PCB light box - hf ballast / tube wattage

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Alt Beer 13 years ago

When buying an HF ballast and fluorescent tube does the ballast wattage have to match the tube wattage?

Is it allowable to use an hf ballast of higher wattage that that of the tube e.g. hf ballast 40W tube 12W ?

Can you parallel tubes to an hf ballast intended for a single tube so long as ballast wattage is sufficient ?

I am building a uv-a light box for sensitised PCB exposure and am not sure how many tubes to use. I am thinking get a higher wattage than needed hf ballast and say two 8 or 12W tubes so if there is insufficient light I could get one or two more tubes and parallel them.

Thanks

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Tom Biasi 13 years ago

The material you are using on the board should specify the light intensity, spectrum, and exposure time needed.

Tom

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John Larkin 13 years ago

match the tube wattage?

e.g. hf ballast 40W tube 12W ?

ballast wattage is sufficient ?

many tubes to use.

tubes so if there is insufficient light I could get

Light boxes with fluorescent tubes cast fuzzy and non-uniform shadows. It's better to approximate a point source some distance away. The sun does that. I've used a warehouse-type mercury vapor lamp, like a street light, 250 watts I recall, overhead about 4 feet away. Great resolution. Sun lamps work well, too.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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Jim Thompson 13 years ago

to match the tube wattage?

e.g. hf ballast 40W tube 12W ?

ballast wattage is sufficient ?

how many tubes to use.

tubes so if there is insufficient light I could get

I have a hard rubber block with clamps and glass plate... put board in there and take it outside :-) ...Jim Thompson

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Fred Abse 13 years ago

Lithographic "plate makers" do that. A vacuum frame atop a 4 foot high box, with an ordinary mercury vapor lamp at the bottom.

"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)

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Tom Biasi 13 years ago

Back when I worked for a company that made microwave oscillators on contract for the military (circa 1970) the shop had a large vacuum plate and an actual carbon arc for exposure.

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fungus 13 years ago

What do you do when it's cloudy?

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Tom Biasi 13 years ago

Where Jim lives the skys are not cloudy all day.

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Michael A. Terrell 13 years ago

And the Buffalo fear to roam...lest they end up on his grill...

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Jim Thompson 13 years ago

I had buffalo at the Pilot's Club in Denver some years back... it's too-oo-oo lean, and sort of bland. ...Jim Thompson

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krw 13 years ago

My wife gets bison burgers once in a while. They are lean but I wouldn't call them exactly bland. Ted's (Ted Turner's restaurant) down the street from work has them, too. A lot of vendors want to take us there but I always have the beef burgers. Buffalo is over-hyped.

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Michael A. Terrell 13 years ago

You could feed it a couple liberals to fatten it up, and add all the spices you want. ;-)

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PCB light box - hf ballast / tube wattage

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