NTC soft start cures 5761 instantflash with 2x Emolis

[jimjones3630]

Many people like and are familiar with Phillips 5761, 35w 6v bulb often overdriven and popular hotwire.

Over driven to 7.1vbulb is a white white color and monstor according to hotrater 1351blumen 878tlumen. Going beyond 1185.

Bulb has it limits, and now with a less than $1 NTC regualtion is possible without high cost. In association with Northern Lights today I was able to power up 5761 with 2 Emolis, nominal voltage 3.7v fresh charge 4.2. 27600mah. 8.02vbat and 6.8vbulb. Wooo Hooo

Will measure fresh charged Emolis as now sure can do it.

 

[jimjones3630]

ran a side by side comparison between 5761 with 2xA123 6.6Vbat, 6.38vbulb and 5761 with 2xEmoli and NTC 8.17vbat, 6.9vbulb.

At 100 yds very very hard to see the difference. Over and Over lighting up same object. At 25 yds lighting up some bushes could tell very little but some difference with the edge going to Emolis. Would think a bulb with .52v less would make obvious the difference but not to my eyes.

 

[medicmerlynn]

Many people like and are familiar with Phillips 5761, 35w 6v bulb often overdriven and popular hotwire.

Over driven to 7.1vbulb is a white white color and monstor according to hotrater 1351blumen 878tlumen. Going beyond 1185.

Bulb has it limits, and now with a less than $1 NTC regualtion is possible without high cost. In association with Northern Lights today I was able to power up 5761 with 2 Emolis, nominal voltage 3.7v fresh charge 4.2. 27600mah. 8.02vbat and 6.8vbulb. Wooo Hooo

Will measure fresh charged Emolis as now sure can do it.

is that a true statement? i can't imagine anything that doesn't way at least 3 lbs to have a runtime that long... but if so... i'm all in! i pieced together my ROP yesterday... well, just the adapter, bulb, and ucl lens... but it seems to be doing quite well... it is definitely a 'white' light. i'm still waiting for AW's 3300mAh C li-ions so i can make a C cell 5761 though...

 

[cat]

Search for 5761 A123, some threads after this one. Only advantage of AW C cells for 5761 is you can use a 2C body. But - as per Jim's / Northern Light's examples - if you can charge A123, that's the simplest, most cost-effective way, otherwise emolis and solder in the NTC. A123 is good. Designed for heavy load, deeper discharge, fast charging.

 

[Northern Lights]

is that a true statement? i can't imagine anything that doesn't way at least 3 lbs to have a runtime that long... but if so... i'm all in! i pieced together my ROP yesterday... well, just the adapter, bulb, and ucl lens... but it seems to be doing quite well... it is definitely a 'white' light. i'm still waiting for AW's 3300mAh C li-ions so i can make a C cell 5761 though...

The run time I got with my AW cell powered 5761 was around 27 minutes but was turning yellow from about 12 minutes on; calculated time out on the 5.43 Amp bulb is 36 minutes. My A123 powered light was always brighter, no NTC with the 6.6Vbat of the A123 needed. It runs very well up to around 23 minutes then begins to show its yellowing and calculates to time out at 26 minutes. Since A123 and Emoli take the highest loads of all lithiums, the run graphs look like a regulated light and the votage stays higer than the AW cells after the first few minutes, (look at Mudmans graph of the AW cell and 5761.) The Emoli and A123 do out perform the 1185 but the optical illusion is they look quite similiar. The 5761 puts out more lumens but also has a larger hot spot, if you ran the 1185 out over the same area it would look dimmer, more area would mean less available light at any one point.
The difference between Emoli and A123 output on the 5761 can be a toss up, they can switch places as to the brightest based on each build's variables because you are working only at 7.2 or 6.6 Vbat nominal and since the NTC has 0.060 ohms residual resistance it drops that voltage into the same range as the A123. Jim has had the Emoli slightly out perform the A123 build and one I threw together was just the opposite.
Both batteries fit in the 3C size and leave enough room left over for a charging jack. AW cells, I presume because of the protection circuit, and the other two all charge nicely in series in the lights I have built.
My three pound MagCharger has 12 AA Powerex 2700 mAh cells, 5400 mAh at 7.2 volts and since the bulb amps are 5.43, you see I get an hour run time.

 

[SafetyBob]

Do you guys think that a 6xAA holder with eneloops would be a good match with the 5761? I think I am going to try a incan mod soon.

Bob E.

 

[jimjones3630]

Bob,
my only personal experience with eneloops is 8xAA quad 2D 1164 drawing just over 4A. With a bulb drawing 5.5A I think you might be disapointed. Maybe I am used to the 5761 running longer and anything else seems short in comparison. I replaced the 8xAA with 2 Emolis with a NTC and 5761.
jim

Do you guys think that a 6xAA holder with eneloops would be a good match with the 5761? I think I am going to try a incan mod soon.

Bob E.

 

[Jenova]

Got a n00b question
Are the emolis protected cells ?


Also would they fit into a c cell maglite ?

Thanks

 

[jimjones3630]

not protected, safe newer li chemistry, don't rapidly vent gas and flames.

will fit c maglite when outter cardboard sleeve is removed and some opening of ID with brake hone, lath. some older c size without the "c" in serial # have larger ID so cells slip in again without their cardboard sleeve.

the thread below has some links about emoli cells

http://www.candlepowerforums.com/vb/showthread.php?t=178188

Got a n00b question
Are the emolis protected cells ?


Also would they fit into a c cell maglite ?

Thanks

 

[Northern Lights]

Got a n00b question
Are the emolis protected cells ?


Also would they fit into a c cell maglite ?

Thanks

No, no need for protection, protection was for a problem not in this chemistry for that matter you can discharge them farther and not damage them and charge them rapidly and in series which allows you to make rechargeable lights that use a jack and can be charged while in the light. That is part of the reason they are being used by RC folks.

 

[Jenova]

No, no need for protection, protection was for a problem not in this chemistry for that matter you can discharge them farther and not damage them and charge them rapidly and in series which allows you to make rechargeable lights that use a jack and can be charged while in the light. That is part of the reason they are being used by RC folks.

Sweet
Where can i purchase a NTC softstart ? Also from what i can recall arnt they like a resistor or something like that

How do you hook it up ?

 

[jimjones3630]

It is a thermistor

http://www.newark.com/72J6730/passives/product.us0?sku=AMETHERM-SL12-1R010&_requestid=243717

google ntc soft start 5761 to find the mod and how to hook it up
jim

Sweet
Where can i purchase a NTC softstart ? Also from what i can recall arnt they like a resistor or something like that

How do you hook it up ?

 

[Northern Lights]

Sweet
Where can i purchase a NTC softstart ? Also from what i can recall arnt they like a resistor or something like that

How do you hook it up ?

Use CPF advance search, key word NTC, and under my user name, Northern Lights and you will find a ton of stuff that specifically address all of your questions that you have and will have, until then let me help.
NTC are thyristors, there are hundreds but one in particular made by amertherm.com and sold by newark.com ($0.70 each) has a 1 ohm resistance and upon starting, in miliseconds reduces to 0.06 ohms at 5 amps. The thyristor has an almost linear reduction propotional to the bulb amps over a narrow range. This one is made to handle up to 10 amps. Just so happens the cool off rate is a near enough match for our hot wires and with a low residual resistance, it works.
If you do not have room in the tail cap you can work it into the ribbing of the switch and cut it into the ground circuit, the wire from the socket to the ground screw (this is something that should be done on all buids to reduce resistance but in this case you put the NTC in the line), other wise make an isolated ground circuit at the tail cap, two ways to do this, OEM spring or the snubber I use when a spring is too long like the AW cell driven 2C size 5761.
I am giving you a series of links for threads. Follow my posts in the threads and from those also follow the links in them.

My first NTC build is here. NTC soft start cures 5761 insta-flashes in MC

2C Mag Tail Cap mod for AW's "C" cells
I put NTC's inside the tubing and isolate the top and bottom braid, the circuit goes through the NTC.

Here is the original tail cap substitute, Here. You can put an NTC in it.

NTC SOFT START 5761 IN 2CMaG AKA MaG61
This link contains a long list in post #3, Jim posted my list, it will lead you to NTC sources and the type of NTC and history.

I put NTC and fuse in this arrangement, you can see it stick out of the shrink, it is round:

Well, sorry I did not hand it to you on a plate, but I did bring the table to you! When you have gotten through this, if you need some help just PM, be glad to get you going on your mod.
NL
PS:
This is Mudman's graph, for the post above that I mentioned it in, Here.

EDIT:
Looks like Jim and I had the same idea and was answering you at the same time!:twothumbs

 

[jimjones3630]

here is another way to install an ntc, learn this from one of NL earlier designs.

http://img50.imageshack.us/img50/9697/ntcfe1.png

the ntc is in line with the copper braid tucked in a piece of .75 inch OD hose.

 

[Jenova]

Nice Hopefully i can try get some hey

 

[jimjones3630]

Nice Hopefully i can try get some hey

pm sent. I'll find out and let you know

 

[Jenova]

How would this one go ?
http://au.farnell.com/jsp/search/productdetail.jsp?SKU=9007156
Its the closest one i can find in aus

 

[Northern Lights]

How would this one go ?
http://au.farnell.com/jsp/search/productdetail.jsp?SKU=9007156
Its the closest one i can find in aus

It wont work.

Go directly to Amertherm.com and pull up the PDF spec sheets. Notice the maximum Amp rating and the 50% amp rating and you can constuct linear chart to correspond to the bulb amps you are using.

SL12 1R010​

Max Steady State Current Up to 65°C 10.0 A​

Resistance @ 100% of Max Current 0.027 oms

Resistance @ 50% of Max Current 0.060 ohms

So a 5761 at 5.43 bulb amps in the hotwire will be left with .06 ohms resistance in the circuit, this uses up some of the overhead voltage but not much. Any other of the NTCs have a higher residual resitance and drop the voltage too much.​

http://candlepowerforums.com/vb/showthread.php?t=170972​

I will edit this a little later and show you what will happen with your choice. gotta go now.

 

[Jenova]

LOL That just went over my head

It wont work.

Go directly to Amertherm.com and pull up the PDF spec sheets. Notice the maximum Amp rating and the 50% amp rating and you can constuct linear chart to correspond to the bulb amps you are using.

SL12 1R010​

Max Steady State Current Up to 65°C 10.0 A​

Resistance @ 100% of Max Current 0.027 oms​

Resistance @ 50% of Max Current 0.060 ohms​

So a 5761 at 5.43 bulb amps in the hotwire will be left with .06 ohms resistance in the circuit, this uses up some of the overhead voltage but not much. Any other of the NTCs have a higher residual resitance and drop the voltage too much.​

http://candlepowerforums.com/vb/showthread.php?t=170972​

I will edit this a little later and show you what will happen with your choice. gotta go now.

 

[Northern Lights]

LOL That just went over my head

OK then just use these:
http://www.newark.com/72J6730/passives/product.us0?sku=AMETHERM-SL12-1R010&_requestid=36864

I will PM about a quick source for just this once!