Flourescent lamp voltages

[rrawlings]

I don't want to ask to stupid a question, but I have built an electronic ballast to drive two F32T8 lamps and have a what seems to be a great design, but I am now wondering how to go about getting the voltage specs for other lamps to be able to "tune" this ballast for other lamps such as T5 lamps. Is there a chart or some other reference that I am not aware of that would tell what kind of run voltages these lamps would like? The ballast has a PFC controlled supply and a PWM output section, so current is very easily controlled as well as voltage. In order to tailor this to other lamps I need to know run voltages for the other lamps, this will allow me to tune the resonant circuit at the output of the half bridge I am driving the lamps with.

 

[smanches]

I would suspect the lamp manufacturer would have datasheets for the lamps in questions. Have you tried searching the manufacturers sites?

 

[rrawlings]

I have searched Phillips and Osram Sylvania and neither seem to have that info. I spoke to a "technician" at Phillips today and was told "that is determined by the ballast" no kidding I explained that that was the part I was building, he seemed very confused.

 

[KeepItSimpleStupid]

its my understanding that you need a high open circuit voltage to start and then you can go into current regulation.

 

[smanches]

Wow, just did a search myself and could not come up with anything. I bet that information is kept secret to promote the selling of thier own ballasts.

Ballasts are an amazing industry, as they burn out very frequently. The maintenance guy at work here says they if they last a year it's a long life. And they're $30-100 each for something relatively simple.

 

[MEJY1988]

Wow, just did a search myself and could not come up with anything. I bet that information is kept secret to promote the selling of thier own ballasts.

Ballasts are an amazing industry, as they burn out very frequently. The maintenance guy at work here says they if they last a year it's a long life. And they're $30-100 each for something relatively simple.

If your ballasts are only lasting a year or less than you have a bigger problem. The problem could range from a bad or poor connection, most likely on the neutral, to heat, pinched wires, power surges, or bad sockets. As long as you keep good lamps in the fixture the ballast should last for quite a while. I would consider getting a professional to take a look, you might have some larger problem waiting to raise its ugly head.

As far as the original post try some ballast manufacturers sites, like Advance, Universal, GE, or Phillips. Good luck.

 

[KeepItSimpleStupid]

Here is a more comprehensive data sheet for a lamp https://www.electro-tech-online.com/custompdfs/2011/02/DATA_SHEET_F58T8PDF.pdf

 

[tcmtech]

Typically fluorescent lights are ran in a constant current mode where their operating voltage will vary greatly depending on the age and length of the bulb. The longer the tube the greater the voltage drop but the current itself stays basically the same.

If you can vary your lamp current while still maintaining a good working voltage you can make a very effective fluorescent lamp dimer.

At one time the Advance company did publish free service troubleshooting guides that gave ratings for their ballasts for every type and its intended application. They had charts for typical lamp working voltage and current ranges as to how they would be measured in the field as just one of the topics they would cover in these service guides..

 

[rrawlings]

I think I have stumbled onto the answers to these questions, only took 6 hours of web searching. Thanks for everybody's input.

 

[BrownOut]

Care to share the answers with the rest of us?

 

[ronv]

IR has a ballast designer software package for a lot of lamps.

 

[rrawlings]

I found the info on the GE site. And I have used the IR software, but we have changed to a different mfg.

 

[Mr RB]

I use a HV dc supply, turn it up until the tube strikes (and is current limited by the supply) then I turn it down and measure DC volts and amps until it is running at rated wattage. Then you can design an electronic ballast around those figures.

 

[Ubergeek63]

I use a HV dc supply, turn it up until the tube strikes (and is current limited by the supply) then I turn it down and measure DC volts and amps until it is running at rated wattage. Then you can design an electronic ballast around those figures.

What type of lamp? What you suggest is a bit dangerous as there is no way for you to respond as quickly as would be needed.

An 8" LCD panel CCFL is typically 4W strikes between 0.9 and 2.5KV and operates at 600V and 6mA at a frequency (optimum) of 60KHz as I recall.

 

[BrownOut]

What type of lamp? What you suggest is a bit dangerous as there is no way for you to respond as quickly as would be needed.

This part of the message is important:

is current limited by the supply

 

[Ubergeek63]

This part of the message is important:

IC... i read the post to quickly. I did not see that particular line in that post, and also missed the bulb numbers in the OP!

 

[Ubergeek63]

I don't want to ask to stupid a question, but I have built an electronic ballast to drive two F32T8 lamps and have a what seems to be a great design, but I am now wondering how to go about getting the voltage specs for other lamps to be able to "tune" this ballast for other lamps such as T5 lamps. Is there a chart or some other reference that I am not aware of that would tell what kind of run voltages these lamps would like? The ballast has a PFC controlled supply and a PWM output section, so current is very easily controlled as well as voltage. In order to tailor this to other lamps I need to know run voltages for the other lamps, this will allow me to tune the resonant circuit at the output of the half bridge I am driving the lamps with.

Well that was a thrilling 5 minute search!

https://www.electro-tech-online.com/custompdfs/2011/02/1930_1350_018482031032850.pdf

https://www.electro-tech-online.com/custompdfs/2011/02/1886_1688_0298520TCP2031028T586520SS.pdf

F32T8 nominal 137V starts at 300V

T5 nominal 137 starts at 425

the site has specifics on hoards of different bulbs

 

[Mr RB]

Those figures look a little higher than the DC figures, which I would expect to have been aboput 80v to 100v for the 8" lamp.

 

[Ubergeek63]

Those figures look a little higher than the DC figures, which I would expect to have been aboput 80v to 100v for the 8" lamp.

DC? 8"? these are 4' commercial lighting tubes. BTW 8"CCFLs run at more like 600-800VAC not at DC.

 

[Mr RB]

I apologise, going from memory I thought a F32T8 tube is 8" length (T8)?

I seem to remember a F4T5 was 4W and 5" length.