Boy, that looked sweet, but the shipping adds up (as a 550 is heavy) and I can't afford a
second one right now.
After not finding any information on the 550's innards on the net, I started to explore the
situation myself. Remember at this point that I had tried the remote from a 750H only to find
that it focused outward, but not inward, and could advance the slide, but not in reverse
(pressing "reverse" only locked up the tray and made the buzz of a solenoid, to be precise).
I found an unlikely ally in a Supermatic 500 I bought at a thrift store 16 years ago. It was
very cheap. The remote was broken with only part of the board and the cord remaining - but
the projector could still be advanced by pressing a button on the projector itself. I later
made a remote of my own using the cord, wired to a momentary-contact button, and I used (not
kidding) a Polaroid print coater tube as the body of the remote - actually looked nice. I
never knew that the Supermatic was a remote focuser until I read a review for it many years
later.
I noticed that the remote socket on the Supermatic was the same socket found on all Carousels. I
cut the cord from the switch, and found (lucky break) that the cord is five-wire, even
though the Supermatic did not use all of them!
Now, what goes for my 550 may not be how every 550 was wired. My 550 does not have a
boilerplate, and I can't find a CAMEROSITY (date) code on it anywhere. I did find a very
small stamping on the metal wall at the back of the cord/remote storage, "41744" - I don't
know if that's a serial number or merely identifies who made that subassembly. Now, the socket at the rear looks like this from the outside (letters added by me):
---UL------UR---
-----------------
---O--------O---
-----------------
--------O--------
-----------------
-O-------------O-
------------------
-LL------------LR
(pardon all those dashes - spaces won't take)
I noticed that there EVERY hole in the socket has an AC voltage potential relative to the
center hole.
I have seen Carousel remotes for sale (at steep prices) that are marked as "for all Carousels
with remote focus". Clearly, that is not so. Other than center shorted to ur=forward slide
advance, the wiring for my 550 is markedly different than the 750H.
Connecting the cord to my 550 - the connections went to the following colored wires:
-----------------
--BLK------RED--
-----------------
-------YEL-------
-----------------
BRO----------WHI
------------------
(If looking at the pins on the plug, it would be reversed: R K, Y, W N)
Note that my cord came from a Supermatic, not a Carousel, but I suspect they're the same. What
I found was that the yellow (center) is a common (as with later Carousels and the Supermatic),
but both the black and the brown are used for focus.
Yellow to red: 27 VAC when open, shorting cycles the system forward and draws 420mA pure AC
Yellow to White: 27 VAC when open, shorting activtes a solenoid and draws 370mA pure AC.
Yellow to BOTH red and white shorted simultaneously cycles the system in reverse (the
solenoid causes the tray to move clockwise rather than counterclockwise), drawing 790mA AC.
Yellow to Black: meter reads 17.6 VAC AND +9.1 VDC when open, shorting drives focus motor to
rack lens forward (for closer focus).
Yellow to Brown: meter reads 14.3 VAC AND -10.6 VAC when open, shorting drives focus motor to
rack lens back toward slide plane (for more distant focus).
While at first I thought this projector may have had two focus motors, the differing DC
voltages imply that there is one focus motor, but two return wires, each with a diode in
different polarity. Contrast this to the later remote focus Carousels with one diode in the
remote itself, and switches that choose the polarity of current fed via a single wire to the
focus motor. One useful indicator to note is that the plug on the Supermatic remote has a
white dot, while the plug for the 750H and the 4400 have a red dot instead (the plug for the
760H, which does not have remote focus, rather autofocus, has an olive dot). I suspect the
original Carousel 550 remotes have a white dot.
It should be easy to build a remote with five moment-contact switches and a box. The reverse
switch will actually be two switches, physically ganged but with red and white not connected
when the switch is open (if they were, the thing would only run in reverse).
In this search, I also discovered that the remote focus in my Supermatic is decidedly dead,
but the new remote will still work to change slides in it as well as in my 550. The optics in
the Carousel 550 seem to be perfectly identical to the Supermatic 500, only horizontal,
resulting in the change to the type DFW bulb. At sometime, a bulb must have broken inside the
550, as part of the top of a DFW bulb was found inside a panel.
I hope that this post can be useful to anyone else who runs across a Carousel 550 lacking the
remote.
