Film-Tech Forum ARCHIVE: A question on dimmers.

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Posted by Andrew Thomas (Member # 7000) on 01-01-2014, 10:41 PM:

So we have our theater up and running and mostly things are going well. We have Jnior automation set up on our 4 Christie series 2 projectors, but the old place has never had dimmers. I'm trying to find what would be the best solution for dimming 6-12 lights in our auditoriums? I suppose we will be using dim-able LEDs...or should we go a different direction?

If there is more information you need before making a recommendation, let me know. Thanks guys!

Posted by Frank Cox (Member # 6258) on 01-01-2014, 11:14 PM:

I have a Kelmar dimmer, and just use standard-issue floodlight bulbs in the fixtures in the auditorium. I suppose that I will someday change them out for something led or whatever, but what's there now is working fine for the time being.

Posted by Dave Macaulay (Member # 813) on 01-02-2014, 04:28 PM:

I recommend the Kelmar dimmers, not cheap but maybe cheaper than finding and figuring out an alternative. They will work with your existing lamps, and Kelmar dimmers should work with most LED replacement bulbs. They also offer an LED output module that is supposed to handle those lamps that don't play nice with the basic dimmer.
There are other dimmers available but the Kelmar ones are made for cinema use and automating them from a Jnior is simple. Finding a dimmer with relay closure control isn't easy, and the network control dimmer I am trying to set up is not user friendly at all.

Posted by Gordon McLeod (Member # 33) on 01-02-2014, 06:15 PM:

I have been told that the CREE brand of dimmable LED lamps from home depot work on any solid state dimmer and have about 98% dimming range
I have yet to play with them
The issue most dimmers have is two fold one the dimmer may not have the minimum load that the thyristor(s) require to aquately and stabily fire
two the ballast in the socket of the LED module is often a switch mode device that can not work well with the chopped wave form most dimmers produce

Posted by Andrew Thomas (Member # 7000) on 01-07-2014, 03:43 PM:

Thank you gentlemen. Any recommendations for vendors?

Posted by Gordon McLeod (Member # 33) on 01-07-2014, 04:24 PM:

The Ash Stevenson are a good reliable dimmer

Posted by Dave Macaulay (Member # 813) on 01-11-2014, 01:23 PM:

The Ash Stevenson is a fine basic dimmer, but try to get any response from the company. I suppose they're still in business - but it doesn't appear that they want to be much longer.
The Kelmar dimmers are good, and work fine with many LED lamps. Plus, Kelmar even answers their phone and replies to emails!!!
Kelmar's major problem for me is that the dimmers are not (and won't be, according to Kelmar) CSA ur ULC approved and thus require special inspection to use legally here in Canada. This adds up to $100.00 to the price of a dimmer.

Posted by Andrew Thomas (Member # 7000) on 01-11-2014, 04:08 PM:

Yeah, I was really impressed by how quickly Kelmar got back to me. Brad's a dealer, so I'll be shooting him an e-mail in the next couple of days about ordering them.

Thank you for the help, everybody!

Posted by Louis Bornwasser (Member # 3063) on 01-12-2014, 04:32 PM:

I have about 30 Kelmar 2400 watt simple up/down dimmers, used. Utility model. email me. louis