I reckon that bloke is nuts having that inside and being so cavalier about basic safety measures.

He spent the first part of that video just waffling on so I skipped that to where he's messing about with the probe and then didn't bother watching the rest but people who do this usually end up getting themselves into a lot of trouble.

Yeah that guy sure could talk!
I just wanted him to turn the volume control up to 11 and short the thing out!
He would then look like a decendant of Tesla, thats the original Tesla, he of the showering sparks, not the guy going to Mars.

Nikola Tesla (one of my heroes) was one of the original nut case inventors who actually made some things work.
Sadly he disappeared right up his own genius and kept making umpteeth "discoveries" that were actually all the same thing repeated.
A Genius never the less.
A great book to read is "the inventions, researches and writings of nikola tesla" Barnes and Noble ISBN 978-1-4351-6795-7.
Yes I have read this 500 page tome from cover to cover several times and how I wish I had been there with Nikola at the time!
Shorting out pole transformers is just a warm up!

People used to try and tame him but to no avail. He just could not make the jump from magnetics to electronics and atom theory in electrical thinking and while history may prove him to be right about magnetics as a tremendous energy source he was lost. Even the American Government could do nothing with him.
He should have been locked into the room next to Hanger 56, given a billion dollars and told to get on with developing a starship warp drive or something. Sad.

Fred.

A common failure during a brownout is failure of universal switchmode power supplies.
When the voltage drops to around 110V the power supply automatically selects this as the input voltage and keeps churning away.
When the input voltage is restored to 240V "Bang" no more power supply.
I've seen this quite a few times.

When the input voltage is restored to 240V "Bang" no more power supply.

... which would be a win for those of us surrounded by RFI.

Silicon Chip have had kits for brownout protectors. One I remember could handle up to refrigerator load, but there were others I think.
I would need one each at least for a refrigerator and a freezer. Hadn't thought of switched mode power supplies being vulnerable so would need one each forTV/hifi and computer set-ups. So don't think it will happen.

Irext, what sort of power supplies do this? I'd be VERY interested to know.

I design SMPSs and I also test goods inwards and production sample SMPSs as part of my job.

Some of the tests I do is run them up and down on a variac, both on no load, full rated load and 50% over rated load. So as well as overload conditions I test for brownout performance. A few SMPSs can't handle a slow increase in power voltage, they generally just don't start.

I have yet to see a supply fail catastrophically on a step or a ramp from 100v to 260v.

I also test for temperature rise in the transformer, secondary diodes, ecaps and the switching device. I'm fussy about ecaps, they are the part that generally causes the supply to slowly fail after about 12 months in service. I will not pass a supply that does not have a primary reservoir cap that is traceable to a datasheet and that cannot be shown to be working within spec. in terms of ripple current and temperature rise / rating.

There are some SMPSs that have a manual 110 / 220v switch but most designs handle the full range without any sort of switchover.

The most expensive SMPS failure I saw was in a VGA projector which was being used at the local high school back in the nineties when projectors were very costly.
The SMPS had catastrophically blown up with many destroyed components.
I can't remember the brand but it was one of the major ones and the field bulletin stated that after repairing the supply it was suggested to disable the input voltage detection circuitry which made it 240V only as this was a common source of failure if the input voltage dipped.
Once repaired it lasted for many years until the lamp got so dim it was unuseable.
Also saw quite a few SMPS supplies bought from RS Components and Farnells back in the 90's and early 00,s which failed when the input voltage from a local generator dipped and came back up.
These were generic brands bought to power 2.5GHZ link equipment on site.
We always carried a few spare supplies.
Ian I'm sure the one's you designed would have this sorted.
Pity we didn't have some of yours back in the day.

From "Notes on the Troubleshooting and Repair of Small Switchmode Power Supplies Version 2.86 (28-Jan-14)":

QUOTE: Supplies that are autoselecting with respect to input power are vulnerable to voltages at an intermediate value between their low and high ranges. At some values, they may autoselect the incorrect input range:

(From: Mike Diack (mobykcbbs.gen.nz).)

A subject dear to my heart due to a recent unpleasant experience - Was using a Picturelel videoconference ISDN codec on a job when, because of a powerline fault, the line voltage dropped to 170 volts. The PicTel has a big Onan switchmode PSU which is autoswitching between 100-120 and 200-240 volts. It got confused, and (regrettably) chose the former.... with very smelly results.

Moral: turn off things with cunning PSUs when brownouts occur

Well I learned something today! Thanks guys!

I have always tried to avoid any automatic state selection in a design. Such an idea in an SMPS seems to me to be an accident waiting to happen. It is possible and not too difficult to design a power supply that does not require such an arrangement.

For a circuit that gets it wrong with catastrophic consequences look no further than the incredibly dumb power supply in the KC Blaupunkt TVs.