Longer XO transformer power cord in the plans?

[John Watlington]

We are considering changing from a "wall wart"
design to an "inline design", for the following reasons:

A - The difficulty in supporting "new" countries, when each
new plug design requires new tooling.   With an inline
design, only the plug at the end of the AC cable has to
change.

B - The "wall wart" design limits the weight of the adapter.

C - A blow to the adapter when it is plugged in frequently
snaps the pins off of the wall wart.   I've seen a number
of "repaired" units that make me worry for the kids safety.

D - It can be difficult to find power strips with the right plug
orientation to accept multiple adapters of our current design.

Right now, we have a 1.5m cable on the wall wart.
I'm thnking about specifying a 0.8m  (outlet to floor) AC cable
and a 1.2m (floor to table) DC cable.   Shorter would be
cheaper, but might result in "dangling" adapters, something to
be avoided.

Quozl's comments are valid.   Not every child needs a
longer cable, and the cabling is a significant part of the cost
of the adapter.

I am still getting quotes to see how this change might
impact the adapter cost, and getting the industrial designers
to think about it.

Comments ?  Suggestions ?
wad

On May 30, 2009, at 9:39 PM, James Cameron wrote:

> I know of no such plans, but the physics of the configuration has a
> bearing ...
>
> 1.  a longer cable has a larger voltage drop, and so a greater  
> amount of
> power is lost as heat, leading to greater inefficiency of power use,
>
> 2.  compensating for the voltage drop can only be done by either  
> raising
> the design voltage on the cable, or increasing the cross sectional  
> area
> of the copper,
>
> 3.  raising the design voltage is an unattractive option, since it  
> would
> expose the user to greater risk,
>
> 4.  increasing the cross sectional area would make the cable much
> heavier, and a substantially higher cost, which would vary  
> according to
> metal prices,
>
> 5.  increasing the length may also increase the trip hazard, and so
> further reinforcement of the sheath and restraint points may be
> required,
>
> 6.  not every child will need an extra two metres.
>
> Can you balance this against against the cost of properly placed
> domestic 110V or 240V outlets?
>
> -- 
> James Cameron    mailto:quozl at us.netrek.org     http:// 
> quozl.netrek.org/
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