why...why...WHY!!! How acurate is the test load???

[deam_87]

Help please, i built my laser, and i used the test load from rkstr to set my microdriver to the desired mA, it said it was around 96.5 or so. but a few days later, i took my laser to the university (because i dont have a laser power meter) and it measured it was less than 20 mW... so here is my question, will the mW go that far down if my batteries are weak, (which in my opinion should not even be weak because i use 3 CR123s) or did i build my test load the wrong way, or is there a way to test the test load to see if its working???...... i made sure that the laser power meter was measuring the 405nm wavelength. I also tried it with my 5mW greenie at its required wavelength and that tested out ok, at around 4.87 mW... so please help i dont know what to do.


sorry for the crapy picture, i used my phone cause its all i had, and the "llllllaaaaaaaaaasssssseeeeerrrrrr.jpg" name was just so i could find it fast lol

oh, and i am using the rkstr driver with the DTO811 diode in it.

 

[maxkillz]

Re: why...why...WHY!!! How acurate is the test loa

yea the mW will drop significantly if your batteries are starting to die. always make sure you have fresh batteries ;D ;D

 

[Hemlock_Mike]

Re: why...why...WHY!!! How acurate is the test loa

I'm not familiar with that meter -- is it a thermal head or silicon sensor?
Is your reading calibrated for the nM of the laser?

Mike

 

[deam_87]

Re: why...why...WHY!!! How acurate is the test loa

I'm not familiar with that meter -- is it a thermal head or silicon sensor?
Is your reading calibrated for the nM of the laser?

Mike

damn, you got me there, but i went to a lab at the university, where they work with very complex laser systems. so i hope they knew what they were doing. i did see though, that he switched it from like 808nM to 405nM....this is the link to the website that sells it http://www.coherent.com/Lasers/index.cfm?fuseaction=show.page&ID=1023&loc=1007&ShowMe=More

 

[rocketparrotlet]

Re: why...why...WHY!!! How acurate is the test loa

Isn't that too much current? If CR123's are 3.6V each, you will have 10.8V going through. I thought you were supposed to keep it under 10V, but I could be wrong.

-Mark

 

[Mohrenberg]

Re: why...why...WHY!!! How acurate is the test loa

Isn't that too much current?  If CR123's are 3.6V each, you will have 10.8V going through.  I thought you were supposed to keep it under 10V, but I could be wrong.

-Mark

i thought it was 12?

and yes your laser will get weaker as the batteries run down....but if it's that close you should just turn it on and it shouldn't take long for them to go dead....you'll know then.
anywho, go ahead and check your batteries first.

rkcstrs test load is very simple, hard to get it wrong putting it together.

btw is your rkcstr driver fixed output or adjustable?

 

[CRFultz]

Re: why...why...WHY!!! How acurate is the test loa

If the batteries are good, and since you are using a rkstr driver, open the circuit and measure the amperage.
You can remove the tail cap and measure between the negative of the cell and the battery case if that apply's to your host.

 

[deam_87]

Re: why...why...WHY!!! How acurate is the test loa

[quote author=rocketparrotlet link=1232681573/0#4 date=1232693954]Isn't that too much current?  If CR123's are 3.6V each, you will have 10.8V going through.  I thought you were supposed to keep it under 10V, but I could be wrong.

-Mark

i thought it was 12?

and yes your laser will get weaker as the batteries run down....but if it's that close you should just turn it on and it shouldn't take long for them to go dead....you'll know then.
anywho, go ahead and check your batteries first.

rkcstrs test load is very simple, hard to get it wrong putting it together.

btw is your rkcstr driver fixed output or adjustable?[/quote]


Its adujstable, only thing i can think of is that it changed when i was puting it all inside the housing...

 

[deam_87]

Re: why...why...WHY!!! How acurate is the test loa

If the batteries are good, and since you are using a rkstr driver, open the circuit and measure the amperage.
You can remove the tail cap and measure between the negative of the cell and the battery case if that apply's to your host.

i will try and do that, im at school now, its 11:30 here and i dont get out till 4 so ill check back then... thanks

 

[laserfreak3d]

Re: why...why...WHY!!! How acurate is the test loa

Help please, i built my laser, and i used the test load from rkstr to set my microdriver to the desired mA, it said it was around 96.5 or so. but a few days later, i took my laser to the university (because i dont have a laser power meter) and it measured it was less than 20 mW... so here is my question, will the mW go that far down if my batteries are weak, (which in my opinion should not even be weak because i use 3 CR123s) or did i build my test load the wrong way, or is there a way to test the test load to see if its working???...... i made sure that the laser power meter was measuring the 405nm wavelength. I also tried it with my 5mW greenie at its required wavelength and that tested out ok, at around 4.87 mW... so please help i dont know what to do.


sorry for the crapy picture, i used my phone cause its all i had, and the "llllllaaaaaaaaaasssssseeeeerrrrrr.jpg" name was just so i could find it fast lol

oh, and i am using the rkstr driver with the DTO811 diode in it.

u probably just killed the diode during the extracting process or while desoldering the pcb board
95 mA should be a ok setting for these diodes
i run both of mine at 100 mA one doing 50 mw and the other doing 75 after the aixiz glass lens

my 50 mw diode was very hard to get the pcb off so that one probably sufferd from a heat stroke

 

[deam_87]

Re: why...why...WHY!!! How acurate is the test loa

[quote author=chIno link=1232681573/0#0 date=1232681573]Help please, i built my laser, and i used the test load from rkstr to set my microdriver to the desired mA, it said it was around 96.5 or so. but a few days later, i took my laser to the university (because i dont have a laser power meter) and it measured it was less than 20 mW... so here is my question, will the mW go that far down if my batteries are weak, (which in my opinion should not even be weak because i use 3 CR123s) or did i build my test load the wrong way, or is there a way to test the test load to see if its working???...... i made sure that the laser power meter was measuring the 405nm wavelength. I also tried it with my 5mW greenie at its required wavelength and that tested out ok, at around 4.87 mW... so please help i dont know what to do.


sorry for the crapy picture, i used my phone cause its all i had, and the "llllllaaaaaaaaaasssssseeeeerrrrrr.jpg" name was just so i could find it fast lol

oh, and i am using the rkstr driver with the DTO811 diode in it.

[highlight]u probably just killed the diode during the extracting process or while desoldering the pcb board[/highlight]
95 mA should be a ok setting for these diodes
i run both of mine at 100 mA one doing 50 mw and the other doing 75 after the aixiz glass lens

my 50 mw diode was very hard to get the pcb off so that one probably sufferd from a heat stroke
[/quote]



but it still lases, and if i add some smoke, i can see the beam. and i dont think it will produce 20mW if it lcd on me or can it?? or does a diode also act this way if its "dead"

 

[potatorage]

Re: why...why...WHY!!! How acurate is the test loa

a "dead" ld can usually put out a focused dot, but it should not even measure on a powermeter, at most <5mW

 

[daguin]

Re: why...why...WHY!!! How acurate is the test loa

but it still lases, and if i add some smoke, i can see the beam. and i dont think it will produce 20mW if it lcd on me or can it?? or does a diode also act this way if its "dead"

Usually, if a diode breaks down, it will produce less than 5mW.  I would check the current in the operating laser.  It is quite possible that it is NOT actually giving the diode 98mA because of either a poor connection or your batteries not actually putting out what you think that they are.  20mW out of 98mA for a DT-0811 would be odd.  I wouldn't call it impossible, but it would be strange.

It is also possible that the measurement was problematic at the lab.  Even EXPERTS make mistakes.  Will it focus enough to burn stuff?  Can you light a match with it?

Peace,
dave

[highlight]**EDIT** [/highlight] Is the lens clean and clear? What kind of lens is it?

 

[deam_87]

Re: why...why...WHY!!! How acurate is the test loa

here is another.

 

[deam_87]

Re: why...why...WHY!!! How acurate is the test loa

ok thanks guys, im going to re-solder all my connections and go on from there.

 

[daguin]

Re: why...why...WHY!!! How acurate is the test loa

here is another.

Nice pic's.  However, it is impossible to tell anything about how much power is being produced from such pictures.

Peace,
dave

ok thanks guys, im going to re-solder all my connections and go on from there.

I wouldn't get "invasive' until you know there is a problem. Have you measured the current in the operating laser?