P60 and P61
- Thread starter Chris201W
- Start date
a99raptors
Enlightened
Educated guess -
The filament causes a lot more resistance. With a lot more resistance, you get a filament that runs hotter because of "wasted" energy in overcoming that resistance. When the filament gets hotter, it lets out more light.
If memory serves me, there are several ways to change the resistance value. Among them, changing the diameter of the filament, using a different material, etc etc.
Problem with more resistance is that more energy is used up, accounting for the limited runtime.
For a more detailed explanation, I yield the floor to Dr. Peter Hauk :)
The filament causes a lot more resistance. With a lot more resistance, you get a filament that runs hotter because of "wasted" energy in overcoming that resistance. When the filament gets hotter, it lets out more light.
If memory serves me, there are several ways to change the resistance value. Among them, changing the diameter of the filament, using a different material, etc etc.
Problem with more resistance is that more energy is used up, accounting for the limited runtime.
For a more detailed explanation, I yield the floor to Dr. Peter Hauk :)
tommymeboy
Newly Enlightened
- Joined
- Jan 29, 2006
- Messages
- 27
I noticed that the P61 I just bought was frosted at the tip,whereas the P60 is not- perhaps that increases the spot size-?
Flash_Gordon
Flashlight Enthusiast
The filament resistance of the P61 is lower. If you have both, and a decent meter, you can measure this. Also, with a good magnifier, you can observe that the P60 filament is much longer. Since the reisistance of a lamp filament is much higher than typical copper wire, this length does make a large difference.
Since the battery voltage is constant, the lower resistance will cause a higher current flow. More emitted light but also much shorter runtime.
The frosting on the envelope tip has to do with beam quality and not output.
Mark
Since the battery voltage is constant, the lower resistance will cause a higher current flow. More emitted light but also much shorter runtime.
The frosting on the envelope tip has to do with beam quality and not output.
Mark
Yooper
Enlightened
a99raptors said:
Actually that's backwards. V = I•R and P = I•V. More light = more power, and this requires more current. To pull more current at a given voltage, you need a filament with LESS resistance.
In layman's terms, a P61 siimply uses a higher wattage bulb than a P60. Think of a common household 100W incandescent bulb compared to a 60W.
The P60 and P61 bulbs are more complex than simple incandescents, with special gas mixes, etc., but that's the gist.
EDIT: Flash beat me to it. Must have posted while I was carefully typing and editing...
a99raptors
Enlightened
:ohgeez: :awman: :xyxgun:
(That's me shooting myself....)
I stand corrected. Thanks for the clarifications!
Guess I shoulda attended those science classes more often.:ironic:
(That's me shooting myself....)
I stand corrected. Thanks for the clarifications!
Guess I shoulda attended those science classes more often.:ironic:
Tremendo
Enlightened
I put a P61 in one of my G2's, and it got used quite a bit a few nights ago. I'm surprised the batteries are still strong. I was concerned thinking it might drop down very quickly, due to the higher output, but that has not been the case. My P61 beam is bigger and brighter.
