14 ms·
Power over fiber
- mcwiggin2 3y agoThis seems super useful for remote sensors in hostile environments.
- falcor84 3y agoI assume that the next step is security researchers demonstrating how power over fiber can be hacked to exfiltrate data ;)
- cwillu 3y agoFrom a reply: “wow. I expected expensive (two digits), but indeed: these are _very_ expensive (three digits).” Honestly, seems pretty reasonable for what is likely an industrial-grade product. I've paid 80 dollars or so per button on a panel with a dozen “simple” push buttons, and there were buttons in that same series that went for a few hundred (for example https://www.digikey.ca/en/products/detail/schneider-electric/XB4BW3445/16607027 https://www.digikey.ca/en/products/detail/schneider-electric...).
- genter 3y agoIf you already have the fiber in place, that's dirt cheap compared to hiring a sparky to run power for a sensor.
- treesciencebot 3y agoI don't understand how people find 3V at 180mA usable, isn't it like 0.5 watts?
- m463 3y agomaybe they could power a repeater with it. (this is a joke btw) EDIT: wait, what if the repeater was amplifying light going the other direction (coming out) or on a different strand?
- aifooh7Keew6xoo 3y agothen you would have rediscovered the Erbium doped fiber amplifier
- deleted 3y ago[deleted]
- lesuorac 3y agoWhile light travels pretty far; it doesn't travel perfectly inside the fiber. So over time you lose all the light. This can be trivially prevented by have amplifiers (analog) along the long cable so that you boost the signal's light level. However now we introduce another problem where the our nice on-off-on square wave starts to look like a gaussian distribution and as it continues to degrade it becomes hard to determine a 0 from a 1 (or say 00 from 01). So instead of amplifying you have a repeater (digital) that re-transmits the original signal (assuming it can read it correctly). Why not just plug the amplifiers and repeaters into the grid? They probably do; it's just there isn't a grid underwater. https://www.synopsys.com/photonic-solutions/product-applications/optical-amplifiers/ropa.html https://www.synopsys.com/photonic-solutions/product-applicat...
- taneq 3y agoWatt are you using it for, though?
- ExoticPearTree 3y agoYou can use it for a low voltage relay switch for example. Recently got a device that has a small LCD, buttons, a small OS and which consumes ~ 20mA at 4V. Nowadays you can do a lot of things with 3V and 100mA.
- londons_explore 3y agoThats plenty for a temperature sensor, PIR sensor, humidity sensor, door open/close switch, a button, CO2 sensor, etc.
- yetihehe 3y ago180mA at 3v is plenty for a lot of pretty beefy microcontrollers.
- willis936 3y agoIt's a perfectly electrically isolated 0.5 W that doesn't need a bulky transformer. Let's say you have a sensor + tiny computer that you want grounded to a high voltage device. You could use this and side step any questions about insulation and isolation.
- rkangel 3y agoThat's loads for people who are used to designing electronics to run off a coin cell or small Li-On battery. My current project avoids peaks of more than 60mA.
- postalrat 3y agoA capacitor would be useful if you need a spike of higher power. If it's the only or you have you will make it work.
- _joel 3y agoActive power draw (average) of an ESP32-S3 is 78.32 mW. Can do quite a lot with that budget.[1] I'm not sure I'd use this personally, but there could be some situation where it's useful I guess. [1] https://esp32s3.com/ https://esp32s3.com/
- slau 3y agoI’ve designed and installed bespoke industrial cameras running on batteries because running any kind of electrical cable would require recertification of the entire factory floor. I’m not convinced this fibre wouldn’t require recertification, but I can guarantee I would’ve spent the time and money to find out if this was an option. Battery operation and maintenance required SOPs, yearly reviews, and a lot of documentation and training. Quiescent current was in the picoamps, and operation spiking in the hundreds of milliamps, which a capacitor or two could easily handle. And if this provides communication as well…
- Aurornis 3y agoAn average AA battery will have 3-4 Watt-hours of capacity. This 3V at 180mA is 13 Watt-hours in a day. So think of it like consuming about 4 x AA batteries every day, or almost 1500 x AA batteries jn a year. You can do a lot with that amount of energy. You won’t be powering a switch or computer, but it’s orders of magnitude more power than small battery operated devices can use.
- ahmedalsudani 3y agoA few lemons/potatoes can power an MCU. 0.5 watts is luxurious. https://youtube.com/shorts/qLTEtXY5-BQ https://youtube.com/shorts/qLTEtXY5-BQ
- whoomp12341 3y agoespecially if the sparky has to scuba dive to install it
- wkipling 3y agoAt minimum 20pc per order...
- cwillu 3y agoDigikey stocks them individually: https://www.digikey.com/en/products/filter/special-purpose-isolators/905?s=N4IgTCBcDaIPYAcAuBLAxgQwDYAIFwHcBTAJxzTgDsA3UpUkAXQF8g https://www.digikey.com/en/products/filter/special-purpose-i... 561.79USD per converter, 540USD if you buy them in packs of ten.
- jetrink 3y agoWhat separates a $300 button from say a $60 button? Is it like an airplane part where has a special rating or is it actually that much more reliable?
- cwillu 3y agoReliability, ruggedness, flexability, serviceability, lots of ilities. The line of switches I linked lets you snap on independent contacts (both normally closed and normally open) that are all actuated by the same button, as well as leds in various configurations, to a baseplate that fits in a standard hole in the panel; the button itself can be swapped out from that baseplate for various reasons (recessed, illuminated, a rotary switch instead of a button, a giant emergency stop button, a 2 or 4-way joystick, etc). Various ratings on the whole mess for dust-proof/splash-proof/water-proof/high-pressure-wash-proof, which is one of the places where the cost starts to go up. Button materials range from relatively cheap plastics up to stainless steel, and potentially heavy duty enough to survive and continue functioning after blows that might shatter a cheaper button. And you'll be able to order compatible replacement parts 20 years from now. That's a big part of it too.
- squarefoot 3y ago> Reliability, ruggedness, flexability, serviceability, lots of ilities. Plus probably some certification+warranty that covers the asses of whoever chose that part in case things go bad.
- breischl 3y ago>you'll be able to order compatible replacement parts 20 years from now. Is that because it's an industry standard, or just that the manufacturer promises, or something? Sheer curiosity - I know nothing about this space. :)
- cwillu 3y agoPromises and history and network effects. Generally you more or less buy into a system of instrumentation. Obviously you can always run wires from terminal A to B across brands, but you can work _much_ more quickly and neatly when working with the standard-for-your-shop stuff. Your shop will have oodles of terminals and buttons and relays in stock, and know exactly where to get the oddball stuff, etc. The resellers and supply houses all keep inventories. If a part does go end-of-life, you'll probably get an email if you've ever purchased that part, advising you to make final purchases for the long term if needed, etc.
- I_Am_Nous 3y agoMost of the cool fiber pluggables are a lot more than a couple hundred bucks, so when they said expensive I immediately thought 4 digits.
- BenoitP 3y ago> efficiently converts optical power to electrical power Damn, I thought it was just a copper pair going along the fibers. I hope they provide some thick safety glasses with that. I don't know if it'd come out as laser light, but 600 mW puts it into class 4 (eyes are damaged at a few 100m distance): https://www.lasersafetyfacts.com/resources/FAA---visible-laser-hazard-calcs-for-LSF-v02.png https://www.lasersafetyfacts.com/resources/FAA---visible-las...
- TheTxT 3y agoMaybe it can first check if something is on the other end before blasting full power
- v7n 3y agoSomething like what? An eye?
- Gare 3y agoSomething that responds to a protocol handshake?
- publicmail 3y agoI think most high power optics do this already, right?
- onionisafruit 3y agoSo a freemason
- moffkalast 3y agoblinks in IEEE
- mikewarot 3y agoIt does that, if I understand what I read about it a year ago.
- engineer_22 3y agoApproximately 30% power efficiency
- yitchelle 3y agoFor layman, can someone explain how much power are the lights emitted? I mean can it be used to burn wood, or the cut through sheets of metal.
- Tade0 3y agoIt's less power than a phone flashlight.
- CoastalCoder 3y agoBut in laser form. Does that change things much?
- zokier 3y agoBeing laser in itself is afaik less of a factor, but being IR and a very small spot are more so.
- Sebb767 3y agoNow this might be my layman knowledge, but "being a laser" seems to imply "a very small spot", no?
- dekhn 3y agoNo, not really. Laser beams have a width and that can be adjusted. As it comes out of the fiber, it forms an expanding cone which you would then modify with a lens (https://content.coherent.com/legacy-assets/literature/white_papers/COHR_whitepaper_Fiber_Delivery_Primer.pdf https://content.coherent.com/legacy-assets/literature/white_...)
- ben_w 3y agoAssuming this calculation is correct, from my experience you can cut plastic and wood: https://chaos.social/@jaseg/111697386931635059 https://chaos.social/@jaseg/111697386931635059 But it won't even mark steel unless you pre-prepare the steel with absorbent inks, and definitely won't cut it.
- dthul 3y agoI wonder if you could send power at one wavelength, and data at another wavelength, over the same fibre.
- raphman 3y agoWhy not both via the same wavelength?
- dthul 3y agoI was thinking that the "power extraction" might attenuate the signal too much, and it would probably lower the power output since you need to modulate the light to transmit data, instead of having it on full brightness all the time. But maybe it would work for certain applications!
- cycomanic 3y agoEfficiency of laser diodes goes down quite a bit with bandwidth. More importantly you typically want the data going the other way (from the powered sensor). If you would use the same fibre for both directions (might be done for space constraints) the issue of using the same wavelength is that there are scattering processes (some fundamental to how fibres work) in the fibre that will cause some light to be back scattered and act like noise essentially. Your sensor would transmit with only very little power so the SNR might be completely destroyed by the back scatter of the high power piwer delivery light. If they are at different wavelengths they can be easily separated.
- raphman 3y agoOh, you are right - I didn't think about the other direction at all. Thanks for the explanation!
- CoastalCoder 3y agoCould they use separate phases of the same frequency, or do things like DWDM preclude that?
- etaioinshrdlu 3y agoHow much optical power could be safely carried over such an optical fiber in theory? What are the limitations?
- taneq 3y agoWhat’s your definition of “safely”? :D
- ExoticPearTree 3y agonot OP, but I put "safe" just a tad below melting point of fiber :)
- internetter 3y agoFor glass fiber, that would be 1700C, but you'd need to be very worried about any damage if you're anywhere close to that
- londons_explore 3y agoThe limitation is the fiber melting. It won't melt along the whole length - there will be some bend/crack/dirt which will make a hotspot, and that hotspot will then absorb more laser light and get hotter, and you'll get a runaway heating. The hot bit will then propagate slowly towards the laser source, eventually destroying the whole fiber. High power fiber optic communication systems have protections in place to detect this happening and turn off to reduce the damage radius. Learn more: https://www.microcare.com/en-US/Resources/Resource-Center/FAQs/Can-High-Power-Lasers-Can-Damage-Fiber-Networks https://www.microcare.com/en-US/Resources/Resource-Center/FA...
- zokier 3y agoLaser cutting machines use optical fibers and can push tens of kilowatts if power, although I don't know what sort of fiber arrangement they do use. But I think that still indicates that you can push a lot of power through fiber.
- bloggie 3y ago
- vectro22 3y agoThe target application for this seems to be high voltage isolation, and common mode leakage immunity. I could imagine this being used to power an active high voltage probe.
- severino 3y agoCould this idea be used, for example, to power a landline phone like it was done with POTS? So no external power was needed for the phone and it even worked in the event of a blackout.
- masklinn 3y agoAccording to SIN 352[0] > the average DC current in the loop and voltage across the phone will be up to 42 mA at 12.5 V (short line), up to 33.5 mA at 10 V, and will be not less than 25 mA at 9 V. So it's around the same values. However the distances are in a different realm entirely: the spec sheet tests over 30m of fiber, phone loops range in kilometers. [0]: https://www.openreach.co.uk/cpportal/content/dam/cpportal/public/images-and-documents/home/help-and-support/sins/documents/SIN_352.pdf https://www.openreach.co.uk/cpportal/content/dam/cpportal/pu...
- rwmj 3y agoHmm, a class 4 laser going into a consumer landline phone, what could possibly go wrong?
- gosub100 3y agoit could be done safely with an interlock on the data side. if it doesn't get a ping every 1ms it cuts power.
- chx 3y agoSure thing. This is 540mW and looking at https://electronics.stackexchange.com/a/36495/27147 https://electronics.stackexchange.com/a/36495/27147 > headphone jacks typically provide only 10-20 mW of output power. microphones draw even less. A handful of mW is plenty to drive even an ARM Cortex M0 not that you need something that complex.
- j4nek 3y agoI was working i a company (EMC testing) which decided to build their own "Power over Fiber" solar cells, also in the 500 or 600mW power range. Yes, you can buy such stuff now from boradcom but these are simply too expensive.
- j4nek 3y agocosts were under 10 bucks iirc, same specs.
- c_o_n_v_e_x 3y agoDo you know the name of the product line or have any part numbers?
- csours 3y agoEver had one of those retaining clips get weak over time? Yea, I'm gonna need some lock out tag out on this cabinet.
- malanj 3y agoThe transmitter module; https://docs.broadcom.com/docs/AFBR-POL2120-DS https://docs.broadcom.com/docs/AFBR-POL2120-DS
- Geisterde 3y agoI am imagining running all the sensors in my data center off fiber and not needing a hamster ball of 24v in every cabinet.
- rwmj 3y agoGetting the server's power consumption down to 500mW would be a ... challenge.
- tompccs 3y agoMust be very niche as lasers operate typically below 10% efficiency. And one speck of dust or defect on a component and you're setting fire to something.
- Aachen 3y agoThe post says it > can provide 3v 180mA from 1.5W 0.18×3=0.54W, so like ⅓ efficient. Maybe that's why it's so expensive compared to other modules which can get away with lower efficiencies?
- hwillis 3y agoThat's the efficiency of the device, not the laser. This device does not include a laser. That said, I don't know of any diode lasers that are that bad. Lasers for this fiber are probably 50%+ efficient and even the high frequency laser diodes are still 30%+
- vanderZwan 3y agoThis would still make the whole system a lot less inefficient than I expected, tbh.
- auspiv 3y agoup to 45% efficient at lower power (0.5W in, 0.225W out) https://www.farnell.com/datasheets/2785190.pdf https://www.farnell.com/datasheets/2785190.pdf
- ajsnigrutin 3y ago> Maybe that's why it's so expensive compared to other modules which can get away with lower efficiencies? It's expensive, because most people don't need that, because they just use a wire to power their device. This has some very niche uses in high voltage insulation (where you need the power on the other side, but really really don't want high voltage to travel back down the line and destroy your device.
- namibj 3y ago
- amelius 3y ago> 3v 180mA from 1.5W So only 36% efficient.
- deleted 3y ago[deleted]
- riffic 3y agoorange site needs a standing rule to avoid linking directly to Mastodon instances unless we know they can handle the hug of death.
- gene-h 3y agoPowerlight technologies(formerly LaserMotive) has demonstrated power over fiber tech that can transmit hundreds of watts[0][1]. The intended application of this tech was for powering underwater remotely operated vehicles(ROV). The same amount of power could be transmitted with a thinner fiberoptic cable than a copper cable, so it would encumber the ROV less. Although other niche applications like powering electronics in regions with EMP or near MRI's were suggested. Powerlight's linkedin currently shows them powering an inflatable christmas decoration with power over fiber. Some of the people at Powerlight found this tech to be ironic because Powerlight was originally founded as a wireless power beaming company. However, some of their customers asked if they could transmit power via wires, so that's what they did. [0]https://powerlighttech.com/power-over-fiber/ https://powerlighttech.com/power-over-fiber/ [1]https://www.laserfocusworld.com/test-measurement/research/article/16561660/lasermotive-announces-laser-power-over-fiber-technology https://www.laserfocusworld.com/test-measurement/research/ar...
- flakes 3y agoThats super cool for the ROV aspect. In university I was part of the underwater robotics program, and optimizing the tether was a huge aspect. We used a fiberoptic line for communication, leaving the rest of the cable mostly dominated by the copper conductor for power. Any weight reduction that can be made for the cable internals is actually two fold. The cable needs to remain neutrally buoyant as to not pull on the ROV and not restrict the pilot. Less internal weight in the cable means less foam/other material needs to be added to offset the negative buoyancy.
- anfractuosity 3y agoWould I be right in thinking a tether would be necessary with a ROV for a high bandwidth live video link as ultrasound seems only usable up to 100s of kHz. I guess the only high bandwidth alternative might be lasers?
- gene-h 3y agoReally bright LEDs can be used for underwater optical communication up to 100 m[0]. I'd really like to see someone make this tech into an FPV system for RC subs. [0]https://optics.org/news/11/9/36 https://optics.org/news/11/9/36
- dragontamer 3y agoWhat's the use-case here? That's the biggest optoisolator I've ever heard of. Someone out there wants a lot of power pushed through electrically isolated islands. Normally, you'd have power on both sides but just send a signal (lower-power light + sensor to detect the light). It seems odd to use this technique to transmit power (Albeit a small 0.5W worth of power or so, but that's enough to run most microcontrollers and even some microprocessors). My guess is some kind of optoisolator situation except you weren't allowed to run power on the other side for some strange reason. But I'm having difficulty thinking of a practical application where these requirements pop up.
- michaelt 3y agoProducts like [1] an oscilloscope probe with ±60,000V isolation. [1] https://www.tek.com/en/products/oscilloscopes/oscilloscope-probes/isovu-isolated-probes https://www.tek.com/en/products/oscilloscopes/oscilloscope-p...
- dragontamer 3y agoWhy would an oscilloscope probe ever draw more than a few mW or even microwatts? I'd expect a normal optoisolator module to work for a probe like that. No need for 180mA+ transferred between circuits. ---------- An oscillator probe is an example where electrical isolation + signal (aka: communications) are useful. But under no circumstances should 500mW of power be sent through such a setup in either direction.
- duskwuff 3y agoThe amplifiers in high-speed active probes can use nontrivial amounts of power. I don't have specific numbers as the probe/scope interfaces are proprietary, but I wouldn't be surprised if some of the wired (non-isolated) probes draw multiple watts. > I'd expect a normal optoisolator module to work for a probe like that. Absolutely not. "Standard" optoisolators tend to be slow and have analog characteristics which are unsuitable for an oscilloscope.
- quailfarmer 3y ago
- Epitom3 3y agoThe company I work for uses these Cisco Meraki devices in their network, some of which support “Power over ethernet”. https://meraki.cisco.com/product/switches/access-switches/ms120-8/ https://meraki.cisco.com/product/switches/access-switches/ms... With these devices, you don’t need to worry about a separate power cable for your network devices.
- martijnarts 3y agoFwiw, Power over Ethernet or PoE has been a widely used IEEE standard since 2003. This is not specific to Cisco, or Meraki. It's common for VoIP phones, cameras, routers, intercoms, etc.
- cryptonector 3y agoThis could be great for power isolation. Think of a micro-HSM application, where you want electrical isolation to protect against over/under voltage attacks.
- samstave 3y agoSo... I have a really interesting anecdote on "Power over fiber" In ~2004 I was the technology designer for the Lucas Arts Presidio Campus - I designed all the physical network, custom cable tray in the DC, the DC power infrastructure for the DC and did all the layout of the devices collapsing into the DC from ILM, Big Rock and other locations. When we designed the network, it was the largest 10G network in the world, all based on FORCE10 equipment, as spec'd by ILM's Raleigh Mann (later netword head for Google)... The original design was for fiber to the desktop, as they wanted all desktop machines to become a part of the render farm when not being used. -- We were doing vendor selection from the RFP and holding interviews for each vendor to present their response to the RFP (The network was ~$50 million (this was 2004, so that was a really large number back then) In the meeting with Cisco, Cisco performed a clown show, but the CTO for Lucas seriously (remember, Cisco 6500s was the core king at the time) Lucas CTO: "Yeah, well we have CAT6 and Fiber to the desktop. When can you give me power over fiber so I can just run fiber to the desktop" Blank stares from everyone. (He sadly died of heart attack shortly after) --- But here we are. We thought a fool, but I guess he was a visionary.
- mciancia 3y agoCrazy that it has been 20 years since 10G was available and it's still very uncommon outside of enterprise
- cmpxchg8b 3y agoI was in LDAC from 2007-2010 and was told that all machines could remote boot to join the renderfarm if required, but I never actually saw it in action. Lucasfilm never picked good CTOs. While I was there they picked someone from Apple who seemed to be more about marketing than anything else..
- samstave 3y agoIt was a money war.... CFO won.
- samstave 3y agoHere is some of the custome tray I designed. https://i.imgur.com/MOzeEBu.jpg https://i.imgur.com/MOzeEBu.jpg Thats from the LDAC DC (You couldnt buy those parts at that time - I had to design them, (super FN obvious FN parts... right) - so I designed them and they later became parametric... but the 90's and well into the 2000's CAD was stagnant. and lame. Then Autodesk took Acid and reall saw what the F was going on... - Whats funny, is that I had to design this by hand, in ORTHO - and do the ISO also by hand in AutoCAD... This and a many other tray objects in that data center. (I did the layout for all the servers hosting Starwars Online) --- Anyway - after many a year doing datacenter design - there are folks at places like FB, Goog, AWS, and they just draw a layout like anyone would Sim City - and connect required resources etc...
- jiveturkey 3y ago> 3v 180mA i suppose you can’t run power and data together, but anyway how does this compare to PoE?
- MattIPv4 3y agoPoE is around 15w at 48v, PoE+ is 30w, and PoE++ is 60 or 100w
- einpoklum 3y agoApparently the price of these things can make a grown man cry.
- orenlindsey 3y agoDidn't know this was a thing. Pretty cool, but doesn't seem like it'd work over long distances.
- NelsonMinar 3y agoI'm a customer of the very best US ISP (sonic.net) in San Francisco. We had a major power outage affecting a quarter of the city, including my home. Everything went down. Except my sonic.net fiber ISP. I asked the CEO how that worked and he responded > Our network is a “passive optical network” in the outside plant - the cabinets on poles just house optical splitters - no electronics. Yes, apparently it's glass all the way from San Francisco to San Jose. I'm assuming they aren't using this power over fiber trick either but it's neat to think they could, at least for limited power needs. https://twitter.com/dane/status/1190054557667053568 https://twitter.com/dane/status/1190054557667053568
- error503 3y agoI'd be surprised if an urban PON deployment was passive over such a long distance. It's theoretically possible, but the economics generally don't make sense, since each fibre strand can only support 32-64 customers each without supporting equipment, and that 60km strand of fibre in a dense metro is worth more than those customers can generally generate on their own. Usually it makes more sense to aggregate the customers onto some higher speed / more redundant backhaul within say 5-10km. More likely the OLTs are housed in a nearby-ish CO / datacentre with provision for running on backup power indefinitely, but not all the way in another city.
- Animats 3y agoYears ago, Bell Labs once developed a fiber-optic telephone handset that obtained all its power over the fiber from the central office. A comment was that the audio wasn't that hard, but the bell was really tough. (It used to be a thing in telephony to be totally independent of local power. Landline phones were powered entirely from the central office end.)
- wingworks 3y agoYep, still a thing here in New Zealand. Though the number of people who still have a landline connection at home is dropping greatly, and the few that also have a phone which can run off the phoneline even fewer. (you need a fairly basic landline phone) Before we got fibre we had our phone just connected to the landline and no power, was great, because it always worked, power cut, still worked.
- Animats 3y agoIn Switzerland, at least, ISDN phones were powered over the phone connection. You could have end to end 64Kb/s uncompressed digital voice, the high water mark of telephony voice quality.
- Bluebirt 3y agoSadly, the bandwidth of the devices is not given anywhere. Would be really interesting for certain applications. This is very helpful in medic applications like MRI.
- deleted 3y ago[deleted]
- vkaku 3y agoThank you for sharing it. My observations so far: - Too expensive to be practical. Currently at $$$ per device. - Few chips exist in that power range for consumer electrical to make it mass produced and available. - Repairs may also not be as practical. We probably need new cold crimpable couplers for this to be field deployable. I would like to see a repairable medium for this to take off. I'm already reading the other replies here and I see potential.