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

 

[Keoke]

You can wire two 6volt bulbs in SERIES and hook these up to your 12volt circuit. This will require that you isolate the ground on the first lamp if it is single wired and grounded to the lamp shell. Wire from shell to input of second lamp must be added. Fiber or plastic washers could be used to isolate first lamp ground side. However, all of this is more trouble then it's worth. Finding 12volt equivilent bulb should be no problem at any auto store with a change over catalog. This would be the better way to go. Futhermore, when bulbs are wired in series, when one goes they all go.

Lots of luck
george

 

[TWINKLE_TOES]

Peter,
<font color=blue>Wow Twinkle Toes you're like some lighting... guru!</font color=blue>
Not really Peter, I am one of the dimmer bulbs in the socket, but I have some good books and happy to help where I can.

You probably have noticed my lack of my particapation in the real tractor stuff, hydraulics, attachments, diesel engines etc.

If you want some practical light stuff on High Intensity Discharge lighting look here http://www.misty.com/people/don/d2.html#l

The HID lights require a ballast and don't beat the lower voltage Halgon lights by much when you consider the losses in the ballast.

You can get a significant advantage over incandescent by switching to the Halogen light.

On a 15 amp circuit you can go up to about 150 watts safely.
This will draw about 12 Amps normal. Two 75 watt lights are about as much as you want. The wire size on my Kubota in the work light circuit is about #16 at best probably closer to #18

My reference books are at work and I will check Monday and see if I can answer your replacement question.

 

[rja]

Thanks to all. I took the advice to replace the bulb. It cost around $8 and was done in under 10min. Works great. Rich.

 

[DaveNH]

Twinkle Toes,

Don't sell yourself short here. Your particapation is extremely valuable. No one can be expected to be an expert in all fields. Having a diverse group, with expertise in all areas is what makes this the best group around. Wether the expertise comes from book learning or pratical field experience doesn't matter as long as the problem is resolved.

 

[TWINKLE_TOES]

Peter,

Geee's, Monday already where was Sunday /w3tcompact/icons/frown.gif

H3 is an ECE, European Motor Vehicle Standard designation. The equivalent American manufacturers designations are:

General Electric 50340
Osram 641521
Philips12336

Your bulb is a Halogen cycle 55 Watt, design voltage 13.2 Volt, 115 Candle Power, with a PK22S base, rated life 225 hours

For a sanity check, look at the lamp and see if it has pigtail wire leads from the base of the bulb. The bulb, tip to base should be about 1 5/8 inches tall .

The only higher power option that I can find is:

G.E. P/N 52130, Halogen cycle 100 Watt, design voltage 13.2 Volts, 187 Candle power, with a PK22S base, rated life 100 hours.

Two 100 Watt bulbs on a 15 Amp breaker are too much, and I wouldn't trade a 225 hour life for a 100 hour life.

Is it possible that the lights you are comparing are headlights to flood lights? Even low power headlights will appear to provide more light output then a high power flood. The candle power numbers above are Average spherical values.

If so what is the bulb p/n for the headlight, maybe I can find a lower wattage that will make them look the same /w3tcompact/icons/smile.gif/w3tcompact/icons/smile.gif/w3tcompact/icons/smile.gif

Hope this helps, it kind of seems that you are "Right sized" now.