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Author Topic: Questionable Change-over logic Stephen Furley Film God Posts: 3059 From: Coulsdon, Croydon, England Registered: May 2002 posted 02-26-2003 09:06 AM                     Early Kinotons had a sort of crescent-shaped rocker arrangement, near the sound head; flick it one way to start, the other way to stop, and push it in for changeover. Later models had push buttons in a similar position. A pair of new FP-30Ds which I ran last year has five buttons, motor start and stop, inch, changeover and one which closes that machine, without opening the other, but they are on the front of the machine, not the operating side, but behind, and underneath the lens. These machines were positioned very close to the front wall of the box, so they are difficult to get at, my arms aren't long enough to reach them while looking through the viewing port, so I have to bend down low enough to look through the projection port, and then tend to get the light reflected in my eyes. Why they put the controls there, I don't know.  |  IP: Logged Steve Kraus Film God Posts: 4094 From: Chicago, IL, USA Registered: May 2000 posted 02-26-2003 09:06 AM                    Yes, Scott. IMHO the forward / reverse unit left a lot to be desired. (Not that there is ever much call for reverse.) The lower spindles utilized Moviola-like clutches so that two were driven going forward, the other one on reverse and these were problematic. Nothing like having the takeup peter out near the end of 2000' reels. And the 5-Star modified with a mag head is no match for the venerable Century R-8 (former 3-D Mag "dummy" placed under a projector head modified for by-pass) with its full Davis-Loop twin flywheels. The units shown are no longer used for interlock projection the facility having acquired a pair of dubbers. Back to the subject of controls, having them all the way at the back of the console is, to me, very awkward, although there is no reason they can't be paralleled with some on the front wall.  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 12-01-2003 07:09 PM                        [digging up old threads] Frank--what did you end up doing? BTW, I just tried it this weekend and the CP650 stays in mute mode even when the sound changeover is switched from one projector to another. Switching to a different format will un-mute it, however. Not that this matters for your place, but maybe someone else will find it useful.  |  IP: Logged Gary Crawford Expert Film Handler Posts: 200 From: Neptune NJ USA Registered: Nov 2003 posted 12-03-2003 11:16 AM                     I found an unplanned way to install an audio mute. We use foot pedals and toggle switches, just like the old days. One sound toggle switch went bad so I replaced it. I couldn't find a switch anywhere that was a DPDT WITHOUT an "off" in the center position. So I installed the new one with the center off and I realized I had a mute! Click it to the middle. I replaced the other switch as well as I liked the ability to mute from both sides. My X-over pedals will trip if you sneeze on them, they are so sensitive. Others I've had in other houses were so stiff you almost had to jump on them. Once I had the X-over shutter on the #2 (right hand) machine fry and was useless. In the meantime I stood between the machines for all X-overs. I could reach the other motor switch just fine across the front of the machine, then manually, by hand, flipped both X-over shutters, then quickly threw the audio switch. Looked fine onscreen, no one noticed.  |  IP: Logged Frank Angel Film God Posts: 5305 From: Brooklyn NY USA Registered: Dec 1999 posted 12-04-2003 02:07 AM                        Scott, what I actually did was.....procrastinate. So far I've done nothing yet except buy the additional switches and then go to the World 3D Festival on the other coast. Then came back and had to do lots of prep for a special screening of 2001 with guest Keir Dullea. And still haven't dug myself out of the pile of work on my desk. But after taking all the good advice here under advisment, whenever I finally do get around to messing with it, this is the way it is going to play out: 1) The existing CHANGE-OVER switch will remain as-is, a standard momentary pulsing of the change-over shutters (one open, the other close) on both projectors. 2) There will be a second switch (existing momentary) that will be converted from what it is now -- a "reverse change-over" -- to an "KILL ALL" switch. As such, it will close both shutters and mute audio. I still don't know if the CP55 will require nothing more than the momentary pulses from the CHANGE-OVER switches and the KILL ALL switches or if I will have to add a latching relay to hold it open or closed, whatever, it will be very simple. And 3) Because of the good advice from you and Joe B, I am adding a small toggle out of easy access at the bottom of the projector switch panel which will have a TEST and a NORMAL mode; it will also have a green LED indication for the normal mode and an anoying blinking red LED indication when it is in the TEST mode. In the NORMAL mode, the KILL ALL switch will be just that, but in the TEST mode, the KILL ALL switch will revert to its original "reverse change-over" function. As you both pointed out, there are legitimate situations where the ability to switch back and forth between both projectors from one location can be helpful. But those are the exception, so I give the projectionist the ability to purposely change the function when he needs that. Now all I have to do is get my butt in gear and do it.  |  IP: Logged Steve Kraus Film God Posts: 4094 From: Chicago, IL, USA Registered: May 2000 posted 12-04-2003 08:51 PM                    Leaving aside the matter of toggles and blinking LED's, the KILL ALL button is easily implemented. The traditional C/O wiring has two circuits, both with a SPST button wired to open near and close far. To have a kill all button first we need to separate the wiring so that close is not tied permanently to the open of the opposite machine. This is most simply done by replacing the SPST C/O buttons with DPST. Power is still fed to both poles but the open and closes are wired to separate contacts so that they are kept separate. Then the KILL ALL buttons are added to both machines. If it were only necessary to close the C/O's it could be done with DPST buttons (power common to both poles, the output contacts wired separately to each C/O close coil). But a third pole would be needed to do the mute on each so simpler to use SPST buttons (maybe the old C/O buttons) in parallel hooked to the coil of a 3PST relay (probably implemented with a 4PDT but 3PST is all that is used). Two poles wired to power and to the two close coils and the other contact wired to the CP's mute feature. A reverse (or anti as I like to call it) C/O button would be simple to wire as a completely separate thing just a parallel duplication of the C/O button from the opposite machine.  |  IP: Logged

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