3 Phase HVDC supply

[G8GT364CI]

All you guys that fool around with high voltage are nuts.

[Zorrobeat]

I like the Moulinex MOTs :)

[tall32guy]

If it's DC I'm wondering why it has a AC hum to it, or at least in the background?

[Kizmox]

@tall32guy Because it has no filter capacitors. There is a lot of ripple which in this case is 2*50*3Hz -> 300Hz

[7ReyZor]

Correct me if I'm wrong, but HVDC has corona, HVAC doesn't. Unless it's just because there are no filter caps?

[Mrpsychotehpyro]

Thats typical 3 phase rectified noise.

As pure a DC as you can get without filters or motor generator sets

[preludefan]

frequency sounds square- must be dc but not very clean dc- very nice however!

[railgap]

I want to know where he found 3 phases in his house. Three circuits != three phases, junior.

[Kizmox]

@railgap

In Finland we have 3 phase service in almost every house. (and the place where this video was taken is an old industrial building with 3x250A service)

This is true 3 phase MOT stack believe or not

[railgap]

@Kizmox Well I'll be damned, I did not know that! I wish it were common here, my Bridgeport could use it. As it is, I have to run a phase converter. :(

[fairyheli2]

@railgap in some buildings it's one phase for sockets, one for lights and one for hard-wired appliances, e.g cookers and heaters.

[TheChipmunk2008]

@railgap Lemme guess, an american?

[railgap]

@TheChipmunk2008 Yes, yet another American who doesn't know everything about every country. Darn.

[TheChipmunk2008]

@railgap Touché :-)

Learning is fun tho... so all is good

[fairyheli2]

@railgap in most countries that aren't England or America, they have 3 phase in their house

[sprogdiklis]

mots overheat?

[tangolobo]

that is F'n cool... I wanna make one! :)

[ubuntupokemoninc]

what would a smoothing cap do would that take care of the 300hz ripple?

[megamarko94]

That's ac not dc

[Kizmox]

@megamarko94

based on what?

[ubuntupokemoninc]

@megamarko94

dc means the electrons are going in 1 direction, it can still be pulsed!

[MadManMarkAu]

@megamarko94 Listen to the 300hz buzz this supply gives off. It sounds like he's using a 3-phase input with a step-up transformer on each phase, with each stepup transformer going through (I believe) a full-wave rectifier (might be half-wave). That makes it DC, not AC :)

[MadManMarkAu]

@megamarko94 As an ammendment to my last comment, it seems he's using a "6 pulse" rectifier, which is for all intents and purposes a 3-phase full bridge rectifier. This also means he has the step-up transformers outputting in what's known as a "delta" configuration.

[neomix21]

@megamarko94 Where can you see, that its not being rectified?

[a380rockerfan]

add some capacitors!

[a380rockerfan]

nice!

[DJSpikesan]

How the hell is this DC???

[Kizmox]

@DJSpikesan

What makes you think its not DC?

[DJSpikesan]

@Kizmox Guess I've just never seen an arc like that on DC. Any time I've dealt with DC it's been with relatively low voltage.

[wow1022]

@DJSpikesan

it's bridge rectified AC which gives a 120hz ripple into DC voltage... only when there is a charged capacitor then it doesn't have that ripple

[DJSpikesan]

@wow1022 So it's like pulsed Dc current? Like in a stun gun?

[wow1022]

@DJSpikesan

but at a much higher pulse frequency

[tomi9311]

kui pitkä kaari tost tulee 30cm ?

[zezimashock]

how do you rectify this?

[Kizmox]

Google for "6 pulse rectifier"

[zezimashock]

thank you :D

[juniortore]

help

[juniortore]

how do you rectify such a hv and high amp?

[jmartis2]

Wow, sounds like a big fly :D

[XGsboty]

Oho! Mistä keksit diodeja mitkä tohon pystyy?

[Kizmox]

Kun on purettuna satoja mikroja niin on satoja mikroaaltouunin diodeita. Niputin niitä aina 4 samanlaista rinnan ja tein 3-vaihe tasasuuntaajan siitä läjästä. Aika kuumiksi menevät mutta ainaki toistaiseksi ovat kestäneet.