Snubber Selection

[Jamie]

"Jamie the FUCKWIT Jerk Off "


** Complete mental retard.

What else would you expect from someone whose real name is " Maynard A.
Philbrook " who works as a code scribbler and has the ham call sign
KA1LPA.

Lives in a dream world with no idea of his monumental ignorance.



..... Phil

Nice to see that you visited my web sight. I hope you learned something
you little insignificant ant!

I've squashed more than you can count boy!, every time I step on one,
Phil and a few others come to mind!


"For you PHIL!!!!!!!!!!!!"

SOME PEOPLE ARE LIKE SLINKIES. NOT REALLY GOOD FOR ANYTHING BUT
THEY BRING A SMILE TO YOUR FACE WHEN PUSHED DOWN THE STAIRS.
http://webpages.charter.net/jamie_5"

 

[mpm]

"Jamie the Jerk Off "


** Bollocks.


** There is no advantage here in using schottky.

� � You fucking ass.

..... �Phil

No Phil, that's true.
MOV's have a finite lifetime (determined by # of protection events),
but very difficult to model.
Basically, MOV's work great right up to the point where they fail.

-mpm

 

[Phil Allison]

"mpm"
"Phil Allison"
"Jamie the Jerk Off "

** Bollocks.


** There is no advantage here in using schottky.

? ? You fucking ass.

No Phil, that's true.
MOV's have a finite lifetime (determined by # of protection events),
but very difficult to model.


** There are NO " protection events " involved here - you pathetic ASS.

The stored energy and back emf current from a relay coil is trivial.



Basically, MOV's work great right up to the point where they fail.


** True of every component ever made.



..... Phil

 

[whit3rd]

mov's only take a wack x number of times before they short.

Not exactly true; the numbers VERY MUCH matter here.
A lightning-strike surge can overheat the MOV and
damage it, but an ounce of relay-magnetic-core can
only possibly store (at saturation) about 0.01 watt-second
of energy. An MOV rated at 1 joule (i.e. 1 watt-second)
won't get hot enough to change at all. It'll cool before a
second switching event occurs, and will last your lifetime.

 

[Jamie]

Not exactly true; the numbers VERY MUCH matter here.
A lightning-strike surge can overheat the MOV and
damage it, but an ounce of relay-magnetic-core can
only possibly store (at saturation) about 0.01 watt-second
of energy. An MOV rated at 1 joule (i.e. 1 watt-second)
won't get hot enough to change at all. It'll cool before a
second switching event occurs, and will last your lifetime.

That maybe true in your view.

Mov's were intended to absorb over voltage when over voltage
is there how ever, when used like they're suppose to be, no over
voltage will appear on a normal use. And it is true that MOV's
do break down over time with even minor suppression activities
even if you don't want to hear it..

Have you ever done a temp check on a wheeling diode after it
has suppressed a few collapses from a coil in a short time ?

You may change your view of things. Internal heating of MOV's
even small. causes their make up to break down.

In all the years of my experience doing this (many), I have never seen
MOV's being used to suppress the collapsation of a field . They are only
used in areas where the voltage isn't expected to be in a dangerous
level on normal operation.

The original idea of a MOV was that in most cases it could clamp
on an over voltage and possibly short in the process how ever, this
would take out the fused link that is suppose to be in the circuit
along with it.

I have replaced a good many MOV's in home electronics that just
broke down over time from constant minor transients on the service and
they just take out the fuse. You replace the MOV and the fuse.

Most of these repairs were not related to mother nature. Those
that were, normally left some ash behind.

Also while we're on the subject, you really want to use a diode
on the coil to suppress as much of the wheeling voltage as possible
with the diode being connected close to the coil. The will help keep
the voltage down at a low level so that that minimum RFI is generated.

You then have this problem of reverse polarity voltage being in the
circuit where it may not be so welcomed when using a MOV because they
aren't polarized! so what do you do to absorb the wheeling voltage on
the damaging side? Use a diode in series? what a hack!.

I think at this point it should be obvious that a MOV is the last thing
you want to put on a relay coil for wheeling voltage suppression.

Even with diodes, there is a noise issue in the R.F. world. Using a
R+C snubber does wonders for that.

Bye.

http://webpages.charter.net/jamie_5"

 

[Phil Allison]

" Maynard A. Philbrook = wacky code scribbler, aka Jamie "

That maybe true in your view.

** Huh ? Maynard is off with the faries.

Mov's were intended to absorb over voltage when over voltage
is there how ever, when used like they're suppose to be, no over
voltage will appear on a normal use.

** Huh ? Maynard is off with the faries.

And it is true that MOV's
do break down over time with even minor suppression activities
even if you don't want to hear it..

** Huh ? Maynard is off with the faries.

Have you ever done a temp check on a wheeling diode after it
has suppressed a few collapses from a coil in a short time ?

** Huh ? Maynard is off with the fairies.

You may change your view of things. Internal heating of MOV's
even small. causes their make up to break down.

** Huh ? Maynard is off with the fairies.

In all the years of my experience doing this (many), I have never seen
MOV's being used to suppress the collapsation of a field .

** Maynard is a software writer and a radio ham - he has no real
electronics experience.

As one can easily tell by reading any of his posts.

They are only used in areas where the voltage isn't expected to be in a
dangerous level on normal operation.

** Horse manure.

The original idea of a MOV was that in most cases it could clamp
on an over voltage and possibly short in the process how ever, this
would take out the fused link that is suppose to be in the circuit
along with it.

** Maynard is still crapping on about lightning bolts.

Must be a big worry for radio hams.

I have replaced a good many MOV's in home electronics that just
broke down over time from constant minor transients on the service and
they just take out the fuse. You replace the MOV and the fuse.

** Maynard is still crapping on about lightning bolts.

Most of these repairs were not related to mother nature. Those
that were, normally left some ash behind.

** Maynard is still crapping on about lightning bolts.

Also while we're on the subject, you really want to use a diode
on the coil to suppress as much of the wheeling voltage as possible
with the diode being connected close to the coil. The will help keep
the voltage down at a low level so that that minimum RFI is generated.

** Huh ? Maynard is off with the fairies.

BTW: Relay makers actually advise AGAINST using diode suppression cos it
slows down the release and prolongs contact arcing.

You then have this problem of reverse polarity voltage being in the
circuit where it may not be so welcomed when using a MOV because they
aren't polarized! so what do you do to absorb the wheeling voltage on the
damaging side? Use a diode in series? what a hack!.

** Huh ??? Maynard is completely off with the fairies.

I think at this point it should be obvious that a MOV is the last thing
you want to put on a relay coil for wheeling voltage suppression.

** Funny how relay makers suggest using them - ain't it ?

Bet they never thought of seeking the opinions of a code scribbling radio
ham.

Even with diodes, there is a noise issue in the R.F. world. Using a
R+C snubber does wonders for that.

** Huh ? Maynard is off with the fairies.

Bye.

** Drop dead - you PITA fuckhead.



....... Phil