maybe at a stretch an integrated circuit consisting of about 3 components.
When you see it as small-scale improvised production it still looks nuts, but not quite as crazy as the real methods.
And of course this improvised stuff was using commercially available wafers, which are really difficult to produce in their own right...
You need a more accurate book then.
My textbook on the physics of electrical components also thoroughly disagrees.
@@KuraIthys It's Jeri and we all know her. She wasn't "close" to making transistors, she actually *made* transistors.
Solar panels should be used as outdoor lights.
OLED screens should trickle charge your phone.
Thanks for coming to my Ted Talk.
I’m sorry but solar panels emits Infrared which is invisible to human’s eyes, also power generated from OLED is not enough to charge your phone as it is so low it turns into useless heat when charging.
Also thank you for hosting a TEDTalk.
r/wooosh
Cole Ikr
@Nopparuj r/wooosh
The first observation of the led dates to 1907 when Henry Joseph Round noticed for the first time that when a potential of 10 volts was applied to a carborundum crystal, it emitted yellowish light.
hey Steve, I'm studying electronics and I gotta say, pretty well made video! if you want to look at other "reversable" electromechanics stuff here's a few examples: Peltier-/Seebeck-Effect (voltage creates temperature differential, but temperature differential also creates voltage), Piezo-Effect (voltage -> crystal lattice deforms, crystal lattice deforms -> voltage), or coupled inductors (current in one coil -> voltage in the other, but also it affects itself. pretty weird.)
Also some motors and dynamos. I was very happy when I found out you can wire two Lego Mindstorms motors together and control one directly by turning the other.
I mean, he touched on the reversibility of the piezoelectric effect when he demonstrated that microphones and speakers are interchangeable :)
@@IceMetalPunk oh yea that's true, i kinda forgot about that video until he mentioned it and even then the memory is foggy...
IceMetalPunk Actually, that’s not really the piezoelectric effect at play, it’s EM induction on the speaker and something more complicated (that has to do with capacitance) on the microphone.
There is no single correct answer to this. There are many different techniques to build a microphone. You can use a magnet attached to a membrane. This membrane is vibrating when you speak on it and the magnet induces a current in a coil. Other microphones use a capacitor with one electrode being a charged isolator (electret). The electret electrode is attached to a membrane similarly as in the previous example. The sound waves make the membrane move again which causes the distance between the electrodes to change. This movement causes a change in capacitance and eventually a change in voltage across the capacitor.
Microphones which use the piezoelectric effect exist, but they have a rather bad sound quality. But they are mechanically sturdy which makes (or made) them useful for some applications.
This reminds me that the earlier Raspberry2 B models had a single diode that caused the computer to reset when a sufficiently powerful light hit the board. For example, a photo flash... this is why those earlier models were called "camera shy".
Fun stuff.
Wow thats true
Daniel Leal it happend with risc proccessors.
Sometimes the led right in rpi begins to glow with our any external power supply
It wasn't a diode, it was the power IC (component no. U16), which was a WL-CSP chip. Basically an integrated circuit without any packaging, attached directly to the board. Still caused by the photoelectric effect, so the principle is the same, but it wasn't a diode.
Realistically this applies to any component, but as far as i know risc is extremely low power, so essentially it's much easier to overvolt.
In case anyone's wondering, the term that encompasses both microphones and speakers is "transducer", or a device which converts between acoustic information and an electrical signal
It's also the same for electric motors and generators. Heh, it's a fun world we live in.
also peltier elements, put a power in one, and one side gets cold and other hot, create a temperature difference and you get power out of it.
And piezoelectric crystals!
All I heard was, you reverse the polarity to solve all your problems.
And unlike diodes or speakers/microphones, electric motors are actually quite often used as generators as part of their normal operation. Eg. regenerative braking in electric vehicles (cars, trains) or pumped-storage hydroelectric power plant. They can be designed in such a way they're effective at both.
NoLlama Yeah, in fact most motors are also good generators, and vice versa.
As always Steve...this was _illuminating_ ! 💡
But for real you’re by far one of the best Science communicators on this platform chap! 🙌
That's interesting considering you commented this 3 minutes after this 5 minute video was uploaded. And every other science video I've watched today. Hmmm...
Rhyme Bito Aha I type comments whilst watching the video bud :) Nice to see you’ve got a similar taste in Science UA-camrs though!
This guys simply does not understand the physics involved here.
_Illuminati confirmed_
Aspect Science
You’re great as well!
This video gave me the idea to test old film camera shutter speeds for servicing them. I made a really simple device which is just an LED soldered to an input jack connected to an audio interface to my PC and then on the other side of the camera shutter I put a laser pointer pointing to where the LED would be on through the shutter, shoot the camera while recording the "audio" signal and then see the audio clip to check the interval. And it works perfectly :)
holy shit. that is absolutely fucking mad genius
this comment is extremely underrated
In my next concert I will sing on a speaker powered by a LED
That would be LED Soundsystem
Don't forget your solar power microphone!
Make sure to use a generator as a fan for wind effects
that would be a massive waste of energy! )
Well, technically the speaker used as a microphone also produces a voltage across it. What you mean is an amplifier connected to a speaker all powered by an LED.
First CGP Grey uploads and now this video? Today keeps getting better!
Within 30 minutes of each other. What a time to be alive.
Now if only vsauce would upload I'd be in heaven.
dont forget Tom Scott
Quick! Someone calculate the odds.
Hah, I came here straight from CGPGrey's vid :).
The reversibility of PN junction is a classical well known into engineering labs.
I remember as a young experimenting with the germanium OC71 transistors, some manufacturers used a glass case painted with black varnish. By removing some varnish from the top of the transistor with a razor blade, the OC71 behaved just like a phototransistor. I built an electronic rooster, a control system for model railways, an RPM counter and a motorised gate control, all with scraped transistors.
Thank you for the inspiring video; the electronic as an hobby has disappeared almost completely (especially the analog parts, which are erroneously considered obsolete), so a video like your is able to recall the spirit and the curiosity of experimental electronics, which appears nowhere along the Internet. Regards, Anthony
Great video! I remember using my cheap on-ear headphones as a microphone when I was a young teen in the late 90s! I always found that whole idea cool :)
So my LED tv is not only a microphone but a 70” camera? Hello big brother!!
Woke
Life=lie
@@superjeffstanton c
LED TVs are just your usual LCD with LED backlighting instead of the usual CCFL bulbs.
LG=Looking Glass?
"LEDs are solar panels"
By that logic, I can make a solar panel by only using christmas lights
Actually, if you search you can find projects of homemade solar panels using only LEDs
YES, AFTER CHRISTMAS YOU PUT YOUR TREE OUTSIDE in the sun to provide electricity until the next christmas
@@RabbitholeIsrael dayum!
But a very inefficient one
What about old LED TVs? Maybe a way to recycle them instead of sending them to the trash pile. Saving the planet one TV at a time.
This is one of those channels which always makes me so happy when there is a new upload! Put myself in knowledge absorption mode! 🤯
Steve Mould: "I like to have my old projects at hand"
Me: "I'm a pack-rat too"
Coming up next :how your fridge can work as a tv and your tv as a fridge
Hahahahaha!
After that: How your toaster can be used as the pc that runs all my teammates computers
Well you can use a fridge to be a heater and a heater to be a fridge
I mean with a Samsung smart fridge you can do at least the first one
I can drive my car forwards and in revverse.
Light Emitting Solar Panels! Amazing. Seriously, I always wondered how you know if the solar panels on cheap garden solar LED lights are good or not, without testing and benchmarks and stuff. This is a super easy way to test them. This could probably even be done "in the field" which is while you're at the shop, so you pick out only the good ones.
2:59 here you go, your daily dose of nightmare fuel. You're welcome.
Does that mean that a led panel with lots of led under the sun (like those on road signs) are constantly sending a reasonable amount of power when off?
yeah, but not enough to induce a change/imbalance in the circuit
But you have a good point :)
The problem with your statement is the word “reasonable”. LEDs are optimized to emit light, and that makes them poor solar cells. Solar cells are optimized to generate electricity, and that makes them poor LEDs.
Cellphone makers listen up - I wanna charge my phone by leaving it in the sun. Make it happen
except the display heats up pretty signifigcantly by absorbing all the light
heat degrades overall lifetime of any electronics, but especially for the battery :/
I had my phone shutting off due to overheating (on a relatively hot day, mind you) after I left it in the sun for a while
You can get USB power banks that have solar panels to charge them.
@@marcusfred4480, that solar panels on powerbanks aren't made for charging them, but only for keeping energy
@@Unerty What??? Lol! I can assure you that the solar panels absolutely put charge in the batteries.
But then they will want $3500 for a phone.
that is so cool. i never thought about how you can literally reverse the roles of solar panels and leds
That was really cool and informative thank you for taking apart your camera so that we can see that
One thing I noticed about solar cells is that covering them from one side, even just a little bit, caused the voltage to drop dramatically, but covering from either adjacent side, even a lot, doesn't lead to as much voltage drop.
Imagine having your phone screen act as a solar panel to charge your phone
well apple did upgrade there firmware so you can charge your phone in the microwave
You could do that, but you’d need infrared vision to read the screen.
@@jamesdeegan7365 It's faster than using their chargers too!
@@jamesdeegan7365 screw you guys because of you not just did my Phone not charge but i wrecked it and my microwave and my phone now i have to buy a new one
Screw you
Nah im just kidding
@@fayenotfaye you ever heard of a window lol
I worked in a Solar Panel Factory for some time and we used the exact Infrared method shown here to diagnose faults and cracks before we sent them out the door! The crazy thing is that I didn't understand how it worked until I watched this video nearly ten years later!
where did you find that concentrated solar cell?
Thanks for the awsome video
I do this every day at work - load up a module into the (pitch black) EL chamber and run a current through it, and use a camera with special aperture and exposure/ISO settings to capture the pattern and check for any cracks. They become very obvious under these conditions. Oddly enough, some of the extremely cracked modules sometime still produce an OK amount of power. Depends on how the damage happens.
If you have solar panels, clean any leaves that fall on them. If they shade the exact percentage of a cell needed to cause a 'kink' in the electrical flow, heat builds up and it can literally catch fire. We do a test called the "hot spot" test that puts various sizes of square tape over a section to find the magical % of a cell that causes the "kink" so the manufacturer can put it in their specs/manual.
Hey there, my father (village mayor) has issues with a company providing public illumination powered by solar panels. We would like to apply this method to check if are some panels faulty. Could you give more practical insight? How much current and what voltage is needed and is a laptop camera or front facing Iphone camera (lacking UV filter) sufficient? We tested both cameras on a TV remote and they worked just fine. Thanks
They use Victron Energy SPM150-12/3a 150W-12V Mono. Optimum operating voltage of 17.86 and opt. operating current of 8.399 A
@@josefhula9811 While I am a somewhat knowledgable tech when it comes to solar panels, my expertise ends at testing and identifying problems. I can tell you a good resource:
ua-cam.com/video/8huUsh9eu8U/v-deo.html
At around 7:20 ish he starts explaining what is needed to capture an Electroluminescence (EL) image.
This video shows how to use a multimeter to measure volts and amps, which you can compare with the info sheet on the back of the solar panel.
ua-cam.com/video/eh6hzMb69gY/v-deo.html
I haven't had the opportunity to vet everything from these videos, but they seem like a good starting point. Sorry I can't be of more help.
One of the best physics demonstrations I’ve seen was when Mr. O’Neil put a wire coil between two plastic cups, strung them to an led, and played music through them by shining a laser he had hooked up to his ipod on it.
Well, you still call it infrared “light”, so yes, IREDs (including those designed for that, like those in a remote controller and solar panels) are also LEDs.
Indeed, most light is outside our visual spectrum.
Omar Omokhodion Yep, though we can still see some NIR from remotes and perceive FIR with our skin as “heat”.
@@0MVR_0 light, electromagnetic radiation, same difference.
Every diode is a light emitting diode, but sometimes only once!
Same applies to almost any component!
Also smoke emitting diode as well.
Nopparuj Oh, yeah, the SED
Yeah and after that once, it becomes a Dark Emitting Diode !!
*ElectroBoom agrees
As an old EE who *thought* he had seen it all, this was AMAZING! Thanks!
yes, check out "silicon devices", they were invented some years ago after the vacuum tube.. ;P
What was that solar cell at 4:00? I would like to find more information about it.
google hcpv
So basically, solar panels , when connected to a voltage source, emit light but we can't see it because they do this in the infrared region and not in visible wavelengths. Good! Thank you.
Manan Varma No, it's just heated up absorber that emits light and wears off in process.
After few minutes of that solar panel loses effectiveness and dependig on type and absorber it could completely stop working
@@Phantom-el6oe So, doing that isn't advisable. LOL I was thinking of doing this. Thanks for saving my solar panel :-)
Manan Varma Always to your service sir
@@Phantom-el6oe Roger That! Thank you sir!
@@Phantom-el6oe No, it's not true, and that is not how diodes generate light! If you had a GaAs or a direct gap semiconductor panel, it would glow, once you apply voltage bigger than the bandgap. But it would not emit IR. In the case of Si diodes, they will not emit light because they are indirect bandgap semiconductors.
Thank you so much Steve! A college asked me for a tachometer today to measure fan speed. We don't have one, but thanks to you i now know led's are solar panels. With a scope and flashlight I made the day :D
Is there a link between the frequency of light emitted by a diode and how it would absorb light? That is, for example, do solar panels absorb near-IR better than other frequencies when they emit near-IR?
This is related to resonance. My hypothesis is that if a solar panel is "tuned" (like a string instrument) to resonate at a specific frequency or wavelength, it should be very efficient at absorbing it AND emitting it.
However, ultraviolet light has *A LOT* more energy than infrared, and more than visible spectrum. This is why the sun is used as source, because it generates more energy without the need for "tuning". Quantum Dots have the special ability to be "tuned" (only at build time), so if you make a QD solar panel with a lot of QDs tuned to multiple frequencies (specially UV) you get A LOT more energy than traditional panels!
BTW cameras with the IR filter removed might not be able to do thermal imaging BUT they can act as a digital night vision.
And it's super easy to modify most webcams!
But needs IR illumination
@@sidharthcs2110 you can do that with your remote control led
No video camera will do thermal imaging. Glass lenses wont even pass the light.
Amazing video Steve. Being a Civil Engineering I can confirm that this video was a great CPD for myself.
"I know there is no one there" LMAO. You're my new favorite human being, at least on UA-cam. :)
Aren't the circuits' schematics at 0:13 reversed in relation to what the battery is doing in the experiment behind?
Shorter is positive.
@@time-lapserpro4370 might wanna look that one up again. (yeah, they're reversed)
i was wondering the same
Good video. Illustrations such as these are needed for my brain to understand anything. Must have some diodes crossed in my head.
2:53 my 13 year old emo self would've created a UA-cam channel just so I can upload videos with visible light filtered out
Filtering out visible light is easy. Just put the lens cap back on.
just a quick question, does this mean Infared leds will act better than regular leds as solar panels?
Great question! Didn't even think of that.
Infrared LEDs can absorb a broader range of the solar emission spectrum than visible LEDs, yes. But both IR and VIS LEDs are bad solar cells.
When I was little I plugged a microphone into a sound system, and when the microphone made noise, I thought I had made a scientific discovery
Her: "Did you put the Christmas lights up?"
Me: *looks at solar panels* "Get a camera." (I am so lazy)
Her: (He's so intelligent)
Me: *Buys Steve a drink*
*Wears off solar panel that cost more than whole Christmas*
we just learned that in school, but with this video I understand it
@@Hallowed_Ground Dud just gave the man an advice..tf is ur problem?
@@fantaisiechopin8240 You're stupid.
nalyd doow you got him there
Mantresh perhaps they’re not a native speaker, but hopefully it improves!
I dont understand anything about this video so. The two combined are important.
Can you explain the bandgap, and why efficient blue LEDs require other elements in addition to gallium nitride? (But I can't promise a Nobel prize)
BitDancer easy. Circle.
Thanks for shining light on such an interesting topic
the same goes for electric motors and alternators, every motor can be used as an alternator and other way round
No it can't, a motor with a commutator acts as a dynamo ie it has a DC output. If you put a DC voltage across and alternator* it will just twitch and not rotate. Some types of washing machine pump motor will act as an alternator.
* I mean a basic alternator, not an alternator with a rectifier &/or regulator built in.
can you light up a LED just with shining a light on a different LED?
Yes! It's not very effective but it should work.
Yeah, though you'd need multiple LEDs to power the one LED to a good enough standard
That is if you're not artificially powering the LEDs, but then again you'd probably need quite a few LEDs
Yes! It's similar to an optocoupler.
Yes but you generally need to have a lot of light shining on the first LED and the second must have a lower voltage drop. done it shining a blue LED onto a green GaAsP led and using the voltage generated to light a hyperbright red LED. You generally will have to shield the blue LED and the green one, as otherwise the light from the red is nearly invisible in the glare, the efficiency overall is so low. You also have to couple the blue and green together well, so flat top ones are best with some tubing joining them.
Wouldn't that just be using a solar panel to light an LED? Hahaha
This guy just explains stuff in a way that I immediately understand.
I feel like I've lost all curiosity at work. how do I fix this? Is it because my work and hobbies overlap too much? I used to do so much experimentation at home. now I can't bear to look at technical things in my spare time. I know I haven't lost my interest because I get excited whenever I see videos like this.
I go through the same thing. If I'm too concentrated on work or am deeply engaged in something, I don't feel like working more at home. When I am bored at work, I can't wait to come home to my projects
puffin juice it sounds like burnout to me! It happens to everyone, your best bet would be to separate your job from your hobby as much as possible.
That’s not to say they cannot be the same type of work, it’s just having them be different helps keep things interesting. If you are working on one type of electronics at work do something else at home.
1:52
Solar Panels, they don't make great LEDs ~ Steve Mould 2019
This is the most useful video I've ever watched on youtube.
*_why don’t we just use redstone?_*
Film scene idea, geeky hero jury rigs a blinking infrared beacon on the roof of a bad guy building by feeding a voltage into the solar panels that their backup can spot on night vision.
Now that would be cool.
One thing that should have been mentioned is that the various corresponding combos (speaker microphone, etc) differ in that they are engineered for optimal performance in one way or another. A large diaphragm works better for emitting sound efficiently over a small spectrum, while smaller diaphragms work better for absorbing sound across a wide spectrum. A lens for a camera is larger so it can collect more photons over a greater physical area, while a lens used for a flashlight that emits light can use a much smaller lens since the light source is concentrated. So while many things can work both ways, it will work very poorly in the reverse manner it was not designed for.
2:04 yes you can call it an LED even if it emits IR. Any diode that emits any wavelength of the electromagnetic spectrum is an LED. Look out for those gamma emissions though OUCH!
I wouldn't worry too much about gamma rays. Most PN junctions are monochromatic. They emit in a very narrow spectrum. If you can't see the light, because it's outside of the visible spectrum, you might just want to check. (I was going to say: "Look into it", but that might be a bad idea!)🤣😁😝
The semiconductor bandgap (1-10eV) limits the photons energy, so you will never get gamma photons (100keV) . The only way to get gamma or X-ray if you put millions of amperes in the diode and it explodes very violently, resulting in lots of UV photons, some X-ray photons, and maybe some gamma photons from excited nuclei.
@@neurhlp Is that what they call a gamma ray burst?🤣😁😝 As far as sending and receiving at the same time, to illuminate, you have to apply enough voltage to forward bias the diode junction. If the LED is exposed to light, than if the voltage is reduced below forward bias, there will still be voltage across the terminals. You just need to load the diode, so it stays just below junction voltage, to get maximum energy back out of it. As far as efficiency, it's actually quite high, considering the very small area of the LED Vs a solar cell. A screen has millions of them, giving them the surface area of a solar panel, and producing close to similar efficiency. The only thing that makes the idea impractical for now, is that each pixel, represented by each LED element, needs a push-pull pulse width modulator, with an inductor. The magnetics would be very difficult to scale down that many into something the size of a lap-top, let alone a smart phone. in theory it can be done, but not practical for now.
Does this mean that you can turn a led tv screen into a solar panel for off the grid purposes?
No. While all LEDs do exhibit the photovoltaic effect, to some degree, they are not at all optimized for this purpose and as such are extremely inefficient.
Its appreciated that he explains a very complex thing with the laymen understanding way
Super one bro, you kind of superman the way your voice and briefings its all awesome, you rock and einstein
So if I leave my deadflash light in the sun, diodes up, it should recharge my batteries?
You can charge those dead 1.5 V cells right up to 0.25 V. LOL
I vaguely remember seeing a write up of a display that exploited this principal. It was interlaced, and the currently dark diodes we're used to measure reflected light from the line that was currently active.
Ever heard anything about the difference between Direct- an Indirect-Semiconductors?!
Propably not!
In fact it's quite difficult to get any kind of 'effective' electroluminescense from Silicon, regardless of other 'tricks' like doping, structuring,..and regardless of the desired wavelength!
Thank god, finally someone in the entire comment section who knows something.
Question: how many usual LEDs would it take to make a decent solar panel ? Thanks for the awesome video 👍
LEDs don’t make decent solar panels. If you optimize an LED to efficiently generate electricity, you end up with a solar cell.
2:46 how did you filter out the visible light?? Did you place some other type of physical filter into the camera, or was there some post processing involved? I'd love to know so I can use such a cool look for projects of my own
Do you have a part number or link to the concentrator PV cell?
For Real! I've been wanting to get my hands on even one for quite a while now.
I had to check this wasn't a troll video after the speakers and microphones fact
I love the speaker-microphone analogy!
solar panel camera next
I wanted to see a mic being used as a speaker.
I made a talk box with one back in the 90s using an SM57 mounted on a stand with a cheap Radioshack 1/8" jack mic nearby wired as an external speaker to a guitar amp. Then I'd just mouth the words with the mic-speaker blaring away into my cheeks and presto - talking guitar.
Now thats an idea right there! ^ Very coolz
Dear Steve thank You! You've just opened a window as when i understood microphones and speaker are two ways of the same principle with Sound frequencies. Now You added Light frequencies!!! 😎🙏🏻🙏🏻
Better clickbait would've had the title the other way around
Infrared is light so LED is correct.
Serious topics like this with real life application and example is what I am here to watch.
Can it run Doom?
Bad Apple but it's played on solar panels
Phones can see IR, I use my phone to test IR LED's.
Back when we had remotes for TVs I would do the same thing to check if the batteries were still good in the remote controls.
@@midwestmangos2452 TV's still have remotes, lol
@@sspence65 LOL yeah they technically do, we just don't use them because we use the smart TV app on our phones.
Not all of them
Newer ones usually have filters
I haven’t met a camera yet that couldn’t see IR. I find that fascinating.
I love your speaking, you’re so chill🤞🏽
I KNEW IT! The government technocracy has us all ensnared! lol
It's like I always say, diodes are a circuit's sphincter.
Your sphincter's glow?
Alistair Shaw you have multiple sphincters?
@@OF01975 yes yes I do. Just in my GI tract alone. The top of my stomach, the bottom of my stomach etc etc.
Alistair Shaw im talking bout the sphincter ur uncle forces entry into
@@OF01975 shockingly enough that is in my GI tract. Try again.
Great content!
Keep the good work mate!
You seem surprised that only 20% of employees at a gigantic profit-worshiping corporation describe themselves as "curious."
As a former R&D engineer at another equally profit-obsessed gigantic corporation, I can tell you what impacts curiosity: it's the profit worship. Because the corporations themselves are constructed as artificial legal entities with the _explicit purpose of generating wealth for shareholders at the expense of everyone else_ , that's exactly the way their leadership are chosen to behave. Layoff employees? Sure, if it'll "increase value for shareholders." What if those employees suffer the worst effects of poverty after the layoff? Not the corporation's problem. That's #HowCapitalismWorks, Steve. What if the corporation can make extra profit by lobbying the government to go to war? Could the executives ever be that inhumane? You know the answer.
I left that giant evil corporation when the evil no longer seemed worth the (substantial flow of) blood money they compensated me with. Now my innovations are limited to the things I can do without the resources of a giant corporation; but at least none of my new work contributes to murdering Yemeni, Syrian or Venezuelan children, unlike the ongoing work of my former colleagues.
The answer is simple: replace profit-motive by service-motive. Instead of allowing "shareholders" to elect leaders, The People can elect them. Instead of firing leaders who don't make enough short-term profit, we fire the leaders whose decisions are bad for everyone, even when that means profits aren't maximized. (If that seems counterproductive, it's because you personally value profit over people.) Nearly everyone can keep doing the same jobs, but simply by replacing profit motive with service motive, we could dramatically change the way human resources are employed, and shift the primary benefit away from a tiny fraction of the wealthiest to the whole of the population. Should we lay off those employees? Instead of considering profit delivered to a few already wealthy executives, we'd consider instead the impact on the community. The layoffs would reduce productivity for obvious reasons, so unless there's something else for all those employees to start doing, maybe the factory keeps running instead. Or, if the productivity is no longer needed--maybe those employees used to process crude oil, and maybe we'd rather build solar panels--then maybe the factory shuts down, and all those employees get some free time to be creative, surviving on Universal Basic Income, while the factory is retooled for building solar panels.
I will suggest that the 'idea' of a corporation - an entity that is a 'legal person' (via the citizen's united ruling by the SCOTUS), and which cannot be harmed in any way, nor jailed, yet in many ways has More 'rights' than a living human being, and whose 'god' is Money, IS the definition of the 'anti-christ'. Simply my 'theory', FWIW.
"unless there's something else for all those employees to start doing, maybe the factory keeps running instead."
Laid off employees can find new jobs that are more productive. Think about the internet you are using, for example. Before internet, we communicated with phones. As internet gradually replaced phones, phone industry needed less and less people. Theses people can work on more productive areas, such as internet, instead of wasting their time doing useless "work" that no one needs.
Unproductive work is far worse than unemployment. Look up former USSR. People can work all day, and still starve to death.
I agree that US "defence" industry should cut to a minimal level that is only capable of defence, as in the days of the founding fathers.
So...my tv is a solar panel
Using an infrared camera to check for defects in solar panels is literally my job lol!!! I use a machine called an EL (electroluminescence) to check for cracks. Thanks for teaching me more about this!
When you said “I know no one is there” thats when you got the thumbs up 🤣 lol funny
thats why solar panel 'eats' power at night
You can (must) use a diode, it will not eat the battery because it is connected in reverse from the battery.
Beautiful way of explaining 🤩
Must be nice to have intelligence to come with your curiosity.
Bjarke Kristensen I find that curiosity helps drive learning and that drives intelligence.