Optical isolation help - Page 1
Forum section: electronics / projects

author: Lycagon
author_rank: Newbie
timestamp: October 13, 2025, 02:56:02 pm
content: I need help modifying an optical isolation system for usb tether.This project has an RF interference zone, so I need a long fiber optic cable in there.maybe you can suggest the one I need to buy and best equipment to mod this with.If it's not easy to save parts I could turn 2 into 1 perhaps.thanks

author: voltsandjolts
author_rank: Unknown
timestamp: October 13, 2025, 03:04:16 pm
content: How long is the fibre?https://www.lindy.co.uk/usb-c4/usb-extension-c222/fibre-optic-usb-extenders-c1606

author: Lycagon
author_rank: Newbie
timestamp: October 13, 2025, 03:46:30 pm
content: 12 feet

author: Lycagon
author_rank: Newbie
timestamp: October 13, 2025, 03:49:48 pm
content: btw; what you're showing is a link to electrical based usb extenders. What I need is an actual fiber optic cable extension only. I'll be running the tethered item without power form the pc side, due to the RF zone problem I mentioned.

author: voltsandjolts
author_rank: Unknown
timestamp: October 13, 2025, 03:59:22 pm
content: Quote from: Lycagon on October 13, 2025, 03:49:48 pmbtw; Nope. You need to look at that link again.QuoteThey are optical fibre data link.Some transfer power, but you don't need to use it:https://www.eevblog.com/forum/reviews/modding-an-optical-usb-cable-to-be-isolated/12ftMust be some serious RF power if a shielded cable can't mitigate that.

author: Lycagon
author_rank: Newbie
timestamp: October 13, 2025, 05:26:26 pm
content: Okay, I took another look, but sorry, anything with metal in it wont work. What I need is a fully optic driven datalink. I don't see anything but a scam when they are charging nearly 700euros for a single strand fiber optic cable worth 9 cents and a few pennies worth of other parts. I'm sure it's cheaper to use led receiver(s) linked to electrical i/o hardware system.So perhaps I need to rephrase the question but we've come this far. I do appreciate you help.edit; 480mbps using the usb 2.0 standard is fine btw. These are only using the datalink for coin mining, although my chip mod to make these bb run a lot faster could be used in the future for server applications. If 5gbps on usb 3.0 isn't going to break the bank on a prototype I'd go that route. I truly know very little about engineering, I'm more of a physicist. My father was the telecommunications engineer and he passed last March.

author: ejeffrey
author_rank: Super Contributor
timestamp: October 13, 2025, 05:39:19 pm
content: You still didn't actually read it. They are fully fiber optic links using LC connectors for commodity fiber optic cables. And I suggest based on your "scam" accusation that your attitude is terrible and you should fix that first.

author: voltsandjolts
author_rank: Unknown
timestamp: October 13, 2025, 05:53:13 pm
content: Sorry to hear of your father's passing, my condolences.The long range extenders are typically fibre only (no power wires) while the shorter range include wires (for power transmission , not data) as a convenience. The shorter range devices are much cheaper and may well meet your needs.That said, for 12 feet of usb 2, I suggest trying a good quality shielded cable.Or perhaps one of the 'boosted' active cables commonly available:https://www.lindy.co.uk/usb-c4/usb-extension-c222/30m-usb-2-0-active-extension-pro-p10075If that doesn't work, run the cable through 12 feet of 1" earthed copper plumbing pipe

author: Lycagon
author_rank: Newbie
timestamp: October 13, 2025, 09:53:12 pm
content: Read it, just didn't understand it. Either my coffee hadn't kicked in or I had too much. Sorry about that. So the wire is only for power supply, I get it now.Now this tells me I can just modify any optical hybrid cable off Amazon like this one;https://www.amazon.com/biaze-Extension-Extender-Transfer-Keyboard/dp/B0F93PB86D/ref=sr_1_3?crid=22BXEH751519W&dib=eyJ2IjoiMSJ9.HHcXQdjeOz_evxabLFcTnk0f7aCFKteDNHNf4sSgbF-K6-o7PZQoFohkbnEl3t5BT9S35YLnzFYZRb_d-rjkQgAmj7LQq_QPAfepfrMp6R9wWIyLxKrKLCN8jAFLpsRY1V7D4jz1h27uEoAZd-0ut8oB7oF7Q34RNFLaBF12O3QYTioxOpi--DQA_gcDZjZi8YerSxZnpsOcahecOv84Wvk0KExUTB9D_zpESPoe-RQ.3h9LdcSn_-FLYY73u3t5r_fCZC7yABX3c3vLUQCPmR0&dib_tag=se&keywords=usb%2Bfiber%2Boptic%2Bcable%2Bextension&qid=1760391949&sprefix=usb%2Bfiber%2Boptic%2Bcable%2Bextension%2Caps%2C151&sr=8-3&th=1...and I think that's exactly what I was looking for. All I need now is to find a tiny yet fast crypto miner I can change the oscillator on to run 1 to 2k times faster. This is something that'll fit in my device that creates a superconductive field running inductive, which is the key to eliminating heat completely. Tested this on much simpler chips with great success many years ago.thanks for your help

author: Someone
author_rank: Super Contributor
timestamp: October 13, 2025, 10:33:05 pm
content: Quote from: ejeffrey on October 13, 2025, 05:39:19 pmCheck the OPs other posts.They know that a USB <- fibre -> USB link only needs "pennies":Quote from: Lycagon on October 13, 2025, 05:26:26 pmBut immediately say they don't know about engineering:Quote from: Lycagon on October 13, 2025, 05:26:26 pmThis likely all links back to their fringe idea to make money with speeding up non-specificsemiconductors, then flipped to arbitrary semiconductors, by adding non-specific RF:https://www.eevblog.com/forum/dodgy-technology/the-kwazimoto-overclock/msg6067485/#msg6067485So non quantified RF is now, I need isolation from massive RFI..... as if adding so much RFI that the connection fails is somehow going to improve the rest of the device.If they can make USB < fibre > USB devices so cheap, probably pursue that as a money making venture (or let us all in on the secret at least).

author: Whales
author_rank: Super Contributor
timestamp: October 14, 2025, 04:33:09 am
content: Optical USB isolation is expensive. Cheap USB isolators only do USB 1.0 or 1.1 speeds. The cost isn't the fiber, it's the electrical<>optical trancievers. LEDs are typically not fast enough for more than a few megabit/s and the driving + receiving circuitry has to do a lot.It sounds like you already have a USB isolator with some length of fiber and you want to cut & extend it? Or you have a USB isolator with no fiber in it? Model numbers and photos would really help.

author: Lycagon
author_rank: Newbie
timestamp: October 14, 2025, 06:44:25 am
content: Is this all you do? Go around finding ways to be stickler about everything here? How bout not being toxic. By the way, I was right. One fiber optic extension may run 700euros, while another that does the same exact thing I found for about $30 on Amazon, so try not being so negative. You're not helping.

author: Lycagon
author_rank: Newbie
timestamp: October 14, 2025, 07:10:15 am
content: No, I need to run fiber only about 12+ feet to my device without any metal. The device creates it's own ionosphere in a superconductive environment, so it's super positive and drains anything of energy at a rate of 500kv and up. Electra-negative material or no material (laser) data transfer is necessary.Reduction of thermal kinetics is exponential in the field, yet it simply cannot exist without being on the extreme side of positive charge. This is why I need optical comms."Somebody" (interesting troll name there) is assuming everyone would agree the optical transceiver should be expensive. From my point of view of past tech items I've seen, the prices have been gratuitously inflated. This was the case in RAM as openly admitted for many years. Only a small percentage of this actually went back into R&D. He could be right or wrong, but one truth is obvious; there are vast differences in pricing among these cables that have identical transfer speeds.Yes there are secrets. None of which I can reveal here as much as I'd like to. I do get a lot of heat as a physicist as well for some of my statements. I had countless rejections to my theory of 1995 that electron neutrinos were flowing to the galaxy core and are the key to powering time itself, but over 10 years later guess what? The $270million Ice Cube neutrino tracking project vindicated my prediction as 100% accurate regarding their flow direction. How could I know this over 10 years before anyone at CERN or on earth? Just saying, not everyone bases what they know on your same school of logic , "Somebody" man. Just mark this down that everyone can still have a learning experience no matter how smart we think we are.

author: Haenk
author_rank: Super Contributor
timestamp: October 14, 2025, 12:16:38 pm
content: "The device creates it's own ionosphere in a superconductive environment, so it's super positive and drains anything of energy at a rate of 500kv and up"yeah, sure, whateverIf you create a black hole in your garden shed, it might even resurrect the dead. Technicall speaking, I'm not sure, what an "energy rate of 500kv and up" means (ignoring the fact that you probably meant kV).I'd go with an USB-network-server, attached to a network switch with optical transceivers into fiber optics cabling, into network switch, into computer with USB network-server-software. (We use such a network-server for an encryption dongle, securely locked away, but necessary for a VM running on a workplace computer.) The switch and cable should be available for cheap as surplus (make sure you get the right modules and cables).That cabling will not be influenced by electrical r magnetic fields.Other than that, this still sounds like BS and SCAM.

author: NE666
author_rank: Frequent Contributor
timestamp: October 14, 2025, 12:45:12 pm
content: Quote from: Lycagon on October 14, 2025, 06:44:25 am"How 'bout" - not insulting the intelligence of your chosen audience with fantastical anecdotal claims, and then claiming foul when they bite?

author: spostma
author_rank: Regular Contributor
timestamp: October 15, 2025, 03:48:18 pm
content: USB over glass fibre extenders are available for a reasonable price, for example:HM1310 5Gbps USB3-only over single mode LC-duplex glass fibre:https://www.aliexpress.com/item/1005009200886603.htmlThis unit provides galvanic isolation between the USB3 host and the USB3 devices,but needs an external power supply at the device side.NB: Only works with the supplied short USB3 A-A cable on the host side.NB: USB1.x and USB2.x devices will not work.A similar glass fibre extender for isolating USB2.0 devices:https://www.aliexpress.com/item/1005001474116880.html

author: SteveThackery
author_rank: Super Contributor
timestamp: October 15, 2025, 05:10:34 pm
content: Folks, folks!You do realise this is the same scammer/bullshitter/fantasist who stars in "The Kwazimoto overclock", currently showing in Dodgy Technology? Maybe you didn't read these:"The device creates it's own ionosphere in a superconductive environment, so it's super positive and drains anything of energy at a rate of 500kv and up.""All I need now is to find a tiny yet fast crypto miner I can change the oscillator on to run 1 to 2k times faster. This is something that'll fit in my device that creates a superconductive field running inductive, which is the key to eliminating heat completely."This from a person who reckons he is "more of a physicist" than his late father. Uh huh. No more comment needed on that.The only reason to keep responding to this guy is for a laugh. Or because you want to learn how to create your own ionosphere in a superconductive environment.

author: Infraviolet
author_rank: Super Contributor
timestamp: October 15, 2025, 05:37:42 pm
content: Lycagon: do you actually need USB? You haven't said but I think it likely your device might have an arduino or something equivalent as it's "core". Is this what you want to make a USB connection to? You realise that most arduino type devices and many other dev boards aren't in need of the full USB performance capabilities, they can receive and send data, even be programmed, in other ways too, USB is merely convenient because computers speak it. You could make a UART connection over infrared instead? I think components are still available working with an old standard called IRDA, which lets you route the TX and RX lines of an asynchronous serial connection over a line-of-sight connection. If the data you need to transfer between the device and your computer is simpler still (by simpler I mean less bytes/second and less need to minimise "ping times") you could use TSOP38238 (or equivalent) modulated 38KHz infrared receivers, at the transmitting end you just blink an IR LED at 38KHz and enable/disable this blinking according to your type of data modulation (on-off keying, pulse length modulation...). You could even buy a receiver for one carrier frequency (56KHz for example) for device-to-pc data and another frequency for pc-to-device data, so the two optical signals couldn't interfere with one-another so easily. You've still got to power the device somehow, or has it a battery included?

author: Nominal Animal
author_rank: Super Contributor
timestamp: October 15, 2025, 09:04:11 pm
content: I've used good old TOSLINK (plastic!) fiber pair for a ~ 2 Mbaud UART serial link between two Teensy 3.0/3.1's, with inverted signals (so the transmission LEDs idle in the OFF state) because the cheap transmitters I could get don't like being continuously on. For bidirectional communications, you do need two cables, two transmitters, and two receivers. Any pair of microcontrollers with closely matching baud rates should work, and many can do the polarity inversion in hardware so you don't need external inverter ICs either. It is very simple and straightforward to do; the hardest part is finding the optical transmitters and receivers nowadays (the Cliff ORJ-5 (FCR684205R) and OTJ-5 (FCR684205T) or -8 ones, or Toshiba TORX1350/TOTX1350 would be my best bet). The data rate isn't amazing at around 200,000 bytes/second, but it suffices for many use cases.Also useful if you want to do your own speaker projects without ground loop issues.Quote from: SteveThackery on October 15, 2025, 05:10:34 pmI respond because these threads are read by many others besides the OP, and are often discovered afterwards via a web search. So, I'm responding at least equally to those people, and not just to OP.

author: Manul
author_rank: Super Contributor
timestamp: October 17, 2025 10:34:27 am
content: I will just add, that electrostatic shielding will likely be needed even when using optic fiber link. You can't have 500kV RF few meters away and expect consumer electronics to not go berserk. Valid for both ends of the link.Other OP claims - no comment.