How fast can I strobe a fluorescent light?

[stl_jones@yahoo.com]

I am currently working on a project where I am strobing a series of LED's with the low frequencies.

This circuit is working, but the I am unpleased with the color quality of the LED's, and have a fluorescent bulb I would prefer to use. Can these lights strobe that fast (60hz-200hz)?

And also, I would need an inverter for this. I've been searching this forum for the past 15min looking for a simple schematic of one, but could only find posts of people complaining that this question is asked too much. So if anyone could point me in the right direction for the inverter, I'd appreciate it.

 

[Sceadwian]

Fluorescent bulbs aren't designed to be strobed. It could in theory be done with a high voltage driver with carefully measured pulses but the tube would have a tiny fraction of it's normal lifespan. Even the 'fast start' ballasts that are common on modern fluorescent drivers shorten bulb life because the voltage required to instantly start the bulb also vaporizes the conductors in the lamp, over time. I would suggest shopping around for some different LED's as higher quality LED's may approach the color quality you're looking for.

Also, in saying 'in theory' you could do it, I mean just that, the bulb wouldn't last more than a few seconds or minutes at best.

 

[crutschow]

Why not just use a standard strobe bulb. They put out a white light.

 

[Sceadwian]

Actually crut, the spectrum from a Xenon flash tube are anything but white, the color quality at best would be considered 'harsh' the CRI is horrible.

 

[crutschow]

Actually crut, the spectrum from a Xenon flash tube are anything but white, the color quality at best would be considered 'harsh' the CRI is horrible.

Scead, they seem to give a satisfactory white spectrum for the flash lamp in a color camera.

And fluorescents certainly do not have a uniform white spectrum. You'll notice that if you ever take a color picture under such lighting.

 

[Sceadwian]

Crut, you're thinkign with human eyes from known photographs you have seen. Look at the spectral distribution of a Xenon flash sometime. As far as camera's go it's the best we can do.

Larger Fluroescent tubes have CRI's approaching that of incandescent sources largely due to modern phosphor blends that bend the UV down into the visible.

 

[crutschow]

Crut, you're thinkign with human eyes from known photographs you have seen. Look at the spectral distribution of a Xenon flash sometime. As far as camera's go it's the best we can do.

Scead, so if it looks white to the human eye and to the camera, then what's the problem? I don't think the op needs a spectrally pure white light.

 

[stl_jones@yahoo.com]

I actually need blue

Thanks for confirming what I thought. I actually am looking to use a blue/purple light.

 

[Sceadwian]

The problem is that's not white =) A person trying to reproduce white light would be shocked stupid to know what the spectral qualities of ideal human optical light is compared to the actual output of many sources, and how that output is perceived emotionally is a completely different subject. stl_jones apparently got what they need from this thread as they started it, I'll leave that to the judges =)

 

[JimB]

Think about it...
...a mains powered flourescent light is already "strobing" at 100hz (Europe) or 120hz (USA et al) as the mains voltage varies at 50 or 60hz.

However, the flourescent tube manufacturers will make the tube phosphor have some persistence, so eliminating the the strobe effects.

Also consider that a strobing flourescent lamp could be a danger in the presence of rotating machinery, depending on the rotation speed, the machine could appear to be stopped.

So trying to strobe a flouro, you are on to a loser before you start.

JimB