Roi_hartmann
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| My plant light that uses 70w CDM-T has started to show slight flickering. Is the lamp closing eol or what could cause this? The flickering is way more infrequent than mains flickering. The color of light is still normal.
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Aamulla aurinko, illalla AIRAM
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Medved
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| It could be the lamp approaching the state, when it won't be able to reignite after the current zero cross, so to hold the arc.
The flicker may come from the phase delays in the reignition point, mainly caused by the voltages superimposed on the mains (e.g. the power grid management data transmission like tariff and load switching or so; the flicker is then a beat frequency between the data carrier and the mains frequencies or their sub/harmonics; I observed it going really with the data packet operating at 1Bd rate here).
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No more selfballasted c***
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Roi_hartmann
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| Hmmm, might be wise to replace the lamp just in case. It operates with timer doing 6h per day so it's on even when I'm not there. The lamp was used when I bought the fixture so I don't know how many hours it has done.
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BlueHalide
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| MH lamp flicker is more common with quartz lamps on magnetic gear, if the ballast is electronic and the lamp has a noticeable flicker its almost always an issue with the ballast, or a severe voltage fluctuation or transient on the mains side, usually electronic HID ballasts will run the lamps all the way to EOL without any flicker. If its a magnetic ballast, then the issue is likely one of the mains harmonics issues medved pointed out, or a near EOL lamp, Ceramic MH does hold its intensity and color well all the way up to EOL
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dor123
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| MH lamps on magnetic ballasts can also flicker, if they triggering the ignitor to restrike them every half cycle.
I've seen such a situation a lot with Venture 70W MH lamps at Hecht park.
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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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Roi_hartmann
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| I had not yet have time to search through my storage to find a replacement lamp for this when today my apartment had short voltage dip of one of the three phases. It wasn't long enought to shut off my computer but long enough to make a magnetic ballasted 36w t8 to need restarting. After that I noticed that this mh fixture had turned off. First I thought it just needs to cool down before restrike but even after a long time it just wouldn't start anymore. The lamp looks used but otherwise ok. I replaced the lamp and the new one started working ok. Strange.
The fixture has magnetic ballast and I think the lamp is ceramic (bulky arctube with sharp corners)
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« Last Edit: November 22, 2018, 01:39:34 PM by Roi_hartmann »
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Aamulla aurinko, illalla AIRAM
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dor123
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| If your MH lamps turned on and never restrike again, probably your fixture have Philips anti-cycle ignitor, which does only one cycle before giving up, and giving up after 50 sec during cycling.
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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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