118mm Halogen Lamp

[SceneMaster]

Hi

 

I've got some lights with 118mm halogen lamps in them most of them are fine and the lamp is nice and clear but on of them has white patches (which I presume to be the fact some little bas***d go they greasy hand on it) but the filament in these areas of whiteness has melted into the glass of the lamp and created two little bubbles of glass where it melted into it. The light and the lamp are still working fine but I think I will change the lamp just incase it fails and for safety reasons but does anyone know what might of caused the filament to melt into the glass (anything to do with the suspected attack of the grease?) And are the white patches what happens when some grease gets on halogen lamps? :blink:

 

Thanks

[Matt]

All I can say is that it must have been some heat to make the glass melt!!! I'd change it just for safetys sake, cant be too careful these days.

[Mush]

Not entirely sure how you could get a droopy filament and an operational lamp still?

Could you post a pic?

 

Tungsten Halogen lamps, TH , used to be known as Quartz Iodide, QH, the Quartz bit refers to the glass which is quartz based to take the extreme heat being so close to the filament, much closer than non quartz lamps.

 

Quartz glass is known as `soft` glass, it is near melting point in operation. Putting fingers on the lamp, apparently dry or not, will leave some grease on the glass. The grease boils and melts the glass with it ,which due to the internal pressure bubbles out.

 

Sometimes the bubble will stay with the lamp working , sometimes it will go Ker..Ferking..Bang!

 

The safety glass on these units is made from toughned glass, like a car windscreen, it will often shatter with the force of an exploding lamp.

Moral, replace duff looking lamps immediately.

 

For the full meal deal on lamps try:

 

http://members.misty.com/don/

[SceneMaster]

The reason why the glass melted (not all the way through though as it still work fine) is that the filament touched the side of the lamp and I just wondered why this had happened? Is there a certain way up the lamp should be fitted? It’s the tube halogen type so it shouldn't need to be a certain way up. Although it does have a glass "bobble" in the centre of it does this mean something? (This looks like a manufacturing process tough and not an indicator of the way up it should be?) The bobble is drawn on the side of the packet. I am going to change this lamp but I just wondered if this had happened to anyone else? :blink:

 

Thanks

[Mush]

K series lamps, 500W is K1, burning position is listed as horizonatl +/- 4 degees, intrestingly K9 300W is listed as universal in same length tube.

 

Think the bobble is a vacuum pinch off.

 

Sounds like yours has had a knock hile running, or been tilted off horizontal.

[Dave]

My understanding (possibly wrong) is that grease on a lamp reduces the heat transmission through that bit of the glass and creates a hot spot, and the glass melts at that point. It might burst or just bubble (or both).

 

I don't think I've ever seen the exact effect originally described.

 

I do know that a lot of the K series lamps sold cheaply these days are unbranded junk of questionable quality, and I have seen filament "droop" on these.

 

I've also heard that the GE lamps of this type (made in Hungary) are not very good either. Apparently GE bought a factory over there. This is in contrast to GE's PAR lamps (made in a factory somewhere in England that used to belong to Thorn, I believe), which most people regard as better than other makes.

 

I have found that linear bulbs with a coiled-coiled filament are more reliable, but they seem increasingly hard to find.

[robloxley]

I do know that a lot of the K series lamps sold cheaply these days are unbranded junk of questionable quality, and I have seen filament "droop" on these.

Equally, most unbranded lamps seem to be of dubious quality and shorter life.

[SceneMaster]

The dead lamp!!!

 

Here are the pics of the lamp. There are two of them both just under 500kb each JPEG unzipped so will be a real bi**h to download on 56K modem which is what I uploaded them on. They are really big so you can see all the detail and un-compressed so it retains the detail so this is the reasoning behind the large files and the format and size of pics so no one moan. (Broadband users you’re sorted) Doesn’t take that long to view anyway I tested the download in the page in the course of writing this post which wasn’t long and that was un-cached pic! I’m rambling now. I’ll stop. :blink:

 

Thanks

 

 

Forget to make the point that this lamp is still working which is very strange (won’t use it thought that would be stupid) maybe I could add it to the schools AV technicians collection of odd gear (mainly computers) and strangely broken electrical equipment!!! :(

[SceneMaster]

The gas in these lamps isn't highly toxic as the lamp has just exploded while I was holding it. I have open the window but I got a good wiff of the gas. :( :o :blink:

[SceneMaster]

What do you mean by being tilted off horizontal do you mean the lamp going from side to side with say the right end of the lamp higher than the left or do you mean the tilting of the lamp forward or backwards on the flood tilt axis? :blink: (I wouldn't have thought you meant the latter as this is what floods are designed to do? :()

[Mush]

Nice pics, asked for a second opinion over at sci.engr.lighting

 

http://groups.google.com/groups?hl=en&lr=&...I.engr.lighting

 

The gas in these lamps isn't highly toxic as the lamp

 

Used to be iodine but think its now more commonly bromide due to cost.Not going to hurt in small quantities.

 

with say the right end of the lamp higher than the left

 

Thats exactly what I was meaning, dig about for the lamp data sheets, 500w dosen`t like being tilted though 300W supposedly will suffer it. Guess going to have to test that outside later :-)....

[SceneMaster]

Hi

 

As a replacement for the lamp I brought from TLC for my flood which was a 300watt (K1?). The old lamp. Unbranded type which was rubbish as this topic showed I wondered if I could use the following lamp form Terralec which looks a lot better and is the same size 118mm and the same wattage (300watt). Order code Q300T. www.terralec.com

 

Q300T HALOGEN TUBE 300 WATT 240V

HALOGEN TUBE 300 WATT 240V

 

230 Volt 300 Watt tube. 118mm

 

Lamp Life 1000 Hours

 

Type K9 (R7s)

 

It is K9 not K1 does this make any differnce considering it is the same size and wattage and looks like it would fit in a K1 bulb holder in my flood and what dose (R7s mean?). They sell a K1 500watt tube which is too powerfull for my needs. But is the same size and is also (R7s).

 

Thanks for any help.

[robloxley]

R7s is the lamp-base type on each end of the lamp

 

K1 is a 500W 118mm Linear Halogen lamp

K3 is a 750W 189mm Linear Halogen lamp

K4 is a 1000W 189mm Linear Halogen lamp

K5 is a 1500W 254mm Linear Halogen lamp

K8 is a 2000W 254mm Linear Halogen lamp

K9 is a 300W 118mm Linear Halogen lamp

K11 is a 200W 118mm Linear Halogen lamp

K12 is a 150W 78mm Linear Halogen lamp

K14 is a 100W 78mm Linear Halogen lamp

K27 is a 200W 78mm Linear Halogen lamp

K28 is a 150W 78mm Linear Halogen lamp

K35 is a 100W 118mm Linear Halogen lamp

 

The Terralec one seems somewhat expensive especially given it's not a branded lamp.

[Tomo]

So what happened to K2? :** laughs out loud **:

[Ike]

The Terralec one seems somewhat expensive especially given it's not a branded lamp.

top tip: the pound shop on piccadilly gardens in manchester used to sell packs of two for a quid which outlast philips ones!