This is topic Failsafe Compatibility in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Robb Johnston (Member # 239) on 03-20-2001, 09:41 AM:
I oversee projection at 3 theatres with different equipment. I was wondering, would a Strong FP-350 Failsafe be compatible with an old ORC VA-301 automation. One of my ORC set-ups has a failsafe that no one knows the origen of, let alone where to get parts for it. IT only reads the end cues when it feels like it, and it is not a relay problem. The GM. of the theatre would prefer that I use available spares before purchasing a new piece. But I am not sure it is 100% compatible.
Robb Johnston
Movidude74@aol.com
Posted by Darryl Spicer (Member # 711) on 03-20-2001, 10:02 AM:
Would you be able to take a picture of the old failsafe in question and post it here. Someone may recagnize it and be able to tell you the make and brand so you can order paerts for it.
Posted by Paul G. Thompson (Member # 655) on 03-20-2001, 12:00 PM:
Robb, they can be made to work.
Posted by Scott Norwood (Member # 30) on 03-20-2001, 01:31 PM:
Just out of curiousity -- why _wouldn't_ a failsafe be compatable with a particular piece of automation equipment? I'm only familiar with the Kelmar failsafes, which simply open and close switches based upon the position of the "feeler" arms/rollers. Are there different types of failsafes that do something substantially different than this?
Posted by Sean McKinnon (Member # 612) on 03-20-2001, 02:13 PM:
Some failsafes use Infrared light to search to detect the film presence but, as far as i know you can make any failsafe work with any automation------------------
I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary
Posted by Paul G. Thompson (Member # 655) on 03-20-2001, 04:11 PM:
Scott and Sean - You are both correct. They can be made compatible. However, if you are using the infra-red one, dont use the power supply rail from the ORC automation. That voltage can be up to 30 volts, and it could shorten the life of the IR units. A little DC Radio Smack power supply will work just fine for the voltage recommended by the fail-safe manufacturer. Any mechanical fail safe you want to use with the ORC VA-(whatever) is very easy to configure and make it work. But before you do that, check the automation schematic for any "Gotchas".... 
Posted by Pat Moore (Member # 380) on 03-20-2001, 07:22 PM:
Robb;
As we discussed, the only question I would have is to power the FP350 failsafe, as it needs 12VDC to operate. The cue and failsafe circuits are dry relay contacts. I'm out of the country and don't have a ready answer to what the low voltage used by the old ORC automation is -- it's either 12 or 24V. Anyone know for sure?Pat
Posted by Paul G. Thompson (Member # 655) on 03-20-2001, 07:36 PM:
Pat, it is supposed to be 24 volts, but I have seen it much higher than that. I could be wrong, but the ORC 24 volt rail is not regulated.
Posted by Gordon McLeod (Member # 33) on 03-20-2001, 08:38 PM:
Get a radioshack calculator 12vdc powersupply to power the failsafe
It is dry contact so the rest will interface
One other option is the sensafe that Ernamann is selling
Posted by Sean McKinnon (Member # 612) on 03-21-2001, 01:54 AM:
Does anyone know if it is possible to make the "motion" detect function of the FM-35 failsafe work with non component engineering automations? Obviously if you hook it up in series it wont start because theres no motion. If anyone knows how I would like to know------------------
I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary
Posted by Bill Purdy (Member # 202) on 03-21-2001, 10:54 AM:
Responding to your query about the FM-35's motion sensor, there is no single answer. Clever people have adapated this function to a lot of automations. In the later days of ORC one of their engineers did a special software version to incorporate this feature. Others have found sneaky ways of using information circuits to trip relays which would then put it in the safety loop. Some automations don't even look at the "break" switch until after the initial seven second period. Study all the ins and outs you have available and see if there isn't something you can cheat into adding this feature after the film is running.On the subject of operating voltage levels: the FM-35 will operate on any DC voltage from 12 to 30. However, it needs to be reasonably clean DC. If it sags below 10 volts between each half-cycle the on-board regulator will not be happy.
At the other end, and these comments apply to any system, you need to be a bit careful with these voltage numbers. Particularly with older systems which didn't use the readily available regulators we have today, a manufacturer might tell you that he has a 24 volt system but when you really get into it you find that his 24 volts is unfiltered. This is OK for simple relay devices but not so good for other things. In other cases it turns out that their transformer is actually putting out 28 volts and then they do have a filter capacitor. When those 28 RMS volts are rectified and fed into a capacitor the peak voltage can easily reach around 40. volts.
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Bill Purdy
Component Engineering
Posted by Pete Naples (Member # 761) on 03-21-2001, 03:54 PM:
I've used the close on fault terminals of the FM35 film motion across a few automations remote stop in put, ok U get no alarm, but it makes this valuable function usable in situations as mentioned above. Christie (is it AM4??) springs to mind as this is the unit I was most recently hooking up FM35's to.
Posted by Steve Guttag (Member # 268) on 03-21-2001, 05:48 PM:
For the motion sensing thing...if you have switched over to LED based sound readers, you can use the exciter circuit in most automations to switch the funtion in and out. Thus the motion will not be activated until after the picture is on the screen and will turn off when the show is over. I would have some sort of bypass switch for the motion sensing though...it is the most sensitive to various film stocks and can false trip.Steve
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"Old projectionists never die, they just changeover!"