Lighting fixture - 120vac to 12vdc

[aggie79]

I found a bulkhead light fixture that I would like to use inside the teardrop. It is 120 volt a/c with a "medium base" lamp socket. I'd like to convert it to 12 volt dc.

Can anyone tell me if the 120 vac medium base socket is the same as a 12 vdc medium base socket?

Thanks.

[madjack]

...I have no idea about the base but I will say to be wary, since the conversion from AC to DC means a 10fold increase in amperage and often(not always) the wiring in the 120VAC fixture is not up to the increase in amperage....
madjack

[JIML1943]

Not saying Madjack is wrong,that might be the case in some some fixtures but i took out the 12 volt light fixture above dining the room table in my rv a few years back and installed a 110 volt fixture with a 50 watt 12 volt bulb with a medium base. Now you have two opinions good luck.

[Elumia]

You can find 12V medium base lamps. the base should be the same. Yes, you should consider amperage if you use the same wattage bulb. One should always use the correct size wire for their application. Wires are sized for amperage. If your are connecting multiple fixtures to the same wire, your load increases on the wire. If you don't know what you are doing consult a professionsal.

You may find a couple 25W 12V bulbs provide you with enough light. There are also Compact Fluorescents with medium base in 12V, 5-9Watts. those will draw less on your battery (I assume you are since you want DC)
Look her for some lamp options (never used them just googled):
http://www.topbulb.com/search/results.asp (search:12v medium base)
http://www.solarcfl.com/12vdc_solarlamp_spiral_full.asp

As JimL noted above, he replaced a 120V with a 50W 12V.
50W at 12V = about 4.2 Amps
60W at 120V = .5 Amps

4 Amps isn't a huge draw, but could be a battery killer if left on long enough.

Mark

[aggie79]

Thanks for the information. This is very helpful.

My plans were to use a 15-watt, 12-volt d.c. bulb/lamp instead of the 75-watt, 120-volt a/c bulb/lamp the fixture is rated for. The fixture will be on a dedicated circuit (separately fused) with no other devices.

[BPFox]

I use 50w, medium base, 12 volt trouble light bulbs in standard 120v fixtures all the time. No problems. Keep in mind that while your 120 v lighting circuit will most often contain several lights, in a 12 volt camping application, perhaps one or two. Amp draw is not really a big concern here.

[brian_bp]

The medium screw base will certainly work for 12V, but I can't imagine deliberately creating this setup myself. There's a far greater choice of 12VDC bulbs for automotive bases than for the medium screw base, and little chance of putting the wrong bulb in somewhere (120V bulb in 12V socket doesn't work usefully; 12V bulb in 120V socket goes pop).

I have one 12VDC medium screw base light fixture in my travel trailer (standard equipment in the vent hood over the stove) and it was an expensive pain to find (from a marine supply store) a 12VDC compact fluorescent bulb to get higher efficiency lighting.

[bobhenry]

Why don't you get the best of both worlds in one fixture ?



The addition of an 1157 auto type socket will allow you to slide in a 12 volt light about anywhere.

With a little creative wiring you can have high , medium and low light selection with one 1157 bulb. Tail light for low brake lite for med and both for high. With the addition of an 1157 amber you have a bug light