Film-Tech Forum ARCHIVE: Harry Potter and the Projector on Fire

This is topic Harry Potter and the Projector on Fire in forum Ground Level at Film-Tech Forum ARCHIVE.

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Posted by Ron Keillor (Member # 1790) on 11-19-2005, 01:52 AM:

Dunbar Vancouver midnite show of Harry Potter* was interrupted at /about 0230 when there was a projector malfunction and the film was seen to burn on screen. This was fortunately after the climax of the film, but full refunds were issued. There had been local TV coverage for the screening,so it made this evening's news. The only inside captures of the event were on cellphones.

Posted by Matt Fields (Member # 3211) on 11-19-2005, 07:59 AM:

Brainwrap

Posted by Steve Scott (Member # 630) on 11-19-2005, 01:42 PM:

Same thing reportedly happened at the nearby Apple Valley Carmike during the midnight screening of EP3. 500-some passes issued. We did a 9 screen interlock at Lakeville with no problems [thumbsup]

Posted by Phil Blake (Member # 2012) on 11-27-2005, 03:40 AM:

We often experience the odd "film Burn" situation here.

Our local power supply is very "up an down" and when the slightest power fluctuation happens the projector motors stop but the dowser and zippers remain open and the lamp continues to burn . The panalogic seems to not detect that the motors stop and everything gets smokey until we manually shut them down.

Posted by Steve Guttag (Member # 268) on 11-27-2005, 08:24 AM:

The Panalogic and other automations with DC power are not going to "see" power fluctuations the way AC automations are due to the filtration in the power supply. It will take longer for it to die down.

The motors on your projectors...are they "pulse" or "latched". If latched, I would be surprised that the motor is dropping out since the automation has control over that...if it is latched, then yes, the automtion would not be aware of the problem.

There are many ways to attack the problem...including setting up a self latching relay on the automations such that if power dies...the automations lose power until it is reset.

However, I think other alterntatives exist....you could use the lamphouse sense line with a relay across the projector motor to interrupt the lamphouse signal such that if the motor is not running, the automation sees a lamphouse fault and shuts the show down. Even if you are not using the lamphouse sensor, you could use the relay on that A/D converter input for a motor sense.

If you have pulsed motor logic, like Kinoton, then convert to latched is another potentially easy solution (for Kinoton, no new parts or wiring are needed).

Posted by Louis Bornwasser (Member # 3063) on 11-27-2005, 10:06 AM:

I am surprised that the automation in use does not have a speed sensor to eliminate this kind of thing. It is required equipment on many non-US installations, such as all of the old Cinemation units. Louis

Posted by Pete Naples (Member # 761) on 11-30-2005, 06:48 AM:

Indeed, in parts of the UK, where ACOP regulations are in force, the equipment must shut down if the projector runs under speed.

Posted by Phil Blake (Member # 2012) on 12-11-2005, 02:29 AM:

Iam not certain how the motors are connected , but they can be started by switch on consol or by "motor on" softkey on the panalogic. , projectors have film sensors which will not allow the automationto start the projector if it has no film , so i imagine the automation has some control over the motrs , just nothing to "see" if the motors stop running.
I am wondering if all these brushless motors stop straight away when the main voltage drops suddenly.

and yes we do have lamp sensors in the xenons.

Posted by Mark Gulbrandsen (Member # 72) on 12-15-2005, 05:03 PM:

Speed sensors aside it would also be very easy to incorporate a power line sensor to shut the c/o and projector down. Similar to how a UPS senses the incomming power.

Mark