my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Lamphouse Air Temperature (Page 2)

This topic comprises 3 pages: 1  2  3

Author Topic: Lamphouse Air Temperature Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-04-2007 09:38 PM                     quote: John Hawkinson Tangentially, I was wondering how involved it is to add a booster supply to an existing rectifier whose no-load voltage is a bit on the low side for striking (an IREM P1-X80 driving a 2K lamp; it just barely makes 80VDC no-load). Is this a straightforward thing to do? I did one today and am doing another tommrrow. I will post a few pics of how its done tommrrow night. Its a somewhat inconvenient sized and shaped box with no quick hanger on it. Also, it is way too large to mount to the side of a 2KW floor standing IREM unless you mount it to one of the blue panels. I mounted mine on the angle area of the non operating side of the DP-70 lamphouse table. There is no need to have it mounted right next to the rectifier. The main thing is that it works great and the lamp is lit before the sound from the contactor arives! Definate proof that light travels faster than sound . Its a tad bit pricy $500.00, but is also well built and less expensive than a new rectifier. Mark  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 06-04-2007 09:41 PM                     Thanks, Mark. Is that for the Xetron "Boost one"? What I really meant was how involved it was to do-it-yourself, i.e. to add on some other supply not originally designed as a booster. --jhawk  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-05-2007 07:09 AM                     Yes, it is the boost-1. It could be built DIY of course. If you call John W. he could probably send you the schematic. DIY for about 100.00 in parts. Mark  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 06-08-2007 03:19 PM                     Hey, Mark, thanks for the pix (in the other thread)! You mention, "Acording to John Walsh at Neumade these older rectifiers are actually intended to operate on 380 volts 3-phase which is the more common AC supply in Europe and at that voltage they do indeed supply 130 volts no-load, later IREM rectifiers are specifically wound for the measly lower AC voltages found here in the U.S." Seriously? I'm pretty sure the nameplate on ours is for 220V, or maybe 240V. Are you saying the nameplate is...finessed? Maybe our model is different. I was going to say I didn't see how it would help, since the current is controlled by changing input taps on the primary side. But then I realize that there's also a strap on inductor that we could change, and that way we could control the running current independently of the no-load. I was planning to throw in a variac for finer current adjustment...perhaps running way overvoltage is a good idea. By-the-by, is there a reason not to build these boosters with switching components? Since cleanliness of the DC isn't such an issue, it seems a lot cheaper and easier... --jhawk  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 06-08-2007 03:34 PM                      |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 06-08-2007 03:53 PM                     I know, I don't like the way it looks Is it required? --jhawk  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-08-2007 07:36 PM                     Exactly what model IREM rectifier do you have. Older IREMS I believe have taps but the later ones have the movable core... The ones I am talking about are the early movable core type circa late 1970's. And as far as building... them absolutely yes... I need 6 more of them and plan on building them in the shop for later installation. While the Neumade box is somewhat convenient it is pretty pricy. I was in the field when I needed these and construction of them on the booth rewind table is somewhat more time consuming as is parts procurement in a town with barely a Rat Shack. Mark  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 06-08-2007 07:56 PM                     single-phase IREM P1-X80/C. Nameplate claims 220V input, and a laughable 85V no-load. But it's a Xetron nameplate, so I don't know what IREM rates it at... I was curious if DIY switching boosters were popular. It seems there's some incidence of DIY high-reactance boosters... --jhawk  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-08-2007 09:57 PM                     This booster would work fine on yours. It works pretty much like the auto ignite relay on a lamphouse does. There is a zener and a relay. When the voltage drops below the zener firing voltage the relay drops out and kills the booster's power transformer. A 90 volt secondary tranny through a bridge rectifier would give you about 130 volts. Use about a 470uf cap on the output of the bridge for storage. Relay has a 48 volt coil and is in series with a 30 volt zener. A 150 amp stud mount diode blocks the boost DC voltage from the rectifier's DC. BE sure to heat sink and cool the diode adaquately. Be sure to adaquately bypass the stud mounted diode. You might have a hard tme finding a 120/240 primary - 3 amp 90 volt secondary tranny... if you do EDCOR will custom wind one for you at a very reasonable price, probably around 50 bucks. I've used them for custom one up audio and power trannys before and their quality is first rate and delivery is really fast. Mark  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-09-2007 08:56 AM                        Most of my rectifiers are IREM, 3 phase units; none have the booster. I have only filed one warranty claim in 15 years with Osram bulbs.(bad weld) Most 2kw bulbs are removed at 4500-5500 hours, still lighting perfectly and with clear quartz. (3500-4500 with 3kw bulbs) I never rotate; but I do super cool. Voltage here is 207-210 volts. FYI: That Italian rectifier was designed in Kentucky about 1963 by the late Frank Riffle when he wanted to import the CX-900 and x-400 lamphouses into the US on behalf of Carbons Inc; later Xetron/Neumade. Frank also designed the 6L6 along with RCA. Frank, was, at one time, the Altec/ERPI serviceman for Louisville, Ky and was the last president of Motiograph. Louis  |  IP: Logged Richard Fowler Film God Posts: 2392 From: Ft. Lauderdale, FL, USA Registered: Jun 2001 posted 06-09-2007 10:45 AM                     The IREM models prior to the N series looked like circular trashcans We have installed boost kits on IREMS and Kneisley rectifiers for a client due to his voltage barely exceeding 190 VAC.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-09-2007 11:36 AM                     The rectifiers I installed thses on are very early N series units. Probably late 70's vintage. Theaters that have a high leg are less suceptable to problems with these early units. Mark  |  IP: Logged Dan Reiter Film Handler Posts: 74 From: Easton PA Registered: Jul 2002 posted 06-11-2007 02:18 PM                     On the IREM'S... The input voltage is pre-wound at the factory. You cannot change it. 380 is for Europe, 220 for the States and Asia. Also, in agreement with the above, the older the IREM, the lower the open circuit voltage. With today's higher-pressure lamps, these older power supplies struggle to fire these newer lamps, especially as the lamps age. That is why you will find that if you say "BRAND X"'s bulb is no good and won't strike after a while, and then put in "BRAND Y"'s bulb, and VIOLA!!! It strikes, that is why. Best thing to do for the older IREM is to put in a full fresh set of diodes, replace the etlctrolytic caps, replace the RA board, and put in a fresh 230VAC contactor. Also, if your booth has a multiple tap feed transformer, kick it up. The IREM won't mind a little more on the front end. In extreme case, a booster unit, like the one noted above is the last hope before taking the plunge for a new power supply. Very much like expecting your 1937 buick to operate like your 2007 BMW.  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 06-11-2007 04:05 PM                        quote: Louis Bornwasser I do super cool We know that, Louis, with your pilot glasses in front of that plane.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 06-11-2007 06:42 PM                     We super cool too. Thats why we see 12,000 hours [lus out of Christie lamps. quote: Dan Reiter Best thing to do for the older IREM is to put in a full fresh set of diodes, replace the etlctrolytic caps, replace the RA board, and put in a fresh 230VAC contactor. I did that before installing the boosters. Same 74 volt no load DC voltage. Shows how long lived the main capacitors in Irems are. quote: Dan Reiter Also, if your booth has a multiple tap feed transformer, kick it up. The IREM won't mind a little more on the front end. Indeed the booths that these IREM's live in have multi tap trannnys feeding every 4 booths. But boy howdy, ya got to be careful there! If you kick up the main tranny then you risk the probability of everything else including the 120 volts going up and there are some pieces of gear that are not going to like that . I disagree on kicking up the voltage. It is normally set once by the electrician or the power company during install. Now if your booth transformers feed JUST the rectifiers thats fine... I agree the IREMS can take it... in fact they're designed to. I just don't think you'll find the booth tranny feeding JUST the rectifier in most installs. I thik the booster angle is the best for rectifiers that can't make even 100 volts no load. I've priced out the components including custom wound power trannys and the cost is less then 120.00 for parts less labor per booster. Mark  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 3 pages: 1  2  3

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.