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NDG700 or NDG7475?

Dutch67

Dutch67

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Alright so I'm in the process of making a 520nm laser.
What I want to know is: What are the major pros/cons of each of these diodes?

I'm not to worried about price but I am worried about divergence, beam visibility at day and night, durability/lifespan, and heat-sinking.

-What is the divergence like for both of these? Is the 7475 really bad? Is the 700 any better?

-How visible are the beams? Is there a major difference between the two? Or are they both somewhat similar?

-Are each of these pretty durable? What is the better max current-to-lifespan ratio for each?

-How hot does each get? Will the drivers and diodes require any special heat-sinking? The host I am getting will have about a 1.5'' diameter.

Alllsoooooo...Is it worth it to give the NUGM01T a chance?

Thank you for any help you can give me :beer:
 





S

Sta

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Lildutchboy7 said:
Alright so I'm in the process of making a 520nm laser.
What I want to know is: What are the major pros/cons of each of these diodes?

I'm not to worried about price but I am worried about divergence, beam visibility at day and night, durability/lifespan, and heat-sinking.

-What is the divergence like for both of these? Is the 7475 really bad? Is the 700 any better?

-How visible are the beams? Is there a major difference between the two? Or are they both somewhat similar?

-Are each of these pretty durable? What is the better max current-to-lifespan ratio for each?

-How hot does each get? Will the drivers and diodes require any special heat-sinking? The host I am getting will have about a 1.5'' diameter.

Alllsoooooo...Is it worth it to give the NUGM01T a chance?

Thank you for any help you can give me :beer:
Click to expand...

Good of you to ask here.
The NDG7475 and NDG700 are actually exactly the same in terms of everything except power. It is speculated that the NDG700 diodes are actually just low-binned 7475s. So the divergence is going to be the same.

There is going to be a visible difference in power, but not a huge difference. The main thing, I think, is that the 7475 will have a visible beam during the day.

If you go with the NDG7475, I suggest 2.4A. If you choose the NDG700, I suggest 1.8A. Straying too far above these values may kill your diode. At these currents they should last you a VERY long time.

1.5 inch diameter is plenty for heatsinking a 7475 - which host is it?


And don't go with the NUGM01T, just taking the lens off may kill your diode.



:)
 
Dutch67

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Sta said:
Good of you to ask here.
The NDG7475 and NDG700 are actually exactly the same in terms of everything except power. It is speculated that the NDG700 diodes are actually just low-binned 7475s. So the divergence is going to be the same.

There is going to be a visible difference in power, but not a huge difference. The main thing, I think, is that the 7475 will have a visible beam during the day.

If you go with the NDG7475, I suggest 2.4A. If you choose the NDG700, I suggest 1.8A. Straying too far above these values may kill your diode. At these currents they should last you a VERY long time.

1.5 inch diameter is plenty for heatsinking a 7475 - which host is it?


And don't go with the NUGM01T, just taking the lens off may kill your diode.



:)
Click to expand...

Thanks for the input! I was hoping there might be a difference in divergence but never mind about that I guess.

It's good to know that the 7475 will be visible in daytime! That is a big deciding factor for me.

My host is going to be a custom make from ElectricPlasma:D
It's going to be based on an older Ehgemus host but it will definitely be different:)

I was just wondering about the 01T because I've worked with plenty of open cans before and never had a problem. I think I'll avoid it just because of the cost and I'd rather not risk it if possible.
 
paul1598419

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It really depends on what your heat sink is made of. A 1 1/2 inch aluminum heat sink is not enough for a 7475 imo. If it is copper, then yes. Both diodes are very inefficient and so get hot the harder they are pushed. And, both are being pushed at those currents.
 
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Dutch67

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paul1598419 said:
It really depends on what your heat sink is made of. A 1 1/2 inch aluminum heat sink is not enough for a 7475 imo. If it is copper, then yes. Both diodes are very inefficient and so get hot the harder they are pushed. And, both are being pushed at those currents.
Click to expand...

It's 1-5/8''. I just went a looked it back up. I might ask for it to be made into a 2'' but I'll think on that. EP doesn't currently have a place to get copper stock so Aluminum will have to do I guess.

I'll just have to be mindful of the run-times:)
 
Lifetime17

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Hi L,
In this case either one is a sweet diode to save a little cash the 700 is a great choice at 1.8A it will do 1100mW the 7475 will do about 1400+mW's . sent you pics of the new hosts and sinks and focus knob made
 
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paul1598419

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I would think you could get by with a 1.5 inch aluminum one if it is long enough. Just be aware of the heat and don't push it for long periods of time.
 
RedCowboy

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What does the 01 look like with the GBall left intact?
How big is the spot at 5 meters or 10 meters?

I would kind of like to build a super compact with a fixed focus.
 
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Dutch67

Dutch67

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RedCowboy said:
What does the 01 look like with the GBall left intact?
How big is the spot at 5 meters or 10 meters?

I would kind of like to build a super compact with a fixed focus.
Click to expand...

I've always wondered what it would be like just leaving the factory lens on it. It would sure save some money and it would definitely keep it safe from particles and such getting inside.

I would probably go that route sometime if I knew that it was focused well.
 
ElectricPlasma

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I actually had 1.75 dia alu planned for the sink. My 07e has a 2 inch sink w/ 4 min runtimes so for this diode I'm sure 1.75" will give a good run time. LMK if you want 2", might have to bump up the price though as it starts to get expensive. Also might look weird with the dual 18650 handle
 
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Dutch67

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ElectricPlasma said:
I actually had 1.75 dia alu planned for the sink. My 07e has a 2 inch sink w/ 4 min runtimes so for this diode I'm sure 1.75" will give a good run time.
Click to expand...


That sounds pretty good! You can have room to do what you want as long as it stays close to the guidelines we talked about:)
 
Lifetime17

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Hi L,
Yes bigger is better in this case something like this ..

Enjoy Rich;)
 

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CaliKirk

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Lifetime17 said:
Hi L,
Yes bigger is better in this case something like this ..

Enjoy Rich;)
Click to expand...

Awesome work Rich!!


The question that I have is, if the 7475 can be safely ran at higher currents, can the ndg700 be pushed to the same wavelengths that the 7475 can? I know that it mostly has to do with case temp, but since the 7454 is more efficient would that mean that the 700 can push its WL further?

Edit: Or would the case temperature be the only factor on both the 700 and 7475, if each had the same case temperature, would they output the same WL?
 
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S

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CaliKirk said:
Awesome work Rich!!


The question that I have is, if the 7475 can be safely ran at higher currents, can the ndg700 be pushed to the same wavelengths that the 7475 can? I know that it mostly has to do with case temp, but since the 7454 is more efficient would that mean that the 700 can push its WL further?

Edit: Or would the case temperature be the only factor on both the 700 and 7475, if each had the same case temperature, would they output the same WL?
Click to expand...

They should push to very similar wavelengths, as case temperature is the main factor. Of course ,different diodes of the same model vary quite a bit, so you get some oddities like my ~525nm 7475.
 
CaliKirk

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Sta- Dang 525? I personally like the tinge of yellow in 532, so I'd love to end up with a 7475 closer to 532.

I guess if price isn't a problem and literally the only difference between the two is one is more expensive and can output more. Then it almost should be a no brainier to choose the 7475, you can always tune it down to output closer to the 700 if 1.4w is too much power. Plus looking at DTRs testing, it looks like even at the same current, the 7475 is putting out about ~100mw more so the added efficiency would be nice as well.
 
Dutch67

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CaliKirk said:
Sta- Dang 525? I personally like the tinge of yellow in 532, so I'd love to end up with a 7475 closer to 532.

I guess if price isn't a problem and literally the only difference between the two is one is more expensive and can output more. Then it almost should be a no brainier to choose the 7475, you can always tune it down to output closer to the 700 if 1.4w is too much power. Plus looking at DTRs testing, it looks like even at the same current, the 7475 is putting out about ~100mw more so the added efficiency would be nice as well.
Click to expand...

Yeah I'm most likely going to be going with the 7475 on this one:D
 
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