stonetek 16x sony closed can

[brtaman]

i have 2 of the 5ohm
i will just connect them parallel then
give me 2.5ohm that is 500mA limit

That sounds good just be careful with the pot then. What is the range on your pot? Do you have any extra 1 ohm resistors? You could add those in series to the 2x5 parallel resistors which would get you to 3.5 ohm or around 357ma, much safer. Trust me when it comes to these laser diodes, it is always better to go the extra mile, will make you a much happier man later. :beer:

 

[rajkosto]

100ohm
waaaay sensitive at the lower range
after that, one turn makes it jump from 300 to 500

i have it set at 300mA now, cant wait for my diode to arrive

is there a special way of putting it into the aixiz module...my older diodes that are fail dont really fit...the one that came with it fits perfectly, but that one is shiny at the edge...the others arent

 

[Morgan]

If theAixiz module was new when you still had a working diode in it, then you have plenty more diodes to squeeze into the module! Because they are a press fit. Once you extract the dead one, it will measure slightly smaller than a new one.

The one of the commonest and easiest ways to press a new diode in is to use the hole in the other end of the module, (The part that usually protects the driver), to go over the pins and slowly squeeze the two together in a vice. Be careful to press the diode in evenly and flush.

Then comes the soldering...

(There is a link on Youtube by Styropro with a tutorial for the PHR harvest that shows the pressing quite well. Hopefully it will be back in the tutorials section soon.)

M

 

[rajkosto]

how do i get it out after that without breaking it ?

 

[Darkarmyofone]

thats a whole different story... you'll be INCREDIBLY lucky if you can get a diode out without damaging/killing it. but if someone knows a way PLEASE share.

 

[danq]

With a linear driver such as a DDL, you can measure the current without hooking the driver up to anything. Just hook the driver up to batteries and attach the DMM to the + - leads going to the diode.

No, that doesn't measure the current!
That would be measuring the voltage across the diode, which is not linearly related to the current.

Actually only one current-measuring method posted in this whole thread will work: measuring the voltage across a 1-ohm resistor that is in series with the LD. The number of millivolts there will equal the number of milliamps going through.

For circuits like the LM317, you can also compute the current based on the feedback resistor and the feedback voltage (as described for the LM317 driver above).

I really don't want to sound too harsh or anything, but you guys who don't really know basic electronics should not be giving advice about such things. Sorry if that doesn't sound nice but part of knowledge is knowing what you don't know...


DanQ

 

[Darkarmyofone]

i think everyone is entitled to their opinion on this dan, i mean if someone ISNT sure about what they post... they usually mention so. and its the responsibility of the "thread starter" in this case to take what he reads with a grain of salt, as ANYTHING anyone sais could POTENTIALY be incorrect if you think about it.

im sure all anyone meant to do here was to hand off some helpful hints to rajkosto. he's new, but hes a fast learner... i think he'll manage just fine.

so Rajkosto... has any of this information helped you in your quest for laser burning goodness?

BTW wasnt being mean... hard to add tone of voice with text lol

YES i gave the only right method for measuring Ma MWAHAHAHAHAHA i am all that is man!.....just kidding, lol

 

[Morgan]

Hi,

how do i get it out after that without breaking it ?

The simple answer is that you don't remove it until it's dead. The press fit is the way it is to ensure good thermal contact and to permanently mount the diode. Once in the Aixiz; it's there to stay. If you try and remove it, you'll likely break the glass window and deform the diode can.

Danq - You a quite right. I try to stay away from giving the electronics advice, (as I have little to contribute!), but I can see bad things happening if someone blindly followed this thread. I would suggest using the, "search", button and doing some trawling. Most of the info is still there since the move. It's just buried in old threads and takes time to find but be patient. *Edit. Once you do find it, please post it again so it is in a current thread.*

Still not asked Stonetek? He'll explain all about the, "Dummy Load", test circuit... Or, use the, "Search", button to find out how to make one.

M

 

[Darkarmyofone]

yeah, i wish all the old tuts and whatnot were organized here as well, the switch was a pain in the arse.

maybe its just me but i havent noticed any horribly wrong information in this thread. maybe a few ideas on how to calculate Ma werent correct. but other than that it seems fairly straight forward to me i guess...

OH i almost forgot. i found that if your working with OPEN CANS (mainly short ones) you can take one of the bars that the diode sled moves on and take your lens out... then CAREFULLY line up the end of the rod against the LIP of the open can, and line it all up in a vice "back of your aixiz module must be on or the diode will crush into the vice" and very SLOWLY tighten it... just tried this for the sake of kowing... and the diode STILL works.

i know what your thinking...why would i risk a diode just to prove a point... well this diode was my "backflashed" diode. it still worked but only put out about 20-30mW. i popped it out and wired it up to an LM317 and SHABAM! she still works.... so it CAN be done. DO NOT TRY THIS METHOD WITH CLOSED CANS, YOU WILL BREAK THE GLASS WINDOW, i speak from experiance.

and remember this works most of the time... but not always. it requires a steady hand and patience

Dark

 

[brtaman]

No, that doesn't measure the current!
That would be measuring the voltage across the diode, which is not linearly related to the current.

Actually only one current-measuring method posted in this whole thread will work: measuring the voltage across a 1-ohm resistor that is in series with the LD. The number of millivolts there will equal the number of milliamps going through.

For circuits like the LM317, you can also compute the current based on the feedback resistor and the feedback voltage (as described for the LM317 driver above).

I really don't want to sound too harsh or anything, but you guys who don't really know basic electronics should not be giving advice about such things. Sorry if that doesn't sound nice but part of knowledge is knowing what you don't know...


DanQ

Uhm, yes it does, I don't claim to be knowledgeable in electronics far from it.

But hooking a multimeter up to the + - leads coming out of the driver and setting the multimeter to current will measure current. It will short the driver and heat up the regulator yes...but current will be measured...I don't remember saying to hook up the DMM in voltage mode...?

Just like hooking up the DMM before the batteries will also measure the current going into the diode....linear driver...

 

[danq]

Thanks Morgan -- yeah, it's hard to say some things without sounding mean; but like you said, following some of the advice could ruin diodes for someone who can't afford a lot of re-try's. I'd rather be the meanie who made someone think about what they say, than the meanie who made someone blow their only diode!

That said, I do try to not butt in too much - realizing that a lot of folks here are young and have some learning to do. On the other other hand, that's why I said part of wisdom is knowing what you don't know ;-)

Now let's all go out and make some light!
I just ordered a 1 Watt red diode (from Huurur...) and I'm going to toast some weeds in my garden!
:beer:
DanQ

 

[brtaman]

Thanks Morgan -- yeah, it's hard to say some things without sounding mean; but like you said, following some of the advice could ruin diodes for someone who can't afford a lot of re-try's. I'd rather be the meanie who made someone think about what they say, than the meanie who made someone blow their only diode!

That said, I do try to not butt in too much - realizing that a lot of folks here are young and have some learning to do. On the other other hand, that's why I said part of wisdom is knowing what you don't know ;-)

Now let's all go out and make some light!
I just ordered a 1 Watt red diode (from Huurur...) and I'm going to toast some weeds in my garden!
:beer:
DanQ

Please read my posts and explain to me how I am wrong in my statement. If you accuse me of spreading faulty info (which seems to work on every LM317 driver I have built), then please be kind enough to reply to my argument.

 

[danq]

Uhm, yes it does, I don't claim to be knowledgeable in electronics far from it.

But hooking a multimeter up to the + - leads coming out of the driver and setting the multimeter to current will measure current. It will short the driver and heat up the regulator yes...but current will be measured...I don't remember saying to hook up the DMM in voltage mode...?

Just like hooking up the DMM before the batteries will also measure the current going into the diode....linear driver...

Yes, of course that measures current - but not the current that the LD will draw.

Your latter point is better, but still won't measure the diode current very accurately. There's this thing called "insertion loss", and a dmm set on milliamp ranges very likely has an impedance that will change the working of the circuit.

 

[danq]

forgot to add explanation:

both of those 2 methods I just posted about will work if you have a dmm with very low impedance... but most dmms only have very low impedance on the amp scales, which aren't as useful in careful calibration of milliwatt diodes.

 

[danq]

DO NOT TRY THIS METHOD WITH CLOSED CANS, YOU WILL BREAK THE GLASS WINDOW, i speak from experiance.

Dark, actually it can be done, if you have just the right diameter & thickness metal tubing. The tubing goes either all the way around the diode can; or just exactly sits on the shoulder at the tip.

DanQ

 

[brtaman]

Yes, of course that measures current - but not the current that the LD will draw.

Your latter point is better, but still won't measure the diode current very accurately. There's this thing called "insertion loss", and a dmm set on milliamp ranges very likely has an impedance that will change the working of the circuit.

Yeah I use the 10amp setting which to my knowledge has a very low impendance.

I only mentioned this method, beside the LM317 1.25/R method, because I have used it before and it worked quite well.

Just one question, how can the current be different to the diode as opposed to the multimeter, when the LM317 is itself limiting the current.

Ex. one driver I have set up, has a 4 ohm resistor, when set to maximum (pot turned to 0 ohm), my multimeter when shorting shows .31 amps...it also shows the same current when measuring current out of battery. 1.25/4...312.5 ma ...so it is right on the money.

I would like an exact description of how the method I presented, just one of the methods mind you (reference/R, was the one I talked about in the later stages of the thread.)

Saying that the measurement wont be exact, is a true statement. Yet one of the major ways of setting current on this forum is based on using diodes for simulating a Vf which is supposed to be similair to the diodes at a given current and measuring voltage through a 1ohm resistor. Yet the Vf of the diode changes with current and not all diodes are the same. This causes quite large differences in output current on the flexdrive, yet is deemed accurate enough for use on this forum.

Even though: Vf is never or in extremelly rare cases the same on a test load and diode.

There are drastic differences in output current on a flexdrive when setting at a different Vf

I believe the shorting method of meassuring the current a diode will be subject to, accurate enough within the scope of what we do on this forum...on LM317 drivers.

As I said I am absolutely open to your suggestions or corrections, yet these methods have helped me build quite a few LM317 based lasers in my time on this forum