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Kiplay's at it again! This time - BluRay!

Things

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well i can't find it on the forum ATM, but i have seen this said here! although a fully new 9V battery, not loaded can float up to even 12V , so when you hook that to your diode, it gets a spike higher than it is meant for. yes a resistor _may_ work BUT adding atleast a capacitor would work even better, but using this simple method, the diode will not last as long as it would with a proper driver circuit, and cooling. as i said above, people truly into lasers, want their diode to last as long as it can, whereas people who have never touched a laser, or are knowledgeable about them, will just use a resistor, since they don't care about the life time or performance, they just want to get it working.
 

Things

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yeah i know it has been said, its just that i can't be bothered going through something like 13 pages of threads looking for it :D
 

Daedal

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;D

There is definitely a spoke... I do see spikes as high as twice the battery charge... and on some CR123A it's up to 3 times as high with a good jolt to it too :eek:

The safe distance to calculate for is 10X as things said... but the resistor is too high that it will dull most of it... but the spike is still there.

Diode hate spikes... and a soft start even in the order of nanoseconds is better for them on the long run... much better.

I do see a lot of problems with a resistor... but then again, what can you say? ::)

GL to whoever decides to go that route ;)

--DDL
 

WahHK

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Then shall I use a BIG BIG capacitor to create a slow start?
e.g. 3F 16V cap ?
 

Things

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yep, if you want a slow startup, and long slow down, use a bigger cap. anything from 47uf and up should work for spikes, and higher than that will create the slow start.
 

Benm

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Daedal said:
There is definitely a spoke... I do see spikes as high as twice the battery charge... and on some CR123A it's up to 3 times as high with a good jolt to it too  :eek:

The safe distance to calculate for is 10X as things said... but the resistor is too high that it will dull most of it... but the spike is still there.
I think it's crazy, no battery delivers 10 or even 3 times its nominal voltage when unloaded. You can verify this easily by measuring with a multimeter of even scope with x10 probes. You can expect 10% over nominal, perhaps 20% in a rare case, but no more than that.
 
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Uh god... 9V instead of 4.5, and 1.5A instead of 60mA...
Damn I hate this bastard! People! Let's go and put kerosene in a family car, and you get a "jet car" for under $100.000! I wonder when he's gonna invent that! :mad:
Jackass...

PS: Sorry if I overreacted, this really pisses me off.
 
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SenKat

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Da_Dude said:
[quote author=spyrorocks link=1194391816/0#8 date=1194411554]Luckily, that guide is what got me interested in lasers :)
Same here!
And, my chair leg just broke.
It skared the hell outa' me. :eek: :eek:
And my but hurts....
:([/quote]

Okay - THAT is funny as hell ! :) HAHAHAHAHAHAHAHA ! {Sorry to laugh at your misfortune, man...we have GOT to be related ! LOL !!!!!}
 
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SenKat

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I am waiting for Hemlock Mike to chime in on the voltage/current facts... I definitely respect his knowledge, as well as 99.9% of the members here ! Catdog brings up a marvelous point, as does Benm - diodes need to be regulated by current, not by voltage, right ? So - in THEORY....if I were to hook a BR diode up to my CAR BATTERY....given enough resistance to bring it down to 20ma (regardless of the voltage) the diode will light up, and enjoy a nice, long, happy, life ! Anyone else care to chime in here about the whole V=!/R mystery, and such as that goes ? Put on your thinking caps, TRY to be objective - put aside your hatred for Kipkay, and his immensely successful tutorials - ones that have brought literally HUNDREDS of people to this forum, and to my site for diode purchases - and THINK about it....Stating the obvious, Jealousy is a rotten SOB - try to remove your feelings, and trust the science a bit - let's see what kind of answers we come up with then :) This preceding message is not meant to flame ANYONE, or any ideas - it only serves as "Mental Floss" to stimulate healthy neuron firings ! :)
 

IgorT

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In my opinion, anyone who can buy a resistor, can also buy a capacitor. Anyone who can solder the resistor, should be able to solder the capacitor.. I mean, what's one more element?

It would still not be as good as driver circuit, but would at least soften the blow to the LD at switch on/off.


One problem, that would still remain, is the current climbing, from heat. As the LD heats up it's resistance drops, which means the current goes up. More current means more heat, which causes the resistance to drop even more, and this can sometimes kill the LD.
I don't know how much the BRs heat up and what this heat/resistance relation is there, but i've seen it happen on red LDs.

Current regulation solves this problem, as it drops the voltage a little, when the resistance drops, for the current to stay the same.


I'm hoping my two BRs come soon, and i hope to learn more when they do. It's possible this is not even such a big issue there. But one capacitor would definatelly not hurt.
 
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SenKat

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Oh - do not get me wrong, a capacitor definitely cannot hurt ! I am just stating the facts - LD's are current ran devices....I coulf, in theory put 400v through a LD if my current was low enough, and it would run until the stated DOD (Date Of Death) which is normally >/= 5,000 hrs for dvd/BR diodes. Make sense ?
 

IgorT

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SenKat said:
Oh - do not get me wrong, a capacitor definitely cannot hurt !  I am just stating the facts - LD's are current ran devices....I coulf, in theory put 400v through a LD if my current was low enough, and it would run until the stated DOD (Date Of Death) which is normally >/= 5,000 hrs for dvd/BR diodes.  Make sense ?
SenKat..

I'm not getting you wrong.. I'm on your side. I also agree current regulation is better. All i said was, if people HAVE to avoid it, they could at least use a capacitor.. BTW: I was responding to the thread, not your post, or i would have quoted you.. Ok? ;)


But i remembered another problem with that circuit.. KipKay's BR obviously lases nicely at 27mA. That doesn't mean others will as well. We've seen here their tresholds can vary A LOT!

Someone with a higher treshold BR could then assume his is broken, or that he killed it, while in reality he just needs more current. So the absolute minimum should be a resistor for limiting the max current, a pot for adjusting it and a cap. And i'm saying this for those, who have an aversion to current regulation ONLY. If they are alergic (maybe they break out in hives) and HAVE to avoid it, this should still be the minimum amount of parts used.
 
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SenKat

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IgorT - I see you point perfectly, regardless of quotes and what not :) If folks are allergic to driver circuits, IMO they should buy one ready made - leave the fun and experiments up to those of us that really enjoy making and breaking stuff :)
 

IgorT

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SenKat said:
LD's are current ran devices....I coulf, in theory put 400v through a LD if my current was low enough, and it would run until the stated DOD (Date Of Death) which is normally >/= 5,000 hrs for dvd/BR diodes.
BTW: You can't really feed the LD 400V and a low current. It's impossible, in theory or otherwise..

You could perhaps run it off of 400V with a huge enough resistor, to drop 395.5V and get 4.5V on the diode and the desired current, if this is what you meant... But the LD would never see this high voltage.. Or if it would, then only for a nanosecond... ;)
 

marconi

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Hi Guys and Gals

I figured I have visited so many times I better reg and say HI :)

Some of you may know me already from maXYZmodules and from PL
I've been following the progress on this board and watching it grow and grow with many good folks since it started..figured this would be a good time to jump in and make a first post.

Wow, this guy Kiplay.   [smiley=rolleyes.gif] ..I hope he has a drawer full of diodes to pump into his new toy.
Anyone who has been around laser diodes long enough has figured it out by now that they are easily damaged quickly by mis-handling and that includes quick and dirty drivers. I know.. I tried every circuit there was and blew-up enough diodes to buy a house..no joke.

While it is true that laser diodes are current devices..they need stabilty in the way they are lit-up. A good rule of thumb is never drive them without spike protection..that includes directly from battery supplies..you might get away with it if the batteries internal resistance is high and only a volt or two unloaded above the diodes Vop. But it only takes that one spike to render all your work put into your project to make that diode turn into an LED.. nothing new there. Altho some dont really care , they would just get another diode.. some of us just cant away with that with the high cost of really good diodes. It gets expensive...anyway.

I have to comment on Kiplay's claim on being the first person to install a BR diode into a Phaser...
For the record back in November of last year when Spec from PL came down to visit . we built several BR units a few using dorcy hosts..
a few into our maxyz. while robert and I were busy doing that Maxy (the_kcar) installed a lower powered BR diode into one of these Phasers.. It looked prettycool, but I liked the dorcey a bit better, less noise and pocket sized.

In fact she made one for green (~60mW and my favorite) and one for red (250mW). altho Im not much of a pointer type of guy ( I get bored too easy) she likes glowies a lot and so she had to do it, We just didnt advertise the fact. we figured knowone would care.
I didnt have the heart to show her Kiplay's unit and claim.. but figured she would sometime... And believe me , none of them are direct drive, hehe.

Ok... Thank you for letting me get that out of my system  [smiley=vrolijk_26.gif]

Now, Back to our regular scheduled program...
 




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