Magic cable - Page 1
Forum section: electronics / general

author: Derresh
author_rank: Contributor
timestamp: January 15, 2015, 05:03:11 pm
content: So... how dose this magic cable workhttps://www.indiegogo.com/projects/sonicable-the-world-s-most-advanced-charging-cableThe only remote possibility I see how it works Battery Charging Specification of the USB 2.0 spec... But is not mentioning it, also the ratings in that paper are different. So any guess on how this works ?The claim here is that if my computer outputs 500 mA with this cable it will magically go to 1A, I don't think physics agrees with that

author: Wilksey
author_rank: Super Contributor
timestamp: January 15, 2015, 05:24:30 pm
content: Some kind of super capacitor type device perhaps with different current limiting resistors?

author: gregallenwarner
author_rank: Regular Contributor
timestamp: January 15, 2015, 05:32:52 pm
content: Sounds like it manipulates the voltage levels on the data pins in order to signal the device that it's plugged into a 1A capable charger. Yeah, sounds like problems to me if you plug it into something that's only capable of sourcing 500 mA and the phone goes on ahead and tries to draw an amp. Those limitations are there for a reason.

author: wraper
author_rank: Unknown
timestamp: January 15, 2015, 05:37:30 pm
content: Quote from: gregallenwarner on January 15, 2015, 05:32:52 pm+1. Many computers nowdays have USB ports with increased current capacity, but not all. Often regular and increased current ports on the motherboard are color coded.

author: Wilksey
author_rank: Super Contributor
timestamp: January 15, 2015, 05:38:40 pm
content: Isn't there different specs for data and power and just power? I guess you would have to make sure it was plugged into a USB wall wart capable of delivering 1.5A+

author: gregallenwarner
author_rank: Regular Contributor
timestamp: January 15, 2015, 05:40:35 pm
content: Yep. It's definitely possible to get more current out of your computer by manipulating the signaling voltages, but not all USB ports are capable of this. Put this device into the hands of the masses and suddenly you've got a whole ton of uninformed, unintelligent, leap-before-you-look, dangerous users out there jamming this thing into every USB port they can find. Statistically, there's a 1 in 1 chance of somebody messing something up.

author: tom66
author_rank: Super Contributor
timestamp: January 15, 2015, 07:58:56 pm
content: Some computer motherboards have the capability to do 1A per port charging. But I would guess it's quite rare on laptops with the low power budgets they are designed for.

author: Monkeh
author_rank: Super Contributor
timestamp: January 15, 2015, 08:08:05 pm
content: Something like this inside the cable:http://www.microchip.com/wwwproducts/Devices.aspx?product=UCS1002-1Nothing new.

author: Monkeh
author_rank: Super Contributor
timestamp: January 15, 2015, 08:16:04 pm
content: Quote from: Richard Crowley on January 15, 2015, 08:12:27 pmNot as simple as a DPDT switch, sorry.If you ignore the blatant abuse of USB ports, it's not a bad product. But a proper charger or a remotely modern computer with BC support is better..

author: Monkeh
author_rank: Super Contributor
timestamp: January 15, 2015, 08:19:02 pm
content: Quote from: 3roomlab on January 15, 2015, 08:17:49 pmThey typically have polyfuses. And very often a 1A one supplying two ports.Oh, hey, this thing is set to a 1A current limit. Odd coincidence.

author: mux
author_rank: Regular Contributor
timestamp: January 20, 2015, 01:38:18 pm
content: I've been busy with a phone charger (and did a failed kickstarter for that... that's another story) and yes, what they do is probably legit and also yes, it is probably going to break some chargers and overload usb ports.They almost definitely have something like a TPS2543 or similar CDP controller inside which engages with the button. That scans the downstream device for compatible charging methods and manipulates the voltage levels on the D+/D- ports in accordance with whatever the phone/tablet recognizes. There are quite a lot of these chips around, they are cheap and they work very well. One size fits all designs, really.They bank on the assumption that:1) The PMICs inside phones and tablets aren't dumb, they don't just start drawing 1A when they are told they can. They will do a scan of the power source, often in steps of 50 or 100mA, very rapidly and measure the voltage drop. They generally take either the externally programmed max current (in this case 1A), a lower current because the battery is already mostly full or whatever current corresponds to a preprogrammed voltage drop. For instance, my Galaxy Note 2 scans in 50mA steps during half a second and settles on a current corresponding to a voltage drop of 200mV.2) Polyfuses on USB ports in computers and peripherals (e.g. monitors) are never actively current limiting and have very large margins. A 1A polyfuse is guaranteed to indefinitely pass through 1A. It won't even blow at 2A, usually. Certainly not for the relatively limited amount of time that a large current is actually drawn.This is all fine for >90% of boards, but you WILL get compatibility problems. A couple of hub controllers actually do implement active current monitoring (especially USB 3.0 and 3.1 stuff), and will just cut off current when they see anything on a logically empty port drawing more than 250mA. This is a growing problem for the future as we go to more well-managed peripheral interfaces! Also, as mentioned before lots of laptops have low-current load switches on the USB ports which means you can permanently damage a USB port if you draw more than 500mA from it (the load switch will just fry).All in all; the product is probably legit and by the looks of it it's very likely just something they bought in wholesale from China as an existing product. They're making an absolute killing on margins. It's not bullshit as far as I can tell. Especially because they have thunderbolt support I highly doubt they actually have in-house electronic design.

author: jadew
author_rank: Frequent Contributor
timestamp: January 21, 2015, 07:02:41 pm
content: I don't know how you guys can think this is legit. They say nothing that would make me think that they know what they're doing, in fact the opposite:"When the switch is OFF: Its like a normal USB cable, charge and sync.When the switch is ON: All of the power is focused on charging, sync/data is disabled."Sounds to me like all they're planning to do is to disconnect the data lines. On top of that, the presentation focuses on how cool it looks and skips over the part where it says how it works.

author: Monkeh
author_rank: Super Contributor
timestamp: January 21, 2015, 08:37:42 pm
content: Quote from: jadew on January 21, 2015, 07:02:41 pmPlease read the datasheets of the chips mentioned by myself and mux above.

author: Derresh
author_rank: Contributor
timestamp: January 22, 2015, 11:40:46 pm
content: Well... so it is using the USB Charging specs that allow for that. Tho they should have mention it that it works only on compatible devices since otherwise this is just magic

author: Monkeh
author_rank: Super Contributor
timestamp: January 23, 2015, 05:00:46 am
content: Quote from: Derresh on January 22, 2015, 11:40:46 pm.. if they're using that type of chip it'll work on just about anything.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: January 27, 2015, 10:29:12 pm
content: Quote from: Monkeh on January 23, 2015, 05:00:46 amUntil the USB port you have it plugged into fries.

author: saturation
author_rank: Super Contributor
timestamp: January 31, 2015, 05:49:15 pm
content: What this cable attempts to do is possible using a purely passive approach, the switch shorts the data lines, but its up to the user to decide its safety or assume the port is smart enough to provide what it can. There is no assurance it will provide more than 500mA in response to the short as it depends on the vendor's implementation of USB standards.Full details here:http://en.wikipedia.org/wiki/USB#PowerA common problem via a USB cable has been the voltage drop across power lines within the cable. Typical cables are 28AWG wire power and data whereas cables supplied with device chargers often >= 24AWG on power lines.One thing this custom cable can supply too is insure the power lines are in the 20AWG range.http://billcprice.com/futureimperfect/2013/09/not-all-micro-usb-cables-are-equal-if-you-have-a-tablet-watch-out-for-2828-awg-vs-2824-awg/Qualcomm addresses the voltage drop issue by using higher output voltage coordinated with the charger circuits in the end device, called quick charger, or adaptive charging on Samsung devices.https://www.qualcomm.com/products/snapdragon/quick-chargeEvolving now is the USB PD standard for up to 100W of power which is an extension of the Qualcomm concept of higher output voltages.If 'magic cable' has some active components to emulate the higher output voltage approach [i.e., step up at input, then step down at output], it would still be limited in that it can't predict if its source can deliver more than 2.5W, so there is no benefit, and its active components would consume some power meant for the charging device reducing the power transfer further compared to dedicated systems like Qualcomm or USB PD.

author: mux
author_rank: Regular Contributor
timestamp: January 31, 2015, 10:27:12 pm
content: Seems extremely unlikely that they do anything on the power side. Higher power PSE/PD type stuff in USB 3.2/Thunderbolt/Ethernet is all based on upping the voltage dramatically while keeping current near or below 2A (to allow for thin cables). We're talking 50V, not 5.5V or something like that.

author: Stonent
author_rank: Super Contributor
timestamp: February 04, 2015, 05:50:39 pm
content: I've heard there are some smart chargers that cycle through the different resistor checks that some phones do until it figures out which one gets the phone to pull the most current.

author: mux
author_rank: Regular Contributor
timestamp: February 07, 2015, 05:18:41 pm
content: Yup, that is exactly what TPS2543 does.

author: Kalidor
author_rank: Regular Contributor
timestamp: June 27, 2015, 03:05:59 pm
content: Shipping time arrived and the backers are whining and raging. Not even that the magic "load twice as fast" button does nothing, the connectors are breaking off and some of the cables doesn't work at all.https://www.indiegogo.com/projects/sonicable-the-world-s-most-advanced-charging-cable/x/10280792#/comments

author: loneoceans
author_rank: Contributor
timestamp: June 28, 2015, 06:42:27 am
content: Quote from: Kalidor on June 27, 2015, 03:05:59 pmAlibaba (and ebay) has a lot of nice cheap nylon braided cables for about 10x cheaper..http://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=nylon+braided+lightning+cableSome of them even look pretty good:http://www.alibaba.com/product-detail/Good-quality-MFI-approved-braided-8_60215517045.html

author: PTR_1275
author_rank: Frequent Contributor
timestamp: June 28, 2015, 08:35:40 am
content: With some panel mount usb sockets we have at work, they list it is 2.5 amp capable. If you plug a 2 ohm resistor across the power lines, it can provide the 2.5 amps no problem (to a "dumb" load). As soon as I plug a phone or tablet in, the maximum I can get out of it is 1 or 2 amps respective to the device. On some older phones that I have tested, if you connect the power but don't connect the data lines, the phone draws the full 2.5 amps.I've seen cables (porta-pow do one) that claim 3 x faster charging, I've not tested one of these "marketed" ones, but 2 cheapies I bought just didn't connect the data line so the usb socket thought it was a dumb load and let the full power through. My iphone 5 won't charge at all on this because there is no data line, but it didn't stop them from saying it will charge the phone quicker.I am not sure if there are any smarts in these cables, the switch could just be bringing the data lines in and out of circuit. They data lines are definitely not going to use a noticeable amount of power. It would be interesting if anyone had bought one if they can tear it down and see how / why it works.Either way, if the phone manufacturer reccomends it to charge at 1 amp, thy risk the phone by trying to push more through? Sure, the battery can take the extra current, but what damage to the regulators etc... Are you doing over time.

author: SeanB
author_rank: Super Contributor
timestamp: June 28, 2015, 08:59:16 am
content: Check with Frankie Tong about those XZYStudios USB monitors, there are some that allow you to change charge mode and give both a monitoring and selectable charge current for the phone.

author: PTR_1275
author_rank: Frequent Contributor
timestamp: June 28, 2015, 09:01:59 am
content: Wow, that's pretty cool. I will look into those ones.

author: edy
author_rank: Super Contributor
timestamp: June 28, 2015, 05:35:41 pm
content: Quote from: Kalidor on June 27, 2015, 03:05:59 pmSounds like this company wanted some cheap advertising. Ever notice how the media blog Internet news sites pounce on this crowd-funding stuff because it gives them some exciting stats to report like number of backers, amount of money funded and growth and over funding percentage.But if they charge a premium price even for "audiophoolery" type stuff they better deliver premium quality built stuff, not dollar store stuff that falls apart!And if there was any more sophisticated stuff going on like chips to control current or talk to the device, don't you think they would have mentioned it? If they aren't saying anything it is probably because nothing too sophisticated is going on. A teardown would be good... but it seems like the product tears itself down for you.