Regarding the USB passthroughs

[techtravis]

As a retailer of the USB passthrough's I thought I would give a better explanation of the usb power output on your computer and why most swear by external batter packs instead of using the passthrough on your computer.

I'm not sure exactly why some usb batteries are more prone to low power issues that others. But I can say that every one of the USB passthroughs returned to me as defective worked fine on my system. Though each person states the new one sent to them works fine. So I'm sure the usb passthrough has something to do with the problem... but not all of it.

See If your computer has alot of devices that are drawing USB power it could present a problem.

Why?

Basically 1 usb 2.0 port can draw up to 5.25volts @ 500ma MAX...
If the usb port you connect the usb battery to is being share by another device then you could see the performance drop significantly.

Most store bought computers only have 1, MAYBE 2 PHYSICAL ports inside the computer.

Most high end computers custom built usually have up to 4 physical ports inside the computer.


What does this all mean? If you have a HP, Compaq, ect. You may have 6 usb ports on your computer...... But INSIDE the computer they all may be shared off 1 physical port. just split via hardware/wires. So that 500ma of power output might not be enough for all the devices.

The Best results I have seen are off my External Battery pack.
Which has an output of 5.5v @ 700ma. Others swear by nothing less than
5.0v and 1000ma or 1.0amp. This is something you will have to decide on yourself.

This is the one I have: works flawlessly and has a nice battery level indicator
DIGIPOWER EBP-USB34 USB Power Charger

If I'm at the computer. I just plug the battery pack into the computer, plug the passthrough into the battery pack and run it that way.

See pictures



Hope this helps explain some of the trouble people are having.
Also as another side note. When USB 3.0 comes out, you should see better results with those ports as the max mah output has increased to 900ma up from 500ma

Below is taken from From Universal Serial Bus - Wikipedia, the free encyclopedia

The USB specification provides a 5 V supply on a single wire from which connected USB devices may draw power. The specification provides for no more than 5.25 V and no less than 4.75 V (5 V±5%) between the positive and negative bus power lines.[17]
A unit load is defined as 100 mA in USB 2.0, and was raised to 150 mA in USB 3.0. A maximum of 5 unit loads can be drawn from a port in USB 2.0, which was raised to 6 in USB 3.0. There are two types of devices: low-power and high-power. Low-power devices draw at most 1 unit load, with minimum operating voltage of 4.4 V in USB 2.0, and 4 V in USB 3.0. High-power devices draw the maximum number of unit loads supported by the standard. All devices default as low-power but the device's software may request high-power as long as the power is available on the providing bus.[18]
A bus-powered hub is initialized at 1 unit load and transitions to maximum unit loads after hub configuration is obtained. Any device connected to the hub will draw 1 unit load regardless of the current draw of devices connected to other ports of the hub (i.e one device connected on a four-port hub will only draw 1 unit load despite the fact that all unit loads are being supplied to the hub).[18]
A self-powered hub will supply maximum supported unit loads to any device connected to it. A battery-powered hub may supply maximum unit loads to port. In addition, the VBUS will supply 1 unit load upstream for communication if parts of the Hub are powered down.[18]
In Battery Charging Specification, new powering modes are added to the USB specification. A host or hub charger can supply maximum 1.5 A when communicating at low-speed or full-speed, maximum 900 mA when communicating at hi-speed, no upper current limit when no communication is taking place. A dedicated charger can supply maximum 1.5 A of current. A portable device can draw up to 1.8 A from a dedicated charger. The dedicated charger shorts the D+ and D- pins together and will not send or receive any information on those lines, allowing for the creation of very simple, high current chargers to be manufactured. The increased current (faster charging) will occur once the host/hub and devices both support the new charging specification.
As of June 14, 2007, all new mobile phones applying for a license in China are required to use the USB port as a power port.[19][20]
In September 2007, the Open Mobile Terminal Platform—a forum dominated by mobile network operators but including manufacturers such as Nokia, Samsung, Motorola, Sony Ericsson and LG—announced that its members had agreed on micro-USB as the future common connector for mobile devices.[21][22]
On 17 February 2009, the GSM Association announced[23] that they had agreed on a standard charger for mobile phones. The standard connector to be adopted by 17 manufacturers including Nokia, Motorola and Samsung is to be the micro-USB connector (several media reports erroneously reported this as the mini-USB). The new chargers will be much more efficient than existing chargers. Having a standard charger for all phones, means that manufacturers will no longer have to supply a charger with every new phone.

[02BLACKTAWS6]

Wow. Great in depth explanation. Thanks.

[ApOsTle51]

500 mA is the quoted USB spec per port ( that motherboard port , not socket )
usb 2.0 standard says 1.5 amps if there is external power, 100 mA unsupported

USB devices may draw up to 100 mA before "negotiation" with the host, after which they may draw up to what the host gives them permission to draw, which is limited to 500 mA due to physical interface requirements

The negotiation requires exchange of information between the devices over the bus.

this means your charger or passthrough must 'talk' to your pc to allow it to up the amperage from low-power mode ( 100mA ) to high power mode ( up to 500mA ). I don't have a passthrough but i know my USB charger doesn't communicate with my PC so it's only allowed to have 100mA. If your PC doesnt recognise your passthrough then it's only ever gonna get 100mA.



take alooky as this thread some good info there :

http://www.e-cigarette-forum.com/for...-computer.html

Ye i know it was a charger in the op but it still stands.



A usb charger inputs and outputs 100Ma so it's right on the edge of working.



just like smokinclam says these are cheap chinese gadgets and i sure am wary of using them.

Some non-standard USB devices use the 5 V power supply without participating in a proper USB network. These are usually referred to as USB decorations. The typical example is a USB-powered reading light; fans, mug heaters (though some may include USB hubs[24]), battery chargers (particularly for mobile telephones), miniature vacuum cleaners, a miniature Lava Lamp, and even toy missile launchers are available. In most cases, these items contain no digitally based circuitry, and thus are not proper USB devices at all. This can theoretically cause problems with some computers—the USB specification requires that devices connect in a low-power mode (100 mA maximum) and state how much current they need, before switching, with the host's permission, into high-power mode.

I bet when you plug in your passthrough or charger the computer doesnt even recognise it as being connected at all. so your only gonna get the minimum allowed ampage delivered to the usb port. If that device wants more it'll try and take it, overloading the port and resulting in what the OP is all about.



again this is why Janty use the Battery in-line with their usb passthrough's , It acts as a buffer for the port. Janty are a big name and know the risks with USB powered devices so they have gone the safer route.

Generic Chinese passthrough manufacturer's couldn't give a monkey's about end user safety and the Supplier is the one liable to any damage.



If your gonna use usb chargers or passthru's i would try to avoid directly plugging them into your PC ports but connect them to a mains powered USB hub, they at least are recognised and will supply a greater amperage to the device. I woudn't say don't use them , many people are using them without problems but as your aware the risks are present.

[somberbear]

yea i had some power issues when i hooked mine up on a hub... so i moved it to an off the computer powered usb hub i had for an old ipod , and bingo good to go better then a fresh battery..... and i can hook up my 901 and pen on pass threws , and charge 2 batterys and charge some of my other usb gadgets.

[KatyS]

thanks for the explanation Travis, explains a few things for me.

[techtravis]

ApOsTle51,

Thanks. I assumed this was the case.

What still throws me off is that when a different passthrough is sent out as a replacement it seems to work fine for the customer. So I assume the passthroughs are supossed to request higher voltage, but they must not be the most QA checked parts

[ApOsTle51]

no problem Travis ,
it's good to see a supplier not bury his head in the sand over the issue but try to inform people about it . Kudos

[The Wiz]

Thanks Travis....This is the "Passthrough Bible" I will refer all new users with questions to...the time you took out to put this together is appreciatedThe Wiz!

[techtravis]

Thanks everyone.

An informed consumer is a happy consumer... Most of the time


Also I would heed ApOsTle51's warning.

Most, if not all usb devices that are manufacture to leech power from a computer's usb port rather than a "normal" usb device such as a printer, webcame, or mouse do have a slight risk of causing damage.

While the risk is low. The risk is still present.


I have also changed my product listing to include a disclaimer.

Note: As with any Non-standard usb devices. (examples being USB-powered reading light; fans, mug heaters, battery chargers, cell phone chargers, miniature vacuum cleaners) There is a very slight chance that the computer and the device may not function correctly. Resulting in damage to one or both devices.

For optimal performance it is recommended that you use an external usb battery like the <a href="http://www.partsguysusa.com/m5_view_item.html?m5:item=Digipower-EBP-USB34"> Digipower USB34</a> instead of directly connecting it to your computer.

Vaporstix.com will not be held responsible for any damage caused to your computer or connected devices for improper use, or usb power overload caused by using the usb batteries.

[Vince1]

So Travis, have you had any issues with short atomizer life using that 700ma unit? I'm looking at a mains power unit rated at 1000ma. Is there a thread where they discuss using this high power source?
And the 300ma mains units are real cheap. Do you think that is high enough? The battery on my pipe is 250ma and it powers the penstyle atomizers just fine. My passthrough is crap compared to my pipe. (maybe the 100ma thing).