Micro Flex v.s. O-Like

[GVLLD M981]

I finally understand the importance of, and have constructed a dummy load (thanks, everyone!!). Let me start by saying that it's constructed wrong, that is, I hurried one together from what I had, which were 4004 diodes, and not 4007 diodes (I ordered some), mine measured a drop of something like .87v across, not the point seven something that they should, so my numbers can only compare to each other, and not to yours, but that's what this is really about.
I built my first laser with one of those 445nm diodes, and I started with an O-Like driver, it was half the price, and I liked that there was nothing to solder, or adjust. I got 2 Micro Flex Drives (and another diode to play with) the other day, and after soldering (I thought I destroyed one doing it, I had trouble with this, I don't see as well as I used to) the jumpers, and some tweaking of the pots, I managed to coax (measured across the one watt, one ohm resistor I used on my dummy load) 1.05 from one, and 1.07 from the other. The O-Like driver, I did to compare it, does 1.03. I'm not sure than the Micro Flex Drive was worth the extra money, and the extra fuss. It is much smaller, and thus better for tight placement, I don't think that the O-Like driver is going to fit into a 12 x 50 module case.
I'm not sure where I was going with this, but I thought I'd share that, since I had the one to compare to the 2 others.
This is the O-Like driver I am refering to:
1W 445nm laser diode driver / 200mW 405nm laser diode driver [OL-445-405-D] - $12.99 : Zen Cart!, The Art of E-commerce

I thought I should have added that I tested these all from the same, single 18650 cell. I know that it's possible to use 2 lithium cells with the Micro Flex Drive, with the addition of a diode, possibly that is what is required to exploit the difference in the rated power output. The O-Like driver is only rated for 1.1 watts, although for all intensive purposes, the difference I can measure between them in a controlled test is negligable.

 

[foulmist]

umm just to inform you the 4001 through 4007 are the same diodes...only difference are the voltage ratings which whatever you use in this dummy load won't matter...

the reason why you get 0.87V drop is because these diode's Vf vary with the current passing through them from 0.7 to 1V and somewhere around that.. the bigger the current the bigger voltage drop you will get...

another thing you can't use 1N400X diodes with current above 1A they are rated for currents up to 1A ... for greater currents you can use 1N540X series which are up to 3A also use a big wattage resistor as it gets really hot (so do the diodes) and heat pretty much alters the readings you get.. more heat means more current (not good) my dummy load consists of 1N5408 diodes and 5W 1ohm resistor and even they get warm and sometimes hot if it operates longer :beer:

 

[GVLLD M981]

Thanks for the info, I'm learning still, I can admit it. I'm glad you pointed that out before I built another inappropriate dummy load, since it looks very much like I was about to just that.