Controlling Non-Dim LEDs

[DLazer]

So I'm ALDing an Opera, and the set designer put in some LED Christmas lights into the set (which, admittedly, look a lot better than my anti-Christmas light self expected). They are non-dim, but we've been able to control them backstage on a spot dimmer (because it dims by resistance), but we really want to put them in the board. We're running an ETC ION. Because of the way normal theatrical dimmers work (to my understanding, rapidly shutting on off rather than by resistance), the LEDs aren't dimmable on the board. They turn on, but no control beyond on off.

Does anyone have any bright ideas on some kind of creative rig to make this possible?

Much thanks.

 

[DLazer]

Also, a friend suggested a sin-wave dimmer pack, but I don't think we can get our hands on one.

 

[MarshallPope]

Give it a shot. We used LED Christmas lights in the stage greenery for the first time for our annual Christmas spectacular, and we were able to make them dim just by adding a string of incandescents offstage per circuit.

 

[DLazer]

Give it a shot. We used LED Christmas lights in the stage greenery for the first time for our annual Christmas spectacular, and we were able to make them dim just by adding a string of incandescents offstage per circuit.

By adding them to the series? Interesting, I'll look into that. Thanks.

 

[65535]

They should be able to dim, you might have to rewire the strands removing the internal diodes and just making them DC put a 250V capacitor in parallel with the strands along with a bridge rectifier and they should dim.

 

[sotalight16]

well you could see if you cant return them and exchange them for ones that do dim. or if you just want them to be static you could plug the resistance dimmer to a circut and use the board to turn off and on. thats it for my ideas but good luck.

 

[gafftapegreenia]

Well, I'm assuming one of these is out of the question: Doug Fleenor Design - DMX 8 Channel Dimmer

I'd try looking for a strings that CAN dim.

Also, I take it you NEED them to dim, and you want more than just on/off control?

 

[mstaylor]

Give it a shot. We used LED Christmas lights in the stage greenery for the first time for our annual Christmas spectacular, and we were able to make them dim just by adding a string of incandescents offstage per circuit.

I think what Marshall is suggesting is the LED string isn't enough of a load and by adding a light backstage it may. I don't know the answer but it's easy to test.
What you don't want to do is hook the resistance dimmer to your electronic dimmers.

 

[WestportLights]

Ah Christmas lights. Now we're in my area of knowledge.

This is a common problem with Christmas lights for those of us that use animated lighting and triac operated dimming boards for holiday displays. Light-O-Rama has 8 and 16 channel dimmer packs (they call them controllers) designed specifically to control Christmas lights. They also sell a DMX converter to make their boards accept DMX commands.

If you already have a dimmer pack/controller, then the below tips can help with the dimming issues:

1. Try reversing the plug, this occasionally helps.

2. Purchase "full-wave" strings that can dim nicely. (personally, I think these look better, and do not flicker as much)

3. Attach a single C6, C7, C9, etc. socket and bulb at the end of the string.

4. Created some terminators/snubbers to install on that particular channel. See link.