ELC 24V 250W lamps

[NJD 0]

We had a lot of trouble with A1/259s a few years ago suffering from what is known as a "moly failure" I forget which manufacturer they were from [the electrical connection through the glass is a piece of metal tape made from molybdenum, and the weld to the pins failed]. I wonder if lamps made at the same time are still finding their way into retail.

 

If a lamp fails open circuit, but the filament is completely intact then it is probably a "moly failure" and it is a manufacturing fault - the supplier should replace it.

 

If the lamp has a premature demise with the usual melted filament then there are 3 possible causes:

Overvoltage, overheating or mechanical damage.

 

If your luminaires are filthy with the fan grille almost blocked (like most we get back for repair) then not only will the light output be rubbish due to the lenses being dirty, the lamps will overheat and have reduced life.

 

Lamps don't like to be moved whilst they are operating, but what they REALLY don't like is to be moved when they are cooling down. At this point, in the 5 minutes after they have been turned off the filament is at its most brittle.

 

Lamp life is inversely proportional to the twelfth power of applied voltage: In other words, increasing the voltage by 1% reduces the life by 12%. Our British mains voltage is defined as 230V +10% -6%. It can legally vary between 217V and 253V. That would vary the life of a 50 hour lamp from 100 hours at 217V to 16 hours at 253V.

 

Mains voltage tends to rise in the evenings due to the industrial load being switched off. If it goes above 253V then the supply company can be made to pay for any damage it causes - but proving it is interesting!

 

If over-voltage is your problem, then choosing the "extended life" switch will solve it. If your luminaire doesn't have an "extended life" switch, then I have a neat circuit to reduce the voltage to the lighting. Copies can be requested from info@njd.co.uk

 

If you just want longer lamp life, then the long life lamps do a better job than simply reducing the voltage to a standard lamp - there is less loss of output.

 

One thing I would never recommend is the M33 conversion. I doubt if anyone can align a lamp in a reflector as well as the automatic machines that make A1/259s. Also, every new A1/259 is fitted with a brand new, perfectly clean reflector.

[Andy Westcott 0]

"Lamp life is inversely proportional to the twelfth power of applied voltage"

 

Ha! I knew there was a direct relationship, but couldn't remember what it was. I'll have to write that down somewhere.... http://www.dj-forum.co.uk/html//emoticons/biggrin.gif

 

Interesting that you recommend to stay with the ELC - That would be my preferred route if lamp life proves to be good enough, as the dichroic reflector helps to reduce the level of IR finding its way through the optics, which can only be good. I thought I'd made up my mind, now I'm turning again..... http://www.dj-forum.co.uk/html//emoticons/huh.gif

 

I would imagine there is a correct orientation for the filament when fitting the lamp also - any views in that? This isn't something I've paid attention to in the past, but I understand filaments should sit horizontally to allow evenly distributed convection currents to aid the 'halogen regenerative cycle' in this type of lamp.

 

Finally, in response to your comments about having problems with bulbs a few years back, my bulbs all date to late '90s, my equipment having been out of commission for a few years. They failed regularly then, and my spares have more recently.

Poor quality lamps it seems, then. http://www.dj-forum.co.uk/html//emoticons/smile.gif

[norty303 0]

QUOTE

One thing I would never recommend is the M33 conversion.

 

Are you saying you wouldn't recommend the Martin conversion for their Destroyer/Punisher or are you saying any sort of 'home bodge' M33 conversion.

 

If it's the former i'd be interested to know why.

 

For your information Andy, we used a pair of Destroyers at a Brighton venue (200 capacity) on Monday and at the end we had the sound guy complaining of headaches because the lights were too bright for him and his desk was the other end of the room. These are at least 3 years old so there definately isn't a problem with diminishing optics on the reflector (or not as you'd care)

[NJD 0]

I can only speak for NJD lights. I wouldn't recommend the use of an M33 because:

 

1. its colour temperature is 3200K against 3400K for a A1/259. That's already 23% down on light output.

 

2. The M33 has a larger filament, which means it is more difficult to focus the light down on a small gobo.

 

3. The A1/259 filament is aligned with the reflector during manufacture to ensure that as much light as possible goes through a 12mm diameter circle 32mm infront of the lamp (that's part of the specification). It was originally designed as a 16mm film projector lamp. It is therefore ideally suited to lights with small gobos such as the Datamoon, Chaos, DMX250 etc. The M33 capsule isn't fixed to the reflector so it can move and is therefore unlikely to remain properly aligned

 

4. The A1/259 has a dichroic reflector which allows the infra-red through. An aluminium reflector focuses the infra-red on the gobo which can lead to overheating.

 

When it is used with a condensor and bigger gobos then the filament-reflector alignment is less critical, so the M33+reflector has less of a disadvantage.

 

The long life A1/259 has a colour temperature of 3100K so it isn't as bright as the 50 hour version.

 

[i'm sure a 50W lighting effect could give the sound guy a headache]

[transeurope 0]

NJD has concisely and expertly stated many points that I have accumulated throughout the years and expressed them in a scientific fashion.

 

Bottom line folks: Dichroic lamps good, capsule bad. Most mysterious failures (ie not caused by jolt when cooling or similar) are caused by manufacturing faults by the "leg" pins.

 

 

[brianmole 0]

Andy, I have 2 Martin Destroyers. The first one I bought about 1995 (nearly £350) has a ELC lamp inside. The second one I bought 2 years ago (£150) when they were discontinued contains an M33 with the 'modded reflector'.

 

The light output looks the same to me

The lamps both last about a year (50 gigs)

 

So, just buy the long life lamps like I have, the conversion is up to you, it does not seem to be an issue. Lamps are cheap enough anyway - if I had 10 Martin Destroyers, I would consider the upgrade as there may be a cost saving over time.

 

The Destroyer is a great effect BTW, runs very smooth & silent, and after all these years of use, the colours don't seem to fade.

[norty303 0]

My point exactly, despite the scientific bit to the contrary, the Martin lights perform excellently regardless of lamp type and have been the mainstay of the pro lighting hire/dry hire market for many years.

 

I save £7 every lamp i go through so its worth it for me. As my units sometimes get stacked on top of my bass stacks i do go through more than my fair share of lamps due to vibration.

[Andy Westcott 0]

I must say that the cost of replacement bulbs isn't really too much of an issue to me, more of a problem was the frequent need to replace bulbs mid-gig. I will obviously go for the long-life bulbs in some guise or another now I know they exist.

 

Regarding the Destroyers as lighting effects, yes, they do all I wish for from a medium/long range lighting effect. The gobo shapes and colours are formed from dichroic material so don't fade, although a regular clean with meths and a cotton bud ensures a bright and sharp display.

 

One issue I have is the need to switch the units on or off at various points through the night, and at the moment this is limited to cutting the power totally. This requires the units to have to re-index each time I switch them back on, causing a few seconds of rattling.

 

Ideally, I would need a simple DMX controller to simply switch off the power to the lamps only, or at least turn the gobo to a blanking position - a feature I believe to be incorporated although my knowledge of DMX usage is almost non-existant due to the lack of my need for it up to now. Any advice regarding this particular use of DMX and the equipment required? By the way, at the moment I simply connect the two together master/slave and let the sound to light do its thing.

 

[brianmole 0]

I could do with a simple blackout thing too!

[NJD 0]

If you must use the capsule lamp in the aluminium reflector, then keep that Brasso handy. Where we use a fixed reflector (for the CSS575 lamp) we repolish the reflector with brasso whenever a product is returned for service - it make a huge difference!

[norty303 0]

The beauty of the Destroyer/Punisher is that they have a function (activated by switching dipswitch 9 on) that means they are controlled by a single DMX channel if you're not into programming loads (in fact, in multichannel mode you can still set dish, gobo, etc to still be sound reactive to different degrees).

 

DMX Value Effect

0-50 Blackout

51-101 Slow Random Action

102-152 Medium Random Action

153-203 Fast Random Action

204-255 Random Speed and Action

 

This is why i like them in conjunction with scans because you can quickly add programs to existing setups without having to program individual steps.

 

Part of the reason why i like the capsule is because i also own a lot of Solar 250's and it's nice only having to carry single types of lamp spare.

 

I suppose it all comes down to your own individual setup and use.

 

 

By the way, has anyone seen the new Martin Mania SCX600 scanner? Now that looks like a nice head, good and robust casing too so should survive in good condition for a long time, so many units just don't seem built for anything other than installs nowadays.

 

http://www.martin.com/product/product.asp?...uct=maniascx600

[ChrisPointon 0]

Hi NJD.

 

I've started a new topic with your question regarding Effects with Metal Halide lamps and prices, because I think it is worth a whole new thread in itself, and may prompt our members to give you relevant feedback on the type and features of products which our members would like to see. http://www.dj-forum.co.uk/html//emoticons/smile.gif

 

Hopefully, it may spark debate and participation on its own thread rather than being tucked away on a topic about ELC Lamps, which may get overlooked by members with no interest in that subject.

 

You can find your question and the new debate By Clicking Here

[Mr_James 0]

Ohhhh.... Why did this have to happen now.... Was playing around with my scanners and my controller, turned them off for a while because I had to go out... came back and turned them on, only one light came on http://www.dj-forum.co.uk/html//emoticons/014.gif damn bulb blew, anyone know if 24V 250Watt ELC lamps are sold at B&Q? lol http://www.dj-forum.co.uk/html//emoticons/wallbash.gif

[superstardeejay 0]

Bear in mind what happened to my table lamp!! http://www.dj-forum.co.uk/html//emoticons/huh.gif

 

Seriously they swapped them without question and they're fine now! http://www.dj-forum.co.uk/html//emoticons/thanks.gif

 

 

[Mr_James 0]

Reading that... a normal household 60watt tesco lightbulb exploded in my brothers room last night, I'd probably only buy them if they were philips or something though.