New Generation 445nm Diodes: Nichia NDB7A75

[DTR]

Yea they are finally catching up with me.
Yet I am still $0.99 cheaper and I can deliver in days not a month.:beer:

 

[IsaacT]

DTR, do you plan on making drivers available in the options on your website soon? I notice that like the single mode 650 you offer, there are no driver setups.

 

[kaunak]

Yeah make sure you buy the diodes from DTR if you're planning to buy them; DTR made the prices drop and not the others on ebay. As far as the divergence specs go, Rick said it was about twice the div. as the old 9mm. This would mean that it's about a 45mm stripe @ 25 feet. Up close and with a 3 element I'm sure these diodes will be much better for burning than the old 7875.

 

[ricktrent4]

Your right DTR is the man on diodes !!!!! the old is better for burning with a 3element lens then the new diode. The new diode is 2x the size of the old one. You have to use a 3 element lens just to get the same as a one element with the new diode.

Yeah make sure you buy the diodes from DTR if you're planning to buy them; DTR made the prices drop and not the others on ebay. As far as the divergence specs go, Rick said it was about twice the div. as the old 9mm. This would mean that it's about a 45mm stripe @ 25 feet. Up close and with a 3 element I'm sure these diodes will be much better for burning than the old 7875.

 

[kaunak]

Your right DTR is the man on diodes !!!!! the old is better for burning with a 3element lens then the new diode. The new diode is 2x the size of the old one. You have to use a 3 element lens just to get the same as a one element with the new diode.

yep it seems they just made a wider emitter region and not higher radiance. That was expected but with a 3 element these diodes will still be great even if the divergence only matches that of the old 9mm with a G2. It will be like 4.5-5W out of the old diodes.

 

[Moe Ron]

Greetings,

Yes, we will need to use the 3 element lenses and a driver pumping 3.5a or higher, then we can see what they can really do. I am using a 2.5a driver now and getting almost 3100mw using the 3 element lens. Waiting for drivers now.
Not sure why I am getting very different results when using my beam expander as the 7875's do a much better job. Will toy around and see what is going on.

cheers,

yep it seems they just made a wider emitter region and not higher radiance. That was expected but with a 3 element these diodes will still be great even if the divergence only matches that of the old 9mm with a G2. It will be like 4.5-5W out of the old diodes.

 

[Moe Ron]

Greetings,

I tried to take a few pics of divergence and point size. I am using the new diode on the left and old on the right. Both are using G2 lenses and are identical builds except the diodes...

My camera is not the best, but you can see the difference in diodes. I only have 1 descent 3 element lens, so will try and get something together to show the 2 like that.


cheers,
Moe

 

[jayrob]

Yea they are finally catching up with me.
Yet I am still $0.99 cheaper and I can deliver in days not a month.:beer:

Just FYI I have a kit for these that should be over 5 Watts using my Mag build kit with 3.5 Amp custom built X-Drive...

2 cell build with voltage monitor option, custom head option, key switch option, etc...

Or you can go with the FlexModP3 driver, but I like the X-Drive better...

At 3.5 Amps using the custom built X-Drive, the 2 X 6000mAh 32650 Li-Ion build will stay in regulation all the way down to 6.4 volts before it begins to drop in output power. (but it's time to charge the batteries at that voltage anyway)

 

[kaunak]

Greetings,

I tried to take a few pics of divergence and point size. I am using the new diode on the left and old on the right. Both are using G2 lenses and are identical builds except the diodes...
cheers,
Moe

The first and 3rd pics really show the difference and the second makes them look pretty similar. I'm sure we can get the beam down to an acceptable div. using a 3 element. I noticed you said you were only using a 2.5A driver. Im sure that when you get a 3.5A+ driver and a 3 element lens the results will be more impressive

 

[ricktrent4]

video of new diode it hit 6w with 1 element and around 5w with 3 element lens http://youtu.be/wJLkAljGnQw

 

[kaunak]

6W with a 3 element lens? Sorry but that is impossible

edit: Oh I see what you mean thats 6w going into the lens

 

[ricktrent4]

your right it's a typo
6w with 1 element lens around 5w with 3 element

6W with a 3 element lens? Sorry but that is impossible

edit: Oh I see what you mean thats 6w going into the lens

 

[rhd]

A bit of a necro post here. What is the target current we're looking for in a driver on these? 3A ? 3.5 A ?

I have a driver that's tested and working for up to 5A that I put together for driving MTG2s. Once I have some confirmation that it looks clean enough on a scope for LD use, I'd consider open sourcing it. It's a fairly inexpensive buck.

 

[Shakenawake]

well according to grey, my version of the PL-E pro is run just under 3.7A.

It's really up to you. I'd go take a peek at DTR's pictures on the diode's page, pick a current that produces an output you desire. obviously the higher the current the shorter the diode life and shorter the duty cycles. these are somewhat costly diodes

 

[dubious speculation]

Well DTR's recommendation was 3.5A for the best balance of power and longevity and 4A if you wanted to push it.

However, being a relatively new diode more testings to show whether or not this diode can take 4A in the long run would be needed.
From DTR's testing's one can see that even up to 4A there is still quite an increase in power.
There is quite a jump in output from 3.5A to 3.6A, although after 3.7A it seems that you are diminishing in returns.

Considering DTR's results, 4A would be like driving the old 9mm at 2.5A, where the extra current can be hit or miss as to
whether or not there is a significant increase in power. In some cases the extra current works backwards on the power and
drastically reduces the life of the diode. Even from 3.6A to 3.7A the power actually reduces (maybe an error in the measurements?)

I would say Shaken and JL's decision on 3.7A is right on the money, but other members
may want to be more conservative. Especially considering that it is still quite an expensive diode.

 

[Moe Ron]

Well DTR's recommendation was 3.5A for the best balance of power and longevity and 4A if you wanted to push it.

However, being a relatively new diode more testings to show whether or not this diode can take 4A in the long run would be needed.
From DTR's testing's one can see that even up to 4A there is still quite an increase in power.
There is quite a jump in output from 3.5A to 3.6A, although after 3.7A it seems that you are diminishing in returns.

Considering DTR's results, 4A would be like driving the old 9mm at 2.5A, where the extra current can be hit or miss as to
whether or not there is a significant increase in power. In some cases the extra current works backwards on the power and
drastically reduces the life of the diode. Even from 3.6A to 3.7A the power actually reduces (maybe an error in the measurements?)

I would say Shaken and JL's decision on 3.7A is right on the money, but other members
may want to be more conservative. Especially considering that it is still quite an expensive diode.

Greetings,

I would agree that 4a with these is like 2.5a on the old 9mm's. I normally use 2.5a and have not had any problems, then again I normally do not run longer than 60 seconds. Right now am waiting on some 4a drivers to arrive.

A bit of a necro post here. What is the target current we're looking for in a driver on these? 3A ? 3.5 A ?

I have a driver that's tested and working for up to 5A that I put together for driving MTG2s. Once I have some confirmation that it looks clean enough on a scope for LD use, I'd consider open sourcing it. It's a fairly inexpensive buck.

Greetings,

If you are going to be making drivers, I would take a few set at 4a, though I am sure some would prefer 3.5a. Likely both would do well.


cheers,
Moe