Re: Power Supplies, Saving Money, and switching vs. Linear?

[nobody@xxxxxxxxxxxx (Dave Houston)]

Europe (CE), California and China have mandated efficiency standards for DC
power supplies that can only be met by switchmode designs making it likely
that linear power supplies will soon disappear from supply channels.

While it doesn't make compelling economic sense for Andrew to replace his
linear supply, at the state level California expects the new standards to
eliminate the need for one new generating station. For China the savings
could be far greater.

not_real@xxxxxxx (Beachcomber) wrote:

>There are always tradeoffs in design considerations.   May I suggest
>thinking about it another way....
>
>For an alarm power supply, normally wouldn't you want that to be a
>mission critical application...  In other words (you want it to keep
>functioning, no matter what).   If that costs you more in terms of kWh
>consumed, perhaps the price is worth it.
>
>In my experience, some of these small plug in switching dc supplies
>are more prone to failure when compared to a good, well designed (or
>over-designed) linear supply.   Generally they a pain to fix and it's
>usually more convenient to replace the whole supply when it goes down.
>
>True, they are small, cheap, and efficient, but unless they are
>designed really well (adaquate cooling & heat sinks, plus fans if
>necessary), switching supplies generally operate with certain
>components under stress (capacitors and the critical transistors) ,
>and again, in my experience, sometimes they just stop working.  YMMV.
>
>Beachcomber
>
>