A scientific pearoast
Working as I do in academic research, I get to play with lots of nice toys. The kit is usually bought from research grants, but in the last few years my funding situation has been, shall we say, less than generous. This has meant that while my salary has been paid and we've had a bit of cash for consumables and travel, the equipment capex budget has been essentially zero. I'm sure this will be a familiar tale to anyone involved in science these days.

So when I urgently needed a high voltage power supply, I was stuck, as they're quite expensive and we didn't have one. OK, brain in gear - I'm desperate here. What do I need to make one?

Source of ac signal - yup, we've got a function generator.
Amplifier - no, but I ordered up a couple of power FETs (big transistors) from RS for a few quid, rummaged around the lab for the other components, and built my own.
DC supply for amplifier - OK, we've got power supplies in the lab.
Step-up transformer - scrounged old Fiat ignition coil from a workmate who does a bit of car work on the side.
HT cable - got from car accessory shop for minimal sum.

So half an hour's work and I had myself a high voltage AC supply. This thing was great. Dr Frankenstein would have been spluffing his pants just watching it in operation. It even glowed a nice shade of purple in the dark. I was especially pleased with the fact that it broke so many rules and regulations:

1 - I had no high voltage warning signs. I used to just yell to people who came in the lab to keep clear.
2 - Large quantities of ozone were generated, for which I had no extraction rigged up.
3 - I had no current limiting. Normally high voltage supplies are required to have current limiting resistors built in to prevent too much current being drawn in the case of a short to earth, mainly through the human body. I didn't bother, so this thing was totally lethal.
4 - No shielding of high tension wires. I had bare wires hanging out the end connected to my experiment. I measured the voltage at 80,000V!
5 - As for electromagnetic radiation emissions, let's just say it wouldn't have been awarded a CE mark. Didn't hear of Radio Tay going off air, but it must have been a close thing!

It also emitted a pleasing high pitched whine (it resonated at 8-9kHz) and crackled and sparked a bit from time to time.

Unfortunately, I seem to have lost the kit in a recent lab refurbishment, but I do have pictures from the original posting. See replies.
( K2k6 has a proper job these days, Thu 27 Aug 2009, 8:54, 6 replies)

Pictures




The day on which these were taken was a bit humid so the glow's not as good as it should be. However, there is a corona discharge between the cable and the earthed coil body, and the little fluorescent tube is glowing all on its own!
( K2k6 has a proper job these days, Thu 27 Aug 2009, 8:54, closed)

Haha
Awesome! *clicky*
( VandenPlas can't think of anything clever - no change there!, Thu 27 Aug 2009, 9:14, closed)

You *are* Dr Frankenstein
AICMFP
( chickenlady b3ta's very own Elizabeth Taylor, Thu 27 Aug 2009, 9:38, closed)

Science *should* be impressively dangerous
This is ace!
( LemonEntryMyDearWatson This time, Moriarty, the hand is on the other foot, Thu 27 Aug 2009, 10:08, closed)

This gives me
The Fear. I'm glad we don't have one in our lab..
(berk, Thu 27 Aug 2009, 10:45, closed)

Having no idea about this thing you call SCIENCE,
I can say that I'm really bloody impressed by this... erm... THING!

Cheers & Click!
( SpankyHanky, Thu 27 Aug 2009, 11:54, closed)