# Philips 5761...Any experience



## wooniris (Jun 7, 2007)

Hi,

Anyone have any experience using the Philips 5761 in a Mag 2C at 7.2 volt?

Will it be brighter than a WA 1111?

Thanks

Chee Hong


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## AW (Jun 7, 2007)

Much brighter than a WA1111.

Output is 765 lumen @6V rated 100 hrs.. Around 900+ lumen @7.2V.


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## wooniris (Jun 7, 2007)

Wow, as bright as a ROP High.


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## AW (Jun 7, 2007)

I would say brighter and whiter. The beam shape is more pleasing too.
24W vs 30W. Of course the 30W bulb will be brighter.


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## lexina (Jun 7, 2007)

It's the brightest 6V (nominal) G4 bi-pin bulb that I can find but at 5A, it draws some serious current. Aw's protected C LiIons works great with it. It's just a little dimmer than a 1185 on 3 LiIons but whiter.


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## nightstalker101 (Jun 7, 2007)

This bulb is great, I have been runing it on 2 of AW's C's and I think it is significantly brighter than the ROP. The Protection on AW's cells work great too. I had the light on a camping trip and the batteries shut off. I had hoped I didn't run them all the way to 3v but when I got home they were still at 3.4. So now I feel much better running the light till the batteries cut out.


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## Northern Lights (Jun 7, 2007)

Yes, my favorite light, I call it my 2CM61 LE. I ran it every night on grave yard shift. It is brighter than the venerable 1185 and brighter than the ROP, it puts out almost 900 torch lumens, 1336 bulb lumens! See Bob_G's post:
http://candlepowerforums.com/vb/showthread.php?t=127925
I use a pr to bi pin adapter made with copper contacts so the resistance is a little lower than other types and this combination will not work with the AW c-cells I have. Presumabley with less resistance my output is brighter than lights that do not trip the protection in those batteries. But that is debatable, depends if the circuits are consistant. Before I tried the AW cells I ran it for months on two 18650, 2600 mAh from BatterySpace.com. Those are tough good cells. I took two of the AW cells and removed the protection circuits then built a 7.4 volt pack using a pcb for that purpose available from BatterySpace. This provided the protection, the ability to use a series charger and a light that came on with one click. I have a mag charger with this bulb too:
http://candlepowerforums.com/vb/showthread.php?t=147344
and built other lights with the 5761 too.
Gosh just search the key work "5761" there are a bunch of posts on this bulb.


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## jimjones3630 (Jun 7, 2007)

I really like the color and beam shap of the 5761. I over moded, tailcap, switch, pedestal spring fix and could not keep it from blowing in a 2c with the excellant 18650 2600mah x2. 

With this bulb resistance is your friend.

Jim


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## Icebreak (Jun 8, 2007)

Is it KIU only or will a FM bi-pin adapter work? I was thinking FM bi-pin is OK because (from the linked thread) Bob_G was using an FM custom torch and Northern Light's bi-pin adapter sounds similar to a FiveMega but using copper instead of plated steel.

Is there a recommended dealer for this lamp?

Since it is white and tight I'd like to try it.


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## Northern Lights (Jun 8, 2007)

FM bi- pin works good, I used one for a few months before I built my own. I get my 5761s from Bulbconnection.com


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## max52 (Jun 8, 2007)

I ordered the 5761 for my 2c with AW Lithium cells. The 5761, to me pulled more amps than the AW cells can take. I used it less than a minute, and after checking the cells, the volts were under 4 volts. I am currently using the 5761 in an 8 AA battery holder in a 2 D Mag with a Kiu Hi temp set-up. I am usuing Rayovac hybrid cells because the diameter can fit an un-bored Mag. Does anyone have experience with the CBP SP2600 cells? They also have a small enough diameter for an 8 AA holder. I just don't know whether these cells can handle the current.


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## Northern Lights (Jun 8, 2007)

max52 said:


> I ordered the 5761 for my 2c with AW Lithium cells. The 5761, to me pulled more amps than the AW cells can take. I used it less than a minute, and after checking the cells, the volts were under 4 volts. I am currently using the 5761 in an 8 AA battery holder in a 2 D Mag with a Kiu Hi temp set-up. I am usuing Rayovac hybrid cells because the diameter can fit an un-bored Mag. Does anyone have experience with the CBP SP2600 cells? They also have a small enough diameter for an 8 AA holder. I just don't know whether these cells can handle the current.


Not this battery but in my MagCharger I use Sanyo 2700 NiMh AAs, 12 of them, 6S2P for 5400 mAh and it holds up for about an hour. PowerX 2700 should do better from what I have learned.
You are absolutely correct on the problems with the AW cells not handling the draw of this bulb. But I have a specific need for the size of the 2C body and if I get 20 minutes runtime I am good. I have noticed when I used the 18650s that the voltage drop was comparable to the AW cells and I would drop from the high 880 torch lumens to about 500 in that time. In any case, for the size it is more output than the ROP or 1185. Better battery systems will get more light for more time.


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## missionaryman (Jun 8, 2007)

I am just about to sell my 2C M61 built using a KIU, AW Protected C cells and a pewter host - let me know if you're interested.

it is brighter than the ROP but I find it about the same as a MAG85, just less than a MAG64


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## Icebreak (Jun 8, 2007)

Northern Lights said:


> FM bi- pin works good, I used one for a few months before I built my own. I get my 5761s from Bulbconnection.com


Thanks, Northern Lights.


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## waynejitsu (Jun 9, 2007)

Has anyone used the AW C cells?
Maybe I am missing it, I am not sire if everyone is talking about AW C or AW 18670 cells?

I currently run 1274 on 2C and 1185 on 3C


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## Northern Lights (Jun 9, 2007)

waynejitsu said:


> Has anyone used the AW C cells?
> Maybe I am missing it, I am not sire if everyone is talking about AW C or AW 18670 cells?
> 
> I currently run 1274 on 2C and 1185 on 3C


Yes, that is what we are saying, AW C cells, depending on the AW cells circuit sensitivity, there seems to be some variation and the internal resistance of the light, many have worked ok. For my lights, it did not on several sets of cells probably because I have very low internal resistance do to some modifying. I used the AW cell as a basis to build a pack from the cell. I read where Missionaryman, lexina, nightstalker101, AW and me have used them in this thread.
The 18650s I refered to and jimjones3630 refers to are the BatterySpace 2600 mAh. These are un-protected too. AWs 18650s are protected and are 2400 mAh, I believe. Hope that helps, at least that what I think we said!:thinking:


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## waynejitsu (Jun 9, 2007)

It helps a BUNCH!!
Thank you

A few other questions-
Where can I get reflectors, aluminum, for high heat?


Why do some bulbs smoke when installed?
I just tried the Phillips bulb with 2C AW batts and several other configurations and they smoke after a minute or so?

Do you sell and custom parts?

Thanks again!


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## jimjones3630 (Jun 9, 2007)

waynejitsu said:


> A few other questions-
> Where can I get reflectors, aluminum, for high heat?
> 
> http://theledguy.chainreactionweb.com/product_info.php?&products_id=808
> ...


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## Northern Lights (Jun 9, 2007)

waynejitsu said:


> It helps a BUNCH!!
> Thank you
> 
> A few other questions-
> ...


I might at some future date offer a bi-pin to PR socket with a mill-max connector, but not now. I use FM cammed reflectors in most lights because I use my lights for a specific purpose and need a flood at about 12 foot distance otherwise the max throw is used. I use Litho fixed focus reflectors in anything I consider a KIU with. I like his smooth beam pattern. For the most part smooth reflectors throw further but can have artifacts in the beam; I use all smooth reflectors. Artifacts can easily be removed by frosting the bulb with Armour Etch from a hobby or crafts store. 5761s work well if you lightly frost the lower 2/3 or area from the top of the element down. Why, because light emitted of the top of the filament casts no shadow and with no frost there all the light escapes, no lumens lost. I have one magcharger in build right now but the other I mentioned uses the factory reflector and it throws well, check out the reference thread I posted above about it. Magcharger reflectors are steel.
Some bulbs smoke if they are in a socket that has ceramic material. I have found that during the manufacturing of the ceramic it can be contaminated with solder flux or absorb moisture. Pelican bulbs for the ROP often smoke from the ceramic. That smoking will fog a reflector. Do not touch a reflector, that makes small scratches, clean it with alcohol spray or lens cleaning sprays. At times I have ever so gently touched up areas with a cotton swab, flooded it off with alcohol and always blow the reflector dry to avoid spots with pressure or canned air.
To avoid this, turn the light on initially without the reflector and run it until it stops smoking.


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## waynejitsu (Jun 9, 2007)

Thank you...,
you have been a real help.
you must be the cpf expert on mags


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## Northern Lights (Jun 9, 2007)

waynejitsu said:


> Thank you...,
> you have been a real help.
> you must be the cpf expert on mags


NO, heck no, no way. 
But CPF is full of experts, I just know how to use the search function very well!:naughty:


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## thezman (Jun 9, 2007)

How many NiMh AA's will this bulb tolerate before it goes p00f ?


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## Northern Lights (Jun 10, 2007)

thezman said:


> How many NiMh AA's will this bulb tolerate before it goes p00f ?


6 but with a hot driver, 7 and you maybe able to get it up to 7.4 with soft start but I have not tried it, base it on what has been told to me.


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## thezman (Jun 10, 2007)

Thanks.

I'm staying with the 1164 on 8.


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## Northern Lights (Jun 11, 2007)

thezman said:


> Thanks.
> 
> I'm staying with the 1164 on 8.


I have a 2D 1164, on a driver for 9.6, but I can't finish it because I haven't found anyone to tri-bore this tube, but my real point is that I am looking at a new bulb, Osram 64430, which subtituting that for the 1164 should double the torch lumens, 2100 t-l and I am looking into using the a123system cells and pumping it to 9.9 volts fror 2200 t-l in a 4C-cell host, all theory at the moment, has a potetial but the real point is the first post by wooniris, 

*The 5761 probably is the brightest bulb in a 2C-cell host!!:twothumbs* For me the 2C-cell is a size I am restricted to for the application I use mine for otherwise if I wanted more light I would grab something else off the shelf.

I just built a second battery pack today using the batterySpace pcb and this time the very same boards did not work, the resistance on this light is so low (0.55 ohms) they would trip, probably the tolerances in the board is too broad and these do not quite take what the first two boards can handle; same light though. I can get it to run if I heat up the filament first by sticking an NTC in the circuit then pulling it out when all set up with jumpers everywhere in the test fixture. 
I measured the Amps on the running 2 AW C-cells on this 5761, it is modified the OEM protection gone and the batterySpace sincgle board for 7.4 volts, 5-7 Amps is substituted. Once running the output of this light was 5.2 Amps. I wish I could get a measurement of how many Amps is pulls on a cold start. I would like to know how far off the boards are.


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## tobrien (Feb 12, 2014)

sorry to bump an old(er) thread, but I am intending on ordering a Philips 5761 for my PhD-M6 battery pack and want to be sure that the Philips 5761 7.2v is the same exact thing as any other Philips 5761 bulb. 

this is what I'm seeing on Bulb Connection's site, but want to make sure it's the same one I need:


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## fivemega (Feb 12, 2014)

tobrien said:


> sorry to bump an old(er) thread, but I am intending on ordering a Philips 5761 for my PhD-M6 battery pack and want to be sure that the Philips 5761 7.2v is the same exact thing as any other Philips 5761 bulb.


*Philips 5761 is not 7.2 volt. It's designed for 6 volts but most of us (flashaholics) push it to about 7 volts using 6AA in 2D M*g with little voltage drop.*


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## Justin Case (Feb 12, 2014)

tobrien said:


> sorry to bump an old(er) thread, but I am intending on ordering a Philips 5761 for my PhD-M6 battery pack and want to be sure that the Philips 5761 7.2v is the same exact thing as any other Philips 5761 bulb.
> 
> this is what I'm seeing on Bulb Connection's site, but want to make sure it's the same one I need:




In theory, an 0.354" diam bulb envelope should fit through the reflector opening in a KT4 TH of an M6. However, in practice, it appears that 5761 bulbs vary in size. Some folks seem to have 5761s that won't fit in their KT4s. I have a supply of 5761s, and fortunately they all fit. You might see if you can verify with Bulb Connection that their 5761s really are 0.354".

Also, the current draw is going to be pretty high for a 5761 in a PhD-M6 at 7.2V. Probably not the best thing healthwise for LiCo 17670 cells, which I assume you will use in your PhD-M6.


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## fivemega (Feb 12, 2014)

Justin Case said:


> In theory, an 0.354" diam bulb envelope should fit through the reflector opening in a KT4 TH of an M6. However, in practice, it appears that 5761 bulbs vary in size. Some folks seem to have 5761s that won't fit in their KT4s. I have a supply of 5761s, and fortunately they all fit. You might see if you can verify with Bulb Connection that their 5761s really are 0.354".


*It's not the bub diameter which may not fit. It's size of bulb base where pins are that may vary from bulb to bulb.*



Justin Case said:


> Also, the current draw is going to be pretty high for a 5761 in a PhD-M6 at 7.2V. Probably not the best thing healthwise for LiCo 17670 cells, which I assume you will use in your PhD-M6.


*Current draw of 5761 using pair of 17670 direct rive will be about 5.5 Amps which is way too much for protected cells but when regulated from 11 volts, current draw at tail cap will be just under 2C.
Anyhow, I prefer direct drive 1185 over regulated 5761 in M6*


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## The_Driver (Feb 13, 2014)

You can get 17650 IMR batteries from Efest and AvidVaper. HJKs test results can be found here. They are suited much better for this application.


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## tobrien (Feb 13, 2014)

fivemega said:


> *Philips 5761 is not 7.2 volt. It's designed for 6 volts but most of us (flashaholics) push it to about 7 volts using 6AA in 2D M*g with little voltage drop.*


thanks! so it is the same bulb though right? just being referenced in the PhD-M6 Bulb Chart Spreadsheet as being overdriven to 7.2v?



Justin Case said:


> In theory, an 0.354" diam bulb envelope should fit through the reflector opening in a KT4 TH of an M6. However, in practice, it appears that 5761 bulbs vary in size. Some folks seem to have 5761s that won't fit in their KT4s. I have a supply of 5761s, and fortunately they all fit. You might see if you can verify with Bulb Connection that their 5761s really are 0.354".
> 
> Also, the current draw is going to be pretty high for a 5761 in a PhD-M6 at 7.2V. Probably not the best thing healthwise for LiCo 17670 cells, which I assume you will use in your PhD-M6.


gotcha, thank you! Yeah the spreadsheet I linked to right above this quote does mention the 5761 bulbs don't always fit, but I figure I'll roll the dice and see. 

And yeah, I'd be using AW 17670 protected cells, but I'm okay with it if they don't last a long time (long term or runtime) because I really want that incredible incandescent output from my M6 haha


fivemega said:


> *It's not the bub diameter which may not fit. It's size of bulb base where pins are that may vary from bulb to bulb.*
> 
> *Current draw of 5761 using pair of 17670 direct rive will be about 5.5 Amps which is way too much for protected cells but when regulated from 11 volts, current draw at tail cap will be just under 2C.
> Anyhow, I prefer direct drive 1185 over regulated 5761 in M6*


hmmm, the 1185 does look like a better bet here. Good suggestion, thank you 


The_Driver said:


> You can get 17650 IMR batteries from Efest and AvidVaper. HJKs test results can be found here. The are suited much better for this application.


I'll definitely have to look into those!


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## Justin Case (Feb 13, 2014)

fivemega said:


> *Current draw of 5761 using pair of 17670 direct rive will be about 5.5 Amps which is way too much for protected cells but when regulated from 11 volts, current draw at tail cap will be just under 2C.
> *



That's not how the PhD-M6 works. The current draw is not reduced to 2C.


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## fivemega (Feb 13, 2014)

Justin Case said:


> That's not how the PhD-M6 works. The current draw is not reduced to 2C.



*So, are you trying to say PhD-M6 regulated to 7 volt when using 5761, tail current draw will be above 5 Amps?
In this case total power will be way above 35 watt.

When current at tail side pulse to on and off, average current is calculated and not maximum. Therefore, continuous draw for 1600mAh cells should be under 3200mA (2C)*


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## The_Driver (Feb 13, 2014)

fivemega said:


> *So, are you trying to say PhD-M6 regulated to 7 volt when using 5761, tail current draw will be above 5 Amps?
> In this case total power will be way above 35 watt.
> 
> When current at tail side pulse to on and off, average current is calculated and not maximum. Therefore, continuous draw for 1600mAh cells should be under 3200mA (2C)*



The high peak current is applied for a long enough time that over current protection of some protected batteries can trip. This can be calculated. For this you need the maximum peak current. With the average peak current and the internal resistance of the batteries you can also calculate how much heat is produced in the batteries. 

Maximum_peak_current = maximum_battery_voltage_under_load / filament_resistance
filament_resistance = applied_bulb_voltage / Bulb_rms_current

applied_bulb_voltage = 7.2V
Bulb_rms_current = 5.5A

filament_resistance = 7.2V / 5.5A = 1.31 Ohm

maximum_battery_voltage_under_load = 3 * 3.7V = 11.1V (approximately)
Maximum_peak_current = 11.1V / 1.31 Ohm = *8.47A !!!
*
This is the current that is pulled out of the batteries when the are fully charged up during the on-phases of the pwm. 
The average dc-bulb-current is obviuosly 5.5A. If you use protected batteries their overcurrent-protection must not trip at 8.47A. 


Unless you have a Fluke 189 or 289 multimeter you cannot directly measure this current at the tailcap! These multimeters have a special "AC+DC"-mode that will measure it correctly. There is another way though if you really need to measure...

Here is the calculation for runtime with the IMR-batteries I mentioned above (I really think these should be used):

bulb_power = 7.2V * 5.5A = 39.6W
battery_watt_hours = 3 x 4Wh = 12Wh (see HJK's test here or calculate it yourself)

Runtime = battery_watt_hours / bulb_power = 12Wh / 39.6W = 0.303h = *18min* and a few seconds

This last calculation is so easy because this type of pwm regulator is around 99% efficient. It doesn't acutally convert voltage or current. It just connects and disconnects the batteries from the bulb in specific intervals.


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