www.elektronik.si

[Dexboy]

Najprej lep pozdrav vsem skupaj

Danes je moj prvi dan tukaj (prav tako v 4. letniku, juhu.. <-- ne bom komentiral hehehe), na forumu sem našel veliko zanimivih in uporabnih stvari (še preden sem se registriral!), pa sem se odločil, da še malo vrnem uslugo

Za zaključno nalogo v 3. letniku sem si namreč izbral "Plazma zvočnik". Verjetno ste ga že vsi videli v akciji - na YouTube. Moj zvočnik sicer ne deluje na principu tesline tuljave ampak imam enostavno iskrišče, SG3525 čip (za zvočno PWM), 2x IRF540, VN trafo iz starega TVja.. iskrišče med dvema varilnima elektrodama (volfram, visoko tališče, super zadeva )..

In kaj je nastalo? Tole
povezava na YouTube

Lahko prilepim vse načrte, če koga zanima, izdelava ni težka, težko pa je najti ene par elementov... VN trafo ter 2 kondenzatorja


LP,


Nejc

[T42]

Meni je to zanimivo.
Kakšna je kvaliteta zvoka in ferkvenčni razpon'

lep pozdrav

[urkonet]

Ja, daj prosim ves materjal gor

[ID]

Lepo prosim, če bi lahko dal gor potrebno dokumentacijo.

[damo]

tudi jaz prosim. rad bi se malce pobahal pred sodelavci z novim zvočnikom v delavnici.

[Jule]

Koliko wattov pa "kuri" ta stvar?

Meni se zdi kvaliteta "povprečna" kar je tudi za pričakovati.

[damo]

pa saj tu ni poanta kvaliteta pa izkoristek, bolj se gre za umetniški vtis.

[Highlag]

Tole bi bilo za med Projekte.

[T42]

[damo]

aha, tud možno. meni se je bolj zdelo kot neka fora, kot pa audiofilska stvar.

[Dexboy]

Ahoj

Bom jutr prilepu vse kar je pametnga, danes [slovenščina je zame španska vas]... zmatran (da se lepo izrazim he-he)

Smo mel 9 ur v šoli.. In potem se človeku zgodi, da zamudi bus ob 15:20 in mora čakati na bus ob 14:30... Jupi
Ok, ta scenarij je pripravljen za naslednji teden, danes sem bus ujel (voznik je zapiral vrata.....)


Zadeva sicer deluje, super (vsaj zame..) ampak bi moral spremeniti nekaj stvari.. Najprej bi rad zamenjal IRF540 z IRF840 (se mi zdi da ni druge razlike, kot da so drugi 8amperski? je to res? če lahko nekdo potrdi prosim..)

Potem druga stvar - prevelik signal na vhodu greje čip - SG3525
Nimam pojma kaj se da narediti..

Tretja stvar: izračunati bi moral pasovni filter, ki bi na čip spustil samo frekvence nad 240Hz in do 20kHz (pač, maksimum)
Lahko da bo že to rešitev, ker se čip preveč greje.



Še kratki odgovori, kar znam povedat hehe

Kvaliteta zvoka je v redu, ni sicer ne vem kaj (prasketanje se rahlo sliši, razen če se poigram s potenciometri, parkrat mi je ratalo dobiti zelo lep in kvaliteten zvok - equalizer na računalniku - nizke tone stran, visoke sem tudi malo omejil)

Poleg tega ima tu Veliko vlogo dobro narejen napajalnik...



aja pa saj to ste verjetno že ugotovili...

POZOR, VISOKA NAPETOST!


P.S.
Priloga: slika sprednje stranice izdelka

[Srecko]

[T42]

Bolj ko gledam tole bolj me grabi da bi prižgal spajkalnik.

Tale že kar dobro igra: http://www.youtube.com/watch?v=cEeWtBAE5LY&feature=related

Še en sub pa mogoče mid pa je zmaga

edit: se ena druga dokaj enostavna resitev.
http://www.hvlabs.com/plasmasonic.html

edit2: >>>> http://www.nutshellhifi.com/library/speaker-design1.html >>>

Plasma Speakers

One day, I’d like to design one of these myself. The "massless" speakers fall into this category ... Ionovac, Magnat, and Plasmatronics (what a name!) They do sound exotic, and measure the same. No resonances at all, and accurate pulse and frequency response up to 100kHz or more. Low distortion too ... like a really good amplifier. Actually, the "diaphragms" do have mass. But it’s not much. It’s the same as the surrounding air, so the acoustic coupling is 1:1. The efficiency is a little difficult to state, though, since the output tubes of the power amplifier are supplying a high voltage that directly modulates a conductive gas with very complex electrical properties.

I first heard the Hill Plasmatronics at the 1979 Winter CES, and I must say I've never heard a tweeter that even came close to that one. The exhibitors darkened the room for dramatic effect, and you could see this weird violet glow through the grill cloth that looked for all the world like a gassy triode ... but it was the tweeter! Not only did it glow, it pulsed along with the music!

The rest of the speaker, though, was a pretty mundane paper-cone setup in a huge cabinet ... oh well. Even so, the Plasmatronics was a wild thing, a taste of the future, like a SR-71 Blackbird in an airport full of commuter-shuttle 737’s. Not too surprisingly, the inventor was a plasma physicist at Los Alamos Labs.

(Talk about being ahead of your time! This was 10 years before the fall of the Berlin Wall, and Dr. Hill was already thinking of ways to peacefully convert atomic swords into sonic plowshares!)

There are a few little problems with this glimpse of Paradise. Previous generations of plasma speakers, such as the DuKane Ionovac tweeter of the Fifties, used RF heating to ionize air, making it conductive. There’s a problem with this. If you ionize air, some of the oxygen molecules (O2) are stripped apart and then recombine as ozone (O3). You also get nitrous oxide (NO2), which is formed by combining nitrogen and oxygen at very high temperatures.

Well, a dose of laughing gas may or may not enhance the listening experience, but ozone really isn’t too healthy, since it irritates and burns the mucous membranes and the eyes. The natural home for these highly reactive gases is far up in the ionosphere, not in your living room.

The Hill Plasmatronics avoided the air pollution hazard by having its own built-in supply of helium, which is a noble gas and thus unreactive even when ionized. Helium is also biologically inert, and being much lighter than air, promptly escapes to the upper atmosphere and outer space. Even in the best-insulated houses it will be gone in a matter of seconds, so it is completely safe.

I remember seeing the helium tank, pressure gauges and all, in a special compartment inside the subwoofer enclosure. Imagine cracking a valve and hearing a very faint hiss of helium gas every time you turn on your hi-fi. Oh, I nearly forgot, you had to swap the helium tank for a fresh one every month. Helium is not a renewable resource, and is only found in a few natural gas wells, so it’s not as inexpensive as other industrial gases.

There are still some interesting plasma-speakers that haven’t been tried yet. For example, one alternative to tanks of helium is a flame speaker (flames are plasmas too), using flammables that release no toxic byproducts of combustion. This leads us to hydrogen and oxygen, preferably generated on-the-spot by splitting water by electrolysis. (You’d water the loudspeaker like a plant!) The hydrogen and oxygen pipes go up to a copper wire mesh (a hemisphere would be the right shape), and the flame is trapped on the surface of the copper mesh.

The system has a computer-controlled power supply that splits the water, monitors the gas flow, and automatically sparks the flame when the correct hydrogen-oxygen ratio is reached. You then polarize the plasma with a high-voltage supply and modulate the flame with a high voltage audio transformer or direct-couple to 211, 845, or 212E plates from the built-in power amplifier. (The flame is modulated in the same way as a conventional electrostatic speaker.)

As far as I know, nobody has ever built a complete system like this before. I hereby throw the idea into the public domain, and wait to see if anybody is crazy enough to actually build it.

Don’t expect to get UL or VDE safety certification for a "loudspeaker" that mixes hydrogen and oxygen gas, high voltage, distilled water, AC power, an open flame, and a microprocessor, all in a domestic environment. Imagine the reaction of the reaction of the insurance company if they discovered how it works!

Aside from these trivial non-audiophile considerations, the plasma-flame speaker would have truly exemplary performance ... very low distortion, perfect impulse response, and a bandwidth of 100kHz or more. Another benefit of the confined-flame speaker is the "diaphragm" can be as big as you want, limited only by concerns like combustion noise, room heating, and fire hazard. As a compromise, a 6" diameter hemispherical flame front certainly wouldn’t be too difficult to build. That would deliver response down to 200Hz or so. It would be lab-standard flat from 200Hz to 100kHz, and no cabinet resonances either.

Just imagine a cold winter’s evening with twin pale-blue flames illuminating the copper-mesh hemispheres, the faint hiss of hydrogen & oxygen gas, the quiet murmuring of the water electrolyzer, and a pair of eighteen-inch-high Western Electric 212E direct-heated transmitter tubes to make it all sing. Add a Jacob's Ladder for visual stimulation and the picture is complete; Bride of Frankenstein has an electrifying night over at Nikola Tesla’s bachelor pad. Careful with that Zippo lighter, Nick!

[Dexboy]

[Dexboy]

Srecko:

jah se zgodi.. sem bil Zelo zmatran ko sem to pisal, skoraj spal sem na tipkovnici


same še to..