Re: Reliability of Networking Hardware?

Walter Roberson wrote:
> Round about two postings later in the thread is usually about the point
> where you start ignoring the fact that older or more delicate equipment
> exists that does not have horking big rectifiers and capacitors
> to get the equipment past dirtiness in the utility power feed
> and that double-inverting UPSes can do a fair bit of line cleanup.
> Looks like this time you've gotten an early start on that.

  Standards that electronic equipment must meet - why appliances
already have internal protection - are more than 30 years old. Your
speculations about big rectifiers and capacitors ignore industry
standards - what electronics did 30 years ago.

  A double inverting UPS is typically $500. Most users instead have
those $100 computer grade UPSes that connect electronics directly to AC
mains when not in battery backup mode. Defined were numbers taken from
many UPSes that are described as 'computer grade' - what most users
have.

  Which UPSes tend to output the dirtiest electricity? Computer grade.
 Why? Computers are and have long been some of the most resilient
appliances. The point. Computer grade UPSes can output dirtier power
because computers are and have been so robust. Spend big bucks for a
double inverting UPS and obtain no advantage. The computer already
makes 'dirty' electricity irrelevant - as demonstrated by 200 volt
square waves and a 270 volt from a computer grade UPS. Computers
already have internal protection that makes hardware protectors on its
power cord irrelevant. UPSes that would harm power strip protectors
and some small electric motors are not harmful to computers. We call
them computer grade UPSes. Computers are that robust as required 30+
years ago.

  Protection at the computer is already inside the computer.
Protection that assumes you have earthed all incoming transients at the
building service entrance - the single point earth ground.

  30 years ago, that DEC or Data General computer had to work just fine
even when line voltage dropped so low that light bulbs were at 40%
intensity. These AC line standards are decades old despite irrelevant
speculations about big horking rectifiers. Back then we had no surge
protectors to waste good money on - and did not suffer damage.
Received on Mon May 1 00:53:19 2006