6 volt light on a 12 volt system?

[rja]

I have always been told that the stupid question is the one not asked. Thus said, here goes...
I have a 6 volt tractor light which was left over from my Ford 8N. I need a rear light on the Kubota L3000. The 6 volt light fits nicely and there is a hot wire already directly underneath it (nice design Kubota!). My question is: will this light just burn brighter and then die or will it be ok? Is there any resister? that I could put on it to lower the charge? Will this hurt the tractor's electrical system? I really hate to junk the old light and spend more $$ on a new one. Please don't laugh too hard and thanks for you input. Rich.

 

[TWINKLE_TOES]

rja,

It will work but only for a few seconds. Check the bulb Part number and I can help with a 12volt replacement be it a sealed beam or replaceable bulb. As far as adding a series dropping resistor, yes this will work but it's power dissipation will be the same as the bulb and require a good sized one with a heat sink or it will get way to hot to touch. For example, say your 6 volt light is 50 watts, then the equivalent resistance will be R=V squared/Power = 36/50=0.72 ohms. A 50 watt light on a 6 volt system will draw, Power/Voltage= 50 watts/6 volts = 8.33 Amps.

If the same light is connected to a 12 volt source with a series 0.72 ohm resistor the 8.33 amps flowing thru a 0.72 ohm resistor will drop (8.33 amps x 0.72 ohms) = 6 volts. The dissipation in the resistor is equal to 50 watts just like the light.

 

[Thomas]

TWINKLE_TOES,
You hit the nail right on the head w/ your answer.
Must have been some<font color=red> Farmall<font color=red><font color=black> education. /w3tcompact/icons/wink.gif

Thomas..NH /w3tcompact/icons/wink.gif

 

[gordon]

You have a much better description than I ever could have posted!! I was going to post a poooofffff./w3tcompact/icons/smile.gif
Nice post Twinkle-toes
Gordon

 

[TWINKLE_TOES]

Thomas,
<font color=blue>Must have been some <font color=red>Farmall</font color=red> education</font color=blue>

If you were a lady Thomas we would have to call you "Clara Voyant"/w3tcompact/icons/wink.gif

 

[TWINKLE_TOES]

Thanks Gordon,

But, I like your answer<font color=blue> poooofffff </font color=blue>. Much more descriptive.

 

[Anonymous Poster]

Twinkel, the light is a Grote sae-fony-91 6493 with a 4.5in dia. bulb marked wagner 6.2v 4511-1 30w d3. (the d3 is a quess due to poor stamping.) Any cross references you might have would be appreicated. Thanks Rich.

 

[Thomas]

/w3tcompact/icons/laugh.gif/w3tcompact/icons/smile.gif/w3tcompact/icons/wink.gif

Thomas..NH /w3tcompact/icons/wink.gif

 

[TWINKLE_TOES]

rja,

Your light is a PAR 36 General Electric P/N 4511, 6.2 volt, 30 watt, 4 1/2 in Dia. 2.75 in deep. 2300 candle power, trapezoidal beam, with screw terminals, 300 hr rated life.

Try this PAR 36 General Electric P/N 4411, 12.8 volt, 35 watt, 4 1/2 in Dia. 2.75 in deep. 3000 candle power, trapezoidal beam, with screw terminals, 300 hr rated life.

The P/N 4411-1 is the same light with slip on terminals.

Other P/N's that will work if they don't get your enclosure to hot:

4460X-1 40 watt(6500 candle power, 33 deg horizontal, 9 deg vertical)
H4460X 40 watt hallide (8500 candle power, 22 deg horizontal, 13 deg vertical)
H7610 50 watt hallide (5200 candle power, trapazoidal beam)

These part number are pretty standard or can be cross referenced to Sylvania/Osram.

If you plan on this as a work light I would stick with the trapezoidal beam.

 

[paccorti]

Wow Twinkle Toes you're like some lighting... guru!

Here is a question for you. I just installed two 50 watt forward facing (Blazer brand rectangular) trapazoid tractor lights. They use a 15 amp fuse. The main tractor lights (on my New Holland TC35D) also use a 15 amp fuse. The main front lights are VERY bright. I'd like to get equivelent brightness from the new tractor lights. I've heard about HID (Hight Intensity Discharge) bulbs. I guess they are those really bright almost blueish lights that you see on some euro sedans. Do you know if those (or something else very bright but still using 15 amp for both) are available for H3 bulbs? Would it be a good idea to use them in the Balzer light?

Peter