USB "charger doctor" (volt+current display)

143 replies [Last post]
Danglerb
Offline
Last seen: 4 weeks 3 days ago
Title: ★★★
Joined: 10/07/2012
Posts: 330
Location: SoCal
http://www.eevblog.com/projec

http://www.eevblog.com/projects/ucurrent/ Thanks nice site. I do know this stuff BTW, but its been awhile since I’ve done it.

This little USB device has a smaller range for current and I believe uses a smaller resistor with much less drop.

__________________

Still a bit dim

HKJ
HKJ's picture
Offline
Last seen: 42 min 32 sec ago
Title: ★★★★★
Joined: 05/24/2011
Posts: 2438
Location: Copenhagen, Denmark
Danglerb

Danglerb wrote:
http://www.eevblog.com/projects/ucurrent/ Thanks nice site. I do know this stuff BTW, but its been awhile since I've done it. This little USB device has a smaller range for current and I believe uses a smaller resistor with much less drop.

This little box is a x100 amplifier and some resistors, i.e. when measuring 200mA (on the 1mV/mA range) it is 200mV on you DMM and that means a 2mV drop over the resistor.

__________________

My website with reviews of flashlights, chargers and batteries: http://lygte-info.dk/

Danglerb
Offline
Last seen: 4 weeks 3 days ago
Title: ★★★
Joined: 10/07/2012
Posts: 330
Location: SoCal
Thanks nice site. I do know

Thanks nice site. I do know this stuff BTW, but its been awhile since I’ve done it. This little USB device has a smaller range for current and I believe uses a smaller resistor with much less drop.

I meant the USB display device, not the uCurrent.

__________________

Still a bit dim

Werner
Werner's picture
Offline
Last seen: 35 min 16 sec ago
Title: ★★★★★
Joined: 10/19/2012
Posts: 2557
Location: Germany
For example with my android

For example with my android phone I get around 0.1A less current with the charger doctor between…

Danglerb
Offline
Last seen: 4 weeks 3 days ago
Title: ★★★
Joined: 10/07/2012
Posts: 330
Location: SoCal
Werner wrote:For example with

Werner wrote:
For example with my android phone I get around 0.1A less current with the charger doctor between…

Measured how?

__________________

Still a bit dim

Werner
Werner's picture
Offline
Last seen: 35 min 16 sec ago
Title: ★★★★★
Joined: 10/19/2012
Posts: 2557
Location: Germany
With battery app, shows

With battery app, shows charging current. With device in between its correct about 7xxmA and without the current increase to 8xxmA. I have tested it several times.
If I choose a cheap cable current decreases further, sometimes funny. For example I have a retractable 3in1 cable from fasttech, mini usb, micro USB, iPad dock connector(old) and this is really garbage.

On my ipad it makes no difference, but I have a 2m cable which almost charges nothing when the screen is on, I now have measured it and current with long cable is 0.8A vs 1.8A without…I played around with a ihustle and other things.
The charger doctor is a neat device, but it is always good to have measuring tolerances and failures in mind…0.1V is still much drop

I don’t know if maybe the datalines are corrupted in the bad cables so that the devices don’t go to fast charge mode or if the voltage over the cable is so high that it doesn’t charge higher. Maybe I should check if the cable get warm…

The ucurrent reminds me on the current measuring PCB I have laying around since HKJ review. I extra ordered the amp range which has 0.1V per Amp or so, that I can use it with multimeter without calculating so much…

HKJ
HKJ's picture
Offline
Last seen: 42 min 32 sec ago
Title: ★★★★★
Joined: 05/24/2011
Posts: 2438
Location: Copenhagen, Denmark
Werner wrote:The ucurrent

Werner wrote:
The ucurrent reminds me on the current measuring PCB I have laying around since HKJ review. I extra ordered the amp range which has 0.1V per Amp or so, that I can use it with multimeter without calculating so much...

It was not really a review, more a "build you own current measuring device with low voltage drop" article.

__________________

My website with reviews of flashlights, chargers and batteries: http://lygte-info.dk/

fartybum
Offline
Last seen: 9 hours 25 min ago
Title: ★★★
Joined: 08/17/2012
Posts: 286
Location: UK
Werner wrote: The charger

Werner wrote:

The charger doctor is a neat device, but it is always good to have measuring tolerances and failures in mind…0.1V is still much drop.

Possibly less drop, than the production tolerance in individual chargers.

Danglerb
Offline
Last seen: 4 weeks 3 days ago
Title: ★★★
Joined: 10/07/2012
Posts: 330
Location: SoCal
First rule of measuring

First rule of measuring stuff, everything matters. I would make a test rig, a dummy load on one end of a USB connection and voltage test points on both ends and do some testing.

With a 1A different I suspect you are correct and its not switching to high current mode. Stock I think USB is only good for 500 ma. but some do more.

Agree, cute device, not much of a measurement tool.

__________________

Still a bit dim

Chloe
Chloe's picture
Offline
Last seen: 1 day 7 hours ago
Title: ★★★★★
Joined: 01/30/2013
Posts: 4322
Location: 联合王国
I think you might be

I think you might be expecting a little too much, given the price.

__________________

spaceboy
Offline
Last seen: 1 day 4 min ago
Title: ★★★
Joined: 05/12/2011
Posts: 389
Location: Edinburgh
Works fine for me.

Works fine for me.

bguy
Offline
Last seen: 2 days 10 hours ago
Title: ★★
Joined: 05/05/2013
Posts: 19
Location: San Leandro, CA
spaceboy wrote:Works fine for

spaceboy wrote:
Works fine for me.

Same here. For the about $3, it tells me what I need.

I tested 2 iPhone 5 lightning cables. One got 500ma no matter what charger I plugged it into. The second got 750ma in all the chargers. My Galaxy S4 got 1A. Both phones were around 95% charged, so that may have lowered the current a little too.

That was testing chargers, both cigarette plug and AC. All capable of 1A or better. On a PC, I get 300ma on my S4, which is reasonable, but takes forever to charge.

asval
Offline
Last seen: 2 weeks 2 days ago
Title: ★★
Joined: 05/22/2012
Posts: 146
Mine arrived a few days ago

Mine arrived a few days ago and I finally got around to testing it with some solar panels

2 Brunton explorer solar panels rated at 1000ma, first one gave out around 700ma and the second one around 500ma

Cottonpickers solar panel rated at 330ma gave out around 100ma

As others said it’s hard to see the display under the sun

Werner
Werner's picture
Offline
Last seen: 35 min 16 sec ago
Title: ★★★★★
Joined: 10/19/2012
Posts: 2557
Location: Germany
I have opened the Case to

I have opened the Case to investigate why the shunt resistor is hanging around a bit angled and it seems to be something small red underneath, maybe to give some distance to the PCB or so? Over the display there was a protection foil which I removed, not sure if this make reflections worse?
I will play with that next week as I want to add a switch to shortcut the data lines for high current charging of phone and tablet with any USB source…

leaftye
Offline
Last seen: 1 hour 21 min ago
Title: ★★★★★
Joined: 07/25/2012
Posts: 3112
Location: San Diego, CA
estore999 did well.  Ordered

estore999 did well.  Ordered mine on 9/10, delivered today, 9/23.

__________________

The low mode should be lower.

MAP list of shame: Niwalker

BLF on reddit

When a man’s freedom is reduced to zero, he commits no crimes.

watalee
Offline
Last seen: 39 weeks 3 days ago
Title: ★★
Joined: 09/23/2013
Posts: 15
Location: Holding the proverbial flashlight
HKJ wrote:I can see that

HKJ wrote:

I can see that Chloe got the nice version, mine is not very nice in soldering:

 

many products made in china are not so good because the prices have to be cheaper and cheaper.

__________________

(This post/thread "may" contain referrals,a little contribution I "earn" in form of points ONLY if you buy the item. The purpose is to redeem items using the points and then making reviews of them in the forums to share info about them. It will not cost you anything. I dont "earn" anything if you ONLY click the link) www.coolicool.com

Pinetreebbs
Pinetreebbs's picture
Offline
Last seen: 6 hours 31 min ago
Title: ★★★
Joined: 07/29/2012
Posts: 522
Location: South Carolina, USA, Earth
Glenn7 wrote:Getting me one

Glenn7 wrote:
Getting me one of these, you can still preorder http://www.kickstarter.com/projects/david-toledo/the-practical-meter-know-your-power

Thanks! I ordered one to get their Fast-Charge 3-in-1 Cable.

Danglerb
Offline
Last seen: 4 weeks 3 days ago
Title: ★★★
Joined: 10/07/2012
Posts: 330
Location: SoCal
Pinetreebbs wrote:Glenn7

Pinetreebbs wrote:
Glenn7 wrote:
Getting me one of these, you can still preorder http://www.kickstarter.com/projects/david-toledo/the-practical-meter-know-your-power

Thanks! I ordered one to get their Fast-Charge 3-in-1 Cable.

Yipes, $19 for 5 bar led, vs $3 for digital readout.

__________________

Still a bit dim

Werner
Werner's picture
Offline
Last seen: 35 min 16 sec ago
Title: ★★★★★
Joined: 10/19/2012
Posts: 2557
Location: Germany
I played around with my

I played around with my doctor and it seems that my phone and my ipad go into high current mode if the datalines are shorted…so I soldered a big blob of solder on the 4 data pins to make them one big pin.
It has worked perfectly.

HKJ
HKJ's picture
Offline
Last seen: 42 min 32 sec ago
Title: ★★★★★
Joined: 05/24/2011
Posts: 2438
Location: Copenhagen, Denmark
Werner wrote:I played around

Werner wrote:
I played around with my doctor and it seems that my phone and my ipad go into high current mode if the datalines are shorted...so I soldered a big blob of solder on the 4 data pins to make them one big pin. It has worked perfectly.

Shorted data lines is the standard usb way to signal a high current charger, but not everybody is following it.

__________________

My website with reviews of flashlights, chargers and batteries: http://lygte-info.dk/

Werner
Werner's picture
Offline
Last seen: 35 min 16 sec ago
Title: ★★★★★
Joined: 10/19/2012
Posts: 2557
Location: Germany
I have a ihustler stick which

I have a ihustler stick which is designed for apple products and this has a bunch of resistors in it so I thought apple devices would need a special thing.
That was the reason for adding a switch, but the housing is so small even with grinding the switch didn’t fit perfectly and the tests with open housing showed me that the shorted wires are always better for my devices.

Shorted wires have a second benefit you don’t need to mind where you charge your device, I always have a bad feeling on public chargers…

HKJ
HKJ's picture
Offline
Last seen: 42 min 32 sec ago
Title: ★★★★★
Joined: 05/24/2011
Posts: 2438
Location: Copenhagen, Denmark
Werner wrote:I have a

Werner wrote:
I have a ihustler stick which is designed for apple products and this has a bunch of resistors in it so I thought apple devices would need a special thing.

Apple is using another ways to signal current on their own chargers, but they must also have added support for the usb standard in some product.

__________________

My website with reviews of flashlights, chargers and batteries: http://lygte-info.dk/

Chloe
Chloe's picture
Offline
Last seen: 1 day 7 hours ago
Title: ★★★★★
Joined: 01/30/2013
Posts: 4322
Location: 联合王国
Werner wrote:Shorted wires

Werner wrote:
Shorted wires have a second benefit you don’t need to mind where you charge your device, I always have a bad feeling on public chargers…

Are you concerned about security or something else?

__________________

Pinetreebbs
Pinetreebbs's picture
Offline
Last seen: 6 hours 31 min ago
Title: ★★★
Joined: 07/29/2012
Posts: 522
Location: South Carolina, USA, Earth
Danglerb wrote:Pinetreebbs

Danglerb wrote:
Pinetreebbs wrote:
Glenn7 wrote:
Getting me one of these, you can still preorder http://www.kickstarter.com/projects/david-toledo/the-practical-meter-know-your-power

Thanks! I ordered one to get their Fast-Charge 3-in-1 Cable.

Yipes, $19 for 5 bar led, vs $3 for digital readout.

Yes, however that price includes one of their Fast-Charge 3-in-1 Cables that enable faster charging of devices, including Apple devices plugged into non Apple USB ports.

I also appreciate them developing a legitimate business selling a well designed/made product versus a cheap and flimsy clone. FWIW, I did buy one of the cheap devices to get the current/voltage readings. Fine for initial testing of chargers and USB ports at home. Once I know their characteristics, I can use the Fast-Charge 3-in-1 Cable to take full advantage of them, at least that is my plan.

Danglerb
Offline
Last seen: 4 weeks 3 days ago
Title: ★★★
Joined: 10/07/2012
Posts: 330
Location: SoCal
Does the cable work, does it

Does the cable work, does it enable faster charging?

__________________

Still a bit dim

Pinetreebbs
Pinetreebbs's picture
Offline
Last seen: 6 hours 31 min ago
Title: ★★★
Joined: 07/29/2012
Posts: 522
Location: South Carolina, USA, Earth
Danglerb wrote:Does the cable

Danglerb wrote:
Does the cable work, does it enable faster charging?

I can’t say until I receive the cable.

What I read here convinced me to buy the cable: http://www.kickstarter.com/projects/david-toledo/the-practical-meter-kno…

This is a link for the cable itself: http://www.thepowerpot.com/product/3-1-fast-charging-cables?ref=cat_img

I hope this helps.

picrthis
picrthis's picture
Offline
Last seen: 1 week 4 days ago
Title: ★★★
Joined: 07/18/2011
Posts: 569
Location: USA
Danglerb wrote:First rule of

Danglerb wrote:
First rule of measuring stuff, everything matters. I would make a test rig, a dummy load on one end of a USB connection and voltage test points on both ends and do some testing.

With a 1A different I suspect you are correct and its not switching to high current mode. Stock I think USB is only good for 500 ma. but some do more.

Agree, cute device, not much of a measurement tool.

Works very good as a measuring tool that it is. I used it to weed out cables used on the same charger that gave me very long charge times and now I can see why. Same charger different cables gave me from 400mA up to 1,700mA so I sorted out my cables using this Tool and my charger works faster now; I got my measurement tools from DX, can’t be beat for the price.

__________________

Fenix TK12, TK15, TK21-U2, Olight M20S, M21 EagleTac T20C MKII XPG/XML(720lm), TX25C2-XML2, SX25A6-XML2 CW Maelstrom G5, X7 Spark SL6-800CW/740NW, SL5-220CW/190NW/210CW/180OW Xeno CUBE Model #E11 V7 XPG/XML CW/NW E03 V2 CW/NW Skilhunt Defier X3 ZebraLight SC600, S6330, SC600 II Scorpion v2 w/Turbo Head CW/NW, Xtar R01, SkyRay STL-V2, 3800-Rev2 3-mode, G6, 818, 850, KING Gold & Black CW/NW UltraFire UF-980L, WF504B TrustFire X8, C8, TR-3T6 (3x18650), X9, J12, J18, X100 Aurora C6 Jetbeam BC40 CW/NW ShiningBeam S-Mini XPG/XML Nitecore TM11 CW/NW, TM26, EC25W/CW, P25, EA8, MH25 Shadow JM07 Pro CW/NW DRY CW/NW DQG Tiny 18650 Black CW Flex Asgard CW World's first Bluetooth programmable Flashlight!

Li-Ion chargers: Pila IBC (Swiss Designed & Engineered) the Gold Standard (UL). Xtar SP2 & VP1, Soshine SC-S1max V3  Nitecore i4/i2 EagleTac & KeepPower 18650 3400mAh Panasonic UL button top cells Eneloops AA/AAA LaCrosse BC1000 Maha C9000 Accupower IQ-238 Opus BM200, BT-C2000

Danglerb
Offline
Last seen: 4 weeks 3 days ago
Title: ★★★
Joined: 10/07/2012
Posts: 330
Location: SoCal
Good for that task, sorting

Good for that task, sorting cables, but not for actually measuring values since its insertion in the circuit changes the current too much.

__________________

Still a bit dim

fartybum
Offline
Last seen: 9 hours 25 min ago
Title: ★★★
Joined: 08/17/2012
Posts: 286
Location: UK
fartybum wrote:Been waiting

fartybum wrote:
Been waiting 33 days for mine, contacted the seller yesterday, he said wait a bit longer Sad , I’ll be claiming when it gets to 40 days.

Claimed a refund from the ebay dealer, it never did arrive. Sad

Danglerb
Offline
Last seen: 4 weeks 3 days ago
Title: ★★★
Joined: 10/07/2012
Posts: 330
Location: SoCal
Chloe wrote:You are really

Chloe wrote:
You are really expecting too much from a 2-3 USD device. :X

Not really, I have no expectation regards price these days, you just never can tell. Its a useful device, but only to compare A vs B, or to see if a device is working or not.

__________________

Still a bit dim

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.