> From: [email protected] <[email protected]> > Subject: Re: Need Short neon bulbs > To: [email protected] > Date: Monday, August 4, 2008, 8:29 PM > Hi Harvey, > > If you are pushing high currents through the neon tubes, a > larger diameter > might be advantageous to you. One-half inch diameter is > between 12-13mm, but a > 15mm tube would not get quite as hot. It would also have a > slightly lower > voltage drop and longer life. I'd suggest using 15mm > tubing with 15mm/60mA > electrodes. > > If the color of the neon discharge changed while in use, it > was probably > from the overheated glass outgassing sodium, CO2 or H2O > vapor and spoiling the > purity of the neon. (Have you tried forced air cooling to > keep the tubes from > overheating?) It is not common practice to use mercury with > neon, but it does > make a temperature sensitive tube that shifts from red to > blue as it heats > up. > > I can fill your tubes with any of the first 5 noble gasses, > He, Ne, Ar, Kr, > and Xe, to whatever pressure you desire. Normal filling > pressure is about 10 > Torr, but the life of these short tubes will be less than > that of longer > ones. A complete set of tubes containing all five noble > gasses costs $120, plus > shipping, while 5 neon filled tubes would be $100, plus > shipping, usually less > than $10. I could probably make the tubes and have them in > the mail to you > within a week of receiving your money order. > > Some other things that you might find useful are as > follows: > > * Larger diameter tubes run cooler and require less voltage > than smaller > ones, but have less light output. > > * Short tubes usually have a shorter life due to the > smaller quantity of gas > contained. > > * Increasing the fill pressure increases the life, raises > the starting and > operating voltage, and increases the operating temperature. > > * Tubes with less pressure run cooler and have a lower > starting and > operating voltage, but do not last as long. > > * Helium has the highest resistance and produces the most > heat, while xenon > has the lowest. > > * There is usually an optimum diameter, length and fill > pressure for each > specific purpose. > > I hope this info is helpful in determining the best > parameters for your > purposes. > > > Best of Luck, > > Tony Greer > Special Effects Neon > 502 Avenue G > Lubbock, Texas 79401 Pioneering the Applications of Interphasal Resonances http://tech.groups.yahoo.com/group/teslafy/

