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» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Kelmar Series IV automation microswitch question

   
Author Topic: Kelmar Series IV automation microswitch question
Frank Dubrois
Jedi Master Film Handler

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


 - posted 09-05-2007 12:42 AM      Profile for Frank Dubrois     Send New Private Message       Edit/Delete Post 
These switches seem to be going out quite frequently. Does anyone know which switch controls what in the automation? My next question is, does it even matter? If one switch (say the 4th one in) goes out, its best to just replace them all up to that point? I'd really like to find out what switch controls what function in the automation, and to this point, can't seem to find that info anywhere. Can anyone help?

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 09-05-2007 08:42 AM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Just replace em all when you pull the cam timer out. Its a very easy job to do and inexpensive. I also reccomend that you place a line down all the cams with a sharpie so you know if you've disturbed any of each cam's settings when its re-assembled. When disassembling be sure to lay the pieces out in the order they came off and then just reverse that order to put it back together.

Expect even less life out of new micro switches and relays since the lead free act took place.... there is now no cadmium in any new contacts [Mad] . They now drop like flies and will continue to do so. I feel that with the days of lead free being upon us or at least until suitable substitutes are found for the metals that were once used that electromechanical automation is pretty much at its useful end.

Mark

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999


 - posted 09-05-2007 08:48 AM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
You know, they could always start "gold flashing" the contacts for the lesser current switches!

Steve

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 09-05-2007 08:59 AM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Not even gold would hold up on the AC connected contacts of switches and relays for very long. Its too soft, would be extremely thin and each arc generated when the contacts open back up would erode it away in no time. It would be good for contacts on anything below about 12 volts and very low current. The only thing that will hold up really well and even better than the original are solid platinum contacts but thats too pricey for mass production. I am hoping that some substitute metal will ultimately be developed that will last... they just haven't found one yet.

Mark

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Louis Bornwasser
Film God

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


 - posted 09-05-2007 12:38 PM      Profile for Louis Bornwasser   Author's Homepage   Email Louis Bornwasser   Send New Private Message       Edit/Delete Post 
Most major suppliers have stopped making cam timers. Louis

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 09-06-2007 09:10 AM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Indeed there are a couple of options available that are mpu based to repace cam timers in existing units but that still doesn't solve the relay aspect of the problem.

Mark

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 09-06-2007 12:24 PM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
Isn't there a resistor (or cap) value that one can put across each micro to reduce the current rush so the contacts inside the micro can last longer?

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 09-06-2007 06:12 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Monte... Its called a snubber.... usually made up of a 10 ohm 1/2 watt carbon film resistor and a .1uf 1200 volt cap in series.

Mark

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Marc Hansen
Film Handler

Posts: 93
From: Seattle, WA, USA
Registered: Dec 2000


 - posted 09-15-2007 06:14 PM      Profile for Marc Hansen   Email Marc Hansen   Send New Private Message       Edit/Delete Post 
quote: Mark Gulbrandsen
Indeed there are a couple of options available that are mpu based to repace cam timers in existing units but that still doesn't solve the relay aspect of the problem.

Mark

How expensive are they and where are they availible?

Marc

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 09-15-2007 08:43 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Any Honeywell switch distributer should stock em. You definately need to get an exact relacement so the nylon conector hooks on correctly!! We get em in at least 100 quantity.

Mark

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