Lazeerer,
Hey. I'm going to be a nit-picky arse here for a second. I just want to clear up a common misconception about this. And maybe you can save some of your time and money.
A good clean transient and a current spike are two different things. Soft start is a nice place to start - but it doesn't really protect from spikes. Lots of times, soft start features are built into smps controllers and ICs because the nature of the smps' start up sequence goes:
A) Begin current flow
B) If error signal is detected, regulation starts up next
C) Allow current
D) Repeat between B and C for entire remainder of operation
The IC cannot regulate anything if there is no error signal, and error signals comes from currents/voltages that are different (higher/lower) than the set value. The "inrush" of current in step A can be more carefully controlled with an very good IC. But an ideal/fast chip will regulate BEFORE a large error signal is created. Most ICs can get away without it just fine - those were probably made for LEDs.
If your startup is halfway decent, a good current spike can still ruin your day by the end of it all. So go ahead and whack the diode with straight up square waves all you want, and it will be just fine. Slow starting it only "rounds" off the front edge of the transient - it doesn't protect the diode from extra-driver-related spikes and the mis-handling caused ones too.
If you're super paranoid - go ahead and just install capacitors on the inputs and outputs of your circuit, and enjoy the steady state stability. But if an actual spike comes your way, be ready with something like a ground short or a LASORB.
The only thing I've seen work consistently, is the LASORB. You can toss your laser diode into a fooking telsa coil if you like - if you've got one of those.
So you could spend all day reading datasheets about smps IC regulation stability and transient control, or you can spend $8 on a little plastic square to do away with your worries.
/boring lecture
Hey there buddy.
I think you gave this Lecture to the wrong member.
This is why i only use my laser drivers because they dont have these issue because i designed them not to.. No one has ever kill a diode due to my drivers causing the issue.
Iam not having any issue with killing diodes to be clear or driver issue to be clear and thats why i showed the video because Rick killed 2 On an UNKNOWN driver.
The soft start iam speaking of is not the built in one that comes on SOME IC's that you are referring to. It is addition to that.
Alot of overseas drivers do not have any kind of protections but maybe a few caps good enough for LEDs and sadly i would not even say LEDs on some drivers Ive seen.
Adding too much Capacitance on the input or output or both can really mess with the Ripple and make the driver perform badly. I would not mess with that unless the driver you bought was not designed correctly and is missing the correct amount of capacitance needed.
Ive added addition Soft Start Sweep to all my lasers drivers i sell these days and can make the sweep up to power pretty much as long as i want. It will never Jump past 50% of the set sweep. I have talked to custom diode makers of rare wavelength diodes with a few Ive bought over the years and the few people in there engineer area have told me countless times a soft start & or "Sweep" to full currant is very important for sensitive diodes.
This is why you see it on ALL high end laser Lab systems. (Like JDSU,MG Coherent etc...) They all have it. I have quit a few different systems and have looked over there controllers for some time now and its usually a 5-10 second soft start sweep.
Its why i have additional soft start on all my Drivers now. I cant even remember how many drivers Ive sold over the years but i have never had one tell me any of my drivers where responsible for killing there diode, so any of the X-Line drivers are all OK.
The issue that people always seem to have is with use of Unknown or LED drivers or very cheap laser drivers from Onehunglow.
Very rarely you ever here someone having issue with any of the laser drivers sold on this forum let alone my laser drivers.
So i dont have the issues you mention though i know many have..
Maybe i was not detailed enough.
But to be clear I do not have any issues with drivers i use or Make.
All my drivers have input and out caps. Of course.
Did you forget what drivers i make.?
Good lecture though iam sure it will help a few.:beer:
It was not boring.:beer:
+4
Rick,
That lab style heatsink setup is OK for testing purposes. Its not large enough.
Further More the Lens.! "IT SUCKS" LOL
Seriously it not glass and is coated for High IR. Unless they have changed it for different model then i dont know but the power loss is crazy. Almost 50%.
It does make a OK beam thats for sure but i would not dare use it.!
I replaced it with a Similar lens to my 50mm lens i showed in the beginning.
I did a thread a long time ago on it.
You can see the thread here.
http://laserpointerforums.com/f46/lab-c-mount-housing-67701.html
I took plenty of picture in that thread. I even modded one for better performing for 5.6mm diodes and using a stock 12mm module in the thread.