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» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Can you check a diode without removing it? (Page 2)

 
This topic comprises 3 pages: 1  2  3   
Author Topic: Can you check a diode without removing it?
John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

- posted 07-14-2006 09:25 AM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
I suspect the photos of the guy "frying" are the real thing. The article says he survived. How? Even if the current going though his body didn't stop his heart, wouldn't vital organs have been "cooked"? I imagine he suffered severe electrical burns over most of his body.

I agree that it is just too dangerous to work on energized power circuits, especially in close quarters like the inside of a rectifier. One slip of the meter/scope lead may shock or startle you into making fatal contact, or throw you across the room. And even if you disconnect the power, don't forget to discharge any capacitors -- the bleeding resistor intended to discharge them may have failed, and you don't want to be "shocked" finding out. [Eek!]

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Randy Stankey
Film God

Posts: 6539
From: Erie, Pennsylvania
Registered: Jun 99

- posted 07-14-2006 10:32 AM      Profile for Randy Stankey   Email Randy Stankey   Send New Private Message       Edit/Delete Post 
quote: Frank Angel
never ever work around electricity alone, especially after hours like many of us do after the theatre closes.
Most places I work or have worked don't have lockouts on the electical service panels. Instead, when I work on electrical equipment, I shut off all the breakers in question then put a piece of gaffer's tape (duct tape) over the service panel door, sealing it shut.

A good strip of 2" wide Permacel will make a racket as it's peeled off the thin, metal door. If I hear that sound, I can go holler at the idiot trying to fool around inside the panel.

I usually do this even if I'm alone in the area. It only takes 10 seconds to do it.

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99

- posted 07-14-2006 11:19 AM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
quote: Mark Gulbrandsen
No, I won't divulge where we get the Semikron diodes from and we do get them in quantity.... You have to learn to do some of that figuring out on your own.
Well now that's a bit rude. You come on here and tell everyone that the diodes you use are better than everyone else's and then refuse to divulge the source? So much for spreading the knowledge and improving presentations worldwide I guess.

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Richard Fowler
Film God

Posts: 2392
From: Ft. Lauderdale, FL, USA
Registered: Jun 2001

- posted 07-14-2006 12:44 PM      Profile for Richard Fowler   Email Richard Fowler   Send New Private Message       Edit/Delete Post 
I generally sell IR 72HFR600 diodes ( instead of the wimpy 42 amp as used in IREM ) for $18.50 SEMIKRON a little more [Smile] Summer and Christmas peak purchase time with 100's out the door [Cool]

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

- posted 07-14-2006 01:06 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
quote: Brad Miller
You come on here and tell everyone that the diodes you use are better than everyone else's and then refuse to divulge the source?
Exactly... Frank is a consumer and out of respect for other dealers that are on this site I won't be the one to tell all except that there is a better diode. Frank is more than capable of figuring it out by doing some very easy studying on each manufacturers web site.

If you send me an e-mail I'd be happy to share it with you since you are a legitamate dealer and its your site so if you in turn want to post it here you can. I just respect other dealers trying to make an honest buck too! I think Richards pricing is more in line with what an 85 amp diode might cost from the average dealer, since we buy large quantities we are somewhat lower than that.. passing some savings on to the customer. The nice thing about the Semikrons aside fomr the double current rating is that they are available with braided lead attached as is used in IREMS or without the leads.

John,

I think that guy survived because he was elevated above earth ground, the phone pole being a poor conductor well above earth ground... literally... had he been standing on the ground he would have been burnt to a crisp in seconds. I'm sure that his body has never been the same again. I would also assume alot of brain damage also occured.

Mark

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Richard Fowler
Film God

Posts: 2392
From: Ft. Lauderdale, FL, USA
Registered: Jun 2001

- posted 07-14-2006 01:31 PM      Profile for Richard Fowler   Email Richard Fowler   Send New Private Message       Edit/Delete Post 
Pricing for competitive purposes [Smile] response expected [Big Grin]
Diode War.....not [Cool]

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99

- posted 07-14-2006 02:14 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
I've got a stack of diodes on the shelf. Perhaps when the day comes that I actually USE some of them, I'll hit you up for that. In the meantime, it has quite literally been about 4 years since I've had any diode failures (all were in Strong consoles big surprise) and before that it was circa 1992 on CFS consoles. I have honestly NEVER had a diode failure in a Christie, IREM, or anything else.

Maybe I'm lucky...or maybe the equipment likes me better. [Big Grin]

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Tim Reed
Better Projection Pays

Posts: 5246
From: Northampton, PA
Registered: Sep 1999

- posted 07-14-2006 02:21 PM      Profile for Tim Reed   Author's Homepage     Send New Private Message       Edit/Delete Post 
quote:
A REAL ELECTROCUTION .... this guy survived the contact with the high voltage...
If he survived, then he wasn't electrocuted. [Razz] (Deja vu. We've had these pix on here before, and I think I said the same thing then.)

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Louis Bornwasser
Film God

Posts: 4441
From: prospect ky usa
Registered: Mar 2005

- posted 07-14-2006 02:47 PM      Profile for Louis Bornwasser   Author's Homepage   Email Louis Bornwasser   Send New Private Message       Edit/Delete Post 
Right, Tim; just like the 6 o'clock news: an electrocution implies death; not recovery. Louis

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

- posted 07-14-2006 05:06 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Brad,
Give em enoughh time and thermal cycles and they will fail. We service a ton of locations in 14 states with all sorts and ages of recifiers with some Christie rectifiers that are 40 years old. We have SLC Consoles that are 10 plus years old. We've also seen alot of rectifier cooling fans in the fail... very dusty out here.

Buildings that have surge protection have less trouble but still eventually experience thermal and then mechanical failures. Most of the IR diodes are epoxy passivated(sealed)and the epoxy is part of the problem eventually letting go at the seal(stem to epoxy). Glass passivated diodes... like Mil-Spec are alot less prone to thermal failures because th glass does not break down over time like the epoxy does.

Mark

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002

- posted 07-14-2006 05:14 PM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
quote: Mark Gulbrandsen
Exactly... Frank is a consumer and out of respect for other dealers that are on this site I won't be the one to tell all except that there is a better diode.
Huh? You tell us all the time that there are better processors (namely Panastereo) than the ones most dealers want to sell us, so where is the difference?

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

- posted 07-14-2006 07:02 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Humm, It should be obvious I think to most. The difference is that I told you the name of the better processor(that was common knowledge among many technicians back then anyway) but I didn't tell you the part number of the better diode. There is no reason that Frank can't investigate this for himself unless of course you think he is too lazy or some other reason... I don't think he is lazy since he wouldn't be attempting to repair his own equipment.... and he will learn something important about being a technician in the process.

Mark

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Frank Dubrois
Jedi Master Film Handler

Posts: 896
From: Cleveland, OH
Registered: Mar 2005

- posted 07-14-2006 07:23 PM      Profile for Frank Dubrois     Send New Private Message       Edit/Delete Post 
Mark,

I hope I havent done something to offend you in the past, but the last couple replies from you havent been exactly cordial. I've always respected your opinion here, but am puzzled at your recent "snob like" replies. I appreciate you letting me know there are better diodes out there, and I would like to get those for our projector, so I didnt see the harm in asking your source. I never expected to get them for wholesale or go into business reselling them, just another place to purchase them. I knew we were getting ripped off on the bearings we were getting, so I found a new place to get them much cheaper. I felt we were probably getting ripped off on our diodes as well..now I KNOW we are. I just wanted to save our theatre some money, not corner the market on diodes.

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002

- posted 07-14-2006 07:41 PM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
Frank - nothing personal. Mark is always like that [Big Grin]
Must have something to do with living in Utah, surrounded by so many funny people. Sooner or later, that gets to you [Wink]

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Frank Dubrois
Jedi Master Film Handler

Posts: 896
From: Cleveland, OH
Registered: Mar 2005

- posted 07-14-2006 07:44 PM      Profile for Frank Dubrois     Send New Private Message       Edit/Delete Post 
oh..Utah [sleep]

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