Ratso
Enlightened
Hi - I need a better understanding about bulbs, and volts / amps / watts. I hear that volts x amps = watts. I assume the higher the watts the brighter the light. Therefore to achieve the higher watt output, the higher the volts and amps the better. (however something isn't right about that, otherwise I would be using 4cell bulbs would burn brighter in my 2cell lights) So what am I missing.
Volts is voltage supplied, not the voltage rating of the bulb. So a bulb rated at 4.8 v would run most efficiently at 4.8 - ~6 volts. 2 cells only supply 2.4v not enough to drive the bulb.
Also I believe that the brightest bulbs are in the folowing order: Halogen, Xenon, Krypton, standard. Are there others? I've seen Zenon as well is this the same as Xenon just a different spelling?
The most common incandecant in high perfromance flashlights is Xenon-halogen. Basically a halogen bulb with a bit of Xenon gas added. Xenon bulbs are just a bit brighter than Halogen but typically don't last as long. Then comes krypton which is a good choice for cheap lights. I believe they last longer than xenon. And vacuum bulbs (practically extinct now), should never be used, because they give less than half the light for the same power and they darken and put out less light over time.
Zenon is Lumilite's trade name for Xenon-Halogen. (nothing special)
So if it's a flashlight that uses 4aa, 4c, 4d, or a 6v lantern battery, whatever combination to come up with 6volts, why don't you use a bulb thats rated at 6v? A KPR113 which is a common 6v lantern battery is rated at 4.8v / 0.75a. So are we basically overdriving this bulb already?
The bulb is overdriven, but within a safety margin. Alkaline batteries drop to about 1.2 volts after a bit of use. The voltage alkalines supply keeps dropping as they run down. So after maybe 15-20 minutes of use the bulb is no longer overdriven. It is not driven hard enough to drastically affect bulb life.
I've found that I can successfully overdrive a KPR103 (3.6v 0.75a) in a 6volt light. The 6v light calls for a KPR113 (4.8v 0.75a) the difference between the two bulbs is is 1.2amps.
Now why can't I overdrive a KPR102 (2.4v 0.70a) in a 3-cell light calling for a KPR103 (3.6v 0.75a)? The difference in volts is still only 1.2 volts, and there is only 0.05amp difference. Does the 0.05 amps really make a differnce? I would find that strange because I've run 6v lights on KPR802 (4.8v 0.5a) bulbs. The amps are much lower in this bulb.
The difference of overdriving a 3-cell bulb in a 4-cell application is dramatic, I would like to find a bulb combination to do the same in my two and 3 cell lights. Any suggestions? Or any suggestions for the best bulbs of 2 and 3 cell lights?
I actually overdrive PR bulb by a bulb rated 1 less cell myself. 4AA lights use KPR103 3.6v 0.75a. This cuts bulb life to less than half but PR bulbs are cheap so I can afford to do this. Any flashlight of mine that uses PR bulbs I overdrive by using a bulb rated for 1 less cell. Except for 2 cell lights, which I use an HPX21 Xenon 2.4v 0.8a. because I can't find any 1 cell PR bulbs.
Here are some suggestions:
2 cell: HPX21
3 cell: KPR 102, HPX21 or HPX20
4 cell: KPR 103, or HPX30
5 cell: KPR 113, or HPX41
They are all overdriven by about 1.5 volts, and you should not leave the light on for a long time or the reflector/lens may melt.
The amps does make a difference. I never use anything less than .7 in most stituations unless I am trying to power a light for a long time. I find that anything under .7 the bulb burns very yellow. The more amps is the shorter you can power the bulb, unlike volts which is the more cells there are the higher the volts.
A quick question about batts: alky aa, c, d batts are supposed to all put out 1.5 volts (give or take a bit). Do they all put out the same amps?
Amps is not put out, amps is the actualy juice which is drawn by the bulb. Batteries supply a certain # of amps per hour. If a bulb draws .75a, a 750mAh (milliAmps per Hour) battery can power it for one hour in theory. The capacity (mAh) of battery goes up with size: AAAA, AAA, AA, C, D, Lantern (4 F batteries in series). Thats why the bigger the battery the longer it lasts. However, the voltage of Alkalines drops as more amps are drawn, so a half used Alkaline battery probably supplies less than 1.2v.
Volts is voltage supplied, not the voltage rating of the bulb. So a bulb rated at 4.8 v would run most efficiently at 4.8 - ~6 volts. 2 cells only supply 2.4v not enough to drive the bulb.
Also I believe that the brightest bulbs are in the folowing order: Halogen, Xenon, Krypton, standard. Are there others? I've seen Zenon as well is this the same as Xenon just a different spelling?
The most common incandecant in high perfromance flashlights is Xenon-halogen. Basically a halogen bulb with a bit of Xenon gas added. Xenon bulbs are just a bit brighter than Halogen but typically don't last as long. Then comes krypton which is a good choice for cheap lights. I believe they last longer than xenon. And vacuum bulbs (practically extinct now), should never be used, because they give less than half the light for the same power and they darken and put out less light over time.
Zenon is Lumilite's trade name for Xenon-Halogen. (nothing special)
So if it's a flashlight that uses 4aa, 4c, 4d, or a 6v lantern battery, whatever combination to come up with 6volts, why don't you use a bulb thats rated at 6v? A KPR113 which is a common 6v lantern battery is rated at 4.8v / 0.75a. So are we basically overdriving this bulb already?
The bulb is overdriven, but within a safety margin. Alkaline batteries drop to about 1.2 volts after a bit of use. The voltage alkalines supply keeps dropping as they run down. So after maybe 15-20 minutes of use the bulb is no longer overdriven. It is not driven hard enough to drastically affect bulb life.
I've found that I can successfully overdrive a KPR103 (3.6v 0.75a) in a 6volt light. The 6v light calls for a KPR113 (4.8v 0.75a) the difference between the two bulbs is is 1.2amps.
Now why can't I overdrive a KPR102 (2.4v 0.70a) in a 3-cell light calling for a KPR103 (3.6v 0.75a)? The difference in volts is still only 1.2 volts, and there is only 0.05amp difference. Does the 0.05 amps really make a differnce? I would find that strange because I've run 6v lights on KPR802 (4.8v 0.5a) bulbs. The amps are much lower in this bulb.
The difference of overdriving a 3-cell bulb in a 4-cell application is dramatic, I would like to find a bulb combination to do the same in my two and 3 cell lights. Any suggestions? Or any suggestions for the best bulbs of 2 and 3 cell lights?
I actually overdrive PR bulb by a bulb rated 1 less cell myself. 4AA lights use KPR103 3.6v 0.75a. This cuts bulb life to less than half but PR bulbs are cheap so I can afford to do this. Any flashlight of mine that uses PR bulbs I overdrive by using a bulb rated for 1 less cell. Except for 2 cell lights, which I use an HPX21 Xenon 2.4v 0.8a. because I can't find any 1 cell PR bulbs.
Here are some suggestions:
2 cell: HPX21
3 cell: KPR 102, HPX21 or HPX20
4 cell: KPR 103, or HPX30
5 cell: KPR 113, or HPX41
They are all overdriven by about 1.5 volts, and you should not leave the light on for a long time or the reflector/lens may melt.
The amps does make a difference. I never use anything less than .7 in most stituations unless I am trying to power a light for a long time. I find that anything under .7 the bulb burns very yellow. The more amps is the shorter you can power the bulb, unlike volts which is the more cells there are the higher the volts.
A quick question about batts: alky aa, c, d batts are supposed to all put out 1.5 volts (give or take a bit). Do they all put out the same amps?
Amps is not put out, amps is the actualy juice which is drawn by the bulb. Batteries supply a certain # of amps per hour. If a bulb draws .75a, a 750mAh (milliAmps per Hour) battery can power it for one hour in theory. The capacity (mAh) of battery goes up with size: AAAA, AAA, AA, C, D, Lantern (4 F batteries in series). Thats why the bigger the battery the longer it lasts. However, the voltage of Alkalines drops as more amps are drawn, so a half used Alkaline battery probably supplies less than 1.2v.
