NotBrightNuf
Newly Enlightened
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What is the runtime for this bulb with 5 1/2 d cells at 6v and 3500mAh vs. wa1185 with 9aa 10.8v 2000mAh?
phillips 5761 runtime
- Thread starter NotBrightNuf
- Start date
Fulgeo
Enlightened
Based on LuxLuthor's fine thread
http://www.candlepowerforums.com/vb/showthread.php?t=179748
The 5761 works out to be 42 minutes vs 35.8 minutes for the wa1185. Be aware that the 5761 will be really yellow at 6.0 volts. I am guessing that you will be using Eneloops for the WA1185 build. I have built two 3D WA1185 Mags using FM holders and Eneloops and they rock! The 5761 really starts "waking up" at about 6.6 volts. It has a nice fat beam and good throw with the proper set up. You will need either two A123 cells at 6.6 volts direct drive or a 7.2 volts set up with a NTC Thermister. For the 7.2+ volt set up 6AA or two Emoli work fine.
See this tread for info on NTC Thermisters
http://www.candlepowerforums.com/vb/showthread.php?t=170972
Happy Mods!
NotBrightNuf
Newly Enlightened
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phillips 5761 and accu power d cells
I have looked at SilverFox's post with battery tests and these accu power d cells do really well with high amp draw at about 10000mAh. I wonder what the runtime would be like using 6 of these in a 6d cell maglite powering a 5761 bulb.
I have looked at SilverFox's post with battery tests and these accu power d cells do really well with high amp draw at about 10000mAh. I wonder what the runtime would be like using 6 of these in a 6d cell maglite powering a 5761 bulb.
mdocod
Flashaholic
Re: phillips 5761 and accu power d cells
very likely would flash the bulb without some sort of added resistance like an NTC or something.
runtime can be calculated by taking the estimated realistic capacity of a cell into a load, and dividing the load into that.
Check this out:
http://www.candlepowerforums.com/vb/showthread.php?t=179748
click on the 5761 and you can check out the bulbs behavior.
Assuming you can manage to get some resistance in there to get your voltage to the bulb down around 7.2V on average, then you can expect around 5.5 amps to flow across the bulb.
The chart with the accupower cells at ~5 amps suggests that the cells will deliver ~10.6AH capacity.
10.6AH/5.5A= ~1.93 hours. Or ~115 minutes. On the conservative side I would just expect a solid 90+ minutes depending on how it is used.
very likely would flash the bulb without some sort of added resistance like an NTC or something.
runtime can be calculated by taking the estimated realistic capacity of a cell into a load, and dividing the load into that.
Check this out:
http://www.candlepowerforums.com/vb/showthread.php?t=179748
click on the 5761 and you can check out the bulbs behavior.
Assuming you can manage to get some resistance in there to get your voltage to the bulb down around 7.2V on average, then you can expect around 5.5 amps to flow across the bulb.
The chart with the accupower cells at ~5 amps suggests that the cells will deliver ~10.6AH capacity.
10.6AH/5.5A= ~1.93 hours. Or ~115 minutes. On the conservative side I would just expect a solid 90+ minutes depending on how it is used.
Last edited:
Lumencraft (Matt)
Flashlight Enthusiast
Re: phillips 5761 and accu power d cells
Hi Nbn,
Sound like a good idea to me, just a warning though. When the head starts to get too hot to touch give it a rest or you may damage your reflector. I lost a 30$ FM reflector doing a run time test in my M*g623 that way. I also have to agree with Mdocod you will likely need some type of soft start or similar with this setup. Good luck.
Hi Nbn,
Sound like a good idea to me, just a warning though. When the head starts to get too hot to touch give it a rest or you may damage your reflector. I lost a 30$ FM reflector doing a run time test in my M*g623 that way. I also have to agree with Mdocod you will likely need some type of soft start or similar with this setup. Good luck.
NotBrightNuf
Newly Enlightened
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- May 2, 2009
- Messages
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Re: phillips 5761 and accu power d cells
How would I find the correct thermistor for my bulb? Are all the thermistors the same?
How would I find the correct thermistor for my bulb? Are all the thermistors the same?
DM51
Flashaholic
Re: phillips 5761 and accu power d cells
Your 2 threads were asking much the same thing, so I have merged them.
Your 2 threads were asking much the same thing, so I have merged them.
mdocod
Flashaholic
Re: phillips 5761 and accu power d cells
Check out digikey as a source for these. The "NTC" as commonly referred to here is more often called an inrush current limiter in the industry.
a search there for inrush or ICL will generate some 400+ results to check out...
for a 5761 you'd be looking for something that runs with as little resistance as possible with a maximum current rating right at about 5-6 amps.
Something like model number SL10 2R005 would probably be around the right ballpark, but that would just be my best educated guess based on a quick glance over there. Every bulb and battery configuration will vary in it's needs depending on many factors, especially things like whether or not you have eliminated a lot of the resistance in the host or not. Picking out a few spare bulbs and a few NTCs to play with is never a bad idea when putting together a high performance build.
-Eric
Check out digikey as a source for these. The "NTC" as commonly referred to here is more often called an inrush current limiter in the industry.
a search there for inrush or ICL will generate some 400+ results to check out...
for a 5761 you'd be looking for something that runs with as little resistance as possible with a maximum current rating right at about 5-6 amps.
Something like model number SL10 2R005 would probably be around the right ballpark, but that would just be my best educated guess based on a quick glance over there. Every bulb and battery configuration will vary in it's needs depending on many factors, especially things like whether or not you have eliminated a lot of the resistance in the host or not. Picking out a few spare bulbs and a few NTCs to play with is never a bad idea when putting together a high performance build.
-Eric
