Neon Tester Screwdrivers

[The Philpott]

I am slightly puzzled that i haven't ever seen any upgrades to the basic Neon Tester design. I was browsing on an IET forum earlier and saw that several bods had had similar thoughts, viz:

-Two (or perhaps even three) resistors of equal value in series, mitigating the effect of a resistor failing s/c (a rather unlikely failure)
This would make the tool bulkier, but it could still be acceptably small- especially compared to a voltpen.

- All the internal components potted in clear resin to exclude (as much as possible) accidental water ingress. Would this increase the energy of the shrapnel in the event of a explosive failure of the tester though..? Heading away from electrics towards ballistics here.

I can't really accept that the proliferation of 'better' testers would have halted development to the point where no-one took the opportunity to develop and improve.
....Or are there hidden consequences to the improvements i have suggested?

Dave

[Maarten]

I think I've seen 2 resistors in series. I think they also use resistors that aren't likely to short or go low.

[raditechman]

Vintage Engr mentioned

BBC-2 colour test film, circa 1967/8

The film with Switch off Isolate Dump and Earth is called "On the Safe Side" It is available on YouTube.
John

[vidjoman]

Back in the late 1950’s I had a neon tester that had the screwdriver blade cut short and put the rest into a plastic tube, I think resistors came in the tubes, and it was therefore isolated. Used as a guide to tell if line output transformers were working. Only needed to get it within about 2-3 inches and it glowed without having to touch anything.

[Andrew2]

Originally Posted by Vintage Engr

That's it, "Switch off, Isolate, Dump, & Earth"

Otherwise you'll be like the poor technician who returns to an H.V. installation, - from a dentist's appointment, only to find out too late that his colleague has reversed the connections of an inductor/capacitor circuit. Big bang!

Anyone remember the BBC-2 colour test film, circa 1967/8?

Sure do, it was one of my favourites and I always stopped work to watch. Mind you, a LOT of them were worth downing tools to watch.
In the TV trade at that time, it was common to wave a neon screwdriver near the line output stage to check if it was doing something. A pretty crude test, but it showed signs of life.