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Thread: Omega Timer With Aristo Cold Light?

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    http://www.spiritsofsilver.com tgtaylor's Avatar
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    Omega Timer With Aristo Cold Light?

    Hi all,

    I just puchased a used Beseler MXT enlarger that came with an Aristo D2 Cold light head. I have never used a cold light head before and I am wondering if my Omega ET-500 timer will handle the inductive loads that a cold light source gives. Your insight on this is greatly appreciated.

    Thomas

  2. #2

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    Re: Omega Timer With Aristo Cold Light?

    It's hard to get consistent results using these heads. If you get one, get one with a heater. It'll have two cords for plugging it in. (A thicker one for the heater and a thinner one for the light source.)

    My suggestion would be to get a compensating timer like the Metrolux. But, I don't really know if they're still made? There are others. The Zone VI would be an option, except that it's no longer possible to get the separate sensors. (On perpetual backorder.)

    These timers adjust for the high variation that cold light sources exhibit by varying the "speed" of time as the light varies in brightness.

    Otherwise, one can help smooth out the variability by leaving the head on prior to printing to make sure the heater is at its peak, and waiting an interval of time between exposures, etc.

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    Re: Omega Timer With Aristo Cold Light?

    Thomas, I am uncertain of the answer re your specific timer. However, along with my Aristo V-54 Cold Light came the following warning from Aristo: "If you are using a digital or solid state timer, check the manufacturers specifications to see if your model is compatible and can handle the inductive load of a cold light head. If you are uncertain, a solid state Contactor model #1200 can be purchased from Aristo which will protect your timer and boost its power handling capabilities to 1200 watts inductive load."

    My setup is with the V-54 Cold Light, the Contactor model #1200 and a 545 Gralab timer. It has worked well for the past six years and is very consistent once it heats up. Neil mentioned this above, and I find the V-54 to be more consistent than the earlier Aristo Cold Light. Assuming that you have the V-54, you may want to add a solid state dimmer made by Aristo.

    Hope this helps. Aristo used to be very helpful answering questions, and probably still are, assuming they are in business.

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    http://www.spiritsofsilver.com tgtaylor's Avatar
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    Re: Omega Timer With Aristo Cold Light?

    Hi Neil,

    Thanks for the reply.

    The head has the two cords that you mentioned. The burning issue right now is whether or not the Omega/LPL ET-500 timer will safely work with the inductive load of the cold light source and, if not, would attahing a voltage regulator or some other device solve the problem. I wouldn't want to buy another timer just to use with the Aristo.

    I E-mailed Omega Satter customer support this afternoon. Hope they respond.

    Thomas

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    Re: Omega Timer With Aristo Cold Light?

    Hi Merg,

    Thanks for that reply!

    The timer manual sets both enlarger lamp and safelight capacity at "Under 500W" each. Do you know that the max output of the Aristo is?

    Thomas

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    Re: Omega Timer With Aristo Cold Light?

    On the back of the Aristo head is states the output as 70 watts. Since 70 watts is well under the timers 500 watt capacity for the enlarger, it looks like there should be no problem. But I'm not an electrical engineer (I slept during that class) and I don't know if the head could induce a load in the timer that would exceed the 500 watt limit.

  7. #7

    Re: Omega Timer With Aristo Cold Light?

    Thomas,

    Years ago, I had a similiar set up. I don't remeber the timer model, but it was an Omega. It would not handle the load (it would shut off or not turn on or something). I am no kind of engineer, but I told my brother in law, who is. He disappeared and returned with something I think he called a "snubber" or something like that. Anyway, it solved the problem, and my set up worked fine. It is probably something like the contractor mentioned above. I did use a Zone VI stabilizer for more consistent results.


    Peter

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    Re: Omega Timer With Aristo Cold Light?

    I had this setup at one time. I built my own contactor loop to handle the load. All that is needed is a DPST NO 10 amp contactor with 120 volt coil...let the timer enlarger lamp outputs supply the coil voltage and have a live 120 volt sitting on each of the double poles of the contactor. Probably a lot less expensive than Aristo's contactor. Any HVAC supply house would have the contactor that you need.

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    Re: Omega Timer With Aristo Cold Light?

    Hi Thomas-

    It sounds like you have the D2 with a V54 lamp which Aristo rates at 70 watts. The high intensity lamp is rated at 110 watts and is very bright. Hence, my mention of a dimmer, but you should be fine without one. You have some good advice above re the contactor; for the record, I paid around $100 for mine in 2002.

    Hope you enjoy printing with the cold light. Always a controversial subject, but after years of condenser printing I made the switch and prefer the look of the cold light prints. However, it does take a different type of negative from those intended for condenser printing.

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    http://www.spiritsofsilver.com tgtaylor's Avatar
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    Re: Omega Timer With Aristo Cold Light?

    Thanks everyone for the replies. I sent an E-mail to Aristo and to Omega-Sater and will post their response if received. Hope I dont need the contractor.

    Yes, it is the V54 model. Has a little sticker on the top with V54 written on it.

    This will be the first time printing with a cold light. From what I've read so far, you are supposed to position the negative as close to the cold light source as possible. so I guess that means to close the head down on the negative carrier regardless of the film format.

    I bought and picked-up the enlarger yesterday afternoon. It is now set-up in my bathroom and looks great. I ordered the instruction manual yesterday so I can properly align it. Using a torpedo level, the stand and baseboard is level. Using a flat piece of glass in the carrier, the negative carrier looks like it could be tweaked a tiny bit but I can't see where you would do that. Haven't figured out how to check the lens stage yet.

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