Bumpyroad wrote:
I was under the impression that the OP wanted to use a standard 120 volt fixture for 12 volt operation. could easily just change out bulbs to 12 volt ones, screw base, and hook B&W wires to 12 volt supply. no code involved I wouldn't think. If he absolutely needs a dual 12/120 operation, it could be completely rewired with additional sockets, etc. and do that. but the wiring would have to all be kept completely separate.
bumpy
My impression of the OPs first post came from the following sentence..
"It needs to be able to work on both 12 and 110."This makes it appear like they are wanting a fixture with BOTH 120V bulb AND 12V bulb.
While this "could" be done it probably "should not" be done since it isn't easy to keep both types of wiring separate in the same fixture without making some sort of "divider"
Now if this isn't the intention of the OPs post that is my mistake and basically a 120V fixture can be "converted" to 12V (which would be powered by your 120V to 12V "converter") by removing the 120V Edison style screw in bulb socket and installing a suitable socket for the 12V bulb of your choice.
I would however skip the 12V incandescent bulb that has the same Edison screw in as a 120V bulb. Causes confusion, much more expensive than automotive 12V bulbs, LARGE, not much choice in wattage (typically 50W) and color temperature.
Another issue you will find with most 120V fixtures, they tend to be, well, extremely large size. Typically 120V home fixtures must be large to accommodate the large edison style bulbs AND the high temperatures given off by these bulbs. Often times these fixtures will look out of place in a RV but thats just my taste.
I have used low voltage 12V under cabinet "puck" lights in my camper, while they do work you have to relamp them from the stock bulb which is for 11.5V to a slightly higher 12.5V bulb in order to not overheat the fixture.
Another suggestion though is retrofitting a 120V fixture with 12V LED lights although I am not a fan of them (I have had too many of these fail).