plasma speaker

Faktisk er du vidne til naturens gigantplasmahøjttaler hver gang du hører torden!

Kig på:

Citat: "... A plasma arc loudspeaker or plasma-dynamic loudspeaker is a loudspeaker that creates sound by varying air pressure through a corona discharge or electric arc. It is an evolution of William Duddell's "singing arc" of

1900 and, in recent times, modern research into spacecraft propulsion in the form of the ion thruster. ... The plasma by-product, ozone, can reach hazardous levels in closed rooms. ..."

DIY Plasma Tweeter ... not for beginners:

Citat: "... It is really simple. It is a modulated RF power amp with a controlled ionic discharge. By modulating the oscillator with the audio signal the flame size changed and so the air pressure changed also . You hear the sound directly through the air without modulating a diaphragm. So there are no moving parts, no distortion and none of the problems other tweeters have. The signal is quite low in level ( I measured 82 dB with my prototypes ) but it is the cleanest sound I ever heard. I use no horns to increase the sound pressure so you dont have to sit in axis of the tweeter, the sound is everywere in the air. ..."

Citat: "... During his experiments Duddel found that by varying the voltage supplied to the lamps he could create controllable audible frequencies from a resonant circuit caused by the rate of pulsation of exposed electrical arcs. ..."

hilsen

Glenn

"Glenn Møller-Holst" skrev i meddelelsen news:gbnhp8$nk$ snipped-for-privacy@news.net.uni-c.dk...

[SNIP]

...og troede at det var fake :) Så lærte man også noget i dag ;)

Hej

Nej, de bliver da også solgt, de koster, men det virker.

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Mvh Max

s=E5 har jeg fundet en jeg vil bygge, det er med en flyback transformer, fra et gammelt tv. i stedet for r=F8r, da det er lidt nemmere at arbejde med

Hej!

Sørg for at være passe på!

Sæt gerne 10Mohm over hver af 4,7uF/200V så de med sikkerhed aflades når højspændingskonverteren slukkes.

Luft ud mens den er tændt og et stykke tid efter den har været tændt.

Ozon angriber bl.a. dine lunger:

The Dangers of Indoor Ozone:

Citat: "... The American Academy of Allergy, Asthma and Immunology (AAAAI) has concerns that high ozone levels result in the detrimental affects on the respiratory system including:

• irritation of the respiratory system causing coughing and irritation in the throat and chest * a reduction in lung function, making breathing shallow and labored * inflammation and temporary damage to the lining of the lung

There have been experiments in which a mouse was killed in 45 minutes at about a 100 PPM concentration of ozone...on the other hand ... One other down side to ozone is it's corrosiveness to certain plastics, most notably plastics used for electrical wire insulation and printed circuit boards.

Outdoors ozone is rarely a problem since the concentrations are very small and dissipate quickly. ..."

Mere information:

Citat: "...

1. How does Ozone (O3) affect human health? ... Short-term exposure to ozone peaks can temporarily affect the lungs, the respiratory tract, and the eyes. ...

2.5 No exposure threshold has been identified below which nobody?s health is affected by ozone exposure. This is because different individuals respond very differently to ozone exposure. A threshold has been determined for lung damage and inflammation, but studies on this topic have generally not tested especially sensitive subjects. ..."

hilsen

Glenn

Mere om ozon:

Ozone Generators Create Home Smog. Air Purifiers That Produce Ozone May Be Hurting Your Health:

Citat: "... You can create dangerous smog levels in your own home with an ozone-generating air purifier. The finding comes from a study of ozone-emitting air purifiers by Sergey A. Nizkorodov, PhD, and colleagues at the University of California, Irvine. The researchers studied 13 air purifiers known to give off small and large amounts of ozone, a major ingredient in air pollution. ... the UCI researchers found that one ozone generator, the EZ-COM Air Purifier, took only a half hour to build up ozone to a smog level that would force school closings if detected in a city's air. ..."

Citat: "... Smog is a problem in a number of cities and continues to harm human health.[2] Ground-level ozone, sulfur dioxide, nitrogen dioxide and carbon monoxide are especially harmful for senior citizens, children, and people with heart and lung conditions such as emphysema, bronchitis, and asthma[3]. It can inflame breathing passages, decreasing the lungs' working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and it dries out the protective membranes of the nose and throat and interferes with the body's ability to fight infection, increasing susceptibility to illness. Hospital admissions and respiratory deaths often increase during periods when ozone levels are high [4] ..."

En del (mange?) fotokopimaskiner og laserprintere har vist ozonfiltre indbygget i dag:

October 1, 1998, Photocopiers 'can make you sick':

Citat: "... Scientists at the National Institute of Occupational Health in Copenhagen have found that ozone produced by photocopiers could interact with other compounds to produce irritating smells and eye and breathing problems. ... In normal atmospheres they do not cause sickness because they are present in very low levels.

However, when they are mixed with ozone, they can cause some of the irritations linked to 'sick building syndrome'. ... After half an hour, the mice's breathing rate fell by 30%, indicating airway irritation. ..."

Placering af printere og kopimaskiner (Indeklima):

Citat: "... Arbejdstilsynets retningslinier omkring anbringelse af printere og kopimaskiner er, at disse bør placeres i særskilte lokaler med god ventilation, da de kan give anledning til hovedpine og irritation af slimhinderne for de ansatte.

Små laserprintere kan dog, hvis anvendelsesgraden er lav og en god ventilation sikret, placeres i samme lokale som de ansatte. Dog bør der vælges en printer, der ikke danner ozon. ..."

hilsen

Glenn

Glenn Møller-Holst skreiv:

Dette er en 20 år gammel påstand under gruppen: "ting kan være farlig". Når vi setter tall på verdiene og relaterer dem til andre dagligdagse forhold, ser vi klart at det i dette tilfellet er reklamefremstøt fra dem som selger ozonfiltre.

HM

havde t=E6nkt p=E5 det samme for ikke at f=E5 et sm=E6ld over fingrene

og det med ozon. dette projekt er kun ment for sjovt jeg kunne ikke finde p=E5 at bruge den i min stue. s=E5 bare rolig

glenn: havde t=E6nkt p=E5 det samme for ikke at f=E5 et sm=E6ld over fingrene

og det med ozon. dette projekt er kun ment for sjovt jeg kunne ikke finde p=E5 at bruge den i min stue. s=E5 bare rolig

Jeg har nogle gange tænkt lidt på at lave sådan et par diskanter. Man burde kunne sætte en tynd folie udenom for at spærre ozonen inde, så den ikke gør skade. De må være tæt på at være ideelle, ingen masse, ingen opbrydninger, rundstrålende, og lineære op til 1 MHz eller noget der omkring. :)

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Ulrik Smed
Aarhus, Denmark

s=E5 fik jeg bygget den. og den virker fint... det eneste hvis man bygger efter det diagram. skal man lige have en lille forforst=E6rker p=E5 hvis man bruger input signal fra en mp3 afspiller eller noget i den stil.

og det er nemt at tage en spole fra et tv, det eneste man skal g=F8re er at vikle ca 10 gange rundt med noget tr=E5d p=E5 prim=E6r side. og sekund= =E6r er fra den ledning der sidder p=E5 toppen af spolen, og til en af ben'ene der sidder i bunden.

s=E5 har jeg bygget en. og den virker :-)

lige 2 sm=E5 tip

1; man kan tage en spole fra et tv. og selv vikle ca 10 gange p=E5 prim=E6r side med noget tr=E5d. og sekund=E6r side er den ledning der g=E5r fra toppen af spolen til en af benene i bunden af den.

2; hvis du vil bruge input fra mp3 afspiller eller noget lignende. kan det v=E6re smart at lave en lille forforst=E6rker evt. med en op amp.

mvh yspede

Kan du give linken til lige netop den *du* har lavet, bare så jeg er sikker på hvilken det er? Jeg synes det lyder meget interessant.

Mvh Hauge

Hej!

Det lyder godt.

hilsen

Glenn

kker

jo det er denne

Det duer nok ikke ret godt med en trafo med indbygget split-diode ensretter. Og det har de jo alle sammen nu til dags. Man skal nok have fat i en af de gamle trafoer hvor der sad en udvendig tripler ved siden af, og bruge den uden tripleren. Det vil jeg gætte på giver en 'renere' gnist. Jeg mener også at de 'rigtige' plasmadiskanter slet ikke laver en egentlig gnist, men mere sådan en tåge fra en spids, inden i et kugleformet gitter. Lidt ligesom det man kan se i mørke fra spidsen af en af de der antistat-pistoler til at 'afstatificere' vinylplader med.

Lyder ellers som et fedt projekt! :-)

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Ulrik Smed
Aarhus, Denmark