I just bought a Zone VI cold light head for my 4x5 Beseler MX and got no documentation. It has two wires for its power input (110v), marked "Lamp" and "Pre-heater". It also has a 3-pin (plus ground, or neutral) DIN inlet that I believe is there to connect the light intensity stabiliser. How do I connect it and how does it work ? Do I have to connect both power inputs ? Does the "Pre-heater" input have to be always on current, or only before the exposure ? Does it need to be connected on a special Zone VI timer ? Is there a way to take advantage of the photocell that stabilises the light intensity output ? If anyone has the manuals or connection diagrams of this device, can he (or she) please send them to me in a PDF file ?

-- George Papantoniou (papanton@hol.gr), April 12, 2002

Answers

George, I don't know about the Zone model, I have an Aristo, but the heater cable gets plugged into the wall outlet before hand and left in. The other plug is for your timer. Hope this helps a little. Cheers

-- Scott Walton (walton@ll.mit.edu), April 12, 2002.

check with Calumet. they bought out Zone VI and support the products.

-- Ann Clancy (clancya@attbi.com), April 12, 2002.

You will have to get either a Zone VI stabilizer, or a Zone VI Tik Tok to use the sensor in the head of your cold light.

You can use the cold light w/o that, however. Plug in the "pre- heater" for a period before you start printing. Leave it on the whole time. By keeping the head heated, this feature helps your prints be consistent. The other plug, Lamp, is used with a timer that energizes when the timer is activated.

Be sure NOT to use a digital timer with that head unless you are ABSOLUTELY sure it [the timer] is rated to be used with a cold light head. Otherwise, you will harm your timer. [Been there - done that]. If in doubt, use a timer that has no digital display.

If you have further questions, e-mail me directly.

-- Alec (alecj@bellsouth.net), April 12, 2002.

On the timer part--I bought a great little relay at Grainger and wired it into my darkroom. My timer just trips a few milliwatts for the relay, but the other switched part of the relay trips the wall power for the cold light. Basically it is the same as the "contactors" sold by the photo people, but mine only cost about $12. Contactors actually have a little more circuitry in them, but the idea is to not run the intial power spike directly through the timer. My darkroom wall has two outlets behind the enlarger, one is straight power for the preheater, and the other is switched by the timer/relay setup.

-- Chris (bwdesert@yahoo.com), April 13, 2002.

Chris: What's the Item / Part number of that Grainger relay ?

I've been advised that an ordainary surge supressor ( the kind used to de-zap the power to your computer) is a way to clean up the pulse from a cold light. In fact, I use a small single-outlet supressor on my 5x7 Zone VI cold light.

I've just started to hook up an 11x22 Aristo lamp for a horizontal enlarger, and I'll bet that baby puts our a pulse that'll zap a 747 at 35,000 feet. I'd planned to use a bigger computer supressor, but your idea sounds to be smaller and cleaner.

-- Reinhold Schable (rschable@quik.com), April 13, 2002.

Hi R.S. I put it in an electrical box, so I can't easily look at the number--sorry. They have a bunch of relays, though. If you have a Grainger you can go to, just describe what you are doing, and they will help. A phone call would probably do the same. Relays like these are used constantly in heating and air conditioning systems. Everything gets turned on and off with them, with the switch just being a little sensor somewhere. Probably every home furnace in the world controlled by a remote themostat has one. We just use a timer to trip them instead. I just got one big enough to switch anything I wanted, so I wouldn't have to worry in the future. Zone VI Studios used to sell a contactor for $80 which I would guess actually had about a $10 relay inside it. I think an actual "contactor" has another circuit to completely separate the incoming timer power from what it is switching. I just used a two-sided relay. I trip one side with the timer, the other side connects wall power through for the light source. That actually puts two relays in the system, because there is already one in the timer anyway. It has worked great for 8 years now.

-- Chris (bwdesert@yahoo.com), April 13, 2002.