Brightest, Best Focused Bulb for PLASTIC Host?

[milkyspit]

I'm in the process of rehabilitating a couple favorite 6V lanterns and want to install the BRIGHTEST and TIGHTEST-FOCUSING bulbs possible, but there's a catch: since the lanterns themselves are constructed entirely of plastic (including plastic lens and reflector), I don't want to use something that will end up melting the reflector and/or lens! :shakehead

By BRIGHTEST, I mean exactly as the word suggests, namely highest lumens.

By TIGHTEST-FOCUSING, I'm envisioning that a shorter filament will focus more tightly than a longer filament could. Does that make sense, or am I mistaken?

I'll install whatever battery configuration makes sense for the bulb. Since I'm running 6V lantern, there's plenty of room inside.

Hard to say what the lens and reflector are made of... but if I were to guess the they seem like perhaps polycarbonate.

Question to you guys, to help this information-challenged modder: what would my best choice of bulb be given the above criteria, for the brightest and most tightly-focusing bulb that ought to be safe for use with a plastic lens and reflector?

:help:

 

[mdocod]

Hi Scott,

Been too busy with LEDs eh?

In my experience with PR base flashlight bulbs, you go up in voltage and brightness, and you loose focus. The lowliest 2 cell bulbs always generate the most extreme focus with pathetic output, while 6D mag xenon bulbs really are no bums in the output department but don't focus as tight. However, in a lantern size host I'm sure just about anything will generate great throw characteristics. General rule of thumb for mags with plastic reflectors is ~10W limit for bulb to keep the plastic solid state.


You might consider a low semi-wattage PAR style pre-focused reflectored lamp assembly, (often called "sealed beam type"). You'll have to take some measurements to figure on which size might fit with some modification, but this is likely to be the way to bring one more to life than any other method possible, since the unit replaces the lens and reflector all in one quick drop-in, you gain the ability to run higher wattage, only limited by what heat makes it's way through that assembly into the housing of the lantern.

-Eric

 

[DM51]

As a general rule:

low voltage = shorter filament
low current = finer gauge filament wire
​

This pic below illustrates that to some extent. The WA 1111 is a lower-voltage (6V) bulb than the WA 1185 (9V), so its filament is shorter. They draw approximately the same current (3.3A) so the filament wire is about the same gauge.

The Philips 5761 is another 6V bulb, but it has thicker-gauge filament wire, indicating a higher current draw (5.5A)

The 4th bulb in the photo is an Osram 64250, and you can see the filament length and gauge is very similar to the WA 1111, indicating a similar specification and performance, which is the case.

None of these bulbs would be suitable for a plastic reflector, BTW - too powerful, so too much heat.

 

[garilla]

I have stumbled across posts like this before and have heard of a bulb called the GH24 made by an english company called Reflectalite they are about $5 a bulb plus shipping. I haven't tried them buy everyone who has raves. I found this post on CPF http://www.candlepowerforums.com/vb/showthread.php?t=64369
The bulbs are supposed to be tough too.

 

[lctorana]

I recommend the Philips HPR71, as used in 6V Dolphin Rechageable lanterns. Results in Lux Luthor's testing thread.

Very likely identical to the Reflectalite GH24.

Both can be overdriven with 6 D cells.

A third option is the Pelican 3854L (the "RoP low" bulb) which is a smidgin dimmer and draws a bit more power, but has two advantages over the other two:
1) it tolerates more overdrive than the other two, so you could go to 7 cells, or even 8 if you use an NTC
2) it might have that tighter focus you are looking for. Not sure about this, it might well be the other way around.

I created what I called "The Roar of the Dolphin" whereby I did exactly this - used a 3854L in a Dolphin, with 8 cells and an NTC in the 509 battery shell. I was able to literally light up clouds with the beam from this torch.

I later moved on to the Halos (q.v.) which at an overdriven 15W, represents the limit of what I would try with a plastic reflector.

But for daily use, the bog-standard Dolphin Rechargeable with HPR71 and 6V SLA is hard to beat and sees most use.


But here's the kicker:

• a cheap, $20 SLA-and H3-bulb "500,000CP" lantern leaves any of these mods for dead, straight off the shelf.
• if you want pencil-beam throw, an equally cheap sealed-beam lantern (e.g. the Energizer 9101IND) will outthrow anything you can put in a reflector by a factor of three or more.

Hope this is helpful.

 

[LuxLuthor]

This is a hard question to answer....mainly because I always swap out plastic parts for metal reflector and glass lens. Limiting samples to those that do not generate significant heat...or at least not at the level to damage plastic was not something I considered. I guess you can look at the temps I logged with overdrive testing, but I didn't make absolutely sure that my Fluke 179 Temp probe was in exactly the same position relative to the filament...but it is a place to start.

 

[Juggernaut]

The first thing I thought when I saw your "Snap-On Heavy Lantern" with that crazy reflector and I shined it out the door is had like a 2x2 degree beam, I flipped it around and noticed you didn't have a Philips HPX 53 bulb "also know as the 34-93201 bulb. This bulb really throws and I was trying to image how much this light would throw with one of those in it:naughty:. It's meant for 6 volt SLA battery lights and pulls about .97 amps and can be over driven with as much as 9 volts from 6 D cells "I've tried" which makes an extremely bright bulb that could rival the ROP low bulb easily. The tightest focusable bulb I have ever seen is the Philips HPR 62 bulb, it's 4.8 volts and rated at only 2.4 watts but it's filament is like that of a pin head! Honestly it is no more then 0.5mm wide x 0.01mm thick! In my 4D Maglite it throws very, very far considering how dull it is. The one thing you have to remember is that these lanterns are un focusable so even if your filament is very small "such as the extreme case of the HRP 62" it might not be the proper height to align it right:mecry:. As for as Par bulbs are concerned, yes these throw very well, bulbs like the 4546 throw further then any bulb for their wattage I know of, through the filaments quality in them can vary widely. I once bought a 4546 and it was so un focused it was use less, while my friend's 70's big Jim lantern has the tightest beam of any bulb I have ever seen, latter during the night at PF12 I pulled out his lantern and walked up and faced the black hole, when I turned the light on it seemed to just make it to the other side and that's with only 2.4 watts!. Though I don't have any other 4546 bulbs that throw as far, his must just have been a fluke:shrug:. The Energizer 9101IND uses the H7550 bulb "from what I can remember:thinking:" which definitely throws very far with a small hot spot, a good deal more then 4546s and such, I had one as PF12 but you weren't outside when I was using it.