8mm Forum: sound sync 16mm projector to external tape

This is topic sound sync 16mm projector to external tape in forum 16mm Forum at 8mm Forum.

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Posted by Doug Arnott (Member # 4049) on January 13, 2014, 03:30 AM:

Hello 16mm people,
Im looking for an affordable way to slave a 16mm projector to sound I record
while shooting. I have 2 Bell & Howell model 1552 filmosound projectors. But of course they are regular optical sound projectors with no way to sync to an outside source. I can shoot with either sync pulse (pedro box signal) or with a pilotone siginal. Im a little lost in the 16mm projector world and was wondering if anyone knows of a model that would slave to either of these 2 signals ? If they even exist out there that is.
Awhile back I read a paper online (that I cant find again now rrrrrrr) where they talked about recording the 60hz pilotone siginal. When played back its about 1 volt. Then amplifying it through an old stereo which should boost it to about 40 volts A.C.. then run that through a 1 to 3 step up transformer giving you a voltage of 120 volts with a frequency that varies to that of the pilotone signal. You should then be able to run a projector with an AC motor in sync with the sound (starting at a slate clipboard
Point of course) its seems to make sense to me, but I'm an electrician not an engineer.
Has anyone ever heard of this method ? Or better yet tried it ?
I would greatly appreciate any thoughts or ideas you guys could give me here.
Thanks !! [Smile]

Posted by Paul Mason (Member # 4015) on January 13, 2014, 04:16 AM:

Hi Doug,
It would be difficult but not impossible to use a pilottone signal to power a 16mm projector due to the power the projector motor requires. You can step up the voltage to 120V but the motor will need 1 or 2 amps current as well so some kind of heavy duty power amplifier would be required to provide this. Much easier would be to use a projector with electronic speed control such as the Bell & Howell TQII and TQIII series (not marketed in the USA). A mod is required to the speed control board to make the speed setting potentiometer accessible. Sync can be achieved by shining the light from one on to the shutter blades of the other and watch for stroboscopic shift when the speed are not matched. Alternatively you need some kind of sync setup such as used in the 1970s possibly with Xenon lamp or oscilloscope, but this beyond my electronics expertise. Good luck anyway.

Posted by Doug Arnott (Member # 4049) on January 13, 2014, 04:57 AM:

Thanks Paul, ill start searching for a B&h tq11 or tq111, anyone know of any other 16mm sync projectors ?

So yeah, hmmm. If I remember ohms law correctly 2 amps at 120 volts is gonna need a 240 watt amp. Thats a big one all right. Thinkin this over.

Posted by Paul Mason (Member # 4015) on January 14, 2014, 03:27 AM:

Doug, I can't help with your other projectors question but I found a Bell & Howell TQ1 instruction booklet (644Q) that quotes 450 watts power consumption. Taking off 250 watts for the lamp, 50 watts for the amplifier and disregarding the 4 watts exciter lamp that leaves 150 watts for the motor.

Posted by Jean-Marc Toussaint (Member # 270) on January 14, 2014, 04:08 AM:

The Bauer P8 can run in sync, Pedro sells an interface.
click here

Posted by Doug Arnott (Member # 4049) on January 15, 2014, 04:39 AM:

Thanks paul,
So150 watts at 120 volts should be roughly 1.25 amps to run the motor,
So 96 watts. A 100 watt amp could do it (maybe) a 125 or 150 should give some safety factor.
Im thinking of trying it with one of those Bass kicker amps. They're cheap enough these days. And mono (which is all I need) and work up to 80 hz , so these should be fine with the 60hz pilotone signal. Just have to be sure im running it with a large enough power supply. (Most of them run at 12volts for automotive use, you know, the ones that rattle your car windows at stop lights from the the thumping rap music ..yucK....LOL)
Then I've got to find the right transformer...my eyes have been going buggy reading the transformer manufacturers web listings and haven't found one yet. Ill track down the right one eventually though.

After reading up on the B&H tqII. I see that its a 220volt 50hz unit. Thats going to
be difficult at best for me to use in the U.S. ....possible but not practicle.
I'd like to figure out a way to use the B&H 1552 projector that I already have 2 of. I think it has an AC motor but I better read up more on that one too. Im hoping I can work out a way here that would work with ANY projector with an AC motor.
Thanks for your input ! And happy filming !!

Posted by Pete Richards (Member # 2203) on May 20, 2014, 11:13 PM:

Yes, the 1552 has a 120V AC motor (not sure if it is actually a universal motor or not though)

See the schematic here, thanks to Paul Ivester.

http://www.paulivester.com/films/projector/bhproshc.pdf

A guy seems to have done what you are describing here:
http://home.provide.net/~djcarlst/19960525.htm

This old article may also be of use.
http://jobs.ascend.com/bstj/vol08-1929/articles/bstj8-1-184.pdf

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