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I’m adding a low voltage dimmer lighting track system and have the option of electronic or magnetic dimming. The electronic is quite a bit more expensive, but the sales people tell me that it’s “quiter”. The system is a Tech Lighting Monorail system at 300w of output. There are more option for the magnetic dimmers and only one electronic.
Any advice/experience with these to options? What conditions cause line noise on a magnetic system if indeed that’s an issue? Thanks!
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Did I say Dimmers? Sorry, I meant transformers! Thanks.
*I've got a magnetic transformer for my low voltage lamps, and I've never heard it. Of course, it's mounted in a metal box under the sink in the kitchen. Could this be akin to audiophiles believing that tube amplifiers have a "warmer" sound? Or that one can hear the difference between zip wire and Monster Cable?
*120v to 24v transformer? Go listen to your doorbell transformer. If it is to loud for you then diffenitly get the electronic:)
*Glanced at tech lighting web site out of curiosity. Some of the cheap magnetic dimmers use a shunt magnetic path like "buzz box" welders and are noisy. Your supplier has straight transformers, but uses a series inductor for dimming - the "compatible dimming coil" A well made 300 W transformer or dimming coil would be nearly inaudible or similar to a 300 W fluorescent ballast at worst. A poorly made transformer can "buzz" like heck if the laminations are not well bonded or there are loose coils or loose armature in the "dimming coil" - either case invites early failure of the transformer or coil. Wife used to sell the BIG GE transformers for substations - some so big she had to arrange shipping thru the panama canal, no chance to fit on a train. Go stand near a 1 MW transformer and you'll know why they are called "big hummers". Even a well made large transformer with no loose coils or laminations will hum (loudly) due to magnetostriction of the silicon iron magnetic core.A 300 W transformer is a lot less than 1MW, but can still hum similar to a fluorescent light ballast, mostly because they have loose laminations, not simply magnetostriction. Doorbell transformers Class II and are 20 W or less, so are usually inaudible to a normal person. Another noise source could be from the "dimming coil" armature being moved by the magnetic field and "buzzing" against its' restraint. No idea what tech lighting charges for a transformer, etc. A 300 W surplus 24 V (or 12V) xfmr is typically <$5, Grainger new price (300W) to mount in standard elec box like doorbell xfmr is <$100. For cheapest approach, you can use a regular 120V incandescent dimmer on the 120 V side of a regular 300W+ transformer, forget about the "dimming coil". A caveat - if the transformer is poorly made with loose laminations, the switching waveform (no longer a nice sine wave) from the thyristor in the dimmer will cause a poor transformer to make lots of noise), the "dimming coil" maintains the sine wave. Caveat #2, if laminations are thicker than 12 mils (really cheap made), the harmonic currents could cause higher core losses and heating of the core. Don't try an incandescent dimmer with fluorescent lights, the ballast is not a transformer and the situation is totally different.
*Hey ArtIs there away to get one of those old huge GE dimmers off your wife.Theres a celluar phone tower over the road Id like to dim and Im running out of 30/30 shells!
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I'm adding a low voltage dimmer lighting track system and have the option of electronic or magnetic dimming. The electronic is quite a bit more expensive, but the sales people tell me that it's "quiter". The system is a Tech Lighting Monorail system at 300w of output. There are more option for the magnetic dimmers and only one electronic.
Any advice/experience with these to options? What conditions cause line noise on a magnetic system if indeed that's an issue? Thanks!