This is topic Slide Projectors on Christie Automation 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=002120
Posted by Tal Marks (Member # 175) on 04-07-2001, 12:30 AM:
Hi.
We are having problems with some of our slide projectors turning on in the middle of the feature. The projectors are connected to the "Auto Option 1" switch on the Christie console. We thought the had the problem licked by replacing bad relays on the automation board, but eventually, they started coming on regardless of a good or bad relay. It's unpredictable as to when they'll come on (either 5 minutes into the trailers or and hour into the feature). It's a real hassle turning them on & off in between intermissions.
I was hoping anyone might have some suggestions or experience with this situation. Four out of our 12 projectors now have this problem.Thanks
Tal.
Posted by Michael Cunningham (Member # 210) on 04-07-2001, 07:27 AM:
There is a highly practical solution, but it requires the services of an electrician. The way mine are set up is to have the power outlet for the slide projector wired into the projector motor. When power flows into the motor, when you press 'START', power is killed to this particular outlet. Never mess with a slide projector again. Of course, these abrupt shut-offs could lead to shortened slide projector bulb life. It's kind of a trade-off.-Mike
Posted by John Walsh (Member # 168) on 04-07-2001, 08:37 AM:
I think you will have to get a copy of the electrical schematic and trace the problem down (or have someone who knows a bit about electronics do it.)It seems a bit strange that four of the automations would do this.... did anyone work on them recently? Did all four start having this problem at the same time?
I don't think simply cutting the power to the slide projector will affect the bulb life. Abruptly powering on sometimes does, which is why they made resistors for light bulbs (they are coin shaped disks that you put into a light socket) to limit the initial current flow.
Posted by Steve Guttag (Member # 268) on 04-07-2001, 08:59 AM:
Are you tying the power of your slide projectors directly to the automation? This automation looks like it was made by Kelmar and is the equivalent of the Series 5 or Series 7. The relays for powering that option are not up to the current load of a slide projector...Normally it is wise to buffer the system with a proper relay.I haven't studied the diagram for this auto in a while but Kelmar normally uses a set of three relays for the hold on this one...there is the Exciter, Failsafe and C/O close. The C/O close is often the culprit since it has high current contacts but is only holding a very low current relay. The resistance in the contacts can be enough to allow the exciter lamp relay and the others to drop out mid show.
Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by Darryl Spicer (Member # 711) on 04-07-2001, 11:02 AM:
If you do have the slide projectors set up using the projector motor as the souce to kill the power. You have to remember that if you have the habbit of turning the motor on and off when threading. This will lead to shortened life of the slide projector bulb. You must learn to forget this habbit and thread machine so it is at the point you want to start the show.
Posted by Steve Guttag (Member # 268) on 04-07-2001, 06:00 PM:
Better yet, find the problem and fix the automaton and, if necessary, buffer the slide projector. Connecting the slide projector relay to the motor circuit is a bit of an extreme reaction and a sloppy solution, in my opinion.Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by Sean McKinnon (Member # 612) on 04-08-2001, 09:14 PM:
I worked at a theatre that had the slide projectors connected with the "Motor" switch and I did not like it. I think it makes the presentation look sloppy, why? you ask 
Because most Automation systems start the motor and lamp but have around a 7 second delay before they open the dowser. This causes a gap where there is nothing on the screen.------------------
--Sean McKinnon
Asst. Manager/Projectionist
Gloucester Cinema 1-2-3