Electrostatic discharge on bus?

[John_H]

tadchem wrote:

Fuel trucks drag a short chain underneath to provide a path to earth for
static as it is generated. Same principle...

One of the worst "vehicles" for generating static electricity
(understandably) is a combine harvester (header).

Many operators drag an earth chain to keep their windows clean!

Experience tells me that it works.

--
John H

 

[operator jay]

"Steve Ralph" <steve@steveralph.f9.co.uk> wrote in message
news:42612f9d$0$537$ed2e19e4@ptn-nntp-reader04.plus.net...

"I Caught Kate" <sittinginthepool@internode.on.net> wrote in message
news:42608FB0.D6FD9610@internode.on.net...
tadchem wrote:

Are you sure the sound came from the pole and not the seat? Most
public buses I have seen have seats with evidence of contact with
questionable substances that could make them sticky. I usually ride
standing up.

Tom Davidson
Richmond, VA



Either that or the seats are loose held only by one or two bolts

My cat goes seriously electric in cold dry weather. I was lying in bed one
night
and the cat was sitting on my chest. I dozed off, then the cat decided
she wanted more attention, and touched her paw to my nose........

sr

The perfect solution here would be to just kill the cat.

 

In article <C6i8e.5602$Mj.49185@news1.mts.net>,
"operator jay" <none@none.none> wrote:

"Steve Ralph" <steve@steveralph.f9.co.uk> wrote in message
news:42612f9d$0$537$ed2e19e4@ptn-nntp-reader04.plus.net...

"I Caught Kate" <sittinginthepool@internode.on.net> wrote in message
news:42608FB0.D6FD9610@internode.on.net...
tadchem wrote:

Are you sure the sound came from the pole and not the seat? Most
public buses I have seen have seats with evidence of contact with
questionable substances that could make them sticky. I usually ride
standing up.

Tom Davidson
Richmond, VA



Either that or the seats are loose held only by one or two bolts

My cat goes seriously electric in cold dry weather. I was lying in bed
one
night
and the cat was sitting on my chest. I dozed off, then the cat decided
she wanted more attention, and touched her paw to my nose........

sr




The perfect solution here would be to just kill the cat.

The same thing happened whenever JMF wanted to kiss me. It
got so bad I'd insist he ground himself out before touching
my lips. Then I got smart and put more moisture in the air.
No more sparking. It also saved computer gear.

/BAH

Subtract a hundred and four for e-mail.

 

In article <_Jmdnaj_zo0lpfzfRVn-uw@comcast.com>,
"tadchem" <tadchemNOSPAM@comcast.net> wrote:

jmfbahciv@aol.com> wrote in message
news5ydnR8c-9smvPzfRVn-gw@rcn.net...

snip

When JMF decided to show off the second to last CPU he worked on,
I had to put a collar thingie around my shoe to prevent an
inadvertant teensy little spark while walking around on the
machine floor. I still don't know exactly what that was. I still
have the shift he had to wear.

Sound like a grounding strap.

Yup. That's what it was called; thanks .

Fuel trucks drag a short chain underneath to provide a path to earth for
static as it is generated. Same principle...

Sure. But a chain is metal and can conduct. I never understood
how this non-metal thingie would work. I'm not sure what the
material was. I thought rubber but then lots of plastic feels
like rubber these days. And the thing only touched my shoe, not
me. The shift's material has a funny feel to it.

/BAH

Subtract a hundred and four for e-mail.

 

In article <ue4361lv4ie79mktrk4eqp70l88j5fgeai@4ax.com>,
John_H <john4271@hotmail.com> wrote:

tadchem wrote:

Fuel trucks drag a short chain underneath to provide a path to earth for
static as it is generated. Same principle...

One of the worst "vehicles" for generating static electricity
(understandably) is a combine harvester (header).

Many operators drag an earth chain to keep their windows clean!

Experience tells me that it works.

Wow! You had windows? ;-)

Charge can be deadly when filling silos.

/BAH


Subtract a hundred and four for e-mail.

 

In article <F9qdndzCU-qspfzfRVn-pA@comcast.com>,
"tadchem" <tadchemNOSPAM@comcast.net> wrote:

jmfbahciv@aol.com> wrote in message
news:jM-dnTbRJqdvkPzfRVn-rQ@rcn.net...

That doesn't work. I know from experience. I would really
like to find a way to degauss myself at will. I get out of
my car and touch my winter coat-wrapped elbow to the car; get
a poke. I still get a huge poke when I remove the
key from the lock.

Your winter coat could be the problem...

Well, I rather ruled that out when I'd get a poke without it
on. Same thing with my boots. I get a poke when I wear shoes.

The instances do diminish in the summer time but then that's
normal.

Is it made with a synthetic fiber?

Yup. What I don't understand is why I don't ground out completely
with the first poke. One of these days, I'm going to remember to
not turn around to lock the car and see if that recharges me. I
know it's a silly notion, but I have to rule out them out, too.

/BAH

Subtract a hundred and four for e-mail.

 

In article <Xns963B473A3FCB9WQAHBGMXSZHVspammote@130.39.198.139>,
bz <bz+sp@ch100-5.chem.lsu.edu> wrote:

jmfbahciv@aol.com wrote in news:29CdnSdjAd5jrv_fRVn-tQ@rcn.net:

In article <F9qdndzCU-qspfzfRVn-pA@comcast.com>,
"tadchem" <tadchemNOSPAM@comcast.net> wrote:

jmfbahciv@aol.com> wrote in message
news:jM-dnTbRJqdvkPzfRVn-rQ@rcn.net...

That doesn't work. I know from experience. I would really
like to find a way to degauss myself at will. I get out of
my car and touch my winter coat-wrapped elbow to the car; get
a poke. I still get a huge poke when I remove the
key from the lock.

Your winter coat could be the problem...
snip

Is it made with a synthetic fiber?

Yup. What I don't understand is why I don't ground out completely
with the first poke. One of these days, I'm going to remember to
not turn around to lock the car and see if that recharges me. I
know it's a silly notion, but I have to rule out them out, too.

Some things act as capacitors and may need to be
discharged more than once.

Right. So why can't I manage to get a discharge a second time
through my coat? If I can't do this a second time, then I'm
a walking spark when I pump gas. So far I always lock my car
before I pump gas to make sure I don't spark.

For example, the picture tube of a TV set. The glass of the tube acts as
the dielectric of a capacitor. When you work on a TV, you must be careful
to discharge the high voltage anode connection on the side of the bell.

After the tube has been discharged, as the glass relaxes and as distant
electric charges make their way to the conductive coating inside the
glass,
the picture tube will 'build up' a charge again.

It is wise to leave your grounding strap connected for several minutes
before you start to handle the picture tube.

This is one of the many reasons I put hardware on my list as a
"guy thing".

/BAH

Subtract a hundred and four for e-mail.

 

[bz]

jmfbahciv@aol.com wrote in news:29CdnSVjAd5kr__fRVn-tQ@rcn.net:

Sure. But a chain is metal and can conduct. I never understood
how this non-metal thingie would work. I'm not sure what the
material was. I thought rubber but then lots of plastic feels
like rubber these days. And the thing only touched my shoe, not
me. The shift's material has a funny feel to it.

They include a conductive filler in the plastic when they make it or they
add a conductive coating after the garment is fashioned.

The 'ohms per square' of the material can be rather high and it can still
act as an effective discharge device.



--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+sp@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[bz]

jmfbahciv@aol.com wrote in news:29CdnSdjAd5jrv_fRVn-tQ@rcn.net:

In article <F9qdndzCU-qspfzfRVn-pA@comcast.com>,
"tadchem" <tadchemNOSPAM@comcast.net> wrote:

jmfbahciv@aol.com> wrote in message
news:jM-dnTbRJqdvkPzfRVn-rQ@rcn.net...

That doesn't work. I know from experience. I would really
like to find a way to degauss myself at will. I get out of
my car and touch my winter coat-wrapped elbow to the car; get
a poke. I still get a huge poke when I remove the
key from the lock.

Your winter coat could be the problem...

Well, I rather ruled that out when I'd get a poke without it
on. Same thing with my boots. I get a poke when I wear shoes.

The instances do diminish in the summer time but then that's
normal.

Static electricity is worse when the humidity is low. When humidity is
high, even the air can act to discharge the charge.

Is it made with a synthetic fiber?

Yup. What I don't understand is why I don't ground out completely
with the first poke. One of these days, I'm going to remember to
not turn around to lock the car and see if that recharges me. I
know it's a silly notion, but I have to rule out them out, too.

Some things act as capacitors and may need to be discharged more than once.

For example, the picture tube of a TV set. The glass of the tube acts as
the dielectric of a capacitor. When you work on a TV, you must be careful
to discharge the high voltage anode connection on the side of the bell.

After the tube has been discharged, as the glass relaxes and as distant
electric charges make their way to the conductive coating inside the glass,
the picture tube will 'build up' a charge again.

It is wise to leave your grounding strap connected for several minutes
before you start to handle the picture tube.



--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+sp@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[bz]

jmfbahciv@aol.com wrote in news:MpCdnYmOfZ5LzP_fRVn-1w@rcn.net:

Right. So why can't I manage to get a discharge a second time
through my coat? If I can't do this a second time, then I'm
a walking spark when I pump gas. So far I always lock my car
before I pump gas to make sure I don't spark.

The pump handle is well grounded. As long as you maintain contact with the
pump or pump handle, you should be discharged. Make sure your car is
discharged by touching the metal part of the pump handle to the metal of
your car. Do this away from the tank filler area before you remove the gas
cap.

THEN open the fuel tank, insert the pump nozzle, and pump gas. Don't move
away from the car while pumping gas, or if you do, be sure and touch a
metal part of the car away from the gasoline tank, before you touch around
the nozzle. You do NOT want a spark around the nozzle, because gasoline
fumes mixed with air are exhausting from the tank as you fill it.

BTW, 1 gallon of gasoline, properly vaporized, has more explosive force
than a case of dynamite.

....

It is wise to leave your grounding strap connected for several minutes
before you start to handle the picture tube.

This is one of the many reasons I put hardware on my list as a
"guy thing".

I doubt the accuracy/univerality of 'guy thing'/'girl thing'
classifications, but understand why people feel that way.




--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+sp@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[w_tom]

Glen and some others have provided a good response. To add
to what he wrote:
The discharge means electricity. Charges are not
electricity. Neither you nor the bus alone accumulate
charges. Both do. Electricity flows from (or to) charges in
you to charges in the bus. The charges don't flow.
Electricity flows from and to charges of different potential.
Charges you may have created by sliding on the seat.

Even that little air gap between you and your hand was an
electrical conductor before your hand actually touched the
metal bar. Even the insulator air conducted electricity -
albeit only for a short distance.

Materials that some consider insulators may be conductors to
electricity of different voltages and current levels. When
discussing static electric discharges, some tables, linoleum
tile, some wall paints, concrete floor, etc all can be
conductors. Even the string on a kite that appears to be an
insulator at lower voltages can be a conductor at higher
voltages. Some things (ie glass) are better insulators than
others (wood). When you touched the pole, you made an
electric circuit between two differently charged materials -
therefore electricity flowed.

Acceed See wrote:

I have discovered several times after I leave the bus seat and grab
the stainless steel pole, there was a pak sound. Is that a ESD? Are
the charges from my hand or the pole?

 

[Rich Grise]

On Sun, 17 Apr 2005 08:09:31 +1000, John_H wrote:

Pharmanaut wrote:
"John_H" <john4271@hotmail.com> wrote in message

To eliminate the effect try grabbing the pole, or any other earthed
(to chassis) part of the bus, while your bum leaves the seat -- which
is the point at which your clothes become charged.

I thought that in a car it was the air rubbing electron off of the
car, which is insulated from ground by it's tyres, that caused you to be
charged. And that you earth the car to ground as you step out... bloody
painful sometimes!

Vehicles on rubber tyres can certainly become charged, though I'd
suspect the culprit is dust rather than air.

It's the friction between the tires (ahem ;-) ) and the road, just
like a Van der Graaf. I got into the habit of touching something
metal _while_ getting out of the car - that takes care of the pants/
car seat issue. Unfortunately, at that point the valet gets zapped.

I've also commonly seen multiple zaps from one charge - when you
draw a one-inch (2.5 cm) arc, it only conducts until enough charge
has bled off such that you can't sustain the arc.

But a 1/8" (1/2 cm) arc, no problem!

Cheers!
Rich

 

[Acceed See]

"I Caught Kate" <sittinginthepool@internode.on.net> wrote in message
news:42608FB0.D6FD9610@internode.on.net...

tadchem wrote:

Are you sure the sound came from the pole and not the seat? Most
public buses I have seen have seats with evidence of contact with
questionable substances that could make them sticky. I usually ride
standing up.

Tom Davidson
Richmond, VA



Either that or the seats are loose held only by one or two bolts

I usually sit when it is an empty row, and without any sternly looking
person behind me. I worry they might come and strangle me like what they
did in the Godfather. I have a constant fear of people coming close to me.

 

[tadchem]

"Acceed See" <invalicd@hotmail.com> wrote in message
news:4264df52@news.starhub.net.sg...

<snip>

I usually sit when it is an empty row, and without any sternly looking
person behind me. I worry they might come and strangle me like what they
did in the Godfather. I have a constant fear of people coming close to me.

Eat more garlic. That'll keep people away.

Also try picking your nose slowly.

And practice belching and loud farting.

And develop an allergy to soap and water.


Tom Davidson
Richmond, VA

 

[I Caught Kate]

Acceed See wrote:

"I Caught Kate" <sittinginthepool@internode.on.net> wrote in message
news:42608FB0.D6FD9610@internode.on.net...
tadchem wrote:

Are you sure the sound came from the pole and not the seat? Most
public buses I have seen have seats with evidence of contact with
questionable substances that could make them sticky. I usually ride
standing up.

Tom Davidson
Richmond, VA



Either that or the seats are loose held only by one or two bolts

I usually sit when it is an empty row, and without any sternly looking
person behind me. I worry they might come and strangle me like what they
did in the Godfather. I have a constant fear of people coming close to me.

The one I hate is insanely fat people...

Ever had one of those sit next to you?

I had a guy sit next to me one week and he PONGED
absolutely ponged. I don't know what it is about
obese people but they smell more then the average
person seems to.

On way to work some weeks there is a lady who takes up
almost the entire two seats when she sits down. It's
sad to see walking heart attacks like this in public.
--
John

Life is short. Try to help each other.