Unicolor Solid State Voltage Regulator Model 744

Discussion in 'Darkroom Equipment' started by chris72, May 14, 2011.

  1. chris72

    chris72 Member

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    Hi,
    please tell me where I can fiind to buy this: Unicolor Solid State Voltage Regulator Model 744?
     
  2. ic-racer

    ic-racer Member

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    Looks like there were two in USA ebay recently selling for $19 and $14 (March 30 and 31) respectively from different sellers.

    I'm not sure about Romania, but in the USA many communities have pretty steady voltage on the mains supply.
     
  3. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

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    You can need a regulator for color work even if the power is, by general standards, quite good - a variation of just a few volts can throw off color balance if you are doing the printing the old 1960's way with a standard condenser head and CC gels. Unicolor was the major source for color printing systems in the 60's.

    Color heads are invariably regulated. That's why 82V bulbs are used so often - you can make a very cheap, and rather good, AC voltage regulator by firing triacs at 90 degrees. Cheap color heads aren't regulated buy use a half-wave rectifier allowing the use of the same 82V bulb. Very good heads often run 12 or 24V bulbs with a ferroresonant transformer.

    A regulator made for 60Hz generally won't work (or won't work very well) at 50Hz, even if you use a transformer to convert 220V to 117V.
     
  4. chris72

    chris72 Member

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    I have a Aristo D2 Cold light, and a Zone VI stabilizer but I don't know if is work. Maybe you van help me. Also we have here 220-240 volts on wall, but I have a transformator for 110 volts.
    How can I use a voltage stabilizer for my cold light? have somebody a skematic? or how to do?
     
  5. ChuckP

    ChuckP Subscriber

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    The Zone VI stabilizer is supposed to keep the cold light output constant. But I'm not sure what happens if the AC input to the stabilizer varies. If the input AC variation is within the design limits of the stabilizer, whatever that is, then the stabilizer should keep the light output constant as the AC varies. Outside the design limits the stabilizer operation may not be able to properly control the light output and variation would be seen. Maybe you can connect a variable AC input to your stabilizer/cold light and see what voltage level causes the stabilizer to go unstabilized.