Re: 3 blown Power supply's in 6 months.



w_tom
07-10-2005, 12:49 AM
Well again Leythos uses words to demonstrate the quality of
his technical knowledge. But Leythos, you might learn
something. Numbers are posted elsewhere in this thread.
Numbers. Remember those things you post insults to avoid?
You only stand by insults. As usual, insults remain your only
technical fact. Numbers? Do you know any good numbers?

Meanwhile for the benefit of others more interested in
reality, linear supplies routinely included current fold back
limiting even 35 years ago. For others, numbers for fuses are
provided in another post to Richard. Numbers that demonstrate
why fuses cannot protect electronic appliances.

Leythos wrote:
> I stand by my statement - you are really a lamer and troll. Not all
> power supply units are designed to protect their circuits against a dead
> short, not all are designed to handle over-current conditions. Sure,
> many of the nicer ones are, but you seem to have very limit scope of
> contact with the real world.
>
> Heck, we still had power circuits in F14 control systems that were fused
> 10 years ago - so much for your 35 years. Oh, and as late as the early
> 90's there were many non-switching PSU's in use in a varied number of
> devices.
>
> You need to get off your small minded, limited experience, little bit of
> knowledge, and learn that you don't seem to know jack-shot about a lot
> of think kid.

Leythos
07-10-2005, 12:49 AM
In article <428159FF.338D02AD@hotmail.com>, w_tom1@hotmail.com says...
> Well again Leythos uses words to demonstrate the quality of
> his technical knowledge. But Leythos, you might learn
> something. Numbers are posted elsewhere in this thread.
> Numbers. Remember those things you post insults to avoid?
> You only stand by insults. As usual, insults remain your only
> technical fact. Numbers? Do you know any good numbers?
>
> Meanwhile for the benefit of others more interested in
> reality, linear supplies routinely included current fold back
> limiting even 35 years ago. For others, numbers for fuses are
> provided in another post to Richard. Numbers that demonstrate
> why fuses cannot protect electronic appliances.

And again you miss a lot, you miss small 24VDC PSU's, the fused circuits
to cover overload on amps, the fuses on all sorts of hardware.

I got news for you - fuses don't just protect LARGE MOTORS, they
protect a entire range of devices that you ignore due to your complete
lack of understanding anything posted in any Usenet group you
participate in.

What part of numbers for power supply units that HAVE FUSES did you miss
- there are hundreds of sites in that google search I presented you with
that you seem to have missed.

Oh, and no one uses Fuses for microsecond protection of anything -
everyone already knows that fuses are slow devices, even fast acting
fuses are slow.

Heck, I even have old Radio's that have 1A or 2A fuses in them to
protect the power output from simple transistors used in the regulator
circuits - but I'm sure you will tell me that those only blow after the
unit is damaged, even though I've replaced them, without replacing
anything else, and the units still work after more than 20 years.

So, come on, tell us again how fuses only protect damaged devices from
injuring people. You lost all credibility when you started your BS this
time.

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w_tom
07-10-2005, 12:49 AM
Fuses in that radio would be required by the UL so that it
does not kill someone. If fuses are routinely blowing, then
fuses are too small - nuisance tripping. That too
demonstrated in another post with numbers.

To protect electronics, a fuse must blow in microseconds.
But again, you damn the numbers. You know better because
undersized fuses in a Radio are nuisance tripping. That alone
is sufficient proof of what? Next you will claim a UPS
provides protection that even its manufacturer does not
claim. Why? Your speculation, as ususal, is proof enough.
Numbers be damned.

For others, numbers are provided elsewhere. Fuse takes
numerous seconds or minutes to protect from an overload. But
after damage has occurred, the higher current will quickly
open the fuse - to protect human life.

Leythos wrote:
> And again you miss a lot, you miss small 24VDC PSU's, the fused circuits
> to cover overload on amps, the fuses on all sorts of hardware.
>
> I got news for you - fuses don't just protect LARGE MOTORS, they
> protect a entire range of devices that you ignore due to your complete
> lack of understanding anything posted in any Usenet group you
> participate in.
>
> What part of numbers for power supply units that HAVE FUSES did you miss
> - there are hundreds of sites in that google search I presented you with
> that you seem to have missed.
>
> Oh, and no one uses Fuses for microsecond protection of anything -
> everyone already knows that fuses are slow devices, even fast acting
> fuses are slow.
>
> Heck, I even have old Radio's that have 1A or 2A fuses in them to
> protect the power output from simple transistors used in the regulator
> circuits - but I'm sure you will tell me that those only blow after the
> unit is damaged, even though I've replaced them, without replacing
> anything else, and the units still work after more than 20 years.
>
> So, come on, tell us again how fuses only protect damaged devices from
> injuring people. You lost all credibility when you started your BS this
> time.
>
> --
> --
> spam999free@rrohio.com
> remove 999 in order to email me

Leythos
07-10-2005, 12:49 AM
In article <42815F9B.9CA0D817@hotmail.com>, w_tom1@hotmail.com says...
> Fuses in that radio would be required by the UL so that it
> does not kill someone. If fuses are routinely blowing, then
> fuses are too small - nuisance tripping. That too
> demonstrated in another post with numbers.

There you go assuming you know why they blew, and that they blew many
enough times to mean they were too small for the reason they were
installed. Fuses that have blown 3 times in 20 years is not significant
in some circuits, but I don't expect you to have any experience in that
area either.

> To protect electronics, a fuse must blow in microseconds.
> But again, you damn the numbers. You know better because
> undersized fuses in a Radio are nuisance tripping. That alone
> is sufficient proof of what? Next you will claim a UPS
> provides protection that even its manufacturer does not
> claim. Why? Your speculation, as ususal, is proof enough.
> Numbers be damned.

You've got to be kidding - many devices can take minutes of excessive
load without being damaged, some hours, you really have never worked
with electrical devices of a varied nature - have you?

> For others, numbers are provided elsewhere. Fuse takes
> numerous seconds or minutes to protect from an overload. But
> after damage has occurred, the higher current will quickly
> open the fuse - to protect human life.

Again, you miss the mark - fuses do take time to open, some open in
milliseconds, some open in seconds, some longer, but since you've not
posted any specific fuse and the load you are suggesting, we can't
really suggest if the fuse blows quickly or slowly.

If I draw 1.05A on a 1A fuse it may never blow, or it may blow after
minutes, but if I draw 1.7A on it, it's going to blow quickly - even
though all of the devices in the rest of the circuit could handle the
load for several minutes without damage - the idea is that the fuse
blows as quickly as needed to protect the circuit and it's parts.

Ever hook a multimeter to a 600V line on the wrong setting? The little
315MA fuse blows in less than a millisecond (I would have to guess), but
there is no damage to the device, and the foil on the circuit board
would vaporize before damage to human, so there was no reason to have it
there to protect the human, it was there to protect the foil traces on
the circuit board or other components inside the multimeter.

None of these REAL examples have anything to do with protecting a HUMAN,
it's about protecting the device.

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Re: 3 blown Power supply's in 6 months.