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#61
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On Mon, 16 Jan 2006 03:27:51 GMT, james wrote
in : On Sat, 14 Jan 2006 18:46:25 GMT, Lancer wrote: +Thats total bull****...What happens if your tip has a 1,000 of static +on it? ESD control is supposed to eliminate the difference in +potential. ANSI ESD standards state that "everything should be at the +same potential" That means the operator or person, all test equipment +and irons. Why don't you do a search on ANSI ESD standards and find +out for yourself... You are cluesless about ESD... **** IF you are properly grounded, once you grab the handle of the soldering iron it will within seconds no longer be at 1000 volts potential. Gee, then why bother to make soldering irons with grounded tips? Maybe you should also read your Ansi Standards a bit more and understand static prevention. Once you are grounded touching any other ungrounded object will dissapate the charge built in it. That charge will drain through your body to ground within a very short period. It's clear that you missed the physics demonstration with the balloon, the glass rod and the rabbit fur. Besides most ICs can shrug off 1KV with no damage. Bull****. Take -any- chip you can find, hook a 1kV source (DC -or- AC) across a ground pin and any non-ground pin, then see if it still works. It won't. Unless it's designed for 1kV I can guarantee that you will fry the chip. Try it again at only 100V and you will get the same results. It is neat to see what a 15KV jolt does to the poly layers and the protective zeners on an IC. If you ever get a chance to do some electron scanning of static damage to the die pad area of an IC, do so. It is a really neat to see what 15KV can do. Been there, done that, got the T-shirt, coffee mug, bobble-head doll and Seahawks jacket. Now if only the Mariners could get their act together..... ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#62
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On Wed, 18 Jan 2006 22:53:53 GMT, james wrote
in : On Mon, 16 Jan 2006 13:31:56 GMT, Lancer wrote: + Maybe you should read Ansi standard ANSI/ESD-S20-1999. It states +Soldering Irons should have a tip to ground resistance of less than 1 +ohm. Companies spends tons of money each year to prevent static +damge, and that icludes insuring that everything is at the same +potential. Including the operator and all equipment he uses. Thats +why iron's that are ANSI rated have a third wire, the ground. It +wasn't put there to prevent the user from being "shocked" ****** maybe you should study Coulomb's and Guass' Law and understand how Static Charges are developed. A soldering iron sitting on a anti-static mat plugged into the wall is not going to develope large electrostatic charge. "Large" is a relative term. What does happen is the tip of a soldering iron is in the strong field of a time varying magnetic field. This comes from the inductance in the heater coil. Putting the tip at ground potential will eliminate any potential charge build up from the time varying magnetic field from teh heater coil. What you are ignoring is that the electromagnetic field from AC current doesn't create -any- potential charge on the tip. The net charge is zero, and any instantaneous potential charge is the result of eddy currents which are almost non-existent. More specifically..... If the tip is the secondary winding of a transformer as you suggest, the effective number of turns on that winding is 1 turn, while the primary (the heater coil) has considerably more than 1 turn. So any voltage developed as a result of electromagnetic induction is going to be low from the get-go. But that voltage is actually lower because the tip is really just a shorted loop and is made with a material that has a very low resistance. Not to mention that the number of primary turns isn't going to be optimum for power transfer, nor does it have a ferro-magnetic core. It's a ****-poor transformer at best. Your theory is further flawed because it assumes an unshielded heater using wire that is wound into a solenoid -- an assumption that, like most assumptions, is frequently wrong. Almost all AC soldering irons these days have shielded heaters, and many heaters are wound to be non-inductive; i.e, they can't induce a current in squat, let alone develop any significant (measurable) voltage on the tip. Then you have the problem that the irons used for chips are only 15-30 watts, and virtually all of those watts are converted to heat (after all, that's the intended purpose of the soldering iron, isn't it?). So here's your theory so far: A tiny fraction of 30 watts (I'm being generous here) is converted to an electromagnetic field, worms its way past the heater's shield where it loses most of its energy to eddy currents, induces a current in a shorted, 1-turn secondary with very low resistance and develops enough voltage to cause damage to..... your imagination. Go back to school. ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#63
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![]() "Frank Gilliland" wrote in message ... Been there, done that, got the T-shirt, coffee mug, bobble-head doll and Seahawks jacket. Now if only the Mariners could get their act together..... Ah, Frank. Now I understand why you tend to get a little ****y in October. :-) |
#64
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Steveo wrote:
Lancer wrote: Dang, sorry to hear that man. What do you do for drinking water, buy bottled? I have well water, and I still won't drink it. All our drinking water is bottled. Hey It looked like you guys had a little bit of rain recently, no? I find myself hoping some of that big state of Texas get's it now (your area), when I'm watching the national weather map. (i usually only care about n ohio) ![]() |
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