Just talking about mains tester screw drivers

[BigWallop]

I've just been reminded of a good story I'd like to share with you all.

It's a story about a mains tester screw driver. The screw driver in question had been dropped on to a hard floor from the top of a step ladder, so the little neon lamp inside died when the fall broke its glass shell. Everybody say Awww !!! But hope was at hand. Yeepee!!! A local supplier could make the screw driver work again by putting a new neon lamp inside it. Yeah !!!!

But the screw drivers owner was a cruel fellow, and told the supplier that he wanted to fit the new neon lamp himself. Boooo !!!! So the supplier didn't want to argue with this cruel man, and handed over the new neon lamp with much haste.

Now, the story takes a lighter twist here, because the mains tester screw driver had an all-in-one neon lamp and resistor unit inside when it was new and shiny and working, the new neon lamp only came by itself without the resistor. The cruel screw driver owner didn't care, he just wanted his screw driver working again, so he could jam it in things to see if it made the neon lamp light up. He was a vicious man indeed.

The new neon lamp was installed in the handle of the poor screw driver. The metal cap was hammered back into the top of the handle. The screw driver was all back together and ready for its first live test. You have to remember that the new neon lamp didn't have a resistor supplied with it. The scene was set, the drums rolled gently in the background.

The screw driver was presented to the live mains electricity for the first time with its new neon lamp installed and................BLAM !!!! The cruel owner was flung off the top of the step ladder on to his back. The screw driver had got its revenge on its cruel owner at last.

The moral of the story is "Make sure you understand how things work, before you go trying to repair them".

The End.

[Lurch]

On Mon, 03 Jan 2005 15:07:12 GMT, "BigWallop" strung together this:

Excellent! Another moral is, "if you've bought some useless piece of crap that was unreliable in the first place, don't bother repairing it".

[Lobster]

Thanks, enjoyed that.

David

(by the way, how's your back doing, BigW?) ;-)

[BigWallop]

ROFL !!! My sentiments as well. :-)

[Ian Stirling]

All neon lights are unreliable, almost by design.

[BigWallop]

ROFLMAO !!!! It wasn't me, David, believe me. I never the use the things.

[BigWallop]

That last bit is a lie (and out of this world with the double "the" in it), I do have a mains tester screw driver, but I think I've only used it to poke holes in a piece of leather.

[Dave Plowman (News)]

I've got roughly 5 in switches etc and never had a failure. Two - one in the cooker hood, and one in the cooker switch are on all the time. So that says to me they're longer lasting than even fluorescents.

[Lurch]

On 03 Jan 2005 16:50:26 GMT, Ian Stirling strung together this:

Well, if the neon was used as an indicator on a 240V supply then it would be fine. The general theory behind using it as a test instrument is the flaw with the neon screwdriver.

[Mike]

How do you rate plasma TVs then ? Not quite the same but ...

[Dave Plowman (News)]

Having watched one over Xmas - and having the opportunity to fiddle so it was giving its best, not at all. Unless you really need the space. Otherwise, stick to a CRT set.

[John Stumbles]

I've been using neon screwdrivers for decades and find them very useful. I'm rarely without one: mostly I use it for mechanical purposes (driving slot-head and small cross-head screws and other less screwdriverey purposes) but because I have it to hand it's my first-line mains tester. I find it gives a reliable indication as long as you know that you have to be touching the contact on the end for it to light up. I'm aware that it may give false positives (e.g. lighting up on an unterminated conductor from capacitive coupling from nearby live conductors) and could give false negatives (the tester may have failed). For the latter reason I make sure it lights up on a known live terminal before putting too much trust in the absence of a indication on the cct under test. The same (false +ves and false -ves) applies to high-impedance digital multimeters, and any indicator will give false negatives if broken.

The moral, to extend on the OP's, is to understand how things work before putting trust in them.

[Ian Stirling]

Neon lights seem to die after a few decades, which is annoying. On reflection, this may not be that much of a problem on a screwdriver.

[Dave Plowman (News)]

Possibly, but I'd hardly call that unreliable in light emitting device terms. ;-)

Dunno if they are susceptible to dropping? Don't trust neon screwdrivers anyway - never have.

[Ian Stirling]

Well, most seem to die after that long, a significant proportion (IME) die after a year or two, or go flickery. LEDs (not cheap white or blue ones) are much more reliable, I can't think of one power indicator LED in any bit of equipment I own that has failed.

I can think of 6 neons that have failed, or gone intermittent in items 2-30 years old. (most under 10)

Not very, unless the electrodes get bent together, or the glass cracks.

[ARWadsworth]

And what better for sticking into the terminals of a central heating wiring box than a neon screwdriver. A multimeter needs two steadily held terminals and usually a head turned 180 deg as shown by the girl on the exorcist to see any clues as to the fault. A volt stick lights up as soon as you enter the wiring box and is so unhelpful.

Neon testers do have a useful but limited purpose in life.

Adam