Electric Shocks!?

[asterix]

That proves my belief that physics degrees are all about remembering extraordinary complicated formulae or equations and of no practical use whatsoever.

But don't let me discourage you!

 

[SimonRoberts0204]

I am told "the most employable skill of a physics graduate is not their technical know-how, but their 'outside the box' problem solving style approach" << yeah right

 

[Arch]

I don't know the physics, but I do know I've ridden under powerlines and heard (and almost felt) them humming, so I'd be happy to believe in some sort of build up of static.

 

[colin-java]

I've had these shocks under powerlines myself.
I googled it the other day, and its cause theirs an electric field, so the static builds up on if you're not earthed.
Its like when you rub a balloon on a carpet, it builds up static, its the same thing.

Then the shock comes when you discharge the static when touching the metal brake lever.

The solution is keep touching something metal as you ride under the powerlines, so no charge builds up.

 

[subaqua]

its an induced charge . there will indeed be a massive magnetic field around the HV line . and you must remember what happens if you move a ferrous object in a magnetic field

 

[Milkfloat]

6 years for the thread resurrection, what was being searched to bring this up?

 

[swansonj]

6 years for the thread resurrection, what was being searched to bring this up?

I've no idea but I'm delighted because it gives me the chance to mix business and pleasure and post this link:
http://www.emfs.info/effects/microshocks/microshocks-from-bicycles/
Any resemblance between the photo on that page and my avatar is, err, not exactly coincidental.

I've had these shocks under powerlines myself.
I googled it the other day, and its cause theirs an electric field, so the static builds up on if you're not earthed.
Its like when you rub a balloon on a carpet, it builds up static, its the same thing.

Then the shock comes when you discharge the static when touching the metal brake lever.

The solution is keep touching something metal as you ride under the powerlines, so no charge builds up.

It sounds like Google may have led you to the above link, which would be very gratifying, as we've (that's the business "we" not the pleasure "we") made a commitment to government to make that information accessible to cyclists who want to find out what it is that happens when they cycle under power lines.

its an induced charge . there will indeed be a massive magnetic field around the HV line . and you must remember what happens if you move a ferrous object in a magnetic field

It is indeed induced charge, but induced by the electric field from the power line not the magnetic. It happens with aluminium or titanium bikes as well as steel.

 

[buggi]

I've no idea but I'm delighted because it gives me the chance to mix business and pleasure and post this link:
http://www.emfs.info/effects/microshocks/microshocks-from-bicycles/
Any resemblance between the photo on that page and my avatar is, err, not exactly coincidental.


It sounds like Google may have led you to the above link, which would be very gratifying, as we've (that's the business "we" not the pleasure "we") made a commitment to government to make that information accessible to cyclists who want to find out what it is that happens when they cycle under power lines.


It is indeed induced charge, but induced by the electric field from the power line not the magnetic. It happens with aluminium or titanium bikes as well as steel.

I was just about to tag you but see you got here first!

 

[Big Dave laaa]

I must confess, I really should know the answer myself - I am a student of Physics at University! I cant seem to find a reason, given that I am on rubber tyres, and at any rate, the breakdown voltage of air at 1atm is about 10,000 volts per metre!

Plus, if it really were the powelines earthing through me, it would be a little more than a slight shock!

I don't know how you finally got on at uni but the actual figure is nearer 10,000 volts/inch not /metre nog sure how this affects any other science in the thread

 

[swansonj]

I don't know how you finally got on at uni but the actual figure is nearer 10,000 volts/inch not /metre nog sure how this affects any other science in the thread

3MV/m, or 30,000 V/cm. But that's not the relevant parameter here. There's no breakdown of the air involved, just induction of charge as the electric field from the power line exerts a force on the charges that are already in the object in question (the person in this case).

 

[subaqua]

It is indeed induced charge, but induced by the electric field from the power line not the magnetic. It happens with aluminium or titanium bikes as well as steel.

cheers for that, I was using my basic generation principles and working on the steel in the bikes components building up the charge then moving along the other conductors/inductors in the bike. in fairness it was end of 1st day back in work and my brain was frazzled. mainly after having to go back 4 points along a distribution network to isolate a transformer as the other 2 pieces of kit have operational restrictions on them and the SF6 gauge was just into the red on the RMU supplying the Trans. the site was NOT happy but has sort of made them realise they need to do the shutdowns to change the knackered worm drives .