looks like my last message didn't make it through http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=3D8944 $5 a meter or so. One of the local robot guys used them to light up his shed http://www.robowars.org/forum/viewtopic.php?t=3D1366&postdays=3D0&postorder= =3Dasc&start=3D208=20 So they seem bright enough and only ~2x the cost of a fluro. On 07/25/2011 02:20 AM, adastra wrote: > Hello again ~ > > First I might point out that the recent discussion of 8' tubes is > interesting, but we are using 3' tubes. > > We make a variety of amusement and entertainment devices, including a > version of the "Walking Piano" as seen in the old Tom Hanks movie "BIG." > > Here is a link to one currently being used at the California State Fair: > > http://www.stagenine.com/rock-u-exhibit/ > > All of the keys play accurate piano tones and the white keys light up whe= n > stepped on. Originally we used incandescent lamps to light them, but > fluorescents make much more sense because the form-factor conforms to tha= t > of the long narrow keys, and because of the current and heat consideratio= ns. > > However, as I mentioned earlier, it is necessary that the key light > immediately when stepped on, particularly since it may only be on for les= s > than a second while a given note is being played. And obviously it doesn= 't > take long to accumulate a lot of starts. > > When we first put together the fluorescent version, all seemed to be well= .. > We are using an electronic "instant start" ballast, (ICN-2P-32)and F30T8 > tubes. As far as I can tell, we are not violating any published specs of > either the ballast or the tube. It does seem, however, that there are > non-obvious (or at least non-specified) considerations which result in > unacceptably short tube life. In fact, it now appears that a couple of t= he > ballasts have failed as well, in that they will no longer light even new > tubes. I realize that this is an unusual application, as compared with a > normal lighting situation, but again, see no published specs that would > prohibit what we are trying to do. > > BTW, the economics are driven by the fact that there are 16 lighted keys = on > our standard piano. LEDs would be good, but unfortunately, to have enoug= h > of them for enough light under each key would break the bank. > > I do appreciate everyone's thoughts and suggestions. Maybe this is just = one > of those "everyone knows" kinds of things, but again, I would really like= to > understand what spec we are violating. > > Thanks again, > > Foster > > >> -----Original Message----- >> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf >> Of YES NOPE9 >> Sent: Saturday, July 23, 2011 9:07 PM >> To: Microcontroller discussion list - Public. >> Subject: Re: [EE] Any fluorescent light experts? (More Info) >> >> Tell us more about your project..... >> How many lights do you plan operate ? >> What is your budget per lighting unit ? >> >> There are vendors that make long life fluorescent tubes. >> I am looking into how they are different than regular tubes. Perhaps th= e >> electrodes are beefed up. >> I think keeping tube filaments warm will increase the lifetime of the >> bulb. >> A smart electronic ballast will minimize wear on electrodes. >> >> Tubes die if the end electrodes are consumed. ( Most likely your >> situation ) >> Tubes die when the phosphors wear out. >> Tubes die when the mercury is exhausted. Modern tubes put in the minimu= m >> mercury possible. >> >> >> 99guspuppet >> -- >> http://www.piclist.com PIC/SX FAQ& list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .