I am planning to get a 12V halogen track lightning thingy like this. (Actually I want to get a bunch of 'em.) It comes with a transformer in the fixture to hook up to the 120V house line. Will it work with a regular dimmer switch, or will that blow up my house?
It should work, if you connect the standard dimmer BEFORE the 12 V transformer. Depending on the transformer’s specifications, you might find that the useful range of the dimmer is compressed towards the upper end of the knob’s travel, but no physical damage should result, AFAIK.
>> Will it work with a regular dimmer switch, or will that blow up my house?
It may or may not blow up the house. Standard dimmers are not designed for anything else that resistive loads and any inductive or capacitive loads can damage them or they may just not work correctly. Better ask at the store and make sure before you buy anything.
The transformers used in low voltage lighting are not designed to used with dimmer switches. Once the voltage falls below about 90 vac, the transformer itself will quit working. You need to place your dimmer between your power source and the lights themselves. The LVL I installed came with a built in dimmer switch which is useful if the transformer is accessible after installation. The instructions that came with my lighting show how to hook up an optional dimmer switch (not included), this would involve running a 2 pair wire from the transformer to your light switch location. You will still require a standard light switch too.
While many ‘standard dimmers’ are not designed for inductive loads, there are indeed newer dimmers that are. Ask in the store, and look around. At least over here it’s possible to find dimmers which also work with transformers.
From the various opinions expressed above it is obviouse that different hardware has different requirements.
Get the information desired from the hardware manufacturer/supplier and be sure that they will stand behind their reccommendations.
In most cases transformers, and/or fluorescents will NOT work with dimmer switches.
If you want to dim the track lights why not use incandesents in the first place and the dimmer switch will work without problems within its load capacity.
Thanks for the suggestions, folks. I will ask around about getting a proper dimmer to work with the transformer. If that fails, I’ll get a regular incandescent fixture instead.
You’d be better off with incandescent anyway. We put 120V 20W halogen fixtures under all the counters in our kitchen, and only then discovered that there are 20 halogen bulbs to replace, at $5 each.
And the nitwit electrician who put them in didn’t wear gloves or use a clean cloth to handle them, so they started going out after only about 6 months of occasional use.
Nitpickily speaking, halogen lights are incandescent.
Something else to remember about halogen bulbs : Their longevity relies on the fact that they are operating at high temperature (i.e. high brightness). If they’re dimmed, the halogen gas won’t re-deposit the evaporated filament, so they’ll only last as long as a regular light bulb. However, it’s likely that ocasional use at full brightness may make up for a period of dimming.
Here are some dimmers designed to work with low-voltage systems. Note that it’s also possible to get a low-voltage transformer that works with a ‘regular’ dimmer; this may be called an ‘electronic transformer’ (as opposed to a magnetic one).
BTW, it is noyt a good idea to use dimmers with halogens. halogens are designed to work with the bulb at extremely high temperature and running them normally at lower temperature will shorten their lives as the metal does not return to the filament as it should at higher temperature.