This is topic Brighter bulb for Elmo GS800? in forum 8mm Forum at 8mm Forum.


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Posted by Xander van der Merwe (Member # 125) on November 26, 2003, 11:28 PM:
 
I was wondering whether anyone has tried to put a brighter bulb in the GS800, say from 100W to 120W or even 150W? I know some have put brighter bulbs in the GS1200s and I would imagine that there is room for a slight increased wattage built into the transformer?

TIA
 
Posted by Mal Brake (Member # 14) on November 27, 2003, 06:49 AM:
 
Xander, the GS800 uses a 12v 100w lamp. The 150w lamp requires 15v for it to work at the correct temperature. The GS can be upgraded from 200w to 250w because both lamps operate at 24v. My friend and myself upgraded the ST 1200HD from 150w to 250w but we had to use an external transformer that delivered 24v.
Mal
 
Posted by Tony Milman (Member # 7) on November 27, 2003, 12:35 PM:
 
Mal

I am interested in your upgrade of the ST1200. Did you use the same bulb as used in the GS1200? Were there any other considerations regarding the additional heat given off etc?

Thanks

Tony
 
Posted by Xander van der Merwe (Member # 125) on November 27, 2003, 01:19 PM:
 
Mal,

So with another transformer it should theoretically be possible? Do these lamps use AC or DC?

TIA
 
Posted by Mal Brake (Member # 14) on November 27, 2003, 05:33 PM:
 
Tony, I posted about this on a different thread a little while ago. The conversions (2) were carried out some years ago and there doesnt appear to be any problems. The cooling on the ST is very efficient. Yes we use the same bulbs as the GS1200 for the ST1200HD.
We fitted changeover relays so the machines will operate 15v 150w lamps for home use. Used as stand-alone m/c's they automatically are set for 150w use. Plugging in the extra lead activates the relay to close the 24v circuit and disconnect the 15v one. We always check which lamp is in the projector beforehand!!
Xander, the bulbs are 24v 250w AC or 15v 150w Ac The UK codes are A1 259 for the 250w and A1 232 for the 150w.(sorry don't know what codes are used outside UK.)
Derann have recently reintroduced the proper 24v 200w lamps for the GS. They are more expensive than the 259 but they concentrate the beam for the smaller 8mm gate. The 259 is intended for 16mm projectors.
Whether the GS 800 is suitable for conversion is another matter. I have not used one so don't know how good the cooling system is and of course the projector is considerably smaller than the ST. Also, not being familiar with the lamp housing I wouldn't know if it would take the larger lamp.
We were lucky to get the transformers from the Widescreen Centre in the days when Tony Shapps sold bits and pieces to improve the light output on projectors. The transformers would have to provide a high secondary current (over 10 amps). I would hate to be the cause of anyone damaging their machines so I would advise caution before attempting anything. I think 200/250w would be too much for the GS800 in any case.
Hope some of this made sense, Mal
 
Posted by Xander van der Merwe (Member # 125) on November 27, 2003, 06:34 PM:
 
As posted in the other thread, I've just received my GS800 and it interestingly had a brand new spare 200w 24v bulb included in the box. I quickly checked the bulb inside the projector to check whether the projector might have been modified, but the internal lamp is as you specified: 100w 12v.
 
Posted by Kevin Faulkner (Member # 6) on November 29, 2003, 05:20 AM:
 
HI Guys,
I wouldnt do any of these upgrades unless you can arrange further cooling at the gate. Warped gates could be the end result or at least film which gets distorted more and more on each projection. Go with care on this one.
The GS1200 should NOT use the A1/259 ELC 250W lamp instead of the ESC 200W lamp. I have done tests on various GS1200's and found that the 250W lamp which draws over 10amps of current will drop all the voltages from the mains transformer. The 200W at 8 amps does not do this. I found this out when my machine became erratic when using the ESS sync system. Changing the lamp back to the 200W version cured all my problems. The transformer runs quite hot with the 250 watt lamp and could of course burn out. Using a 250 W ELC lamp is no brighter than the 200W ESC as the ESC has a more compact fillament for the super 8 gate. Buy new lamps from Derann which will ensure you dont eventually end up with a burnt out transformer. [Frown]

[ November 30, 2003, 09:31 AM: Message edited by: Kevin Faulkner ]
 
Posted by Mal Brake (Member # 14) on November 29, 2003, 01:21 PM:
 
Kevin, I DID urge caution, all I can say is the conversions worked for us and have done for 18 years. The widescreen centre were selling these transformers specifically for upgrading the light output on projectors. This was over 20 years ago. With regard to the GS, of course you are right about using the ESC lamps, but they where hard if not impossible to find and Derann themselves offered the 259 as a replacement a few years ago.

When we bought the GS 4 years ago it was fitted with the 259.Mal
 
Posted by Paul Adsett (Member # 25) on November 29, 2003, 06:28 PM:
 
I have tried the 250watt ELC lamp in my GS1200 and it seems to work ok. However, based on Kevin's measurements (which he posted on the old Forum), it must be overloading the transformer, and so I now use the 200watt EJl lamps. These are not as bright as the 250 watt ElC , but I do not think it is worth the long term risk of burning out the transformer by continually using the 250w ESC. Presumably ELMO would have put in a 250 watt lamp as original equipment if they thought the transformer was capable of the electrical load.
Now that Derann have found a source of the 200w ESC lamps, I shall be replacing the EJl lamps
 
Posted by Kevin Faulkner (Member # 6) on November 30, 2003, 09:41 AM:
 
Hi Mal,
Yes I had forgotton that WS Centre sold a conversion. The trouble is that most people just change the lamp from the ESC to the 250W ELC and that DOES cause a drop in voltages. If that is happening then it must be overloading the transformer which wont go on for ever under those condition.
Paul I was surprised you remember that about the voltages on the old forum but yes you are right I did post that info.
I could never understand why my machine gave unreliable ESS results and then found that it was OK with the lamp switched off. Putting an ESC lamp in also cured the probs which is what prompted me to do those voltage checks and confirmed my suspicions.
I now only use the ESC lamp and its great that Derann have now got Eiko of Japan making them again as they were the people who were making them for Elmo.
So if you want ESC lamps go to Derann they have them in stock at £27.99 each.
Bit of sales pitch there for you Duncan, commision please! [Wink]
Kev.
 


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