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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
Wesdaman14 said:
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GGW-H20L 6x Sled GB!!! THE EPIC GB THREAD LAWL!!!
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
Wes, actions speak louder than words... host your own 6x group buy, and undercut these prices if you can. I know if I were hosting a group buy I'd charge an overhead fee for my trouble unless I was also dying to get some things at a real cheap price. Amkdeath is free to charge whatever he wants for the sleds, and they're a significant amount less than what was paid before. If you want to charge less, go on ahead, though you'll probably get disillusioned if you're not also making something from your effort.
Just don't go tromping into someone else's shop advertising your own wares. People will shop elsewhere on their own if they want to.
Wes, actions speak louder than words... host your own 6x group buy, and undercut these prices if you can. I know if I were hosting a group buy I'd charge an overhead fee for my trouble unless I was also dying to get some things at a real cheap price. Amkdeath is free to charge whatever he wants for the sleds, and they're a significant amount less than what was paid before. If you want to charge less, go on ahead, though you'll probably get disillusioned if you're not also making something from your effort.
Just don't go tromping into someone else's shop advertising your own wares. People will shop elsewhere on their own if they want to.
IgorT
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
How come you did a no-lens test? In my experience the no-lens power measurements can be very unreliable and not too repeatable.
What kind of difference did you get between a no-lens and a yes-lens measurement? Was the diode in an AixiZ module without a lens?
In any case, how long did it last? Was it climbing in power?
Kage said:
How come you did a no-lens test? In my experience the no-lens power measurements can be very unreliable and not too repeatable.
What kind of difference did you get between a no-lens and a yes-lens measurement? Was the diode in an AixiZ module without a lens?
In any case, how long did it last? Was it climbing in power?
Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
Far better is to put a very small resistor in series with the circuit or LD, and then measure the voltage across the resistor. If you use a 1 ohm R, the voltage that you measure will be equal to the current that's passing through it - so for example a 200mV reading would represent 200mA. This is both more accurate and safer for your LD than using the dmm's current setting.
Using the current-measuring part of a meter is not usually a very good idea for this. Most meters will have a significant internal resistance, and that could foul things up a lot. Depending on your driver circuit, setting the current with a dmm in series and then removing the dmm from the circuit could result in a significant increase in voltage to your driver - and thus also to your LD.thesk8nmidget said:
Far better is to put a very small resistor in series with the circuit or LD, and then measure the voltage across the resistor. If you use a 1 ohm R, the voltage that you measure will be equal to the current that's passing through it - so for example a 200mV reading would represent 200mA. This is both more accurate and safer for your LD than using the dmm's current setting.
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
:-?
I measured mine without a lense, to get around the variability of using different lenses; I thought that way everyone could be measuring the same thing, regardless of which lense they use.
Come to think of it, the LD mounting cylinder (heatsink) should make a difference too - because there may be side-wall reflections (or not), different lengths/diameters, etc.
DanQ
Igor, do you have any ideas on why that would be the case? Especially if care is taken to capture the whole beam in the power meter's sensor... I don't see why that should be not repeatable ??? I'm not doubting your opinion on this, just confused about why it would be that way.IgorT said:
:-?
I measured mine without a lense, to get around the variability of using different lenses; I thought that way everyone could be measuring the same thing, regardless of which lense they use.
Come to think of it, the LD mounting cylinder (heatsink) should make a difference too - because there may be side-wall reflections (or not), different lengths/diameters, etc.
DanQ
Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
I have a set of very small & very fine files, mainly designed for working with models and such, it was super easy to cut the heatsink with one and twist it off. Very easy, less then 1 min because the metal is so soft.
I have a set of very small & very fine files, mainly designed for working with models and such, it was super easy to cut the heatsink with one and twist it off. Very easy, less then 1 min because the metal is so soft.
IgorT
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
I thought so too, Dan.. But i don't trust the no-lens measurements anymore.
There are two reasons i say that:
- Theoretically, from the point where the entire output is within the active area of the thermopile, the reading should not change with distance. But if you bring the diode closer, the reading climbs, even tho the same amount of light is hitting the active area of the thermopile. It's hitting a smaller area with a higher energy density, but for a thermopile, that shouldn't matter. This could be from the IR - the thermopile measuring heat coming from the diode, so it will show more, and how much more will depend on the distance - the closer, the more FIR you will measure..
- If the diode is in an AixiZ module simply without a lens, the fast axis of the output diverges so fast, that it hits the inner walls of the module - the threads where the lens-nut is. When you use a lens, the ideal lens would be deeper in the module, than at the point where light hits the walls of the module. This way it can collect all the output and get it out. But without a lens, some light will hit the module walls. This will reduce the output.
Another possibility is, that the reflections of the light from the walls of the module cause the measurement to vary with distance, even tho the main light cone covers the active area of the thermopile from the start.
But the main reason i say that is, that every time someone measures the difference between a no-lens and a yes-lens output, they get a different percentage of difference. A part of this will inevitably come from the fact, that short wl's pass acrylic materials harder, than longer wl's, but that's usually a small percentage.
It is repeatable, if you always do it the same way, but it doesn't seem to be too repeatable between different testers.
Ideally, the no-lens measurement should be done without a module, with the diode so close, that the fast axis is within the active area, and with a FIR filter in between, with a known transmittance for 405nm. At least that's how i imagine it. I don't really know how diode manufacturers measure the raw output. It could also be a very high NA lens of known 405nm transmittance.
danq said:
I thought so too, Dan.. But i don't trust the no-lens measurements anymore.
There are two reasons i say that:
- Theoretically, from the point where the entire output is within the active area of the thermopile, the reading should not change with distance. But if you bring the diode closer, the reading climbs, even tho the same amount of light is hitting the active area of the thermopile. It's hitting a smaller area with a higher energy density, but for a thermopile, that shouldn't matter. This could be from the IR - the thermopile measuring heat coming from the diode, so it will show more, and how much more will depend on the distance - the closer, the more FIR you will measure..
- If the diode is in an AixiZ module simply without a lens, the fast axis of the output diverges so fast, that it hits the inner walls of the module - the threads where the lens-nut is. When you use a lens, the ideal lens would be deeper in the module, than at the point where light hits the walls of the module. This way it can collect all the output and get it out. But without a lens, some light will hit the module walls. This will reduce the output.
Another possibility is, that the reflections of the light from the walls of the module cause the measurement to vary with distance, even tho the main light cone covers the active area of the thermopile from the start.
But the main reason i say that is, that every time someone measures the difference between a no-lens and a yes-lens output, they get a different percentage of difference. A part of this will inevitably come from the fact, that short wl's pass acrylic materials harder, than longer wl's, but that's usually a small percentage.
It is repeatable, if you always do it the same way, but it doesn't seem to be too repeatable between different testers.
Ideally, the no-lens measurement should be done without a module, with the diode so close, that the fast axis is within the active area, and with a FIR filter in between, with a known transmittance for 405nm. At least that's how i imagine it. I don't really know how diode manufacturers measure the raw output. It could also be a very high NA lens of known 405nm transmittance.
amkdeath
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
no donations, though I did pitch in a bit to get him a slightly discounted price. He said he will do the whole testing shenanigans and such.
in the meantime, I am eagerly awaiting my V2 barrel!!! OM NOM NOM!!
also, any tips on getting diodes out of aixiz modules safely? I can do it with an open can, because the little metal backing supporting the DIE sticks up a bit so I can pop it out safely with a gentle tap using a rod and a hammer. The canned ones however reduce impact time as the rod taps, resulting in a crushed can and a diode that has not budged.
any suggestions?
back to work on that FAQ. BATCH 3 MEMBERS PAY UP!! Link on post #3 of the thread.
Kenom said:
no donations, though I did pitch in a bit to get him a slightly discounted price. He said he will do the whole testing shenanigans and such.
in the meantime, I am eagerly awaiting my V2 barrel!!! OM NOM NOM!!
also, any tips on getting diodes out of aixiz modules safely? I can do it with an open can, because the little metal backing supporting the DIE sticks up a bit so I can pop it out safely with a gentle tap using a rod and a hammer. The canned ones however reduce impact time as the rod taps, resulting in a crushed can and a diode that has not budged.
any suggestions?
back to work on that FAQ. BATCH 3 MEMBERS PAY UP!! Link on post #3 of the thread.
rkcstr
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
Some people have their own things they made using a piece of steel antenna tubing, something they machined, or I just use a small 1/4" brass fitting I got from the hardware store that I grind the outside and inside a little and it fits nicely over the can and within the hole of the Aixiz module so you can just press it right out without damaging the diode.
Some people have their own things they made using a piece of steel antenna tubing, something they machined, or I just use a small 1/4" brass fitting I got from the hardware store that I grind the outside and inside a little and it fits nicely over the can and within the hole of the Aixiz module so you can just press it right out without damaging the diode.
amkdeath
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
ok thanks.
rkcstr said:
ok thanks.
Kage
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
How come you did a no-lens test? In my experience the no-lens power measurements can be very unreliable and not too repeatable.
What kind of difference did you get between a no-lens and a yes-lens measurement? Was the diode in an AixiZ module without a lens?
In any case, how long did it last? Was it climbing in power?[/quote]
I agree IgorT. The diode was mounted in an Aixis module with a clear acrylic lens screwed in past the infinity point enough so the beam spread out over about a cm or so on the thermal sensor. I was attempting to profile this diode by taking Current and Power measurements every 10mW. The actual power measured was 130mW after the lens, and I was turning up the pot to reach 140mW when the LD turned into an LED right before my eyes - never reaching 140mW. I have been using a conversion factor of about 1.33 times the after-lens power to approximate the actual LD output power, but it is hard to verify the accuracy of that number! With all the testing you do, you probably have a much better idea what the actual loss is these lenses. Does 25% loss sound right?
IgorT said:
How come you did a no-lens test? In my experience the no-lens power measurements can be very unreliable and not too repeatable.
What kind of difference did you get between a no-lens and a yes-lens measurement? Was the diode in an AixiZ module without a lens?
In any case, how long did it last? Was it climbing in power?[/quote]
I agree IgorT. The diode was mounted in an Aixis module with a clear acrylic lens screwed in past the infinity point enough so the beam spread out over about a cm or so on the thermal sensor. I was attempting to profile this diode by taking Current and Power measurements every 10mW. The actual power measured was 130mW after the lens, and I was turning up the pot to reach 140mW when the LD turned into an LED right before my eyes - never reaching 140mW. I have been using a conversion factor of about 1.33 times the after-lens power to approximate the actual LD output power, but it is hard to verify the accuracy of that number! With all the testing you do, you probably have a much better idea what the actual loss is these lenses. Does 25% loss sound right?
IgorT
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
Oh, ok, that makes much more sense now..
I was once assuming 25% losses, which would mean there is 33% more power behind the lens, which i see is what you used.. The acrylics definitelly have a low NA, clipping the outer edges of the fast axis of the beam, a low transmittance and reflective losses. So theoretically it is possible. At least for shorter wavelengths, which pass acrylics even harder.
In the graph which was "corrected" to show the guesstimated raw output, i asked Rkcstr to multiply the powers wih 1.28. I don't really know how high the losses are, but i have some indications of how much more there is behind an acrylic lens. But it's still just a best guess.
In any case, now that i know how you did it, it's even weirder. What was the current at that point? 140mW isn't all too much. Even a PHR would survive this for many hours continuously. Are you sure you did everything right? No cap-zapping and such? I can't believe they would vary so much. As writer diodes, i would expect them to be fairly consistent.
Kage said:
Oh, ok, that makes much more sense now..
I was once assuming 25% losses, which would mean there is 33% more power behind the lens, which i see is what you used.. The acrylics definitelly have a low NA, clipping the outer edges of the fast axis of the beam, a low transmittance and reflective losses. So theoretically it is possible. At least for shorter wavelengths, which pass acrylics even harder.
In the graph which was "corrected" to show the guesstimated raw output, i asked Rkcstr to multiply the powers wih 1.28. I don't really know how high the losses are, but i have some indications of how much more there is behind an acrylic lens. But it's still just a best guess.
In any case, now that i know how you did it, it's even weirder. What was the current at that point? 140mW isn't all too much. Even a PHR would survive this for many hours continuously. Are you sure you did everything right? No cap-zapping and such? I can't believe they would vary so much. As writer diodes, i would expect them to be fairly consistent.
IgorT
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
I like my lasers to last as well.
What current did you use? Did you measure the power? I would be very happy if these diodes could provide 150-170mW of power after acrylics reliably.
Ace82 said:Blu-ray laser built! will post some pictures in a little while...
Without power meter, I'm assuming it's making 150-160mW. I like my lasers to last.
I like my lasers to last as well.
What current did you use? Did you measure the power? I would be very happy if these diodes could provide 150-170mW of power after acrylics reliably.
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
Oh, ok, that makes much more sense now..
I was once assuming 25% losses, which would mean there is 33% more power behind the lens, which i see is what you used.. The acrylics definitelly have a low NA, clipping the outer edges of the fast axis of the beam, a low transmittance and reflective losses. So theoretically it is possible. At least for shorter wavelengths, which pass acrylics even harder.
In the graph which was "corrected" to show the guesstimated raw output, i asked Rkcstr to multiply the powers wih 1.28. I don't really know how high the losses are, but i have some indications of how much more there is behind an acrylic lens. But it's still just a best guess.
In any case, now that i know how you did it, it's even weirder. What was the current at that point? 140mW isn't all too much. Even a PHR would survive this for many hours continuously. Are you sure you did everything right? No cap-zapping and such? I can't believe they would vary so much. As writer diodes, i would expect them to be fairly consistent.[/quote]
to add to this.. how many volts were you running?
when i was using my 5 volt supply it peaked at like 62mw at 200ma i used my 9 volt power supply and all was good 160mw and then it climbed
IgorT said:
Oh, ok, that makes much more sense now..
I was once assuming 25% losses, which would mean there is 33% more power behind the lens, which i see is what you used.. The acrylics definitelly have a low NA, clipping the outer edges of the fast axis of the beam, a low transmittance and reflective losses. So theoretically it is possible. At least for shorter wavelengths, which pass acrylics even harder.
In the graph which was "corrected" to show the guesstimated raw output, i asked Rkcstr to multiply the powers wih 1.28. I don't really know how high the losses are, but i have some indications of how much more there is behind an acrylic lens. But it's still just a best guess.
In any case, now that i know how you did it, it's even weirder. What was the current at that point? 140mW isn't all too much. Even a PHR would survive this for many hours continuously. Are you sure you did everything right? No cap-zapping and such? I can't believe they would vary so much. As writer diodes, i would expect them to be fairly consistent.[/quote]
to add to this.. how many volts were you running?
when i was using my 5 volt supply it peaked at like 62mw at 200ma i used my 9 volt power supply and all was good
160mw and then it climbed
IgorT
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Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!
Umm, the voltage does not matter, as long as you give the driver what it needs. The supply voltage to the driver under load has to be more than the driver's minimum input voltage.
If you do give the driver the voltage it needs, it will regulate the current by giving the load just enough voltage for the desired current to flow, and adjust this voltage, in order to keep the current constant. You can change the input voltage, and as long as it is within the driver's input range, the output voltage will not depend on the input voltage in any way - it will always be exactly what the load needs for the current you set.
If you give the driver too little voltage, things become dangerous! You may think the diode current is 200mA, but in reality, your dummy may have a lower Vf than the actual diode. Because the dummy has a lower Vf, the driver was able to regulate the current through it. But as you then switch to the actual load with a higher Vf, the driver will not be able to regulate the current through it! This is where things become interesting. As the diode works (at a lower current, than you think it works at), it slowly warms up. It's Vf drops, and as it drops, the driver can suddenly pass more current through it! After this it warms up faster from more current, and passes even more current, and theoretically, it could drop in Vf enough for the driver to start regulating the current. Or it could just climb towards the current that is actually set.
The really dangerous part is this: If you "set" (or rather think you set) the current through a dummy when the driver does not get enough voltage even to regulate the current even through the dummy, the current you see on the meter will be lower than what you actually set the driver to. As you then connect the diode to the driver, thinking that the current is where you want it, the driver will try to do it's best, but the voltage will just not be enough. If you then suddenly do give it enough voltage, the current will shoot up to where it is actually set to!
A driver out of regulation with the Vf dropping with heat, allowing more current to flow, could explain the power climbing. As could a combination of this and the wrong current setting made with a driver out of regulation.
This is why i asked you how sure you were of your current. Do you really know if it was 200mA? Was it 200mA from the start, or did it climb there as the diode heated up? Could it have been set higher (set outside of regulation)?
This is why it is VERY important to verify that the voltage is in the right range when dummy loading. If you set a constant current driver under the right conditions, the current will always be the same. If you set the driver under the wrong conditions, the current could actually be set much higher.
But you can test this, if you haven't changed the driver setting yet. Put a dummy load on the driver, and measure the current. Then make sure the driver is getting what it needs (whatever that is, different for every driver, with linear drivers it depends on the load).
To simplify: When you gave the driver 5V, the current was not 200mA. When you gave the driver the right voltage, the current was 200mA (if it was set correctly, under the right circumstances).
This could be the reason for your diode being dead. So it is quite important to set everything up correctly, or at least to figure out what happened, or the data is useless. If your power changes with the drier input voltage, then you're doing something wrong - the current is not what you think it is.
If you haven't turned the pot yet, test the driver on a dummy with a high enough input voltage. It probably is 200mA, and the climb was just from a funky diode, but it would be good to know for sure.
Umm, the voltage does not matter, as long as you give the driver what it needs. The supply voltage to the driver under load has to be more than the driver's minimum input voltage.
If you do give the driver the voltage it needs, it will regulate the current by giving the load just enough voltage for the desired current to flow, and adjust this voltage, in order to keep the current constant. You can change the input voltage, and as long as it is within the driver's input range, the output voltage will not depend on the input voltage in any way - it will always be exactly what the load needs for the current you set.
If you give the driver too little voltage, things become dangerous! You may think the diode current is 200mA, but in reality, your dummy may have a lower Vf than the actual diode. Because the dummy has a lower Vf, the driver was able to regulate the current through it. But as you then switch to the actual load with a higher Vf, the driver will not be able to regulate the current through it! This is where things become interesting. As the diode works (at a lower current, than you think it works at), it slowly warms up. It's Vf drops, and as it drops, the driver can suddenly pass more current through it! After this it warms up faster from more current, and passes even more current, and theoretically, it could drop in Vf enough for the driver to start regulating the current. Or it could just climb towards the current that is actually set.
The really dangerous part is this: If you "set" (or rather think you set) the current through a dummy when the driver does not get enough voltage even to regulate the current even through the dummy, the current you see on the meter will be lower than what you actually set the driver to. As you then connect the diode to the driver, thinking that the current is where you want it, the driver will try to do it's best, but the voltage will just not be enough. If you then suddenly do give it enough voltage, the current will shoot up to where it is actually set to!
A driver out of regulation with the Vf dropping with heat, allowing more current to flow, could explain the power climbing. As could a combination of this and the wrong current setting made with a driver out of regulation.
This is why i asked you how sure you were of your current. Do you really know if it was 200mA? Was it 200mA from the start, or did it climb there as the diode heated up? Could it have been set higher (set outside of regulation)?
This is why it is VERY important to verify that the voltage is in the right range when dummy loading. If you set a constant current driver under the right conditions, the current will always be the same. If you set the driver under the wrong conditions, the current could actually be set much higher.
But you can test this, if you haven't changed the driver setting yet. Put a dummy load on the driver, and measure the current. Then make sure the driver is getting what it needs (whatever that is, different for every driver, with linear drivers it depends on the load).
To simplify: When you gave the driver 5V, the current was not 200mA. When you gave the driver the right voltage, the current was 200mA (if it was set correctly, under the right circumstances).
This could be the reason for your diode being dead. So it is quite important to set everything up correctly, or at least to figure out what happened, or the data is useless. If your power changes with the drier input voltage, then you're doing something wrong - the current is not what you think it is.
If you haven't turned the pot yet, test the driver on a dummy with a high enough input voltage. It probably is 200mA, and the climb was just from a funky diode, but it would be good to know for sure.
