This is topic Strong power supply poll in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=003793
Posted by Joe Beres (Member # 678) on 08-01-2002, 10:26 AM:
We are going to be putting in some new lamphouses and and power supplies. I think we are going to go with the Strong Ultra 80 running a 3000w lamp. The question of which power supply remains. I am leaning towards the switching supply, as space is a major issue in our booth. We only run about 4 films a week, and the auditorium and the booth are used for other types of events. Our projectors are on casters and are moved out of the way, if need be. One option I am considering is to hang the switching power supply on the pedestal to allow for easy moving. The high reactance supply would not allow that. I know that the switching supplies cannot be serviced in the field, but as we run changeover and we don't run constantly, that might be a risk I am willing to take. I would really like to get your opinions on this though.
Posted by Richard Fowler (Member # 893) on 08-01-2002, 10:47 AM:
Using switchers in your situation pose minimal risk in your low use situation and would make a compact package on the side of your pedestal....Most xenon followspots for shows are switchers and in our current rebuilt consoles we are using switchers which can be changed out in less than a minute.
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com
Posted by Paul G. Thompson (Member # 655) on 08-01-2002, 11:03 AM:
I agree with Richard. The reliability of the switcher power supplies has increased over the years, and I don't think you will have any major problem with them as long as you keep the blowers clean so the power supplies cannot overheat.
During the tour of the Strong International facilities switcher shop, the pile of switchers that were in for repairs were the older ones that have been in service for many years.
Considering how many switchers are in service throughout the world, the repair pile I saw was not that significant by any standards.
Posted by Mark Gulbrandsen (Member # 72) on 08-01-2002, 12:01 PM:
We ahve hundreds of Strong switchers in this area, many are in theatres I service. Frankly I have more ignitor problems than I switcher woes. There are things you HAVE to be careful of with switchers though. NEVER BUT NEVER let the positive lead short to ground. This means almost certain death for most switchers. Keep in mind that the solid state device ALWAYS fails to protect what ever fuse(or breaker) is supposed to do the protection. On the 3kw units it is best to go with the large MIL SPEC amphenol connectors. There have been failures of the tiny screw down terminals on 3kw units in the past. I have never had an Amphenol fail though. Also keep the screws tight inside the twist lock AC connector. I have had several of these burn up recently as the screws either come loose or the terminals, or wore suffer from compression set.
Other than these probs they are extremely reliable.Mark G.
Posted by Jason Black (Member # 684) on 08-01-2002, 04:21 PM:
Hey Paul,
No more weenie? LOL
Posted by Paul G. Thompson (Member # 655) on 08-01-2002, 04:32 PM:
Posted by Rick Sanjurjo (Member # 1365) on 08-01-2002, 10:50 PM:
Mark,I got a good laugh from "solid state device ALWAYS fails to protect what ever fuse(or breaker) is supposed to do the protection" it sure seems to be true. The fuses and breakers are there to prevent the internal wires and pcbs from catching on fire when a device does fail. Typically if a fuse is blown in a switcher there is something very wrong inside.
Rick
Posted by Rick Long (Member # 213) on 08-01-2002, 11:36 PM:
In my opinion, using switching rectifiers is the kindest thing you can do for your xenon bulbs. Despite some negative publicity about them in the past, I did a check against files i have from 15 years ago (damn, I never throw anything out) and the number of rectifier calls i had with reactance types are about the same.I have found that bulbs last a lot longer with switching supples. It may, however, be worth your while to keep one spare rectifier in the booth.
Then again, Fairview Toronto, ran 5 theatres for 12 years with 3K switchers with never a failure.
Posted by Mark Gulbrandsen (Member # 72) on 08-02-2002, 12:30 AM:
Rick,
Back in my good ole days of repairing Crown, Phase Linear and other early high power audio gear we came up with that saying. It is definately true in 99.9% of all breakdowns on early stuff. Sure the fuse, or fuses will blow, but so does every output transistor, driver transistor, and pre-driver in the amp! It was alot of fun in those days back in the early 70's. I once remember the guy that put 20 amp fuses in the output stages of his ESS power amp. These ESS amps were very tempramental to begin with and the 20 amp fuses, instead of the usual 5 ampers, resulted in the top cover grill assemblies of his ESS AMT-1 Speakers going up in flames! I'll never forget my thoughts when I got into work that morning and saw the skelton of those speakers sitting there for repair...it was a truly hilarous moment.
Its nice that we don' have failures in power amps like that anymore. Semiconductors sure have come along way in general and its a nice thing.
BTW: Rick, Its good to see you posting here. This place is alot of fun and does alot of good for all involved!!
Mark
Posted by Joe Beres (Member # 678) on 08-03-2002, 08:08 AM:
Thanks for the advice, fellas. Paul, I don't think your pic is rotating yet.
Posted by Paul G. Thompson (Member # 655) on 08-03-2002, 12:04 PM:
Yeah, Joe. I know.....bummer. I'll have to ask Brad if he will do that for me. Brad??????? I like my "Punk" picture, too. <hint hint> 
Thank you.
(if it is not too much of a hassle)
Posted by Brad Miller (Member # 2) on 08-03-2002, 02:23 PM:
2 pic rotation does not work well with the server.
Posted by Paul G. Thompson (Member # 655) on 08-03-2002, 03:42 PM:
Oh. I didn't know that.
Posted by Don Sneed (Member # 955) on 08-03-2002, 06:10 PM:
I hate those Strong switcher power supplies, the 2K is ok but those 4K really bites !!! I do have to admit they are easy to change, but they are unreliable...I have suggusted to my bosses we go back using the old reliable High Reactance power supplies, an example is we open four theatres here in the state, 14-18 screens each with Switcher power supplies, 4-theatres in Japan, 10-screens each with High Reactance power supplies....no problem with the Japan theatres, but we have already changed at least 3-4 at each theatre using the switcher power supplies.....maybe you guys are having great luck with them, but I want to go back using the "Reliable High Reactane" type....Now this crappy "DC" igniter that Strong now use, that you can not manule strike....really Sucks !!! Who thought of that one....whoever did had some damn good smoke !!! I need to come party with you !!!
Posted by Richard Fowler (Member # 893) on 08-03-2002, 08:07 PM:
Most D.C. ignitors do not have a provision for manual strike. the one we use has a sensitivity circuit which can be adjusted if low voltage or old bulbs are a problem. Outside of the early Strong switcher with its multiple problems ( land fill material, which you must credit Strong with offering an improved product ) most units we source from three manufacturers have been pretty reliable....we have lost a couple due to improper installation or direct electrical shorts in the wrong place. Not knowing the construction of the larger switchers you are using, there may be a design issue for that size which is different than the smaller units such as multiple switcher boards working to give the final output to the bulb ( saves on design and construction costs, decreases reliability ). Classic magnetic rectifiers have their place but sometimes since they are "easy" to fix we have had many situations where a quick fix hides a dormant operational problem which can be costly in the long run.
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com
Posted by Rick Sanjurjo (Member # 1365) on 08-06-2002, 08:51 PM:
The manual ignite button on consoles only bypasses the autostrike circuit. The AC igniter needs something to tell it when to light the lamp, the autostrike circuit monitors the power supplies DC voltage and turns on the igniter at the correct time. The DC igniter works directly of the power supplies DC voltage so it doesn't have an autostrike circuit.If there is no autostrike board to bypass then there is no use for an emergency ignite button. There are two failure modes with a DC igniter, one the power supply isn't working, or two the igniter isn't working. In either of these failure modes an ignition button will do nothing to help the lamp light. Rick