The Exigo: A high performance USB charger

[nathancrum]

Hi guys,

We recently launched our Kickstarter for the Exigo USB charger:
https://www.kickstarter.com/projects/1386151743/exigo-usb-charger



http://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.

[tszaboo]

Wow, that is a 250 dollar USB charger, without hub functionality, wireless charging or built in battery

[Gallymimus]

Wow, that is a 250 dollar USB charger, without hub functionality, wireless charging or built in battery

Turns 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.

[mikeselectricstuff]

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 matter

Most modern devices will survive even extreme levels of electrical noise, but long term affects are largely unknown.

Because there AREN'T ANY! But we'll mention is to  help fool gullible idiots who don't know better

<0.1uV/sqrt(Hz) output regulator spectral noise spec (no load)

No load figure is completely meaningless, but again,  But we'll mention is to  help fool gullible idiots who don't know better.

Unparalleled charging experience

excuse me while I throw up.

High precision +/- 10mV RMS output

RMS...? I thought you said it was low noise....

What a load of bollocks.

[Gallymimus]

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 matter

Mike, 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.

[Gallymimus]

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 vomit

I 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.

[Skimask]

40 suckers so far...

[jeremy]

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.

I hope you weren't serious about that? here is one, right next to the speaker: 5.jpg on this page

https://www.eevblog.com/forum/reviews/siglent-sds1000-7'-oscilloscope-anatomy/

[Afrotechmods]

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.

[John_ITIC]

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 is able to 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 $12.99
http://www.amazon.com/iFlash%C2%AE-Fastest-Smartphones-Universal-Compatibility/dp/B00B6RQLI6

By 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.

[Gallymimus]

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.

I hope you weren't serious about that? here is one, right next to the speaker: 5.jpg on this page

https://www.eevblog.com/forum/reviews/siglent-sds1000-7'-oscilloscope-anatomy/

sorry, 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).

[mariush]

Mike, 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.

When 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 9 http://www.usb.org/developers/powerdelivery/PD_1.0_Introduction.pdf

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?

Not 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 

[Gallymimus]

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.

Thanks 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.

[Gallymimus]

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 is able to 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 $12.99
http://www.amazon.com/iFlash%C2%AE-Fastest-Smartphones-Universal-Compatibility/dp/B00B6RQLI6

By 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.

Thanks 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.

[c4757p]

Looking nice is an important aspect of something at this price point.

Indeed - 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.

[Gallymimus]

Mike, 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.

When 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 9 http://www.usb.org/developers/powerdelivery/PD_1.0_Introduction.pdf

Maybe,

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.

[John_ITIC]

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.

I 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/0982379382

Anyways, it will be interesting to see how you guys will do.

[fubar.gr]

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.

[mzzj]

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? 

[mzzj]

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? 
 

Sorry, 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?

[mikeselectricstuff]

Mike, 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.

Anything 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.

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!!!

Bluetooth headsets
Bluetooth keyboards
Pretty much anything with a low capacity cell.
A specific example :

paypal : mike @ whitewing.co.uk.

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.

It doesn't add to your credibility that you don't even know how to use an apostrophe.

Most USB cables have an impedance on the order of 100 to 200 mohms.

It's DC, the appropriate  term is resistance

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.

True - 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.

[mrflibble]

Interesting project. From a psychology point of view.

[mhwlng]

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

[tszaboo]

Wow, that is a 250 dollar USB charger, without hub functionality, wireless charging or built in battery

Turns 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.

My 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 USD
4x LMZ22005 5A SIMPLE SWITCHER® Power Module 4*6USD
Charging port contoller: TPS2513A 2*1USD
PCB: 5 USD in quantity (European manufacturer)
Assembly: About 4-5 USD, European manufacturer
Housing: I cannot give you an estimation.
OLED 20 USD
Whatever MCU platform 10 USD

That 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.

[Gallymimus]

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.

I 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/0982379382

Anyways, it will be interesting to see how you guys will do.

I'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.