Re: fluorescent lamp operating voltage

On Sat, 18 Feb 2006 13:34:31 -0500 Victor Roberts <xxx@xxxxxxxxxxxxxxxxxxxxx> wrote:
| On 18 Feb 2006 11:35:50 GMT, phil-news-nospam@xxxxxxxx
| wrote:
|
|>On 8 Feb 2006 02:32:18 -0800 meow2222@xxxxxxxxx wrote:
|>
|>| phil-news-nospam@xxxxxxxx wrote:
|>|
|>|> I'm curious if it is possible to operate a fluorescent bulb directly at a
|>|> voltage above the gas breakdown voltage, still current limited by a ballast
|>|> (magnetic or electronic), and not need a starter at all?
|>|
|>| Once a tube conducts, its operating voltage falls, so it wont run at
|>| above strike voltage.
|>
|>So if the strike voltage is Vs, and I apply Vs+Ve, where Ve is some
|>variable amount of extra voltage to be sure I'm well above variances
|>in the bulb or other conditions, what would the tube do after it
|>conducts?
|
| The voltage on the lamp drops to its normal operating value.
| The voltage difference between your fixed voltage source and
| the lamp is taken up by the ballast inductor.

Yes, I understand once the current is flowing, the bulb impedance
drops way low, and its voltage drop in the circuit becomes the
operating level. But what voltage (Vs) do I need as a minimum to
make this kind of setup work (and yes, I understand this varies
across different bulbs ... I want to understand the range of what
this is).


|>| The C ballast fitting much discussed here a while ago used only a
|>| series ballast to run a 2' 20w tube on 240v, there was no starter or
|>| starting circuitry. Some tubes started up fine in this, with some
|>| nothing happened, no light at all.
|>
|>Can the tube be specifically designed to work that way?
|
| Almost any fluorescent lamp can be instant started, but the
| life will be longer if the electrodes are designed for this
| type of operation.

That's fine. I'm wanting to understand what supply voltage could be
used to make this work, not so much for making it an instant start,
but for making it simple (e.g. no extra starter circuit and single
pin bulbs).

--
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| (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ |
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