# Bright/white 18v PR bulb?



## BatteryCharger (Jul 5, 2008)

I just bought a cheap 18v tool set from Harbor Freight, which came with a flashlight. It works surprisingly well for the price. I'm going to upgrade the crappy 1.2ah NiCd cells to 3.8ah NiMH, but the bulb needs some work too.

What is the brightest/whitest bulb I can get with a PR type base? I don't want to bother modifying it further than a bulb change at this point. The light is very bright as is, (6w) but also very yellow.


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## lctorana (Jul 5, 2008)

This is the only 18V PR lamp I've ever heard of:

http://www.lampco.co.uk/results.asp?section=Lamps&capcat=Other&capdetail=P13.5s&volt=16-30V

Because of this, it may well be the one already in your lamp. But it's nice to have spares.


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## mdocod (Jul 5, 2008)

i'm not sure what the exact design is on it, so I can't be certain, but I wonder if a bi-pin to PR adapter might fit in it. Usually they only fit in maglites, but it *might* be worth a try, especially if it has a metal reflector, a 12V 2000 hour bi-pin with G4 base would work pretty well, (20W would be a good starting point  )


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## LumenHound (Jul 5, 2008)

See if you can find a KPR180 locally. It's the 11 watt 18 volt bulb that comes standard in many 18 volt flashlights. This bulb is the stock bulb for the Home Depot's orange house brand (RIDGID) R849 flashlight that comes in one of their cordless tool combo kits.


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## BatteryCharger (Jul 5, 2008)

LumenHound said:


> See if you can find a KPR180 locally. It's the 11 watt 18 volt bulb that comes standard in many 18 volt flashlights. This bulb is the stock bulb for the Home Depot's orange house brand (RIDGID) R849 flashlight that comes in one of their cordless tool combo kits.



Hmmm...that sounds perfect, I'll go check HD. 

Unfortunately it has a plastic reflector, so I can't go too high with the watts. I'll probably put an LED in it eventually...


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## BatteryCharger (Jul 5, 2008)

Well, I found some 18v Dewalt bulbs at Home Depot, that's all they had. Didn't get them because I didn't have enough cash on me, but they say "made in japan", so they must be better than the chinese one I have now.  Couldn't find a wattage for it though....


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## LumenHound (Jul 5, 2008)

Sears should have them in the tool section with a Craftsman label on the pack for less than $2.00 each.


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## BatteryCharger (Jul 6, 2008)

LumenHound said:


> Sears should have them in the tool section with a Craftsman label on the pack for less than $2.00 each.



Unfortunately I hate k-sears with an anger stronger than 10 atom bombs.


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## brighterisbetter (Jul 7, 2008)

LumenHound said:


> See if you can find a KPR180 locally. It's the 11 watt 18 volt bulb that comes standard in many 18 volt flashlights. This bulb is the stock bulb for the Home Depot's orange house brand (RIDGID) R849 flashlight that comes in one of their cordless tool combo kits.


I've actually got the R849 and want to mod it for flood only. It would be really neat to use it for working underneath cars in the garage and not have to turn focus ring to suit each application. I'd be willing to spend up to $75 to convert it to led, say a SSC P4, but not sure what resistor to tie inline. After disassembling the light, i found it's direct drive, basically the 18v battery right to the bulb with a clicky-switch to toggle on-off. Any ideas on how to start this mod? I should mention that I am somewhat savvy with a dremel, but don't have any thermal epoxy. Also, this light does have a metal reflector for those who weren't sure.


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## LumenHound (Jul 7, 2008)

That reflector is what I'd call a medium stipple so altering it isn't going to give you much more flood. Have you considered frosting the envelope of the stock bulb to help in evening out the rings when the head is twisted to full flood? Something else you could try is a frosted lens or even just covering the front of the lens with peel and stick window privacy frost may produce what you're after. If you can't find privacy frost then look for clear peel and stick shelf liner Mac Tac. It's frosted.


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## brighterisbetter (Jul 8, 2008)

as far as i can tell, the reflector is totally smooth. ideally, what i'd like to do is install a u2swoi p4 direct drive off 18v, but from what i understand, i need an inline resistor to drop down the voltage. can anyone confirm this is correct? heat won't be an issue, i don't plan on extended runtimes, just short bursts of no longer than 20 seconds at a time. any additional electronics needed to adapt from 18v to whatever the p4 requires, i think 3.4v?? what resistor would i need? thanks for the advice, and if i'm heading in the complete wrong direction tell me now so i don't screw something up beyond repair.


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## LumenHound (Jul 9, 2008)

brighterisbetter said:


> as far as i can tell, the reflector is totally smooth.


 
Hmm. Interesting. My R849 came with a stippled reflector. Is yours a smooth mirror finish type reflector? That would work great with a seoul P4. Direct driving a single resistored seoul P4 from a 18 volt pack is not the way to go. You would end up burning more than 75% of the pack's power in heat across the physically large 10 watt voltage dropping resitor (roughly 14-15 ohms depending on the individual led if you drive the led at one amp) you would have to use. You could get away with a smaller sized 5 watt resistor for short burst duty cycle use but you likely won't be happy with a limited 20 second burst after the first dozen uses. One, or even two full minutes is way more practical in real world usage. The R849's mostly plastic bulb mount pedastal is not going to wick away tons of heat so you should give some thought to heatsinking. How were you going to mount the led so that it would work with the reflector? What that host flashlight needs is a proper converter board that will take the 18 volts from the pack and efficiently drop it down to a safe level that drives the led at the current level you intend to drive the seoul P4 at while maximizing battery power.


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## brighterisbetter (Jul 10, 2008)

See, this is why I love CPF, everyone is always looking out to help the other guy, providing information that may prevent him from making a big mistake. Thanks for the reply. Yes, it is a metal mirror-finish smooth reflector. I'll take pics tonight and post them here. And after some thought, I agree with you that 20sec. burst are not practical real-world usage, more like 2min. as you suggested. As far as installing a heatsink, which one do you recommend as far as the driver board/module, something available from DX or from someone here in the forums? I gave some thought as to whether I wanted a permanent solution as far as 'no turning back', being that the mod would make it impossible to revert back to the oem incandescent just dropping in. In a previous post, I mentioned that I'm pretty handy with a dremel, so it would be no problem cutting out the plastic bulb housing to fit a heatsink as I don't plan to use the focusing ring once installed. But yes, I think it would be best to snug the P4 up next to the reflector, if that means opening up the reflector hole, so be it. Ideally, I'd like to spend no more than $60 to do this mod. If it exceeds that, I'll just scrap it and figure something else out. What about this driver, would 18v be too much: http://www.dealextreme.com/details.dx/sku.13557
Or this one: http://www.dealextreme.com/details.dx/sku.13553
With this emitter: http://www.dealextreme.com/details.dx/sku.2026
What about the heatsink??
Or with this emitter/star combo: http://www.dealextreme.com/details.dx/sku.1302
Could I use this emitter without a driver or resistor: http://www.dealextreme.com/details.dx/sku.5848
While I'm a huge fan of these forums and flashlight collecting in general, I'm relatively new to the electronic geometry and circuitry of customization, though I'm learning more everyday. Any help would be greatly appreciated. If it makes it easier to respond, please just post what YOU WOULD DO, with part #'s or whatever, and I'll make it happen. Will post pics of when mod is complete. Thanks again.


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## brighterisbetter (Jul 11, 2008)




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## LumenHound (Jul 11, 2008)

I've never tried any of those Max 16 volt input DX converters on an 18 volt pack so I can't endorse any of them. When you get above 16 volts input you start to get into the higher quality converter boards like the ones that *TaskLED* produce. 

I'll snap some close ups of the R849 head on Monday (it's in my toolbox at work) and post them so that anyone considering an upgrade beyond the nice 18 volt KPR180 11 watt bulb for their particular brand of 18 volt shop flashlight can get an idea of the limitations this particular host presents when it comes to converting to LED.


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## brighterisbetter (Jul 11, 2008)

I added pics of the reflector that came in mine, in person it's a totally smooth mirror finish, also a pic of top of battery pack if that helps anyone, and one of the light itself with lens cap off.


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## LumenHound (Jul 14, 2008)

I had a closer look at the reflector and it turns out I thought it was stippled because of the lousy aluminium coating it has. Mine looks as if it was lightly sprayed with aluminum and that's all. It's grainy and dull. It's going to get returned to the store for a proper one.

The good news is that the reflector is 75 mm in diameter so there is ample room after removing it from the head to install 4 of the Kai 18 volt (max) Cree Q5/R2 25.5 mm drop-ins wired in parallel if one wanted plenty of brightness for a few minutes.


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## brighterisbetter (Jul 29, 2008)

http://www.dealextreme.com/details.dx/sku.11836
Well I wanted to try and run just one of these as a trial, then upgrade to 4 modules in total wired in parallel as suggested by LumenHound. So blindly, I connected leads from the Ridgid lamp socket to the contacts on the module, hit the switch, and  Instaflash all the way Should have used a DVM on the battery pack prior to hitting switch, as it read 19.4v after full charge and sitting about 2 wks. Oh well lesson learned.


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