Dimmer Flickering on an iPC

You can slow down the DMX output from the iPC by going to the network window, choosing the virtual DP, press "settings" and look at the "DMX" section. Frankly though, the better plack to tweak the DMX settings is at the Pathport output node where it feeds the dimmers.

With that being said, I'm not entirely sure DMX timing changes will solve your problem. How old are the dimmers, and are they natively DMX dimmers, or do they have some kind of converter? What kind of load do they have on the dimmer that is flickering?

A common fix for SCR dimmers flickering at low levels is to add a ghost load of around 25 to 50% of the rated output. So if you have a 20 amp dimmer trying to run a strand of christmas lights, plug a 500 watt fresnel into the same dimmer and hide it somewhere. Dimmers (especially older dimmers) don't like to run very low-current loads.

Thanks for the reply. I am not sure about the dimmers. As far as I know they are less than 2 years old and native DMX, but I will have to confirm that. They might have moved dimmers out of their old space and re-installed them.

They are not sure where the issue is coming from, so I will pass your info on to them. Sounds like it's probably a Pathport or dimmer issue.

A related question. You can slow down the DMX refresh rate, can you increase it past 25/sec or is that the limit? Does the limit very between consoles or DP-8000s/2000s? Thanks again.



Travis

Eric,

Some more follow up info.

Dimmers are Electrol DX Series. They are new. (Less than 2 years old.)
Customer is running 750-watt lamps. The problem shows up across several racks, a couple of channels each. Each rack has it's own 400 amp service. He's going to check the Pathport nodes. Thanks.



Travis Slyter
Ruehling Associates, Inc.

[quote=tbslyter]A related question. You can slow down the DMX refresh rate, can you increase it past 25/sec or is that the limit? Does the limit very between consoles or DP-8000s/2000s?

Yes you can increase it, and yes there are different limits.

The DP-2000 cannot go above 40 or 44 (I forget which)

The DP-8000 can go much higher than this....I have never tried above 60 on DP-8k though....

Not sure how this translates to internal widgets on the XPe based consoles.

Hope this helps:)

I can't imagine a modern dimmer being that sensitive to DMX signal timing. 15 years ago, perhaps, but not now. I wonder if something else is going on here.

Can you describe what they are seeing a bit more clearly? When they set the channel to zero, they get a slight flicker, but when they set it to 1, it stops? Most quarz lamps won't even start to glow until 4 or 5 percent, unless the dimmer (or Pathport system) is using some kind of pre-heat on the channel. Do the lamps ever go fully off? Is the lamp emitting visible light at 0 and 1%? Do they get flicker at 50%, or Full?

One more thought: Make sure the analog inputs are disabled if they are not using them. That could be feeding garbage into the control logic.

The signal timing varies by product type, but staying below 30 is generally the safest.