Good stabilizer for enlarger

haris · May 17, 2006

Hi,

I have Meopta Magnifax 4 and its original transformer for colour head. Lately I noticed light getting brigter and darker in nonregular short intervals (parts of second). I guess my house power lines or transformer doesn't give stabile power. What is best ways to stabilize power? My thoughts goes to two directions:

1. Computer UPS,

2. Do you remember in old days of vacuum tube TVs those power stabilizers, you connect them into power wall socket and TV into those gadgets.

And what if house power is stabile, but transformer gives unstabile output?

Any other efficient way, and does anyone tried to use computer UPS for enlarger? In theory it should work, but does anyone knows that in practice?Yes, I know there are stabilizers for enlarger transformers, but as any gadget which has "photo" label, they are extremely more expencive than same gadget without "photo" label

Thanks.

Chan Tran · May 17, 2006

A UPS is probably the cheapest and it should work fine. There are more expensive stabilizer but I don't think you need it. The transformer should not cause the problem, unless it's about to go. I would not get one that has "photo" label on it though.

RH Designs · May 17, 2006

Haris - before investing in a stabiliser, check the lamp holder contacts and clean them if necessary. Corrosion is quite common and can cause the symptoms you describe - I have had this happen on more than one enlarger and it's easily cured by cleaning the lamp pins.

Regards
Richard

pentaxuser · May 17, 2006

RH Designs said:
Haris - before investing in a stabiliser, check the lamp holder contacts and clean them if necessary. Corrosion is quite common and can cause the symptoms you describe - I have had this happen on more than one enlarger and it's easily cured by cleaning the lamp pins.

Regards
Richard

The metal sleeves inside the ceramic block into which the lamp pins fit can get corroded due to electric "arcing". You might want to clean the insides of the sleeves. I understand there is a very thin file you can buy which is the thickness of a large sewing needle and will fit inside the sleeves. The less efficient alternative is a small sewing needle which you can wiggle inside the sleeves to clean the worst of the corrosion. If all else fails you can buy a new ceramic holder. Best of luck

pentaxuser

haris · May 18, 2006

Thank you all.

Peter De Smidt · May 18, 2006

Most computer stabilizers/upcs don't really provide much stabilization. I once bought a $100 APC one, and it would only kick below 90v and above 140v. That's not much help. If you really have voltage problems, I recommend a used Sola CVS transformer. These are big and moderately expensive, but they actually work. They last a very long time.

rbarker · May 18, 2006

I agree with Peter about computer UPS units. Most are designed only to kick in under serious brown-out or over-voltage situations, relying on the tolerance of the computer's power supply for anything else. Even many "stabilizers" have fairly broad operating ranges, so checking the specs is a good thing.

haris · May 18, 2006

Thank you. Well, issue is not if I would stay totaly out of power, if that happens I would start printing session again. Problem is, during printing session, small and fast changes of light from light bulb, which of course make exposure timing unreliable.

I will first try to clean bulb contacts and bulb housing contacts as Richard (RH diesigns) and pentxuser suggested, and if that doesn't help, then I am in search for good stabilizer

Thank you all again, best regards.

Roger Hicks · May 18, 2006

Dear Haris,

Although my wife Frances Schultz and I run our enlargers through a UPS (unreliable power), I strongly suspect that over a 10- or 15-second period, variations are trivial in MOST countries (experience based on rural California and rural France, but e.g. India looks different). If you are really suspicious, connect a voltmeter across the supply then start worrying if it varies consistently.

Cheers,

Roger (www.rogerandfrances.com)

haris · May 19, 2006

Thanks Roger,

Well, I noticed this first when tried to make proof sheet. I waited for some time hoping light will stabilize, but it constantly blinks, that is light doesn't go off and on, but it goes dimmer and brighter in very short intervals (parts of second), and irregulary. This is independent of days or part of the day (no matter if it is morning or night or beggining or end of the week...)

I will try all suggestions I received from you good people, and see what works.

Thank you all very much, best regards,

Haris

Chan Tran · May 19, 2006

I think you have loose connection rather than a problem with you incoming power. Can the enlarger be used without the stabilizer you have now? If yes then try it without the stabilizer. Bad stabilizer can cause the problem.

Roger Hicks · May 19, 2006

I'd certainly back the suggestion to check all connections. Most UPS units should stabilize the power enough to stop the kind of thing you are experiencing.

If I were nearer Sarajevo (or CAPAJEBO, as the English wife of a Sarajevan acquaintance misread the Cyrillic road-signs) I'd give you a stabilizing transformer; I think I have an old Durst one around somewhere, though it may have got lost in the last 2-3 moves. Check other old pro labs to see if anyone has one.

Cheers,

Roger

haris · May 22, 2006

Chan, Roger, and all, thank you.

Chan, you were right to the point. It was not transformer or power stability problem. From lowering and raising of enlarger head (or some uncarefull pulling of cable), cable which connect transformer to the ceramic bulb carrier lost connection, in fact connection was left only on small part of cable, rest of cable was torn. So, that not only make power problems, but also make very high temperature (who knows elecric and physics, knows that smaller cable means bigger resistance to the electric power, and byprodoct of electric resistance is high temperature on cable and connection. Only surprise for me was that 12V can produce such high temperature...) which melted plasic housning in which cable has connection to ceramic bulb housing. Luckilly for me I know how to repar that (in highschool my hobby was electronic, you know making receivers, amplifiers and such so now everything is in order. I only kick myself in a.. for not thinking about connectors at first place, considering my highschool hobby... That shuld be first thing to think about...

So, thank you all again for suggestions and help.

Ragards.

Good stabilizer for enlarger

haris

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