Found good home for my Pro Series 3 LS/LD bulb

Charles Bradshaw

Flashlight Enthusiast
Joined
Sep 14, 2002
Messages
2,495
Location
Mansfield, OH
Some time ago, I bought a 2 cell Pro Series 3 low dome PR base bulb for 2 cells (3 volt). I got it for my 2D Mag. It turned our to be dim with a pea green corona (from side emission) in that light. It also flickered every time the Mag bulb stem (mount) moved. Dimming and brightening. It drove me nuts, since there was no sure way to get it to be bright and focused at the same time. So I put it back in its case and put it with my other bulbs.

Recently, I came across an old Radio Shack metal mini that I got my dad. This light is sort of like a minimag, except that it has a different style head, and uses a PR-4, K4, or KPR104 PR base bulb, and 2 AA batteries.

I thought to myself: I wonder if the PS3 that I have would work well in here, using a pair of Lithium AAs??? I just tried it and left it on for a while (to test for overheating). I get a nice bright, smooth focused beam (smooth reflector), and most importantly, I no longer get the pea green corona.

I tried it in my PT Solo with both reflectors and didn't get the focus I hoped for, though maybe the new HD version LEDcorp has will do well there.

Well, at least that $40 bulb will no linger go to waste, sitting in my incandescant flashlight bulb box.
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Note: the Radio Shack Metal Mini had 2 versions. The original version could be used as a candle, while the final version could not. This is the original version.

So, if you have the same situation I had, and have one of these metal minis sitting around, put the 2 cell PS3 in it and feed it a pair of lithium AAs.
 

Larry1582

Enlightened
Joined
Aug 10, 2002
Messages
302
What suggestion would you have for the yukkie 3 cell ProSeries bulb that I have?
 

Charles Bradshaw

Flashlight Enthusiast
Joined
Sep 14, 2002
Messages
2,495
Location
Mansfield, OH
Larry, the only thing I can think of, is it must have a different reflector than the Mags have. What I got with mine in the 2D Mag was a yellowish centerspot, with a hint of green, and a pea green corona. That corona is the result of the shape of the Mag's reflector. All C and D size Mags use the same reflector.

The reflector in the RS Metal Mini, is a cone shape. The resulting beam, while not white, is a greenish yellow color, but not the yucky pea green. Partly this is due to the 3.66 volts (before load) driving the LS emitter.

You will need to be careful of heat buildup in the brass heatsink of the bulb, so that the reflector/bulb housing doesn't melt.

I hope someone reads this topic and has a good suggestion for you.
 

monanza

Flashlight Enthusiast
Joined
Nov 1, 2002
Messages
1,311
Location
Santa Clara, Ca
If your bulb looks yukkie green then over-driving it will improve color and intensity. Without knowing a bit more about what light you are using your PS3 in and what type of LS you got in it I can think of a few suggestions.

First if you are using it in a 3 C cell light then try it in a 3D cell light. The internal resistance of a D cell is typically lower than a C cell so it should drive the PS3 with a higher current.

Second if you have tried it in a 3 D light then try using 4 C cells instead. The current may be a bit high for continuous use but it should be OK for a few seconds while you test the output intensity and color. Once you have confirmed that the output is improved you can try adding different resistors somewhere between 1 and 3 ohms. Start with a high value resistor and reduce the resistance until you reach the sweet spot for your particular lamp. *edit* On second thought and just to be on the safe side don't run it without the external resistor because I do not know what kind of resistor they have in your PS3. I was assuming something on the order of 1.5 ohms which may or may not be correct.

A third suggestion: If you are using a 3D cell light you can use an AA adapter to run it with 6 or 9 AA cells in a 4.5 Volt parallel-serial configuration. This should reduce the effective internal resistance of the batteries and raise the current that drives the LS.

The PS3 I got was a beautiful white High Dome LS and quite bright in my 3D Mag.

Cheers.
 

The_LED_Museum

*Retired*
Joined
Aug 12, 2000
Messages
19,414
Location
Federal Way WA. USA
I had 2-cell and 3-cell lamps and somehow accidentally switched them - the 2-cell bulb is history now. No funky blue pissed off color or anything... it simply went dark after a few seconds in a 3-D Maglite.
Now I know what $40 whirling down a commode looks like.
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I have heard that early units had a fuse in the base that had to be changed by LEDCORP when the lamps were overloaded like this, but I've heard this has been omitted in more recent versions of this lamp.
 
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