Century's "Magic Box"

[Jim Cassedy]

Today's Tech Trivia:
I recently acquired several folders of advertising sheets for CENTURY PROJECTOR
products, mostly from the mid-to-late 60's to early 70's. Most of the products I've either
seen and actually worked with (like their then-new transistorized sound systems with
plug-in modules, or their "cine-focus" blower device to cool the film gate, etc) - -

And then there was this thing! I've never seen one, and I can find little other technical
info about it. It was obviously designed to work with reel-to-reel systems which were
still more prevalent than platters in 1968, which is the date on this ad sheet. I'd be
curious to know if anyone here knows anything more about this device or has seen one.

CenturyBoxAd_0.jpg

[Leo Enticknap]

Forgive me for sounding over cynical, but it seems somewhat over-hyped to me. If I read the ad correctly, all it does is to kill the motor and lamp after each reel runs out or if the film breaks. If so, then the only labor it saves is that of the projectionist walking over to the other projector after a changeover, closing the dowser, and pushing the off button: something that takes all of fifteen seconds!

[Brad Miller]

I would have to say the obvious reason for this is so when a takeup belt breaks, the print doesn't get mangled to crap. The shutting off of the projector motor and arc lamp is merely a convenience.

This makes me wonder when the traditional "failsafe" with a basic microswitch was introduced to the industry to perform this task.

[Leo Enticknap]

The blurb says that it detects "the slightest speed-up of the take-up spindle." If the belt broke, the spindle wouldn't speed up: it would stop dead. Unless that description is incorrect and the thing actually kills the projector motor and lamp on any sudden, large change in the speed of the take-up spindle, up or down, I can't see that it would be any help if the belt broke. If it only detects a big, sudden increase in the take-up spindle's RPM, then the only failure mode it would protect against is the film breaking. As you point out, there is a much easier way to do that, in the form of a lever that rests on the surface of the film passing under it, that falls when no film is present, opening a switch in the process. These were standard equipment when I started as a projectionist in the '80s, and had been for some time. Presumably this Century device is a forerunner to those.

[Jim Cassedy]

Yes, my first thought when reading this ad was that a simple, gravity operated, fail-safe switch
would do the same thing, with far less complexity. 'Automations' as we know them today
weren't quite in wide use in 1968, but a fail-safe switch and a simple relay/contactor wired to
the projector motor and either the change-over dowser or the (carbon) arc power supply would
seem to have been an easier, and probably cheaper, solution.

I do sometimes wish I had a fail-safe switch here to kill the motor on the out-going projector
after doing a change-over. I like to double-check threading, focus, framing, etc on the incoming
reel right after doing a change-over, and I don't like the end of the film reel slapping around on
the take-up on the other machine until I can get over and switch it off. (especially with 70mm)
Many of the told booths I worked when I started in this biz had dual projector controls at each
machine, so you could start or stop either one from whereever you were at. Fortunately, most
of the 70mm prints now come with a crapload of extra leader at the head & tail to protect the
print, and that extra tail leader usually gives me just enough time to check the reel I just started
before needing to get over and turn the other machine off before it the film runs out.

[Ryan Gallagher]

I think the selling point was the no film contact aspect. I can’t see it detecting any breaks until the film passes the lowest drive sprocket, same as most fail-safe installs?

surely not for belt breaks, cause now you got two belts that can fail. lol. “Solid State” was not as big advantage to mechanical as they made it out to be in the “space age”.