2D Mag85 Questions

[RichS]

Never! :thinking:

I'll just wait for you to sell yours when you upgrade.

BTW, I was just being cautious because of this line from AW: " Recommended Max. Continuous Discharge Rate : 5A"

Smart man! Dang, I sell my stuff too cheap...:mecry:

Good point on the AW's discharge rate specification on these cells. I actually did ask him if it his C li-ions would safely power a Philips 5761 before purchasing my first two. He said it would work but it would be pushing them hard - which it is. This is when I decided to buy the C driver for soft starting to ease the start-up draw. They have over-discharge protection and they can be pushed up to 6A and still be below the li-ion safety limit of 2C. But anything over 5A will still cause these batteries to sag more than desired. AW mentioned to me in another PM that too high an amperage will cause the voltage to sag even on LiIon cells. He said that a 1 -1.5C draw should maintain a reasonable flat discharge.

Also, I'm sure if I constanty ran them at 5.5A this would probably somewhat reduce their overall life-cylce. Fortunately the multi-level driver gives me a choice. So it certainly makes sense for AW to state 5A as a recommended max discharge rate, but I'm not pushing them beyond a safe limit with the Philips 5761.

 

[Stereodude]

I think I will wait for AW's "D" cell Li-Ion's before building a Mag61.

It won't be as hard on the cells, have less voltage sag (aka be brighter), and it'll have a longer more useful runtime. :naughty:

 

[RichS]

I think I will wait for AW's "D" cell Li-Ion's before building a Mag61.

It won't be as hard on the cells, have less voltage sag (aka be brighter), and it'll have a longer more useful runtime. :naughty:

Well, it would be less hard on the cells, but I don't think it will be any brighter. If you saw how white this beam is on high, you'd know any more voltage and it would go

Actually, the slight sag of the C cells is just enough to keep me from being forced to add artificial resistance. AW's driver took most of it away. I think if you're going to go with the D Cells you better either use the stock switch, or wait on the AW regulated driver. Now that would be a nice Mag61 build!

But it still won't be a 1400+ lumen light that will fit in a jacket pocket like the 2C. :devil:

 

[Stereodude]

I think if you're going to go with the D Cells you better either use the stock switch, or wait on the AW regulated driver.

I'm not so sure about that. Supposedly a Mag with AW's switch has about 250mΩ of resistance after the tailcap mod (seems high to me though). That means with 5.0A of current there is a voltage drop of about 1.25V. Meaning the 8.4V from the 2 D Li-Ion ends up as 7.15V at the bulb. That isn't nearly enough to poof a 5761.

I suspect a Mag with AW's switch and the tailcap mod is more along the lines of 100mΩ, which would mean you'd get a .5V drop to the bulb at 5A. That would put 7.9V to the Bulb which is right at the very ragged edge. That's where the soft start of the switch comes into play. :naughty:

Is there any word on when AW is coming out with a regulated driver? Do we even know if he's working on one? :thinking:

But it still won't be a 1400+ lumen light that will fit in a jacket pocket like the 2C. :devil:

Maybe I have a jacket with really big pockets?

 

[RichS]

I'm not so sure about that. Supposedly a Mag with AW's switch has about 250mΩ of resistance after the tailcap mod (seems high to me though). That means with 5.0A of current there is a voltage drop of about 1.25V. Meaning the 8.4V from the 2 D Li-Ion ends up as 7.15V at the bulb. That isn't nearly enough to poof a 5761.

I suspect a Mag with AW's switch and the tailcap mod is more along the lines of 100mΩ, which would mean you'd get a .5V drop to the bulb at 5A. That would put 7.9V to the Bulb which is right at the very ragged edge. That's where the soft start of the switch comes into play. :naughty:

Is there any word on when AW is coming out with a regulated driver? Do we even know if he's working on one? :thinking:
Maybe I have a jacket with really big pockets?

Ok, but you're braver than me! :green: Actually, at 7.9v it did go in Lux's destructive bulb tests. Even if it was a little lower (7.7 or 7.8) it may not pop but I bet you'd get no more than 2 hours of life out of the bulb...

Yes - AW is working on a regulated version of his driver, thus this thread:

https://www.candlepowerforums.com/threads/173558

I asked him how long it would be before these were ready before I purchased his current incandescent driver for my Mag85 build a week ago, and he told me it would still be a while yet.

 

[Stereodude]

Yes - AW is working on a regulated version of his driver, thus this thread:

https://www.candlepowerforums.com/threads/173558

I asked him how long it would be before these were ready before I purchased his current incandescent driver for my Mag85 build a week ago, and he told me it would still be a while yet.

Interesting. I'll admit I'm not a big fan of the lack of user adjustability. Having to buy a new regulated switch every time you want to change from one light design to another say from a Mag61 to a Mag85 kinda blows. :sick2:

 

[2xTrinity]

Interesting. I'll admit I'm not a big fan of the lack of user adjustability. Having to buy a new regulated switch every time you want to change from one light design to another say from a Mag61 to a Mag85 kinda blows. :sick2:

Yeah, that is a bit annoying. IMO a crude way AW could have included user adjustability is as follows -- have the RMS voltage ouptut set by a trimpot that is user adjustable WHILE the driver in installed in the light, perhaps with an exposed adjustment screw near the switch opening.

Then, ship the drievr with the voltage automatically set to its lowest possible setting. Install the appropriate bulb in cells, then with the light, allow the user to gradually turn the trimpot until the bulb reaches an ideal color temperature (say >3500k, indicating it's close to "flashing" point).

 

[RichS]

Well, I'm not sure that I would call them annoying, I know there are plenty of people on pins and needs waiting on these. I think they will bring the world of hotwires to a whole new level. Albeit, you want to decide a mod that you are going to use and keep for a while before buying one.

I am actually not sure I will be upgrading to one of these from the current ones though. I really like the idea of having regulated output, but AW enlightened me to the fact that PWM (which the current models use for levels) is much more efficient than a boost or buck regulator. Since I want to use this as an all around go-to light for outdoors, levels are important to me. Here is what AW said about PWM in incandescents:

"The PWM regulation has the best efficiency ( 99+% ) and the normal PWM flash will not be noticeable at any rate because of the incan after glow. The best buck regulator has a max of 80 % effic. and a boost regulator is 70% at best. Both the buck / boost driver will not be able to handle the amperage demand in incan lights like PWM does because the heat generated is huge from efficiency loss."

 

[2xTrinity]

Well, I'm not sure that I would call them annoying, I know there are plenty of people on pins and needs waiting on these. I think they will bring the world of hotwires to a whole new level. Albeit, you want to decide a mod that you are going to use and keep for a while before buying one.

I am actually not sure I will be upgrading to one of these from the current ones though. I really like the idea of having regulated output, but AW enlightened me to the fact that PWM (which the current models use for levels) is much more efficient than a boost or buck regulator. Since I want to use this as an all around go-to light for outdoors, levels are important to me. Here is what AW said about PWM in incandescents:

I think you misinterpreted what he was saying -- he doesn't mean that the regulated drivers are any less efficient -- the new regulated drivers are still PWM drivers.

The fact that a filament has thermal inertia, ie takes time to heat up and cool down, means that no additional filtering is required -- driving an incan with 50% duty cycle PWM is effectively half the voltage. This is essentially how household dimmers work, they simply "chop off" part of the sine wave input, which is why adapting fluorescent or LED technology to work on incan dimmers is a huge nightmare.

So in stead of letting the user select the duty cycle, the "driver" selects the duty cycle based on the state-of-charge the battery, so as to maintain constant brightness.

I probably will buy one and simply order it with a spec. suitable for the philips 5761, which should work for a number of 6V bulb should I decide to use a different one.

 

[Stereodude]

You can do Buck at better than 90% as well as boost. I have no idea what AW is talking about. You can get better than 95% even. You can build a switching regulator that can power a incandescent light without too much difficulty. :thinking:

 

[RichS]

You can do Buck at better than 90% as well as boost. I have no idea what AW is talking about. You can get better than 95% even. You can build a switching regulator that can power a incandescent light without too much difficulty. :thinking:

Ok, well I won't argue the point since I'm not an expert on this, but I still tend to view AW as somewhat of an authority on the subject for the time being. I haven't seen many other incan drivers for sale around here, and I've seen what his can do. And with the demand for a regulated driver, you'd think someone would be selling them if it were easy.

Just my .02

 

[Patriot]

Oh, my friend, let me tell you....

The Philips 5761 is the best bulb (IMHO) to use with 2 AW C batteries - in the right config of course.

AW C batteries are rated at 3300 mAH. The max you should push li-ions is 2C, which would be 6.6A for these cells. So first, at max draw you are within the safety limits using these batteries with the PH 5761.

On hight it honestly looks about 30% brighter than my Mag85 which puts out around 1300 lumens.

You've got my attention! This sounds great, but so far It's not computing for me. I'm trying to understand how the 5761 on 2C's is that much brighter than the mag85. I guess I need to go study the charts again. :thinking:

 

[RichS]

You've got my attention! This sounds great, but so far It's not computing for me. I'm trying to understand how the 5761 on 2C's is that much brighter than the mag85. I guess I need to go study the charts again. :thinking:

I don't know how, but it is!! And I have witnesses.

Actually, this is what I expected originally when I built my first Mag61. I looked at LuxLuthors Most Powerful Mag Mods list, and saw the Mag61 two steps higher than the Mag85. I couldn't imagine an even smaller Mag brighter than the Mag85 which I thought was a beast. So I decided to go ahead and build the Mag61.

I ran the first Mag61 on Eneloops and FM battery holder. It was brighter than my M6 HOLA, but about 30% less bright than my Mag85. But this build is easily brighter by 25-30%. It is very white too, which could mean it is very close to the edge voltage-wise. One thing that may make the output seem like so much more than the Mag85 is the very large hot spot. It is definitely much bigger, but also seems more intense than the Mag85.

 

[RichS]

Thanks for the clarification. I thought I read that the new regulated drivers would not be using PWM for levels. So now I'm going to have to upgrade....dang it....oh well, that's what the MP is for!

I think you misinterpreted what he was saying -- he doesn't mean that the regulated drivers are any less efficient -- the new regulated drivers are still PWM drivers.

The fact that a filament has thermal inertia, ie takes time to heat up and cool down, means that no additional filtering is required -- driving an incan with 50% duty cycle PWM is effectively half the voltage. This is essentially how household dimmers work, they simply "chop off" part of the sine wave input, which is why adapting fluorescent or LED technology to work on incan dimmers is a huge nightmare.

So in stead of letting the user select the duty cycle, the "driver" selects the duty cycle based on the state-of-charge the battery, so as to maintain constant brightness.

I probably will buy one and simply order it with a spec. suitable for the philips 5761, which should work for a number of 6V bulb should I decide to use a different one.

 

[Patriot]

Ok, I went and looked at the bulb charts again and at 7.4V the 5761 is just over 1300 bulb lumens. At 11.1V the 1185 is just a hair under 1300 bulb lumens. The difference is that the 5761 on 2Cs will sag more that 3Cs in an 1185. So yeah.....I guess I am surprised that it's brighter. What formula mag85 are you running?

 

[LuxLuthor]

Only the AWR Hotdriver has had adjustable POT to use it with various voltages, but is no longer available.

AW's regulated model has very high stamped together quality, and will likely be more stable and have multi-level output. I don't see that big of a downside to plan ahead and use one AW driver for a given bulb....now that we pretty much know how they all perform.

Having played with tons of combinations of hotwire mags, you really need to take into consideration the actual delivered voltages in a direct drive setup that compares 1185 vs. 5761. Without regulation, you are dealing with a battery drain curve dependent on many factors. There are significant differences also in bulb filament & color. For example, I greatly prefer the 1166 bulb in AWR hotdriver set at 12.6V vs. 1185 set at 11.0V because of the bulb quality/color, even if less total lumen output. Same point with direct drive of 64625 on 11 NiMH cells vs. 64623 on 13 NiMH cells.

 

[RichS]

Ok, I went and looked at the bulb charts again and at 7.4V the 5761 is just over 1300 bulb lumens. At 11.1V the 1185 is just a hair under 1300 bulb lumens. The difference is that the 5761 on 2Cs will sag more that 3Cs in an 1185. So yeah.....I guess I am surprised that it's brighter. What formula mag85 are you running?

Well, I am updating my Mag85 (thus this thread), and I just sold my 3D Mag85 on CPFMP. It was running 3 x AW18650s w/ modded tailcap but had the stock switch, so definitely more resistance than my new Mag61. My new Mag85 (thanks to the suggestions here) will be a 3C Mag w/ 3 x AW Cs along with an AW C incan driver. So...until the rest of the parts arrive the jury is out on the difference between the two, because only then will the build type will be apples to apples.

I guess I should have mentioned the build differences, but I guess I was thinking they are both li-ion configs. But the C batteries will definitely sag less than the 18650s, and the AW driver of course has much less resistance than the stock switch. So if you're right and the 1185 should about match the 5761, and I'm going to be very pleased with my new build!!

 

[RichS]

There are significant differences also in bulb filament & color. For example, I greatly prefer the 1166 bulb in AWR hotdriver set at 12.6V vs. 1185 set at 11.0V because of the bulb quality/color, even if less total lumen output. Same point with direct drive of 64625 on 11 NiMH cells vs. 64623 on 13 NiMH cells.

This is exactly why I decided to update my Mag85. I was about to abandon this build after I saw how bright the Mag61 could be in a more compact host, but the Mag85 has such a nice beam pattern and smaller spot, I wanted to update it as well. It always had a nicer, whiter color than my Mag61 too, but I think the Mag61 is just about as white on high now. I probably wouldn't run it on high for long though, and on low/med the 61 is much more yellow.

So, as the motto goes...I got both!

 

[2xTrinity]

This is exactly why I decided to update my Mag85. I was about to abandon this build after I saw how bright the Mag61 could be in a more compact host, but the Mag85 has such a nice beam pattern and smaller spot, I wanted to update it as well. It always had a nicer, whiter color than my Mag61 too, but I think the Mag61 is just about as white on high now. I probably wouldn't run it on high for long though, and on low/med the 61 is much more yellow.

So, as the motto goes...I got both!

Yeah, I really like the more compact filament packinging on the 1185, and the fact that the bulb is smaller than the 5761, so it will fit in the smaller-opening reflectors -- this actually leads to a significant number of more lumens making it out the front, as a significant fraction of the bulb lumens disappear down the "hole" in the base of the reflector, which represents a fairly big angle in the case of the 5761.

 

[LuxLuthor]

This is exactly why I decided to update my Mag85. I was about to abandon this build after I saw how bright the Mag61 could be in a more compact host, but the Mag85 has such a nice beam pattern and smaller spot, I wanted to update it as well. It always had a nicer, whiter color than my Mag61 too, but I think the Mag61 is just about as white on high now. I probably wouldn't run it on high for long though, and on low/med the 61 is much more yellow.

So, as the motto goes...I got both!

That's the spirit! In reality, there are so many variations as we are discussing....each with pro's and con's that it is good to play around experimenting. It makes this a fun hobby. Many who don't have a brilliant white 5761 are not driving it with enough voltage and amps.