Isolation transformer

spamfree · 2007-05-05T04:42:06+00:00

I'm trying to find out why these are used as safety precautions inservicing mains connected equipment. Seems to me that not beingelectrically connected to the mains is a moot point. Surely the poletransformer isolates me from the generating dynamo at the powerstation, but my outlet can surely still kill me. Induced currents cansurely be as dangerous as directly conducted currents?Wikipedia states under this heading:"In electronics testing, troubleshooting and servicing, an isolationtransformer is a 1:1 power transformer which is used as a safetyprecaution. Since the neutral wire of an outlet is directly connectedto ground, grounded objects near the device under test (desk, lamp,concrete floor, oscilloscope ground lead, etc.) may be at a hazardouspotential difference with respect to that device. By using anisolation transformer, the bonding is eliminated, and the shock hazardis entirely contained within the device."Why would things connected to the same ground have dangerous potentialdifferences from that ground?Could some kind soul 'splain this to me, please?jack

May 05, 2007 66 Replies

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Charlie Siegrist 19 years ago

Circa Mon, 07 May 2007 23:11:35 GMT recorded as looks like Rich Grise sounds like:

It's good to visit a nut house now and again. Keeps life in perspective. I was an altar boy at masses at the Catholic nuthouse/old-folks-home in Altoona, PA as a child. A good experience. Humbling.

Phil has good ideas, and is worth listening to, if you can handle the bluntness. He's just a bit testy, that's all; I would hardly classify him as crazy. I will always disagree with a notion to keep someone silent, regardless of their point of view. Now, if one should start to really shout and overwhelm the signal on the channel, ie. suck up far more than their share of the bandwidth, then f*ck 'em, that's what kill files are for!

My $0.02; nothing more, nothing less. All drinks the next hour are on me!

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Charlie Siegrist 19 years ago

Circa Mon, 07 May 2007 23:09:33 GMT recorded as looks like Rich Grise sounds like:

FWIW I am officially British pissed at the moment. Thanks for asking.

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Charlie Siegrist 19 years ago

Circa 5 May 2007 22:32:10 GMT recorded as looks like jasen sounds like:

Discharge it. Take a wooden-handled awl and strap a copper braid to it (the metal part, for those who have a hard time following). Ground the braid, and touch the tip of the awl to the anode of the CRT (while firmly grasping only the wooden bit of the awl). It'll thrill the grandchildren and make the set a bit safer for work.

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Rich Grise 19 years ago

I use a screwdriver.

But, LEAVE IT THERE. It's amazing to watch the volts rebound when you take off the short - the glass itself gets charged, somewhat like an electret, and it takes a significant amount of time for that charge to bleed off, given that glass is an insulator.

Be Safe! Rich

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Marra 19 years ago

An isolation transformer will still kill you if you get across both sides of it. But you can grab one or other ends with out being killed. Also you can touch earth and the transformer with getting a shock.

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Phil Allison 19 years ago

** Beware - Google Idiot on Loose

** Completely irrelevant to the danger of using one with potential faulty electronic equipment and THEN making that same assumptions.

** LOL

Totally irrelevant link !!

......... Phil

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spamfree 19 years ago

I guess he's just a loudmouth moron. I wondered what makes him tick. Must be some personality disorder that would make someone constantly try to upset everyone. I wonder why he posts here. Some sort of inadequacy? jack

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