LED+Incandescent = Excellent color rendition (TwinTask)

Wurkkos

stamat

Newly Enlightened
Joined
Oct 28, 2005
Messages
44
I have always liked the good color rendition of incandescent bulbs, but they tend to become a bit yellow towards the end of (alkaline) battery life.

Today I borrowed a StreamLight twin Task 3AA from a colleague and bridged the switch so that both the LED and xenon would light up at the same time. The color rendition was excellent. The bluish LEDs complemented the incandescent bulb nicely.
http://www.streamlight.com/product/product.aspx?pid=46

What I noticed was that the bulb quickly became way too hot to touch. I am afraid that this would fry the LEDs sooner or later.
Also the runtime would surely drop under two hours.

Advice humbly requested from the knowledgeable members here:

Q1: Is there available on the market a lower power 3.6V/3AA bulb that would fit the Twin Task? I think the Twin Task bulb is physically bigger than the 2AA Maglite bulbs (and is made for different voltage of course). I could never find the power/current rating of the bulb.

Q2: Would the LEDs die from the heat of the bulb between them?

Q3: Has anybody already experimented combining LEDs with incandescents?

Thanks in advance
 

KeyGrip

Flashlight Enthusiast
Joined
Sep 18, 2006
Messages
2,536
Location
Back in Santa Cruz
I can only answer Q3: The SureFire Aviator was the first light to combine an incandescent lamp and LEDs. So far I believe it and the Streamlights are the only ones around.
 

jugg2

Enlightened
Joined
Nov 15, 2007
Messages
949
Location
Georgia
I can only answer Q3: The SureFire Aviator was the first light to combine an incandescent lamp and LEDs. So far I believe it and the Streamlights are the only ones around.

I will ask this since I don't have an A2: Can you operate the incan and the LEDs at the same time?
 

Icebreak

Flashlight Enthusiast
Joined
Aug 14, 2002
Messages
4,998
Location
by the river
Your twin task lamp is 3.6v 0.600a

The strion is 3.7v 1.86A. I've also heard is was 1.66A.

Are you sure that your lamp is bigger than a Mag? It looks small by brightguy's pic. I don't know if the Strion lamp would fit but it would likely make it somewhat less hot. Many of us use this in our SF A2s.

I'm going guess that your modification may be just fine the way it is. It wouldn't be the first time someone did something simple to a light and created an excellent performer. I find your discovery to be terrifically interesting. The fact that you really like the beam is a good sign.
 
Last edited:

stamat

Newly Enlightened
Joined
Oct 28, 2005
Messages
44
Your twin task lamp is 3.6v 0.600a

Are you sure that your lamp is bigger than a Mag? It looks small by brightguy's pic.


Thanks, Icebreak! After reading your post I realized I could actually measure things myself:
Incandescent Bulb: 600mA
LEDs: 165 to 170 mA
Estimated battery voltage of 3 AA batteries: 4V (very approximate)

Bulb total length: 20mm
Pins length: 9mm (approximate)
Bulb diameter: 4mm (approximate)
So you are right - the bulb is not that big (just looked big when it burned my fingers :) ).

As far as the other bulb - it would be more powerful and would produce even more heat. I guess I will just bridge the two stages of the switch and enjoy the results instead of worrying unnecessarily.
 

Icebreak

Flashlight Enthusiast
Joined
Aug 14, 2002
Messages
4,998
Location
by the river
As far as the other bulb - it would be more powerful and would produce even more heat.

In theory it should work the other way around. In a given incandescent host if a lamp rated with a higher Voltage is used it's filament should attain a lower Color Rendition Index and lower surface temp. That's why folks stick 3 cell lamps in 4 cell lights or cram 4 cells into a 3 cell light etc., to get overdrive and heat up that wire.

I guess I will just bridge the two stages of the switch and enjoy the results instead of worrying unnecessarily.

I'm not an LED modder and can't remember the numbers for Vf for 5mms but it looks like you may have a winner there. The SF A2 shows a mixture in the beam at close range but at around 8 feet the LED mixture is almost unnoticeable, if at all. How does your modded 3AA TwinTask look at around 12 feet?
 
Top