The Exigo: A high performance USB charger - Page 1
Forum section: electronics / general

author: nathancrum
author_rank: Contributor
timestamp: August 24, 2014, 09:44:20 pm
content: Hi guys,We recently launched our Kickstarter for the Exigo USB charger:https://www.kickstarter.com/projects/1386151743/exigo-usb-chargerhttp://www.apparentlyconnected.com/We asked for some feedback here previously and got some good advice. Thankfully once we started testing the prototype subsystems we measured some significant performance advantages and the quality advantages are just a bonus now. We also added an OLED display for live feedback so that it's not just a black box.https://www.eevblog.com/forum/crowd-funded-projects/apparently-connected-advanced-usb-charger-survey/Thanks.

author: tszaboo
author_rank: Super Contributor
timestamp: August 24, 2014, 10:41:03 pm
content: Wow, that is a 250 dollar USB charger, without hub functionality, wireless charging or built in battery

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 24, 2014, 11:08:51 pm
content: Quote from: NANDBlog on August 24, 2014, 10:41:03 pmTurns out you can't charge a device at high currents while there is a data connection. In fact the data lines are forced to specific voltages in order to communicate the charger's current output capability.I did a lot of research on USB charging and it's actually much more of a PIA than most people realize.Wireless charging and battery also present problems for high speed high power charging. I've got a Qi charger and it never charges as fast as a wired connection. Battery solution is a different kind of product and no one talks about what happens when the battery dies in a few years, buy a whole new charger I guess.OLED display is my favorite feature on the Exigo. But I'm a data nerd.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 24, 2014, 11:09:45 pm
content: What a waste of time.How many devices can pull 3A? They will be expecting to have to deal with standard USB ports or chargers so won't even try to draw that much.5.5V may cause excessive power dissipation in devices using a linear regulator to charge a single cell, at best they will go into thermal limiting and charge more slowly.Low noise... You're charging a battery dude, it doesn't matterQuoteBecause there AREN'T ANY! But we'll mention is to help fool gullible idiots who don't know betterQuoteNo load figure is completely meaningless, but again, But we'll mention is to help fool gullible idiots who don't know better.Quoteexcuse me while I throw up.QuoteRMS...? I thought you said it was low noise....What a load of bollocks.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 24, 2014, 11:24:53 pm
content: Quote from: mikeselectricstuff on August 24, 2014, 11:09:45 pmMike, I'm afraid you are quite wrong on a few points.One, prior to the IPAD 4, nothing would draw more than 2.1A now the max is 2.5. What do you think will happen in 6mo as devices become more power hungry? 3A is very reasonable and future looking.Two, Linear regulator? Really? If you can find a modern product that uses a linear regulator in it send me your paypal email and I send you $20!!! Seriously though, Everything has a PMIC (Power Management Interface Controller) in it. The 5.5V is really about overcoming the voltage drop in the cable so that the DEVICE see's 5.0 to 5.5V. We've collected a lot of data and are happy to share it with you. The voltage boost works and helps. What you might not realize is that the PMICs will throttle down the current draw if they see less than 5V at the device pins.Most USB cables have an impedance on the order of 100 to 200 mohms. At 2A that's a LOT of voltage drop. The voltage boost really helps with this. It's also why we are going to be supplying low gauge USB cables.Interestingly the loss of voltage from the cable had the LARGEST impact on our charger measurements.Shoot us a PM if you want to see the raw measured data. It's pretty interesting.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 24, 2014, 11:28:03 pm
content: Unparalleled? Yes, user interface, adjustable charging parameters, and informational display. I'm not familiar with much else that can do that. Sorry you don't like marketing speak. It's the way of the world my friend, but at least it's true with our product.Charging faster. That's real too.Please use a baggie for your vomitI think you misunderstood the 10mV precision spec, that's regarding the DC output not the noise level (though it could be worded a little better).We've got good loaded noise specs too (gotta find them and didn't publish them yet). You many not care but audiophiles will. As you know, high harmonic content switching noise can propagate right through any filtering in the mobile device and end up on the line out/headphones. I agree the audiophiles go to the extreme but that's why they buy separate power supplies for their USB DACs.Overall you have fair comments Mike for a jaded pure engineer. But I gotta say the linear regulator comment is a boner!Anyway besides hating on it, tell us what you'd LIKE to see in something like this. What get's you excited about USB charging (heheh if that's even possible!!). I know yer not all hate and have a LOT of good ideas too, some of your sculptures are awesome.

author: Skimask
author_rank: Super Contributor
timestamp: August 24, 2014, 11:54:13 pm
content: 40 suckers so far...

author: jeremy
author_rank: Super Contributor
timestamp: August 25, 2014, 12:11:21 am
content: Quote from: Gallymimus on August 24, 2014, 11:24:53 pmI hope you weren't serious about that? here is one, right next to the speaker: 5.jpg on this pagehttps://www.eevblog.com/forum/reviews/siglent-sds1000-7'-oscilloscope-anatomy/

author: Afrotechmods
author_rank: Unknown
timestamp: August 25, 2014, 12:26:14 am
content: I will try be constructive.I feel like your MSRP of $295 is unrealistically high, limiting your target customer base to mainly businesses with huge budgets. I could buy an oscilloscope with $295. If I was trying to get funding for my department it would be difficult for me to make the case to management as to why they should spend $300 on chargers when everyone who has a phone or tablet already has a charger that already works. And even if our chargers died on us, you could buy 4x Apple 12W original chargers + cables which would be UL/CE certified for $100. Just because terrible $5 chargers exist doesn't mean I have to spend $300 to get a good charger.One of your main product differentiators is a 3A charge rate which is a hard sell because there isn't any device on the market that can currently make use of this. But let's say in 1 year's time the iPhone 7 charges at 3A - what's stopping me from buying 4x Apple 3A chargers for $120?I think your industrial design and the OLED display is attractive, but adds a lot of money to the BOM without increasing useful functionality to the end user. I say this because I can't see myself spending much time looking at a charger charging. If I want to know how fully charged the device is I can just look at the device. I don't think most people would be interested in knowing the exact voltage and current being output at any given time, they are satisfied with the simple little battery bar in their phone slowly going up.

author: John_ITIC
author_rank: Frequent Contributor
timestamp: August 25, 2014, 12:36:18 am
content: I congratulate you on a great marketing job. Looks very slick. I'm quite confident that the "crowd" will find your products cool. I'm not convinced, though, that the electrical engineers hanging out here will see the benefits quite as easily.All iPod, iPhone devices do come with free chargers and adding a "premium" one will not actually improve the charging time. I assume that Apple, Samsung and other reputable vendors have correctly designed its chargers to provide adequate charging current for its devices.Even though a battery source isableto provide a higher current doesn't mean that a load will actually consume more current. The current consumed is of course dictated by the input impedance of the battery charging circuitry in the device being charged and not by the capabilities of the charger.Personally, in case I needed a multi-port charger, I would grab one from Amazon for $12.99http://www.amazon.com/iFlash%C2%AE-Fastest-Smartphones-Universal-Compatibility/dp/B00B6RQLI6By the way, how did you get this approved by Kickstarter? I thought that "renderings" were not sufficient and that a prototype was required? Were your two PCBs enough to pass the KS review process?Thanks,/John.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 25, 2014, 12:41:00 am
content: Quote from: jeremy on August 25, 2014, 12:11:21 amsorry, you misunderstood and I need to reword what I said. I meant a linear regulator on the input of a mobile device (phone tablet) feeding the charger circuitry).

author: mariush
author_rank: Super Contributor
timestamp: August 25, 2014, 12:43:29 am
content: Quote from: Gallymimus on August 24, 2014, 11:24:53 pmWhen they're going to need more than 2-3A, they're going to switch to usb 3.0 and negotiate 12v @ 1A or higher.. see slide 9http://www.usb.org/developers/powerdelivery/PD_1.0_Introduction.pdfQuoteNot only that, but is this device capable of customizing the voltages on D- and D+ just in case Apple comes up with another hack...my 2 cents.. too expensive, too big, hard to carry around... another thing that's painfully obvious to me... is there a laptop adapter style power adapter powering that box, or there's a smps inside the box

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 25, 2014, 12:45:11 am
content: Quote from: Afrotechmods on August 25, 2014, 12:26:14 amThanks for the feedback. I think you are spot on with your comments. This is definitely a high end not for everyone product. Really appreciate you taking a look though. Glad you like the industrial design. Looking nice is an important aspect of something at this price point.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 25, 2014, 12:49:11 am
content: Quote from: John_ITIC on August 25, 2014, 12:36:18 amThanks for the comments John. It's not actually true that the OEM chargers do as good of a job. We never would have thought it was true until we tested it and actually saw a significant improvement over OEM (specifically IPAD 4, and Samsung Galaxy S4). I am pretty sure it was because of cable losses. I can understand Samsung not being able to predict cable losses with a variety of USB micro cables, BUT with Apple they expect you to use the OEM lighting cable. So, it's befuddling, but our charger provided about 25% more power to both devices while charging.As for you Kickstarter question. They are getting weird with their rules. When we asked, they hassled us. When we put up the project they didn't even look at it. Then they came back and hassled us again. If you read the rules though they specifically state you can not use rendering that might be confused for a finished poduct. We added the indication on the pictures to be clear so there won't be confusion.

author: c4757p
author_rank: Super Contributor
timestamp: August 25, 2014, 12:52:40 am
content: Quote from: Gallymimus on August 25, 2014, 12:45:11 amIndeed - in fact, I'd say it's this thing's entire raison d'être.Seriously folks, just buy a nice picture to hang on the wall.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 25, 2014, 12:53:22 am
content: Quote from: mariush on August 25, 2014, 12:43:29 amMaybe,Traditionally Apple hasn't stuck with the standards. The power delivery spec you cited is actually a bit old and is deprecated. Just a few days ago they released the new connector for the power delivery spec ( I don't know the details but the SMSC guys at the Microchip Master's conference were talking about it a few days ago). I agree though, PD is going to be the future if it catches on. We're already working on a PD deviceand we are also waiting for the dust to settle on it so we're not chasing changing specs.

author: John_ITIC
author_rank: Frequent Contributor
timestamp: August 25, 2014, 01:51:39 am
content: Quote from: Gallymimus on August 25, 2014, 12:49:11 amI would not consider voltage drop in a cable be a reason for replacing my free iPad charger with a $295 one, even if the charging time did go down 25% from 6 hours to 4.5. But then again, I would not buy monster speaker cable either. Lamp cord sounds just as good and I don't worry about the cable losses in the scheme of things.Somehow, though, this reminds me of Dave's 2009 video regarding Audiophile Audiophoolery...Also, it reminds me of a book I recently read regarding making claims few can verify.http://www.amazon.com/Making-Them-Believe-Legendary-Testicles/dp/0982379382Anyways, it will be interesting to see how you guys will do.

author: fubar.gr
author_rank: Unknown
timestamp: August 25, 2014, 06:31:40 am
content: I am frustrated with car chargers and am in the process of designing one of my own for my personal use, so I've done quite some research on the subject. So here are some comments:I agree OEM chargers can be underperforming too and I don't think it is just due to the voltage drop of the cable. Simply put, a tiny, tightly packed, plastic, non ventilated charger is going to overheat no matter what and thermal protection will kick in limiting the current.Car chargers are even worse, because they are totally engulfed by the lighter socket. To make things worse, the lighter socket is usually in the center console of the car, right above the exhaust pipe path, so it is already warmer than the rest of the car's cabin.Your product will encounter the same problem if there's no proper thermal management.The price for your product seems a bit steep at first glance but is probably not totally out of whack. A proper DC to DC converter, negotiation chips for each port, mcu and OLED screen is going to cost money. Heh, a good DC to DC controller chip alone can cost several times more than a fully assembled chinese crap charger.I have no doubt that your product does what it advertises and that the final price is fair considering the BOM. Problem is that Joe Average will scream bloody murder if the product was priced at $50, let alone $290!I think you are well into diminishing returns, basically trying too hard to solve a minor problem that most people do not care about.

author: mzzj
author_rank: Super Contributor
timestamp: August 25, 2014, 08:50:37 am
content: Does this run on separate 12 v or so power supply?You plan to buld your own power supply or buy something readily availlable?Fancy aluminium box for crazy price, included with cheapets chinese 12v power brick that makes all yourlow- noise, reliability, safety marketing talk worthless?

author: mzzj
author_rank: Super Contributor
timestamp: August 25, 2014, 09:09:37 am
content: Quote from: mzzj on August 25, 2014, 08:50:37 amSorry, only checked your website and skipped kickstarter website altogether. So it runs on external 24v power supply.How did you budget your agency approval tests, ie CE and FCC emc sirectives among others?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 25, 2014, 09:15:46 am
content: Quote from: Gallymimus on August 24, 2014, 11:24:53 pmAnything that draws this much will be very much the exception, and will come with its own charger. Paying to provide multiple ports with that capacity is a waste of money.QuoteBluetooth headsetsBluetooth keyboardsPretty much anything with a low capacity cell.A specific example :paypal : mike @ whitewing.co.uk.QuoteIt doesn't add to your credibility that you don't even know how to use an apostrophe.QuoteIt's DC, the appropriate term is resistanceQuoteTrue - there are a lot of crappy USB cables out there. But anything supplied with a 2A charger is going to have a decent cable. The problem is when people lose/break it and use a cheap crappy one.It's an unnecessarily over-engineered expensive solution to a problem very few people will see as worth spending that much to solve, so you're trying to hype it up with irrelevant details and marketing waffle.The vast majority of people will leave stuff to charge overnight, so charge time will not be an issue for them.

author: mrflibble
author_rank: Super Contributor
timestamp: August 25, 2014, 09:23:17 am
content: Interesting project. From a psychology point of view.

author: mhwlng
author_rank: Contributor
timestamp: August 25, 2014, 09:23:53 am
content: I use this Anker 40W 5-Port Charger for both charging and powering any 5V device (replaces 5 wall-warts) :http://www.amazon.co.uk/dp/B00GYNW1TA

author: tszaboo
author_rank: Super Contributor
timestamp: August 25, 2014, 11:59:25 am
content: Quote from: Gallymimus on August 24, 2014, 11:08:51 pmMy problem is that there is nothing in it, which would justify the price.Yes, wireless charging is slow, I give you that. There is usually a 6-7 hour period in my day, when I'm not doing anything.There are battery product with replaceable cells. And I dont need a OLED display. Why would I? There is a screen on my phone/tablet/ebook which tells me when the charging is complete.But seriously, you can probably sell this product. It already sells. Although this is an electronics forum, people kinda aware how much something should cost. Just a quick calculation:60W laptop power supply (FSP): 25 USD4x LMZ22005 5A SIMPLE SWITCHER® Power Module 4*6USDCharging port contoller: TPS2513A 2*1USDPCB: 5 USD in quantity (European manufacturer)Assembly: About 4-5 USD, European manufacturerHousing: I cannot give you an estimation.OLED 20 USDWhatever MCU platform 10 USDThat is about 100 USD + housing.And I chose deliberately stupidly expensive components.So you have 4*4A charging capability. To charge 4 tablet, as nothing else seems to take this amount of power. Well, I don't have 4 tablets.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 26, 2014, 12:08:37 am
content: Quote from: John_ITIC on August 25, 2014, 01:51:39 amI'm not going to argue with you on your comments. They are fair and the same one's I'd apply to a monster cable product. We are definitely targeting those who want to squeeze the last little bit of performance and style out of their gadgets. It's not for everyone.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 26, 2014, 12:11:28 am
content: Quote from: fubar.gr on August 25, 2014, 06:31:40 amThanks for the comment. It is amazing the crap they put into $5 chargers and you are right, a good regulator IC and quality mosfets cost more by themselves. We are intentionally on the high side of that cost/value curve, but we wanted to take a shot at the very best. We'll see how it goes. If it doesn't work out we'll regroup, pivot, and make another go at it.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 26, 2014, 12:14:27 am
content: Quote from: mzzj on August 25, 2014, 09:09:37 amActually one of the reason's we'll be using a pre-approved off line power brick is that it removes the CE and UL testing requirements. FCC is technically still required, unintentional radiator compliance doesn't cost much (few thousand).As for your other comment regarding a cheap power brick, we don't want to use crap, but we would like it to be reasonably cost effective. As for the quality of the power brick, the multiphase and LDOs do a great job cleaning up whatever crap might come out of the power brick.

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 26, 2014, 12:26:59 am
content: Quote from: mikeselectricstuff on August 25, 2014, 09:15:46 amhahah, chasing me after apostrophes?You are right I must be a terrible engineer. Does your simple website make you a bad engineer? I doubt it, you are probably awesome at what you do.using devices that aren't really in the realm of this product as a reason that linear regulators mean our product sucks? Really? okay, so don't buy it for a chinese bluetooth headset, who cares about that, clearly our target is cell phones and tablets which do use switching PMICs and the LDO comment is still a BONER. Does boner even mean anything in this context or did I make up a new meaning for it?Impedance vs resistance? Really? Trying to ding me on that? I won't even go to the trouble to say it's the same thing if your imaginary contribution to the impedance is zero. BUT, I know you know I know you already know that. Yer just trying to get under the proverbial skin.That's good that your grasping for reasons to hate, that means any real issues with the product have been fully discussed to completion.Mike in all seriousness, thanks for the interest and comments. I had no expectation that we'd get any less criticism on EEVBlogHow long have you been consulting for anyway?

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 26, 2014, 12:27:47 am
content: Quote from: mhwlng on August 25, 2014, 09:23:53 amThis is an awesome basic charger. I have 2 of them!

author: Gallymimus
author_rank: Regular Contributor
timestamp: August 26, 2014, 12:32:27 am
content: Quote from: NANDBlog on August 25, 2014, 11:59:25 amyer not terribly far off, OLED is actually quite a bit less. Don't forget DACs for trimming the output, quality LDOs for noise for the audiophiles.Also don't forget the all important margin, we have to sell it, make money, and leave room for distribution and retail which is unbelievable, especially when you don't have leverage. Trust me we're not trying to rip off the world, or we'd have done a project on indiegogo. How much do you think gross margin should be, then markup for wholesale distribution, then retail?

author: Monkeh
author_rank: Super Contributor
timestamp: August 26, 2014, 01:04:54 am
content: What an amusingly pointless device, and yet I have a topical question.Where have you found USB A receptacles rated for 3A continuous?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 26, 2014, 08:52:27 am
content: Quote from: Gallymimus on August 26, 2014, 12:26:59 amIt just looks bad - If you don't care about getting that right, what else don't you care about getting right?QuoteSimple, yes. but correctly spelt and punctuated (typos notwithstanding).QuoteJust pointing out that your out-of-spec high output voltage could potentially cause problems.I sort of got the impression that a major point the whole point is that you have one charger for all your stuff.QuoteAbout 30 years

author: fubar.gr
author_rank: Unknown
timestamp: August 26, 2014, 10:20:19 am
content: Quote from: mikeselectricstuff on August 26, 2014, 08:52:27 amThis is simply a feature most USB charging controller chips have. If the controller detects a high current draw device (by setting the voltages on D+/D-) and some other specific conditions apply then it will raise the voltage a bit to overcome the voltage drop of the cable.It poses absolutely no threat for devices with linear regulators.

author: Monkeh
author_rank: Super Contributor
timestamp: August 26, 2014, 10:24:45 am
content: Quote from: Gallymimus on August 25, 2014, 12:49:11 amBut they modelled the supplied charging cable pretty much perfectly.You did test that cable, right?

author: tszaboo
author_rank: Super Contributor
timestamp: August 26, 2014, 11:41:46 am
content: Quote from: Gallymimus on August 26, 2014, 12:32:27 amYes the profit margin. Many KS project fails to understand how this works. Kickstarter is not a platform to sell premium products with premium price. People dont want that. It is not a sale platform.At kickstarter people actually lend their money to "kickstart " the production of something. You know, the money otherwise you end up getting from a bank with interest or making shares or some other way, which costs you money.Asking for a loan to make something with premium profit is not honest IMHO. Especially if it is a consumer product, which typically sells with very low profit margins. Alternative products sell for the fraction of the price. The last 1 or 2 days two units were sold.I always ask people selling things: Tell me honestly: would you buy this?

author: Monkeh
author_rank: Super Contributor
timestamp: August 30, 2014, 08:46:07 pm
content: It appears we scared them off by not accepting their project with open arms as the future of USB charging devices.

author: Flump
author_rank: Frequent Contributor
timestamp: August 30, 2014, 09:31:36 pm
content: haha

author: classical
author_rank: Regular Contributor
timestamp: August 31, 2014, 02:54:14 am
content: The automatic selecting of the correct circuit to provide "fast charging" is a very good and helpful thing.I guess, a price sticker of 10 or 15 USD above the "Anker 40W, 5Port" charger mentioned by mhwlng would motivate some customers.

author: marcan
author_rank: Regular Contributor
timestamp: August 31, 2014, 06:41:27 am
content: Quote from: classical on August 31, 2014, 02:54:14 amThe Anker charger already does that. Marketingese aside, that's what PowerIQ is.http://www.ianker.com/poweriq/poweriq.htmlTI has a chip that does this for you automatically:http://www.ti.com/lit/ds/symlink/tps2543.pdfThis isn't news. Yes, most el cheapo USB chargers out there are garbage, but you can get adecent 25W 4-port charger for about 15 bucks. I have one of those; tore it apart and it looks solidly built on the inside, and the output was pretty clean on the scope, and I'm never going to pull more than that much power out of 4 ports (my only high-current device is a tablet); all I did was remove the stupid Apple style divider resistors and turn the ports into standard DCPs. I can see shelling out $50 for a premium charger, but $250 is just way past the sensible pricing threshold.

author: classical
author_rank: Regular Contributor
timestamp: August 31, 2014, 08:52:22 am
content: Thanks, marcan for the info about the Anker PowerIQ. I also just found the TI TPS 2511http://www.ti.com/lit/ds/symlink/tps2511.pdfdoing the same.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 31, 2014, 09:15:49 am
content: I think the kickstarter figures say it all...

author: tszaboo
author_rank: Super Contributor
timestamp: August 31, 2014, 09:32:45 am
content: Quote from: mikeselectricstuff on August 31, 2014, 09:15:49 amWow, they sold it to other five people other than family members.

author: classical
author_rank: Regular Contributor
timestamp: September 01, 2014, 08:58:19 pm
content: The 0.5A of slow charging could be not enough to enable continuous operation for tablet (status display for home automation) or smartphone (navigation).Gesendet von meinem K1 turbo mit Tapatalk

author: amyk
author_rank: Super Contributor
timestamp: September 02, 2014, 06:03:07 am
content: Quote from: Gallymimus on August 26, 2014, 12:26:59 amHow many of them do?This is the block diagram of the charger part of a PMIC used in ahugenumber of smartphones, including the one I have. Does this look like a switching charger to you?

author: tom66
author_rank: Super Contributor
timestamp: September 03, 2014, 09:26:50 am
content: I'd like to see a charger which interfaced with an app on the phone. When the battery reached 90%, it would stop charging.Most phones charge to 4.25V to get the absolute max capacity out of the cell, but if you stop charging at 4.15V, the cell lasts much longer. (And stop discharging below 3.2V.)Ever wondered how you can get long life out of electric car batteries? Don't charge them fully. Tesla stop at 4.16V/cell abs max (and 3.2V/cell abs min) and rate the batteries for 8 years in a punishing automotive application.

author: Dago
author_rank: Frequent Contributor
timestamp: September 03, 2014, 12:51:25 pm
content: Quote from: tom66 on September 03, 2014, 09:26:50 amMight not be a fair comparison to compare Tesla batteries to mobile phones because the chemistry is not the same (currently tesla is using Panasonic cells with lithium-nickel-cobalt-aluminum oxide chemistry which has a longer lifetime).

author: Refrigerator
author_rank: Super Contributor
timestamp: September 03, 2014, 03:47:38 pm
content: Quote from: mojo-chan on September 02, 2014, 09:34:10 amI guess he spends his whole night watching porn.Fast charging is pretty punishing to mobile devices that use Li-Ion batteries but many devices use them because of their high evergy density. Some use Li-Po batteries that can achieve high charging current but there aren't many out there.IMO if you try to fast charge Li-Ion batteries they just become ticking bombs waiting to burst into flames.

author: brabus
author_rank: Frequent Contributor
timestamp: September 09, 2014, 11:22:17 am
content: Quote from: Gallymimus on August 24, 2014, 11:24:53 pmSamsung Galaxy SII i9100 uses a linear regulator.I wait before listing the next products, because I have a question: do you give 20$ for every one?I have a more serious technical question. Is the output voltage of your super-charger fixed to 5.5V, in every circumstance?If this is true, may I ask you the reason for such a technical choice?Please do not be offended, I just want to understand your point.Last question: do you offer any form of warranty for damages caused by your out-of-spec charger?

author: CanadianAvenger
author_rank: Regular Contributor
timestamp: September 09, 2014, 04:46:07 pm
content: Quote from: mojo-chan on September 09, 2014, 03:40:55 pmYou can probably do that now without a special cable, by taking advantage of the fact that there is a pull-up on D+ or D- that is used to identify LS or FS/HS, and device presence.

author: Monkeh
author_rank: Super Contributor
timestamp: September 09, 2014, 06:02:52 pm
content: Quote from: brabus on September 09, 2014, 11:22:17 amWhat's out of spec about it?Quote from: mojo-chanYou mean like Samsung do with their 2A chargers?

author: brabus
author_rank: Frequent Contributor
timestamp: September 10, 2014, 04:16:53 pm
content: Quote from: Monkeh on September 09, 2014, 06:02:52 pmCorrect if I am wrong, but I remember a 5V nominal voltage with a +/- 5% tolerance, hence 5.25V maximum, isn't it?

author: tszaboo
author_rank: Super Contributor
timestamp: September 10, 2014, 05:18:36 pm
content: 2.0 is specified 5V +/- 5%USB 3.0 is 5V +0,25V/-0,55V (Why USB-IF, WHY??)

author: Monkeh
author_rank: Super Contributor
timestamp: September 10, 2014, 06:00:09 pm
content: Go fetchhttp://www.usb.org/developers/docs/usb20_docs/usb_20_081114.zipand read the VBUS ECN.Yes, it's very recent.

author: tszaboo
author_rank: Super Contributor
timestamp: September 10, 2014, 06:21:56 pm
content: Quote from: Monkeh on September 10, 2014, 06:00:09 pmThis is interesting. Hovewer:"OEM’s can design products that support the higher power levels of the Type-C connector and provide VBUS levels at or above 5.25V..."So you need the type C connector for that.

author: Monkeh
author_rank: Super Contributor
timestamp: September 10, 2014, 06:24:37 pm
content: Quote from: NANDBlog on September 10, 2014, 06:21:56 pmNo, you don't, and that's not the specification, that's a reasoning. VBUS has been raised to max 5.5V, simple as.

author: Monkeh
author_rank: Super Contributor
timestamp: September 11, 2014, 12:14:56 pm
content: Quote from: mojo-chan on September 11, 2014, 06:31:38 amThat's what Samsung 2A chargers do, and I have tested this. The output voltage of the charger rises with increasing current to offset the volt drop of the supplied, characterized cable.

author: marcan
author_rank: Regular Contributor
timestamp: September 13, 2014, 02:34:52 pm
content: Quote from: Monkeh on September 11, 2014, 12:14:56 pmI must say this sounded way too smart for Samsung and you just made me test my 2A charger, but you're right. 5.01V at the port no load, 5.08V pulling ~1A. I'm not sure where I put the original cable right now, so I can't test it, but that sounds reasonable for a decent cable. Clever.

author: grenert
author_rank: Frequent Contributor
timestamp: September 13, 2014, 03:06:29 pm
content: Ist kaputt:https://www.kickstarter.com/projects/1386151743/exigo-usb-charger/posts

author: amyk
author_rank: Super Contributor
timestamp: September 14, 2014, 01:09:38 pm
content: Quote from: marcan on September 13, 2014, 02:34:52 pmIt's nothing more than a minor change to the regulation loop, even some of the cheap (but not cheapest) no-name adapters have it.

author: tszaboo
author_rank: Super Contributor
timestamp: September 14, 2014, 03:30:55 pm
content: Quote from: grenert on September 13, 2014, 03:06:29 pmThat is actually good. Looks like lesson leared.Good luck with the redesign!

author: marcan
author_rank: Regular Contributor
timestamp: September 14, 2014, 05:00:01 pm
content: Quote from: amyk on September 14, 2014, 01:09:38 pmOh, I know it's easy to implement, I'm just surprised they bothered/thought of it. I don't think any of my other adapters do it, but then again the rest are either cheapies or multiport ones (with shared regulation) where it wouldn't make sense.

author: timb
author_rank: Super Contributor
timestamp: September 21, 2014, 10:59:17 am
content: By the way, Mike was right about linear regulators being everywhere with regards to USB battery charging. LiPo charging chips come in two flavors: Linear and Switching. Go check out TI's product portfolio.Increases voltage = increased heat = higher chance of things breaking.Sent from my Smartphone