DC Adapter question

Hi,
I just moved from the UK to the US. I brought my Wireless access
point/router with me, but I need to get a new DC adapter for it so that it
works on the 110V supply here.

It says on my UK adapter that the output is: 7.5V DC 1500mA 11.25VA

Every universal adapter I find that has 7.5 as an option, seems to have a
current rating of either below, or above the 1500mA I need. They are usually
either about 1000mA, or 1700mA etc.

Does anyone know if this is a required rating, or if it will automatically
only take the current required, as long as it's set to 7.5V ?

For example, if I get the one with only 1000mA rating, will it not work? If
I get the 1700mA one, will it be too much and blow the wireless access
point?

Thanks for any help,
Daniel

On Tue, 07 Jun 2005 17:25:44 GMT, "Ann-Marie"
<(E-Mail Removed)> wrote:

>For example, if I get the one with only 1000mA rating, will it not work? If
>I get the 1700mA one, will it be too much and blow the wireless access
>point?

the AP will take what it needs, so the rating should be at least equal
to what you had before.

Was the UK supply only rated 220-240V on the input and not
multi-voltage ?

Getting a spare for the equivalent AP (or a whole AP) off ebay would
be another approach.

and don't use channels >11 :-)

Phil
--
spamcop.net address commissioned 18/06/04
Come on down !

Get the higher one, it will only draw the current it needs. Check that it's
the regulated and not unregulated type and check the polarity is correct.

--

Kenny Cargill


"Ann-Marie" <(E-Mail Removed)> wrote in message
news:sMkpe.2181$(E-Mail Removed) ...
> Hi,
> I just moved from the UK to the US. I brought my Wireless access
> point/router with me, but I need to get a new DC adapter for it so that it
> works on the 110V supply here.
>
> It says on my UK adapter that the output is: 7.5V DC 1500mA 11.25VA
>
> Every universal adapter I find that has 7.5 as an option, seems to have a
> current rating of either below, or above the 1500mA I need. They are
> usually either about 1000mA, or 1700mA etc.
>
> Does anyone know if this is a required rating, or if it will automatically
> only take the current required, as long as it's set to 7.5V ?
>
> For example, if I get the one with only 1000mA rating, will it not work?
> If I get the 1700mA one, will it be too much and blow the wireless access
> point?
>
> Thanks for any help,
> Daniel
>

Thanks for the replies.
Next problem, the only place I've found that supplies universal adapters
with any kind of current above about 500mA seems to be some canadian place
called mainelectronics, but their ordering/shipping seems a bit crappy.
Other than E-bay, any ideas on other US places that I could get more of a
range of universal adapters? I've already tried places like radioshack, but
they're all low current.

Thanks again
Daniel.


"Ann-Marie" <(E-Mail Removed)> wrote in message
news:sMkpe.2181$(E-Mail Removed) ...
> Hi,
> I just moved from the UK to the US. I brought my Wireless access
> point/router with me, but I need to get a new DC adapter for it so that it
> works on the 110V supply here.
>
> It says on my UK adapter that the output is: 7.5V DC 1500mA 11.25VA
>
> Every universal adapter I find that has 7.5 as an option, seems to have a
> current rating of either below, or above the 1500mA I need. They are
> usually either about 1000mA, or 1700mA etc.
>
> Does anyone know if this is a required rating, or if it will automatically
> only take the current required, as long as it's set to 7.5V ?
>
> For example, if I get the one with only 1000mA rating, will it not work?
> If I get the 1700mA one, will it be too much and blow the wireless access
> point?
>
> Thanks for any help,
> Daniel
>

"Ann-Marie" <(E-Mail Removed)> wrote:
>Hi,
>I just moved from the UK to the US. I brought my Wireless access
>point/router with me, but I need to get a new DC adapter for it so that it
>works on the 110V supply here.
>
>It says on my UK adapter that the output is: 7.5V DC 1500mA 11.25VA

The 7.5 VDC may (and may not, but we don't know) be important, so
you'd best stick with something very close to that.

The 1500mA is a minimum. Which means that the unit you describe below
as 1700mA is just fine. The only catch with the current is that if
it says some specific voltage at a specific current, as the actual current
drawn goes down the actual voltage delivered will go up. Hence you don't
want to use something able to supply twice the required current simply
because it will be so under loaded that the voltage will be significantly
higher than what it would be with a full load.

However, as noted, the voltage doesn't always make any real difference
either! Lots of units are powered with "switching" power supplies, and
the voltage chosen is merely a convenient one. "Convenient" may be the
best deal they can get on purchasing bulk orders, or may be related to
a size that is commonly available.

One example that has been discussed in detail in this newsgroup is the
power supply for Linksys WRT54G routers. They come with a 12 VDC 1A
supply. The unit will work off a supply of less than 5 volts to more
than 20 volts though. The actual power used stays about the same, so
as the voltage goes down the current goes up. Using a 6 VDC supply
it would be a good idea to have one rated at 2 Amps. An 18 VDC supply
would probably do fine if rated at 750 mA.

As Jeff Liebermann originally pointed out, with the WRT54G the upper
voltage is probably limited by when the capacitors blow up (literally).

>Every universal adapter I find that has 7.5 as an option, seems to have a
>current rating of either below, or above the 1500mA I need. They are usually
>either about 1000mA, or 1700mA etc.

The 1700 mA unit is perfect.

>Does anyone know if this is a required rating, or if it will automatically
>only take the current required, as long as it's set to 7.5V ?
>
>For example, if I get the one with only 1000mA rating, will it not work? If
>I get the 1700mA one, will it be too much and blow the wireless access
>point?

The 1000 mA unit would almost certainly work. The question merely how
long before it failed. Not if, just how long. At that difference in
rated current, it might fail within minutes. It might take months.
You'll have the 1700 mA one stuffed in a box on a shelf, just in case,
long after the device it powers has been tossed into the trash.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) (E-Mail Removed)

Another solution is to get a 110V to 240V AC transformer, then you can use
your existing adapter.

--

Kenny Cargill


"Ann-Marie" <(E-Mail Removed)> wrote in message
news:WDlpe.2193$(E-Mail Removed) ...
> Thanks for the replies.
> Next problem, the only place I've found that supplies universal adapters
> with any kind of current above about 500mA seems to be some canadian place
> called mainelectronics, but their ordering/shipping seems a bit crappy.
> Other than E-bay, any ideas on other US places that I could get more of a
> range of universal adapters? I've already tried places like radioshack,
> but they're all low current.
>
> Thanks again
> Daniel.
>
>
> "Ann-Marie" <(E-Mail Removed)> wrote in message
> news:sMkpe.2181$(E-Mail Removed) ...
>> Hi,
>> I just moved from the UK to the US. I brought my Wireless access
>> point/router with me, but I need to get a new DC adapter for it so that
>> it works on the 110V supply here.
>>
>> It says on my UK adapter that the output is: 7.5V DC 1500mA 11.25VA
>>
>> Every universal adapter I find that has 7.5 as an option, seems to have a
>> current rating of either below, or above the 1500mA I need. They are
>> usually either about 1000mA, or 1700mA etc.
>>
>> Does anyone know if this is a required rating, or if it will
>> automatically only take the current required, as long as it's set to 7.5V
>> ?
>>
>> For example, if I get the one with only 1000mA rating, will it not work?
>> If I get the 1700mA one, will it be too much and blow the wireless access
>> point?
>>
>> Thanks for any help,
>> Daniel
>>
>
>

A power supply current rating is the maximum available current. Any
equipment connected to it will draw no more current that the equipment
rating. Your wireless access point/router will draw no more current than
the rating of the wireless access point/router (which should be printed on
the unit.)

I suggest you check the Wireless access point/router label for the DC power
consumption. The rating of the 220 VAC adapter you have has a rating that
seems to me to be very high, much higher than the two 120 VAC adapters used
by the two wireless access point/router units I own (12 VDC @ 300 MA and 12
VDC @ 500 MA.) Your adapter supplies up to 11.5 Watts, as compared to 3.6
Watts and 6 Watts for the two I have.

One thing to consider is the flood of very inexpensive wireless access
point/router units in stores like CompUSA and Office Depot. If you are
willing to wait for a mail-in-rebate, the price can be as low as $8 US for a
802.11g Motorola wireless access point/router (my $8 US Motorola is Model
WR850G.) This price is less than half the price of a 7.5 VDC @ 1500 mA
adapter; RadioShack, for example, charges $39.95 US for a 3 to 12 VDC @ 1000
mA multi-voltage adapter, and $34.95 for a 40 Watt 120 ACV to 220 VAC
transformer with US type AC plug and UK/European AC socket.)

Phil Weldon

"Ann-Marie" <(E-Mail Removed)> wrote in message
news:sMkpe.2181$(E-Mail Removed) ...
> Hi,
> I just moved from the UK to the US. I brought my Wireless access
> point/router with me, but I need to get a new DC adapter for it so that it
> works on the 110V supply here.
>
> It says on my UK adapter that the output is: 7.5V DC 1500mA 11.25VA
>
> Every universal adapter I find that has 7.5 as an option, seems to have a
> current rating of either below, or above the 1500mA I need. They are
> usually either about 1000mA, or 1700mA etc.
>
> Does anyone know if this is a required rating, or if it will automatically
> only take the current required, as long as it's set to 7.5V ?
>
> For example, if I get the one with only 1000mA rating, will it not work?
> If I get the 1700mA one, will it be too much and blow the wireless access
> point?
>
> Thanks for any help,
> Daniel
>

Sorry, I left out the POINT of checking the power requirement level on the
wireless access point/router. You need only get an AC adapter with the
correct voltage and sufficient current rating to meed the requirements on
the label, and not the current rating on your 220 VAC adapter. A lower
current adapter will be much easier to find, and much cheaper.

Phil Weldon

"Phil Weldon" <(E-Mail Removed)> wrote in message
news:Clnpe.676$(E-Mail Removed) k.net...
>A power supply current rating is the maximum available current. Any
>equipment connected to it will draw no more current that the equipment
>rating. Your wireless access point/router ....

Depending on who made it, I just get the power supplies from the
manufacturer site. Some even have dual voltage supplies for use both here
(at 120) and elsewhere at 240.

Ann-Marie wrote:
> Thanks for the replies.
> Next problem, the only place I've found that supplies universal
> adapters with any kind of current above about 500mA seems to be some
> canadian place called mainelectronics, but their ordering/shipping
> seems a bit crappy. Other than E-bay, any ideas on other US places
> that I could get more of a range of universal adapters? I've already
> tried places like radioshack, but they're all low current.
>
> Thanks again
> Daniel.
>
>
> "Ann-Marie" <(E-Mail Removed)> wrote in message
> news:sMkpe.2181$(E-Mail Removed) ...
>> Hi,
>> I just moved from the UK to the US. I brought my Wireless access
>> point/router with me, but I need to get a new DC adapter for it so
>> that it works on the 110V supply here.
>>
>> It says on my UK adapter that the output is: 7.5V DC 1500mA 11.25VA
>>
>> Every universal adapter I find that has 7.5 as an option, seems to
>> have a current rating of either below, or above the 1500mA I need.
>> They are usually either about 1000mA, or 1700mA etc.
>>
>> Does anyone know if this is a required rating, or if it will
>> automatically only take the current required, as long as it's set to
>> 7.5V ? For example, if I get the one with only 1000mA rating, will it not
>> work? If I get the 1700mA one, will it be too much and blow the
>> wireless access point?
>>
>> Thanks for any help,
>> Daniel

This place has them.

http://www.altex.com/

William Lee



"Ann-Marie" <(E-Mail Removed)> wrote in message
news:WDlpe.2193$(E-Mail Removed) ...
> Thanks for the replies.
> Next problem, the only place I've found that supplies universal adapters
> with any kind of current above about 500mA seems to be some canadian place
> called mainelectronics, but their ordering/shipping seems a bit crappy.
> Other than E-bay, any ideas on other US places that I could get more of a
> range of universal adapters? I've already tried places like radioshack,
> but they're all low current.
>
> Thanks again
> Daniel.
>
>
> "Ann-Marie" <(E-Mail Removed)> wrote in message
> news:sMkpe.2181$(E-Mail Removed) ...
>> Hi,
>> I just moved from the UK to the US. I brought my Wireless access
>> point/router with me, but I need to get a new DC adapter for it so that
>> it works on the 110V supply here.
>>
>> It says on my UK adapter that the output is: 7.5V DC 1500mA 11.25VA
>>
>> Every universal adapter I find that has 7.5 as an option, seems to have a
>> current rating of either below, or above the 1500mA I need. They are
>> usually either about 1000mA, or 1700mA etc.
>>
>> Does anyone know if this is a required rating, or if it will
>> automatically only take the current required, as long as it's set to 7.5V
>> ?
>>
>> For example, if I get the one with only 1000mA rating, will it not work?
>> If I get the 1700mA one, will it be too much and blow the wireless access
>> point?
>>
>> Thanks for any help,
>> Daniel
>>
>
>