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New SHARP 450nm 1650mw

DTR

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The data projector diodes have a fair amount of headroom so the machine can increase current to compensate and make up brightness as it accumulates hours, likely as it gets warm too, they are really robust and I remember when they used to fail if pushed too far, now they bounce back, but I bet this sharp will pop and go LED like the early projector diodes would.

Yea the Osram diodes are like that.. Take the PLTB450B. It will blow not go into a state like the N!ch!a where it will get to hot to the point that lasing literally shuts down. Think it is due to expansion in the diode but will come back when turned down. The PLTB450B has a 1.2A nominal and 1.6A max. it holds its curve well past 1.8A. Looks like the hard knee comes in around 2A which if you try to set up a unit with 2A it will not last long. I find the osram and sharp diodes are similar or at least compared to N!ch!a or mitsu diodes.
https://laserpointerforums.com/threads/osram-1-6w-pltb450b-450nm-laser-diode.87402/

If this is similar then I would think 1.6A is well in the danger zone for this diode but this is only one example.


@ paul
This is my diodes actual pinout

64108

That is what I would expect as I have never seen a two pin or case neutral three pin with the polarity as described. Probably a typo when editing the datasheet to sell with these diodes.
 
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RedCowboy

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Ok I only have the 1 diode on hand so I can't compare against another but here's a crude test with a DTR G2, seems like it doesn't like more than the 1.6a factory max rated current.

 

trinh hong phuoc

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Looking at the parameters, this is probably only 50% correct, a bad datasheet, maybe they were drawn by the sellers.
64118
 

DTR

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Ok I only have the 1 diode on hand so I can't compare against another but here's a crude test with a DTR G2, seems like it doesn't like more than the 1.6a factory max rated current.

Ok I only have the 1 diode on hand so I can't compare against another but here's a crude test with a DTR G2, seems like it doesn't like more than the 1.6a factory max rated current.


Yea you have to push to the max just to get the typical power with a G-2. It should be quite a bit over at max. Also the forward voltage is way off typical @ 1.2A you are showing 0.5V under where it should be and pushing it all the way up to 2.2A just gave a 4.6V/4.7V flasher on your display. So if these values hold with other samples this diode in my opinion is not even close to what is described in the datasheet.

I was told to expect SB478L691 compared to your SB478JN91 and the SB478K91 in the OP. So we can see if these batches are different.

My perception has always been that a secondary effect of thee extreme binning most LED''s and LD"s go though give them unsurpassed quality control as just about any defect that would affect the diodes reliability or efficiency would be brought out during that process. I find when I am working with my extremely reliable sources(not china) I can't note ever receiving a defective diode or one I could say with certainty that it was not damaged. If defective or not meeting spec or reliability then that is more than likely the bin they were sold as from the manufacturer. They sell off defect bins or undesirable bins to gray market sellers to get rid of them. I noted on the 490nm diodes they were tested for the batch to only have average failure between 500 hours and 2000 hours. While nice diodes for us to get that sounded strange. Why so short. Were they dumped as they did not meet the specs of the intended end users.
 
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RedCowboy

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Yes I noticed the different can numbers, it's not as special as I hoped, I think the osram pltb450b is better.
 

paul1598419

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My point on the data sheet is concerning the pinout of Sharp diodes in particular. Most, if not all, are taken from the top of the diode. Now this data sheet may be thrown together by the seller, but it may be that they took the pinout as it was expressed in the original data sheet. I know I can't be the only one who has seen the pinout of these diodes taken from the top of the diode.

Besides, the pinout is exactly what I would expect it to be. If you take it from the bottom of the diode it looks backward to what I would expect.
 
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RedCowboy

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My point on the data sheet is concerning the pinout of Sharp diodes in particular. Most, if not all, are taken from the top of the diode. Now this data sheet may be thrown together buy the seller, but it may be that they took the pinout as it was expressed in the original data sheet. I know I can't be the only one who has seen the pinout of these diodes taken from the top of the diode.

Besides, the pinout is exactly what I would expect it to be. If you take it from the bottom of the diode it looks backward to what I would expect.

The diodes can window is drawn in dash dot dash dot denoting you are seeing it through the back of the diode, so they mixed up the pins number 1 and 2 between the 2 drawings, my pic at the bottom is correct.

6413064131
 

Lifetime17

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The diodes can window is drawn in dash dot dash dot denoting you are seeing it through the back of the diode, so they mixed up the pins number 1 and 2 between the 2 drawings, my pic at the bottom is correct.

View attachment 64130View attachment 64131
Hi,
Now this is the correct pic of the pin out, When I look at my diodes the notch I set to the right with the POS+ pin on top.
Thank you Red good drawing stating the correct pin positions.

Rich:)
 

paul1598419

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The diodes can window is drawn in dash dot dash dot denoting you are seeing it through the back of the diode, so they mixed up the pins number 1 and 2 between the 2 drawings, my pic at the bottom is correct.

View attachment 64130View attachment 64131
Yes, I get that the diode, as shown, looks as though it should be taken from the back, but Sharp often does not show their diodes this way. All of the data sheets I have looked at are taken from the front of the diode, so you get a mirror image of the view from the back This would be exactly what you would expect from the seller's diagram except that it looks like they used it from another data sheet. If you knew that Sharp normally shows diodes this way you would already know that you should be wary of a view that looks backward to what you have seen many times. I believe that the seller used a different data sheet image to show the diode the way that Sharp portrays it in the original data sheet because they didn't have an image they could use easily.
 

RedCowboy

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Yeah, those diagrams are usually taken from the top of the diode, so it is likely not backwards.
Yes, I get that the diode, as shown, looks as though it should be taken from the back, but Sharp often does not show their diodes this way. All of the data sheets I have looked at are taken from the front of the diode, so you get a mirror image of the view from the back This would be exactly what you would expect from the seller's diagram except that it looks like they used it from another data sheet. If you knew that Sharp normally shows diodes this way you would already know that you should be wary of a view that looks backward to what you have seen many times. I believe that the seller used a different data sheet image to show the diode the way that Sharp portrays it in the original data sheet because they didn't have an image they could use easily.
LMFAO make up your mind.
 
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RedCowboy

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Yes it's pretty square looking beam would be cool from a pen, maybe driven @ 1.2a where it looks plenty bright and won't make as much waste heat.
 

Lifetime17

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hiRed,
Thanks as far as the max a pen would be just fine with the WL at 1.6A or lower to be safe and efficient .

Thank you Rich:)
 

paul1598419

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LMFAO make up your mind.
What are you talking about?! Sharp uses diagrams that show the diode's polarity from the front of the diode. Knowing this, you would naturally assume it would be a mirror image of the diode taken from the back. There is no ambiguity here. Just in your mind's eye.
 

RedCowboy

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Is it a sharp data sheet or a Chinese sellers data sheet ?

Look I don't care if the Chinese seller draws in crayon on a dirty napkin just so long as it's accurate, as far as what you think someone should second guess based on what something should have been........that's worth less than half a squirt of warm whizz to someone who just bought a diode from a Chinese seller, not from Sharp.

My statement that the datasheet is incorrect stands regardless of what you think I should have second gussed based on what something should have been but clearly is not.

p.s. Your words = " I believe the seller used a different data sheet. "

---edit---
I see how they meant to show the outer lip of the can as solid lines and the dot-dash-dot drawn window/pins is to show looking through from the top in order to see the pins............it's not very good as the window circle should have been solid just like the can lip was solid otherwise it's inconsistent and the pins shown as dot-dash-dot only would have been better, to show top and bottom features both that way is misleading, even worse when posted as a semi fuzzy pic, I think I will just meter anything from sharp from now on if that's the only drawing.

Furthermore my original drawing with the caption " Is this the correct pin out " is neither right or wrong as it was a question, I have removed my question drawing as not to confuse anyone reading and I have put only images without a question up as the pinout, it seemed reasonable to show what I was asking originally.
 
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