TELECOM Digest OnLine - Sorted: Re: Why is Motorola USB not Blackberry USB?

Re: Why is Motorola USB not Blackberry USB?

Emily (
Fri, 29 Dec 2006 08:01:08 GMT

On Fri, 29 Dec 2006 01:46:56 GMT, DevilsPGD wrote:

> Depending on the device design, the chargers may or may not be
> interchangeable. I'm currently charging my girlfriend's Blackberry on
> a Motorola USB charger I purchased for my Razr.

Hi DevilsPGD,

The part of your statement that gets me is the part that says U S B.
If it's USB, then it should be USB. Right?

For example, like you, I also have a Blackberry and a Motorola Razr.

Here is a pairing of USB DEVICE requirements with the USB POWER
SUPPLY capabilities:
DEVICE = Blackberry 8700 SUPPLY = TCPRIM2ULSSN 5.0vdc 750mA
DEVICE = Motorola V195 SUPPLY = PSM5037B 5.9vdc 375mA
DEVICE = Motorola RAZR SUPPLY = DCH3-05US-0300 5.0vdc 550mA
DEVICE = Motorola Earbud SUPPLY = FMP5185B 5.2vdc 450mA

Can I "assume" if I hook the Motorola V195's USB power supply (5.9vdc
375mA) to the Blackberry 8700 device, that the Blackberry will be getting
more voltage than it 'expected' and that the current it will try to suck
out of the charger will be more than expected (due to the higher voltage),
yet the current the power supply can supply will be half of what it
expected (due to the 375 mA limitation of the power supply).

If this is true, this implies that USB chargers are NOT interchangable!
(The T-Mobile store clerks just might have been right.)

But, what irks me is they all have the SAME CONNECTIONS!
They all "LOOK" the same to me!

Does EVERYONE label all their USB chargers so they don't mix them up?
Or am I missing something fundamental here. If it says it's a USB
charger, but that we can't use them interchangably, then are they
REALLY USB power supplies?

I'm still confused on the fact that the charger advertises it is USB but
it's not USB if it doesn't fit all USB devices.

Can someone clear up the USB part of the confusion here?

[TELECOM Digest Editor's Note: Actually, Emily, they do _not_ all
'look the same' or 'have the same connections'. If you look closely at
the pin from the power supply unit to the unit, you will see that many
of them _do_ look a lot alike, but the tip will have a different
colored ring on the bottom; and usually the sleeve is a bit too large
or a bit too small to fit into the entrance of the unit being powered.
I think the street parlance for those little differences is to make
the units 'idiot-proof' against people who would otherwise pick up the
incorrect power supply to use with one external device or another. I
have three cellular phones here; and three external power supplies to
use with them. Not one of the three power supplies will work with the
other two phones. Or maybe they would if I was able to trim down the
sleeve a wee bit, or expand the hole (being plugged into) a wee bit,
but I am unwilling to be patient enough to work with those microscopic
little things. Regards the varying degrees of power supplied, I do
not think there is any 'standard' for USB. PAT]

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