Fluorescent Tubes, finding a T12 ballast or using something else. - Page 1
Forum section: electronics / beginners

author: Jackster
author_rank: Frequent Contributor
timestamp: July 27, 2016, 04:18:07 pm
content: Hi all.So we have these T12 bulbs we use for filming.The company that makes them sell the ballasts at £120 a pop.As you can see, there is not much there,http://kinoflo.com/Top%20Buttons/Support/Ballast%20Boards/Boards/VG5R_Ballast_Board.htmlhttp://kinoflo.com/PDF/repair/Ballast%20Board%20Repair%20Parts%20-%20VG5R%206800177%20Rev%20C%20Schematics.pdfWe are on a bit of a student budget atm and while we can get a load of their bulbs, the ballasts are another story.So looking for alternatives.Trying to find a T12, electronic ballast that can power a T12 tube with 75w.Even better would be one that could dim the bulb!Any ideas?I have tried Google, searched OSRAM and Philips to no avail.Closes thing I could find was a T8 80w ballast from OSRAM.http://www.lampshoponline.com/osram-qtp5-2x80/From the sounds of it, one can run a T12 bulb with a T8 ballast with the ballast seeing less life.The other way round, seeing the bulb life lower.I am okay with this as the ballasts are pretty cheap and we wont be running them 24/7 for 50-100k hours...But will the extra 5w be okay?ThanksJack,

author: MosherIV
author_rank: Super Contributor
timestamp: July 28, 2016, 08:14:14 pm
content: HiI am affraid I do not know that much about flourescent lighting.Why do you need electronic or high freq drivers?Will normal mains freq flourescent light ballasts work for what you are doing?(You can pick up normal light strips from diy stores quite cheaply)Yes, 80Watt balast will be ok driving 75Watt light, not the other way round.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: July 28, 2016, 09:02:22 pm
content: Are these just the straight-up 8-foot T12 bulbs that were used in practically every warehouse up until the late 90s? While they're being phased out now, I can't imagine that huge stocks of them aren't available. The only problem I see is is that they're pretty much considered garbage nowadays, so buying one will involve visiting scrapyards or used building supply places.The T8, T5 and T12 lamps all have different operating voltages, so I doubt using a T5 ballast on a T12 is going to work. The other thing is that I'm more familiar with what happened in North America, I'm not sure 8' T12s were popular in Europe.(Edit, I'm not saying it won't work, just that it'll require some experimentation since you're operating outside the specifications. Also F96T12 is your googling term.)EDIT 2 - Maybe we're talking about F72T12 sign bulbs? Better let us know what bulb you are working with here.

author: IanB
author_rank: Super Contributor
timestamp: July 28, 2016, 09:17:08 pm
content: You can readily buy T12 lamps and fixtures in the USA. I bought some dual 4 ft ones recently for my garage for probably $15 each, which means the ballast would only have been a few bucks.(I like the T12 lamps as they have a much softer, more dispersed light, which is much more pleasant on the eyes without needing a diffuser.)

author: Jackster
author_rank: Frequent Contributor
timestamp: July 29, 2016, 02:56:36 pm
content: Thanks for the replies guys!They are 4' long T12 bulbs.http://cvp.com/index.php?t=product/kinoflo_488-k55-sThey also come in 2' longhttp://cvp.com/index.php?t=product/kino-flo_242-k55-sI meant to post this link for the ballasthttp://www.bltdirect.com/osram-70-watt-t8-dimmable-high-frequency-twin-ballast-daliGot confused with so many options. :pQuote from: Paul Moir on July 28, 2016, 09:02:22 pmF75T12 (I only just found out what that meant).

author: IanB
author_rank: Super Contributor
timestamp: July 29, 2016, 04:35:30 pm
content: Yes, I think it wasn't fully clear that these are special high output F75T12 lamps. Therefore I suspect you might need the particular light fixture designed for that kind of bulb. Since it is a specialty item the ballasts won't be the common or garden cheap ones used for regular T12 lamps.Have you looked on Aliexpress or somewhere like that for a source in China?

author: Jackster
author_rank: Frequent Contributor
timestamp: July 30, 2016, 07:00:15 am
content: Quote from: IanB on July 29, 2016, 04:35:30 pmHardly anything on Ali.Found out that other people have used Fulham Workhorse 5 ballasts. They support a wide range of tubes and auto sense what tubes and combinations are there.Going to get one and try next week.

author: SeanB
author_rank: Super Contributor
timestamp: July 30, 2016, 06:59:29 pm
content: Your only issue is the ballast is expensive, and you need a HF ballast as opposed to the regular ferroresonant instant start ballast, which operates at line frequency, and thus will cause flicker with your video. But, as the tubes you have are bipin, they will be usable with almost any 75W ballast, with no real issues, especially as you are only looking for a limited life.

author: IanB
author_rank: Super Contributor
timestamp: July 30, 2016, 08:46:59 pm
content: Question, since I don't know much about this: modern electronic ballasts that will drive a pair of F40T12 lamps are two-a-penny, and they apparently operate at high frequency since I see no discernible flicker. Would such a ballast drive a single F75T12 tube instead of a pair of F40 tubes?

author: SeanB
author_rank: Super Contributor
timestamp: July 31, 2016, 08:26:51 am
content: Short answer is no, they typically use 2 separate driver stages and output inductors, so you have to have a lamp in each side. Most use a single driver IC, which has 2 sdeparate stages in it, and which controls both lamps simultaneously, often providing separate EOL protection for each lamp as well, or on some a single lamp failure or disconnection will turn the other one off for ease of changing. Those also tend to lock out restart till power is cycled.However almost all use a NXP driver, as they almost always follow the old Phillips layout and design for the circuitry, though more modern ones also include an active PFC stage as well, using a small 8 pin PFC and FET after the bridge rectifier, powered from the main SMPS chip.

author: Purduephotog
author_rank: Regular Contributor
timestamp: January 02, 2017, 12:15:43 am
content: I don't know if you ever solved this or not.So the Fulham workhorse ballasts you can get on eBay. They'll do nicely. They have an extensive catalog.Reading the tube is a bit different than I'm used to. 800ma is about double t12 current, and the tube is marked ho (high output) so that means this sitehttps://www.fulham.com/contact-us/wiring-diagrams/&ved=0ahUKEwjc1f7YlqLRAhUBbSYKHUAOBWAQFgg1MAU&usg=AFQjCNHS2_5Oa4XyR3PHesiJUOO_NGKQIg&sig2=uk4hwZUq469HRX2qd5QSawIn a pinch you can double or triple outs. Look up ODNO fluorescent.