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Author Topic: Smart Tri-Level 3K Dimmer Voltage Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 06-24-2010 07:01 PM                     Is there any way to adjust the load voltage other than the trim pots? I have a pair of these on a screen. One controls stage lighting and the other house lighting. On both, the voltage for "full dim" will only go down to 24.5v on one and 27v on the other leaving the bulbs with too much glow that is quite distracting (especially for the stage lighting). There are 4 stage and 10 house bulbs. All bulbs are R40 120watt.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-25-2010 01:37 AM                        Contact Sonic in Iola Kansas. They purchased the Smart dimmer line (along with Kneisley.) Louis  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 06-25-2010 02:02 AM                     Yeah they actually installed them last year with our digital conversion. They couldn't figure it out either. I have the same set up on another screen and don't have this problem. The voltage on those will go down to 17-18v. It still has a glow, but its much less noticable. It has the same number of bulbs and type as well. I seem to remember reading a post on here some time ago where the guy that designed these dimmers made mention of this fact. Maybe he'll chime in.  |  IP: Logged Catalin Balaceanu Film Handler Posts: 36 From: Pascani, Iasi, Romania Registered: Mar 2006 posted 06-25-2010 03:14 AM                        Hey Jeremy, I was in the same situation as you, with this dimmer. Not having an official service provider for Smart devices here in Romania, I just took the problem in my own hands and started fiddling around with it. Look for a green multi-turn trim pot on the board. Apparently, this trimmer, that tweaks the transition time between off and on status of the lights, has something to do with this. Here's what I did: I switched the dimmer to "off" position (ofcourse, the bulbs still had a minor glow) and started to sloooowly rotate the multi-turn pot until the lights were completely off. Just pay attention to the evolution of the glow as you rotate; if the glow will increase, just start rotating the other way. I also noticed that the glow will vary according to the size of the load. The dimmer will behave totally different if it will have a 50W lamp on it, compared to...say 2000W load. Now, this was MY experience with it. If you want to try this out, I don't want to be held responsible if something goes wrong. If you want to wait for Oscar Neundorfer's advice, he's the one who should be asked about this dimmer. Good luck!  |  IP: Logged Oscar Neundorfer Master Film Handler Posts: 275 From: Senoia, GA Registered: May 2000 posted 06-25-2010 04:50 AM                        Jeremy, It has been way too long since I designed this dimmer, so I am going on faded memories here. I believe Catalin is correct. The multi-turm trimpot was there to limit the minimum load voltage to solve problems in some cases where the load would interact with the triggering of the SCR's and cause some flickering or other anomalies. Ususally this problem occured with magnetic low voltage lighting that uses a transformer. The earlier units did not have this trimpot, but it sounds like you have a late model. You cannot hurt anything by adjusting this. It may solve your problem easily. Catalin mentions a green trimpot, but I seem to recall it as being light blue in the units made by SMART. You need a thin flat screwdriver blade to adjust it. Usually a processor alignment tool will work fine. Oscar  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 06-25-2010 05:15 PM                     Thanks for the replies. Are you referencing the R2 trim next to the C2 capacitor?  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 06-25-2010 10:44 PM                     I have forwarded the schematic and test procedure to brad to upload to the site  |  IP: Logged

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