dor123
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| I've noticed that my Iwasaki/EYE MTD70SDW-7S/3500K Ra96 MH lamp that I bought from Aliexpress, have longer hot restrike period than my rest white QMH lamps. It takes 5 mins to cool down while the rest takes up to 4 mins to cool down.
Why this is happening?
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
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I lives in Israel, which is a 220-240V, 50hz country.
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Medved
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| Ra96 sounds to me like the lamp is designed to operate at higher temperatures, what means better thermal insulation of the burner. Better thermal insulation means longer thermal time constant and that means longer warmup/cool down times. While the cool down would be affected way more than the warmup.
If this is the case, they very likely reduced the heat transfer by reducing the convection (as that part is easier to alter than the radiation heat transfer when the burner size is fixed - modification in the outer fill). And because the convection and conduction is very likely the dominant mode affecting the cool down, the cool down to restrike temperature would be affected way more than the warmup (with warmup, the final settling happens at temperatures where the radiation transfer is the dominant one, so not that large change).
But all this is just my speculation...
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No more selfballasted c***
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dor123
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There is no sodium in this lamp, only thallium. dysprosium and probably also neodymium for the 3500K color. Hence the Ra=96. Also: The lamp warm up about 2 mins like my other white MH lamps, and the arc is almost straight, because of my Philips electronic ballast. @James or @RRK may know. |
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« Last Edit: September 19, 2024, 08:26:03 AM by dor123 »
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the international date format (dd.mm.yyyy).
I lives in Israel, which is a 220-240V, 50hz country.
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dor123
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the international date format (dd.mm.yyyy).
I lives in Israel, which is a 220-240V, 50hz country.
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RRK
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| If you compare the arc tube of your Iwasaki lamp, you'll see it is much thicker than arctubes from usual today's Chinese lamps in 'Venture' style. So my guess longer restrike is a result of notably higher thermal mass. Old CMH made of thick alumina all have long run-up and restrike times because of this, too.
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dor123
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| Ahh. Because my two Philips MHN-TD 70W ES: One 730 and one 740, If they don't have problems with hot restrike, tends to restrike after 4-4:30 mins, despite their arctube design.
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Logged
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the international date format (dd.mm.yyyy).
I lives in Israel, which is a 220-240V, 50hz country.
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