Mag61: Direct Drive or Soft Start?

Ok, I've been doing some research and I have decided my next hotwire will be a Mag61.

If I read right the formula goes as follows:

Mag
Phillips 5761 Bulb
7.2v worth of Batteries
Bi-Pin adapter
Borofloat Lens
Aluminum Reflector

For the bulb adaptor I wanted to use: https://www.candlepowerforums.com/threads/179891 so that I can retain the stock cam focus mechanism of the Mag.

However I did read alot of talk about 6.8v being the correct voltage and lots of folks insta-flashing their bulbs.

My mag 61 will most likely have no resistance mods other than a recessed tail cap and that is just to fit in the batteries, I'll be using 6 Elite 5000mAh Sub C cells rated at up to 30 amps discharge.

I worry that a freshly charged pack, or even one that has rested may be too much voltage. I have the same pack in my ROP and it will read 8.4v off the charger.

According to Lux's bulb testing 8v on this bulb is a no-no.

Soooo....can I use the FM Bi-Pin Slug and keep the focus mechanism? Is there some crazy voltage sag that will keep the bulb from going poof? Or will I have to get one of the fancy soft starting switches I keep seeing threads about.

Thanks for the help!!! :twothumbs

Well, I insta-flashed one on a set of eneloops(6 cells) 1 day off the charger. So I would say soft starting is a good idea for it.

There are ways to soft start other than the awr hotdrivers.

Daniel

I use 6 eneloops and an AW soft starter, hot off the charger it'll flash every time, but just a few hours later and it's fine, and the 61 works very well on the lower levels, the 11 goes brown, 61 stays nice and white. Enjoy

smopoim86 said:

There are ways to soft start other than the awr hotdrivers.

Daniel

Click to expand...

Really? Expand on that please.

The AW softstart would be one. The AWR and AW are different things. Easy to mix up though.

scottaw said:

I use 6 eneloops and an AW soft starter, hot off the charger it'll flash every time, but just a few hours later and it's fine, and the 61 works very well on the lower levels, the 11 goes brown, 61 stays nice and white. Enjoy

Click to expand...

So does it still flash WITH the soft starter when hot off the charger? Or is that without the soft starter?



EDIT: Just looked at the Soft Starter a little more...I think that warps the build budget a little too much. Don't suppose there is a less fancy way to soft start? :green:

Beer, the answer to your question is not a simple yes or no. The problem is that you must take into account the resistance of your light...which to some degree lowers the delivered voltage from my low resistance setup bulb testing.

I made this other post which the moderators have been kind enough to add to the "Pinned Interest" topic in this section. I tried to keep the thread concepts simple & used an example to answer this very question.

Remember it is mostly the startup, higher ("spike") voltage that flashes the bulb because it starts out cold.

I am with Lux with this one. This can get very, very complicated.

One solution, and easy at that, is to just charge your batteries a little bit less and work your way up from there. You are trying to control alot of juice with those sub-c's.

You could try to build your own soft starter (I think JimmyM built some and had alot of good diagrams too) using FET's. But what a pain.

Just charge to a lower level. Works every time.

Look at our ramblings about NTC's which may be a solution too.

Bob E.

Thanks,

I read lux's simple guide and it seemed to help. But them I started reading the NTC thread....and was completely lost again. I don't think thats the route for me as I had no idea what I was reading...thermal issues with the NTC being to close to the bulb, putting reistors in series with the NTC....what?

I may skip the 5761 and start looking for a bulb with a little more headroom befor instaflash...or I may just say the hell with it and try charging the batts less. I'm sure I'll end up poping a few bulbs along the way. :green:

I think the ROP bulb has spoiled me in terms of resistance to insta flash

I have been looking for an inexpensive solution to the 5761 on 6 AA batteries.
The NTC was cheap to buy but introduced too much resistance to the circuit.

My solution was to purchase an extra tailcap and now my 'hot' battery pack is used with the tailcap with the NTC. No flash. After a few minutes use, ( the time being a guess) I swap over the tailcaps and finish the remaining charge with my direct drive tailcap ( with no resistance).
It works for me and was a $10 cost to purchase the extra parts.

I love my Mag61. With my mod I used 2xA123 batteries, 2D Blue Mag, FM Bi-Pin adapter, FM MOP Reflector with cam, resistance mods and currently a 50mm Diameter, 308 FL aspherical lens. I have not been able to insta flash or wear out my 5761 lamp yet. I give up a few 100 lumens only driving it at 6.6 volts but it rocks. Inside bounced off a wall it does not look much better than a AW1111 mod. Outside thou it performs on the level of a AW1185 mod. Great throw, phat beam and 25+ minutes of runtime. Two other points. The Philips 5761 is an inexpensive lamp at $5.00 each and I can fully charge my A123 batteries in less than 30 minutes.

Beer said:

Thanks,

I read lux's simple guide and it seemed to help. But them I started reading the NTC thread....and was completely lost again. I don't think thats the route for me as I had no idea what I was reading...thermal issues with the NTC being to close to the bulb, putting reistors in series with the NTC....what?

I may skip the 5761 and start looking for a bulb with a little more headroom befor instaflash...or I may just say the hell with it and try charging the batts less. I'm sure I'll end up poping a few bulbs along the way. :green:

I think the ROP bulb has spoiled me in terms of resistance to insta flash

Click to expand...

If you have some money to spend, I'd go for the AW Incan Driver with soft start. Really fantastic are (but that's what I think) the 3 brightness levels [30 - 60 and 100 %] You won't need a bi-pin socket since AW's driver has already a Kiu socket.

I have two D mag61's with an AW Incan Driver. Simply fantastic!

C Incan Driver: https://www.candlepowerforums.com/threads/185688
D Incan Driver: https://www.candlepowerforums.com/threads/177316