The risk to circuit boards.

I recently used a a static grass applicator in the usual way.
A few days
later, my Digitrax PM42 (a current sensing device used to protect the layout
against short circuits etc) has frozen up on all four power districts rendering
it unserviceable.  The layout had not been powered up since before installing
the static grass.

Is this sheer coincidence or could it be that the current
produced could have found its way onto the PM42's circuits?
When you consider
the amount of current sensitive circuit boards that one can install, this could
clearly be a real issue.
Has anyone any advice or experience regarding this
situation?

Regards Charlie

A static grass applicator runs at around 1500V, the slightest touch of the voltage, directly to the rails or possibly via wet PVA alongside the track will fry any electronics on a railway, as that is rated normally around 15V that's 100 times less. That sort of voltage will actually jump a small distance.

Once I get round to the stage of scenic work, all Electronics will be removed to a safe distance before waving a converted bug swatter around. Says he hoping he remembers.


Q

Hello Charlie,

I made a static grass applicator from a fly swatter and used it on a layout, nothing happened to my controller but then it is a homemade 3 transistor pulsed feedback effort. The voltage may be 1500 but the amperage that could have caused some damage is very small indeed.

Having said that though if a controller is made using logic chips and especially unbuffered ones then merely handling them without earthing your hands will blow them. 

But even worse than that; I was trying to do overgrown with grass track and the problem I had with the stuff was that the slightest bit of 'grass' that got on the rail stalled a loco, I run 0-4-0's and they do need all four wheels on the rail. It took me ages to get rid of it all in the end I had to resort to a brass suede brush. Months later I was still picking bits off!

Never again lol

Cheers - Jim

In future, I will always disconnect whatever I can.  From a Digitrax point of view, this entails pulling off the BDL168, PM42 and SE8C terminal blocks.  Of course this still leaves the DS64s and many other components with other manufacturers being vulnerable.
I believe that this is a real issue and one that folks need to consider before reeking havoc with a Static Grass Applicator.
Regards Charlie

I suppose this can be added to the list of reasons to not hard-wire everything in.

of course you could just use the old balloon method,, still works for me
:thumbs;-):cool:
Owen

Hi Owen

"balloon methord"

As some one about to start the scenic bits could you please elaborate.

Thanks

Andrew

Hello Andrew,


I think the idea is to scatter the grass glue it until not quite set then inflate a balloon and rub it up and down a sleeve wool perhaps, acrylic, cotton as well I think, this statically charges the balloon hole it above the grass and there we go! it's upright!!


Cheers - Jem

got it in one:doublethumb
:thumbs;-):cool:
Owen

Picture the scene….

Lovely calm Sunday morning, my first packet of static grass fibres, PVA diluted in yoghurt pot and slapped on.

Cat dozing on sunny window-sill.

Long sausage balloon inflated and rubbed vigorously on Marks and Spencer's finest lambs wool Christmas present pullover.

Fibres sprinkled.

Balloon brought close to fibres, but even closer to signal box finial.

BANG!

Exploding balloon.

Air-born cat [Think Tom and Jerry]

Yoghurt pot of dilute P.V.A, everywhere.

Everywhere includes Marks and Spencer's finest lambs wool Christmas present pullover.

This having come 24 hours after strimming wet grass too close to newly washed bedding on washing line…..

I too have never used static grass fibres since.

Doug

Doug
That is a very clear explanation on how to do static grass with a balloon.
What happens if you do not have a cat? Can you substitute anything else?
Andrew

Well, in biblical terms, grass seems to have come before cats or even finials, so as long as one models following recognised patterns of terra forming, it should all be right as 9/- (nine pence). 

Any bright spark know the derivation of the above monetary quip?

Cheers,

Bill:)

[user=1779]Chiefnerd[/user] wrote:

Doug
That is a very clear explanation on how to do static grass with a balloon.
What happens if you do not have a cat? Can you substitute anything else?
Andrew

You can usually statically charge a balloon by rubbing it on your head

[user=1814]Longchap[/user] wrote:

Well, in biblical terms, grass seems to have come before cats or even finials, so as long as one models following recognised patterns of terra forming, it should all be right as 9/- (nine pence). 

Any bright spark know the derivation of the above monetary quip?

Cheers,

Bill:)

Old English proverb, "As fine as fippence, as neat as nine pence.  …" OED2. Apparently there was a ninepence silver coin.

Nigel

[user=1916]ZeldaTheSwordsman[/user] wrote:

[user=1779]Chiefnerd[/user] wrote:

Doug
That is a very clear explanation on how to do static grass with a balloon.
What happens if you do not have a cat? Can you substitute anything else?
Andrew

You can usually statically charge a balloon by rubbing it on your head

:It's a no no Only if you still have hair :pathead

[user=401]pnwood[/user] wrote:

[user=1916]ZeldaTheSwordsman[/user] wrote:

[user=1779]Chiefnerd[/user] wrote:

Doug
That is a very clear explanation on how to do static grass with a balloon.
What happens if you do not have a cat? Can you substitute anything else?
Andrew

You can usually statically charge a balloon by rubbing it on your head

:It's a no no Only if you still have hair :pathead

Doug


PS

"Old English proverb, "As fine as fippence, as neat as nine pence.  …" OED2. Apparently there was a ninepence silver coin.

Nigel"

IIRC a Ninepence piece was square….Right  angle?  [Pub quizzing comes in useful at last!

Just thinking….

D

Only if you still have hair!   Ah that,s why i just get this squeaking sound .

[user=31]sparky[/user] wrote:

Only if you still have hair!   Ah that,s why i just get this squeaking sound .

I always thought the squeaking sound was the rusted hinges on my wallet!

Terry