Hi,
Here's a description of how to use the 108" automatic screen offered by Lumenlab- without the use of a step-up transformer.

Disclaimer/Warning:
I was asked by Kellie to post this- and I am by no means an expert on the subject of automatic screens, electronics, or the general non-burning down of houses. Anything described here is done at your own risk, and while if done correctly- is safe- I can not, nor can lumenlab, account for your ability to do basic wiring.
This involves mains-level AC. It has the potential to be lethal. Bad wiring also has the potential to burn down the house. If you do not feel comfortable handling this- do not attempt the mod/project described here.

Background:
Ok, now that that is all out of the way.... I was sitting over at my friend Scott's apartment the other week, and over the course of some drinks we cracked open a broken 108" automatic screen to do some troubleshooting.

A riddle inside of a mystery wrapped in a fortune cookie:
First off, the "remote" is next to useless, I suggest putting it away in a box. There were a couple hours of staring at the electronics within the remote, trying to figure out what exactly was going on. And, the short answer is "not much". As far as I can gather, it does nothing but ensure that the wrong voltage is powering the motor. To call it 'over-engineering' is besides the point, the thing is can be replaced by a simple switch.

The Motor:
The motor, for those who have not cracked it open, runs natively at 110v AC. This happens to be the same as north american house mains-voltage. In other words, you do not need a step-up transformer for it to operate. There is some interesting wiring going on inside the motor, what would normally be the safety-ground (the round pin on the standard 3 conductor connection) is connected to one of the motor "hot" connections, both "grounds", that is, the outs on the motor are connected to the neutral (the smaller of the two flat conductors), and the other hot is connected to "line".

Theory:
How this operates is that 110v AC is switched to one of the two inputs on the motor, this determines the direction of motor spin. Once the motor winds far enough in that direction- a switch is flipped inside of the housing that disconnects power from the corresponding input. All of this prevents the screen from over-winding.

Bypass:
First, you need a fairly beefy soldering iron. Second you need a single-pole double-throw switch with center "off". This switch needs to have the minimum rating of 110VAC 2 Amps. You will need a multimeter to check your work. You'll also have to devise a way of housing this switch (and I would advise against metal housing for the sake of simplicity and safety), the more industrious of you could surely devise a way to wire a wall-switch to an outlet- but since I'm not certain about the implications of this and your local electrical/building code- I'll leave that in your hands. You'll also need a way of connecting a standard IEC power cord between the motor and your switch- either by splicing this box in the middle of a cord, or by including an IEC inlet, and IEC outlet.

Here it is... wire the center terminal of your switch to the hot conductor of your inlet or cable splice. Wire the outlet so that the neutral will bypass the switch altogether, and is connected with the neutral wire on the inlet. Now, wire the ground on the outlet to one of the two remaining terminals and the hot wire on the outlet to the other. What is happening here is that the switch is selecting which input on the motor receives power. Pretty simple. A variation of this arrangement can be done with a DPDT switch, which may be better- as there is a varistor within the motor assembly which presumably functions as some sort of over-voltage protection which would require the electrical connection of all conductors in order to work. But I really do not believe that it is necessary. Also, the motor has no safety ground. This is fine- as safety grounds are included almost exclusively as a way to prevent electrocution in the event of a lightning strike- as well as to help protect against a massive shorting between mains power and a metallic case. If you are so unlucky as to be touching the enclosure for the screen- when it is hit by lightning, then you'll still be protected since the neutral side of mains power is always grounded eventually. If you are using a metal case for your switch enclosure, you should wire the safety-ground on the inlet side to the metal of the case. But this is not required for non-metallic cases (since there is little to no chance of a short), and can simply be left floating. I specified the use of a switch with "center-off" as another safety issue. It isn't absolutely needed, but I figure that it's best to be on the safe side.


Ok, Sorry if this was overly confusing, it's one of those things which is incredibly simple to visualize- if you already know what's happening.. I'll come back here for the next while to answer questions that you may have. And if there's sufficient demand- maybe a diagram or two. Also, I purposely left out instructions on how to do soldering/wiring. If that isn't something you've already had a bit of experience with, again, you shouldn't take this on.

Robin

Can you do a simple diagram of what you mean? I think I understand, but... Or maybe a photo if you have one?

Hello Lothar,
Here's a simple wiring diagram. The next time I have a unit in front of me I'll take some pictures.
To elucidate what otherwise may seem cryptic: L= line, G= ground, N= neutral. SPDT= single pole double throw switch.

Robin

If anyone has any snapshots of their work, or finished product I would like to see it please

You don't need any of that.

The unit will operate off of 110v US current.
Look at the end of the plug, you'll see one prong marked N=neutral the other is marked L=Line.
Cut the plug off and replace it with a male cord end.
The wire going to the part of the old plug that was marked "L" goes to the brass colored screw. The wire going to the part of the old plug that was marked "N" goes to the silver screw.

Phil

Thank you very much, this is most helpful.

Big thanks to Rturner!
I open the switch box and it is really simple ! I finally cut the ground (E) pin, and redressed the two others (L and N).
I pluged it in the wall and the red light lights up, and the relay button are working !
I did not tried it with the screen yet, but I will send you a picture of my "new" plug tonight and will test the screen also!

Now, I only hope the screen was working before I cut the plug, because I think I just screwed up the waranty !!

Martin L.

EDIT :
It works perfectly
pretty easy to do:



I would suggest to test it with wires first before cuting and bending pins !

Martin,

Are the plug modifications shown in the picture the only changes that you made, or did you have to change wiring inside the controller module (In the middle of the power cord) or inside the motor housing compartment of the screen?

~Archilea

No change at all !!
I did tested it and it works perfectly !
So just cut the pin, and redress the 2 others and you'll be fine !
I did open everuthing to be sure this would work before I cut a pin ... and everything looks OK so I cut the pin !!

Seriously .. this is very simple and for the price Lumenlab is selling the screen right now, THAT s a deal

Don't be shy, look at the plug, cut the ground pin and redress the 2 other pins!
Hehe .. I didn't thought it would be that simple

Martin L.

I am sorry for the pictures not available now ... my computer is down !
PM me your e-mail and will send you the pictures !

Thanks - That worked great!

If you want me to host them, I can do it, otherwise I think that you can jut resize them down to 110K or less and upload them to the forum...

I ordered one of these screens and received it a few days ago. What I got doesn't seem to match what everyone's talking about, though.

For one, I didn't get a remote. No cable, either. Just a standard male plug like you'd find on the power supply on the back of a computer. Plugging a power cable into it causes the screen to come down, but then there's no way to get it to go up. I pulled the cover off the area housing the motor, and found that by fiddling with the two switches inside, I could get the screen to go back up...

So I decided to rewire. Only problem is, the motor seems to be malfunctioning. It seems the motor will randomly switch directions. The motor's got 4 wires: two yellow, one red and one green. My understanding of this is: attach both yellow to the neutral on the plug, and then connect the hot wire to either the red or the green, depending on which direction you want the motor to spin. Well, in my case, attaching it to, say, the red wire, will cause the motor to spin, but if you disconnect power, and reconnect a few times, the motor will suddenly spin the other direction -- all with the red wire. Does it for both wires actually.

There was also a 250V capacitor wired into the original circuit. I was too stupid to take pictures of how they had the thing wired originally, but the motor had the problem of randomly switching directions the first time I plugged it in (screen came down a few inches, then started going back up. pulling on the bottom of the screen would cause it to switch directions again, and go all the way down -- so long as I kept pulling the screen).

Is my motor malfunctioning, or am I just stupid and connecting this thing wrong?

I figured out the wiring for the motor. The two yellow wires are connected to neutral, and the green and red are connected to each other via the capacitor. Connect the hot wire to one end of the capacitor, and the motor goes one way, touch it to the other, it goes the other way. Pretty dang sure this is NOT how it was wired when I got it, because the ground wire was connected into the circuit somehow.

Now I just need to re-wire the DPDT switches (the ones that stop the screen when it's all the way up/down) to a 12V SPDT relay to get the projector signal wire controlling it...

I'll post some images when I'm done

Boy, I hope someone still reads these.

Here's the thing, I bought one of these automatic screens a couple of years ago but never got around to setting it up (you know how it goes...).
Like some of you, mine came without any wires or controllers whatsoever, but thanks to your comments on this forum I was able to wire up a SPDT switch, center normally off to control the screen and I finally got the thing up there.

However...the screen will not roll up all the way. It is like the little sensor switches are off because I can certainly roll it down farther than I'd prefer it, but it will only roll up to about of foot of complete concealment. I can hear the little switches doing their thing, and they are consistent, but apparently they're not properly calibrated.

Anyone have this problem? Know any solutions?
Any help would be greatly appreciated.
Thanks.