View Single Post
  #36   Report Post  
Posted to sci.electronics.repair,alt.comp.hardware.pc-homebuilt
Michael A. Terrell Michael A. Terrell is offline
external usenet poster
 
Posts: 12,924
Default Power supplies with solid polymer caps


Daniel Prince wrote:

Jeff Liebermann wrote:

The problems start when there are competing products. I call it the
Walmart effect. Walmart, Kmart, and many online vendors specialize in
selling solely on the basis of price. If there are two competing
products, differing only a few pennies in selling price, *ALL* their
orders will go to the lower priced product, with nothing to the higher
priced equivalent. Walmart aggravates the effect by setting the price
at some artificial low level, and challenging their vendors to meet
their price goal.


It seems to me that there is a good opportunity here for other
retailers. If a retailer sold only electronic goods that were well
made and well designed, they could sell them for ten to thirty
percent more than the junk sold at Walmart and Kmart.



Maybe ten times as much, if you are selling real quality.


I think many consumers would be willing to pay a little extra for
devices that would probably last four to ten times as long. This
would be especially true if they had two (or more) cheap-junk brand
devices fail.



Have you ever designed consumer electronics, or worked in electronics
manufacturing? have you ever tried to buy top quality components, or
run 100% incoming inspection. It isn't cheap.


The retailer could require vendors to only use non-junk capacitors
with voltage ratings at least three times the voltage the capacitors
would be exposed to.



You don't understand much about electrolytics, do you? The ESR goes
up with the voltage rating, along with the physical size. That requires
a different board layout, which raises the resistance & inductance of
the copper traces, which causes more problems. It becomes harder to
filter the ripple current from the CPU power supply, causing more
erratic behavior.

It is the ripple current through the electrolytic that degrades it,
to the point of failure. All of this is the reason that the
electrolytics for the CPU are so close to the CPU socket. Your method
would cost more, and have a shorter life.


They could also require that no part of the device ever get more
than 30 degrees warmer than the temperature of the room it is
used in.



That's a joke? Even mainframe computers with dedicated air
conditioning ran hotter than that.


The devices could have much longer warranties and the store could
advertise itself as "The quality store". I do not think this would
require excessive advertising, especially after the first few years.



You can call yourself whatever you want, but you are not going to get
much quality improvement for a 30% (retail) cost increase.


--
The movie 'Deliverance' isn't a documentary!