On 2018-07-29, R.Wieser  wrote:
> The Natural Philosopher,
>
>> Its more a case that a higher voltage needs less current for the same
>> power.
>
> True. But you need to be able to convert that power to a lower voltage to
> again become usable.  Where with AC that can be easily managed with a simple
> transformer, that doesn't work as well for DC.

You'll generally want some form of voltage regulation at the load
end of the run in any case (to compensate for losses in the cable)
and while in the past that may have been a linear regulator these
days switch mode supplies are relatively simple to design thanks
to off-the-shelf chips.  Given the reduction or elimination in
heatsinking and/or active cooling you are likely to find such a
solution is actually cheaper and more compact than a linear regulator
to boot.

SMPSes work theoretically losslessly by charging and discharging
(usually) an inductor so while a linear regulator would take a
higher voltage at full current the current decreases with voltage
in the case of an SMPS.

--
Andrew Smallshaw
andrews@sdf.org

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