Author Topic: 175 Watt Clear MV Bulbs just showed up at Walmart  (Read 2216 times)
MikeT1982
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175 Watt Clear MV Bulbs just showed up at Walmart « on: May 30, 2012, 01:00:26 AM » Author: MikeT1982
Hey guys, I'm curious what this is all about.  I was at Walmart lastnite doing some grocery shopping and decided to walk over to the electrical section to scope out the price of converting the 30 or so 60W  soft white incandescents I have around the house over to Sylvania 13 watt Micro-Mini CFL bulbs.  I love the incandescents but they are hard on my electric bill and i also have at least one burn out somewhere every 3 days it seems.  I lamped with incandescents though as i love their light. Anyways I was kind of shocked but I saw 4 Brinks 175 watt clear mercury vapor bulbs for $9.99 each and may buy one as I haven't seen these in stores for white a while.  I thought they were banned.  I live in Pennsylvania US.  Finally I ask if I should buy one, what would happen if I expiriment by powering it from an old 1970's neon sign transformer I have that is 9kV@60mA.  I use it to power a Jacob's ladder in my garage I made for fun.  I realize that this is 540 watts but NST's seem too docile current wise to cause damage to such a solid looking bulb.  Would it actually arc the main electrodes and vaporize the mercury and run stabily do you think due to such a low current and high voltage?  I would only do this as an expiriment, as I know to run it properly I should have the correct ballast and igniter etc.  Thanks a million ahead of time! :-)

Mike T
« Last Edit: May 30, 2012, 01:03:01 AM by MikeT1982 » Logged
funkybulb
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Re: 175 Watt Clear MV Bulbs just showed up at Walmart « Reply #1 on: May 30, 2012, 08:09:33 AM » Author: funkybulb
neon sign transformer is too much voltage and too little current to run your clear MV lamp. a good way to take out your neon transfomer, it just as bad runing one on microwave oven transformer. and MV lamp dont used igniter. it just use contant wattage auto transformer that give 240 volt OCV. while it ballasted around 125 to 140 volts about couple of amps, the purpose of the ballast is to limit the current or other wise the lamp will be taking more power to desturct them self as it negative resistant lamp. it use a starting probe and resistor inside the lamp for starting until the main arc takes over. BTW the mercury lamp are not banned yet. there is a talk of banning lamps in 2016. It just MV fixture and ballast is what banned.
« Last Edit: May 30, 2012, 08:16:32 AM by funkybulb » Logged

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Medved
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Re: 175 Watt Clear MV Bulbs just showed up at Walmart « Reply #2 on: May 30, 2012, 05:08:45 PM » Author: Medved
@Mike: The MV would definitelly not warm up at all, the 60mA is simply too little for a 1.7A (if I remember well) lamp.
As Funkybulb wrote, the NST would run hotter because of the low discharge voltage, but I don't think it would fry out - even with Neon tubing the transformer operate near short circuit current, as the Neon tubing operating voltage is way below the NST OCV.

But there is a real danger for the lamp:
The lamp is designed to work with strong thermionic electron emmission on cathodes, what mean in normal operation there is only little voltage drop between the gas and the electrode, so the posittive ions are accelerated only to very little energies, so they are not able to cause any damage to the surface (except few seconds after ignition, till the electrodes reach the emission temperature - therefore the starting cycles are so damaging to HID's). But for that the electrodes have to be quite hot (nearly 1000degC). But as the only source of the required heat is the discharge, it have to run on sufficient current.
But the 60mA is far from sufficient. Therefore the electrodes would remain cold, so the electrons would require strong electric field instead, what meean the voltage drop on the gas-electrode interface would be high. And this high voltage would accelerate the ions to high velocities, so give them the momentum to damage the surface they hit - so destroy the electrodes by the sputtering, so turning the tube black quite early.
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MikeT1982
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Re: 175 Watt Clear MV Bulbs just showed up at Walmart « Reply #3 on: May 31, 2012, 11:53:50 PM » Author: MikeT1982
Thank you very much guys! :-) That is very interesting info that helped me to understand them better.  I used to thing that current was the only thing that could damage a discharge lamp of excessive but now I understand!! And also on the proper gear! Can I ballast one by seriesing say a trio of paralleled 60 watt incandesnents and nothing else with one? I have 120vac here in US. 
« Last Edit: May 31, 2012, 11:59:51 PM by MikeT1982 » Logged
funkybulb
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Re: 175 Watt Clear MV Bulbs just showed up at Walmart « Reply #4 on: June 01, 2012, 01:05:31 AM » Author: funkybulb
series ballasting with incadescent on 12O volts, wont fire up the lamp as the OCV is too low to start the Arc.
for that experment. you need 240 volt and the OCV would be line voltage. and a 200 watt incandescent bulb to start out with. you have to drop half the voltage to run the lamp after it first fired up.
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No LED gadgets, spins too slowly.  Gotta  love preheat and MV. let the lights keep my meter spinning.

MikeT1982
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Re: 175 Watt Clear MV Bulbs just showed up at Walmart « Reply #5 on: June 02, 2012, 02:10:06 AM » Author: MikeT1982
Very neat thank you very much! :-) I actually think I will purchase a correct base as well as ballast from ebay, maybe advance since they are very good in my opinion and I do a little set up on the board with a clear mercury vapor, however after hearing that the brinks are built quite cheaply I may buy a Sylvania 175 clearly as I have seen on YouTube complaints about the thin glass of the brinka leading through too much UV radiation, something I definitely don't want! Besides on eBay they currently have your choice of a clear Sylvania or frosted for seven dollars I believe! :-)
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