Welding vs MAC/Credit cards?????

[ahidley]

I was doing some TIG on aluminum this week and I had my wallt in my pocket with my mac card and credit card. The magnetic strip is now not reconized in the MAC machine with the MAC card. My credit card is reconized in the same machine.

Does the EMI (electro magnetic interferance) change the magnetic strip on cards?

I was using an inverter type square wave welder

[DFMiller]

Whats a MAC card?
Mag cards can be demagnetized with an alternating magnetic field. Current in conductor produces and E and H field. Thus a pulsing current produces a magnetic field.
Dave

[ahidley]

You are kiddin right?

[EVguru]

I wandered too close to one of the NMRs at work (the exclusion lines need to be re-marked) and my cards still work.

[flathead4]

Since both welders and credit cards have been around for quite some time, it would most likely be common knowledge if using the former would damage the later.

Tom

[ckelloug]

I could see arc welding as being theoretically capable of blowing out the RF powered smart cards since the arc is a source of powerful wideband rf noise. Don't know if any of the rf powered smart cards are used as credit cards though normally.

[Black_Moons]

Pertty sure the EMI could kill a 'chip and pin' card. I would think the lead from the welder would need to go right next to your wallet to affect a mag strip. Of course, that COULD happen....

Also, Not all cards use the same mag strips, Some mag strips are much easier to write/erase then others.

[johnnyd]

Since I'm obviously too ignorant to know any better, I'll again ask the question....what's a MAC card?

[ak95xj]

My atm card and cell phone seem to take a beating from all the grit, metal shavings,grease etc thats on my fingers or clothes..Never noticed any damage from nearby welding yet..

[flylo]

I know new welders have affected my credit card,a new mig,a new tig & a 3in1. But I pay it off when due. Them & banks don't make a nickel off me. So what do I drag home tonight? A Lincoln Ideal-Arc 300 amp AC, 250amp DC with the round top, round wheel with a knob to infinatly adjust the amps built into a 4 wheel welding cart on wheels & a steel top to weld on,& hooks for the cables. This one didn't affect the card $200/Cash with extra long leads,an extra cord & 4 8" HD BB castors for another project. This thing weighs a ton but it does have the power. Sorry for getting off topic.