Strange pic 16f877a memory loss

[comwarrior]

lightning will still strike a plane...

[Melanie]

Yes, but theoretically shouldn't do any damage as the aircraft is itself 'floating' and not connected to a 0v 'Ground'. The engines, chassis and all metal surfaces are bonded together along with busses to provide a local electrical return path. Composites (such as Carbon Fibres) usually (though not always) have an integral mesh or carrier strip which is bonded to the vehicle 'ground'. In flight it could be quite common for an aircraft to be charged at quite a high potential - so it's 'ground' is not at 0v, but some arbitrary 'floating' (pun intended) value.

You could connect a PICs Vdd to several hundred kV (and happilly run it) - providing Vss is never more than say five volts lower than Vdd... I have an application for a domestic boiler Gas Ignition board using a PIC where Vdd is actially 0v (Ground) and Vss is -5v (it's easier then to use Comparators to detect if you have a flame as it creates negative ions). You can mess things around quite happilly providing you stay overall within the Datasheet parameters.

[aratti]

Have you forgotten the Faraday cage principle?

Al.

[Acetronics2]

Yes, but theoretically shouldn't do any damage as the aircraft is itself 'floating' and not connected to a 0v 'Ground'. .

Hi, Mel

Only theoretically ...

Ten years ago thunder striked my house ...

and I got damaged electronics aboard one of my model planes : a receiver and two servo amps were damaged.

the model ( wood built ) was hung to a metal tube ( connected to ground ) of the central heating by a piece of string ...

so it was really " floating " ...

I do think cables act like a transformer secondary if lightning passes closer enough ! a good magnetic shielding of the enclosure looks necessary too ...

Alain

[Ioannis]

Alain, were you inside the house when the thunder stroke?

Ioannis

[sayzer]

Alain, were you inside the house when the thunder stroke?

Ioannis

I will do my best guess:

I guess he was outside his home trying to test his hand made volt meter to see whether he could take a reading from the lightning or not.
(and If so, to see what the deviation could be)

Am I close?

[Acetronics2]

Alain, were you inside the house when the thunder stroke?

Ioannis

Hi, Ioannis

I quietly was sleeping in my bed ... and was awaken by an unusual "bang".

Thunder striked in my wife's father room ... making a nice hole in the plaster of the wall, to reach the grounded central heating tubing.

Of course there was plaster powder spread everywhere !!! ... somewhat funny. my father in law appearance was funny too ...

I saw for the first time what happens to transformer windings : every turn is cut into two parts and thrown everywhere... astonishing !

Also Noted Aluminium shielded TV cable takes fire ( dangerous ! ) ... but not Copper shielded one !

My scope ( plug was not connected ) trace also was disturbed for seveal month ... not to say more than a year ... ( Trace rotation : 3-4 ° + small sine for Grounded input instead of the line )

Neibours told me they had seen the Fireball come to the house ... had like to see it too !!!



Hi, Sayzer

you're totally out on this one ... I was experimenting with Mel's Leyden Jars !!!

I wonder was to try your wonderful Turkish invention ( remember : a 12 kW laser to make a solar Windmill rotate ... video + distinguished professor interview provided ...)

ROFL

Alain

[Ioannis]

Amazing how you make it out of it.

I am sure neighbours had an impressive show. I don't know about you though!

Have you thought of installing an lightning arrestor? People think that the thunder will not strike twice but I 've heard otherwise very often.

Ioannis

[Acetronics2]

Hi, Ioannis

a Thunder Arrestor is a soltion for High buildings, Castles, Churches ... I always heard a couple of Birch trees make it well ... If no mains lines around.

Now, Thunder is like water: you can channel them, but never stop them ...

Why wouldn't thunder strike twice at the same place ??? ... if everything rebuilt as it was ... no reason !!!

But as clouds are randomly placed and constituted ... difficult to get twice the same HV Generator characteristics !!!

Regards
Alain