can MadMax+ drive 5W LS ?

[snake]

Hello All,
if MM+ drive a 1W LS at 600-700ma.. then can it drive a 5W ?
certainly better use Nimh with it..
any idea?
Thanks

 

[shankus]

I'm not sure about this. The 5 W luxeon is four 1 W dice in series-parallel. So, the forward voltage of the 5 W is twice that of the 1 W.

But, someone with more knowledge than I will chime in soon enough.

 

[Chief_Wiggum]

Here's a great table I use all the time to figure out what drives what:

http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=TheSandwichShoppe&Number=256150&PHPSESSID=&fpart=1#Post256150

 

[snake]

thanks for the link!

 

[Beretta1526]

Yeah, THANKS Cheif!

 

[jcciv]

I have seen that table, but it is not completely accurate. For example, I have a 5W being driven by a BB 500 on 1x123, and I have a BB 750 driving a 5W on a McLux head that works with both the 1x123 and 2x123 bodies.

Maybe it's not recommended, but it WORKS.

 

[Doug S]

[ QUOTE ]
snake said:
Hello All,
if MM+ drive a 1W LS at 600-700ma.. then can it drive a 5W ?
certainly better use Nimh with it..
any idea?
Thanks


[/ QUOTE ]
The output voltage would exceed the IC's maximum voltage rating which is 6V. Assuming that the IC can handle the overvoltage, this arrangement should work with 2x123 or with 4 or 5 NiMh cells. Try at you own risk.

 

[jcciv]

Why can't you underdrive a 5W with a MM?

 

[dat2zip]

MM can't put out more than 5V.

 

[jcciv]

So it won't drive a 5W at all? Just wondering. The BB 500 under-drives a 5W very well, IMO.

 

[Doug S]

[ QUOTE ]
dat2zip said:
MM can't put out more than 5V.

[/ QUOTE ]

Whoops, that's right. On the MM Wayne has tied the feedback pin [pin 1] to ground which selects the preset 5V output. Now that I think about it, there was some discussion a quite awhile back between Wayne and I about whether this IC can be made to put out more than 5V. The datasheet clearly indicates that it can but Wayne's real "hands on" experience with it suggests that in cannot. Per the datasheet, a resistive voltage divider network on the feedback pin should allow setting the output to any voltage greater than 2V.

 

[Entropy]

Theoretically, it can go to any voltage.

In reality, chances are that going much past 5V will result in loss of magic smoke.

 

[dat2zip]

The IC max voltage spec is I believe 6V, so, if you did dial it past 6V it would self destruct itself.

Maxim specializes in low voltage ICs using a low voltage CMOS process which is typically rated for 5 volt operation and a max of 6V. There are a few exceptions but if you see Maxim, think low voltage.

National, Linear Technology, TI and others make mixed mode version of CMOS or bipolar and address mid range and higher voltages.