ndg7475 build question?

BobMc · Sep 20, 2016

I'm planning on a build with a ndg7475, dtr's tests say that it can run up to 2.8 amps, was wondering if anyone has made a build running that diode that hot? Its going into a fairly large copper heat sink so hopefully she'll like it there?

Lifetime17 · Sep 20, 2016

Hi BM,
No the 7875 runs at 2.4A tops.. It's a 9mm diode and if you lucky you may get 3W's plus if it's a good one.. Buddy....DTR sells drivers already set to 2.4A in a X Dirive or a SXD

Sorry BM oops wrong diode but not far off on the Amp's Both can take 2.4A tops

Rich

BobMc · Sep 20, 2016

Lifetime17 said:
Hi BM,
No the 7875 runs at 2.4A tops.. It's a 9mm diode and if you lucky you may get 3W's plus if it's a good one.. Buddy....DTR sells drivers already set to 2.4A in a X Dirive or a SXD

Rich

I think were talking about different diodes the ndg 7475 is a 520nm listed as 1 watt. I think your looking at the ndb7875 which is a 3 watt 445. Not to worry I made the same mistake myself. They are real close, had to double check dtr website just to be sure. I'm liking be home for so long, do you know how much trouble I can cause at the house if I try? Life is good !!!:yh::yh:

Sta · Sep 20, 2016

BobMc said:
I'm planning on a build with a ndg7475, dtr's tests say that it can run up to 2.8 amps, was wondering if anyone has made a build running that diode that hot? Its going into a fairly large copper heat sink so hopefully she'll like it there?

Don't push the 7475 over 2.4A, you risk shortening its life. I keep mine set right at 2.4A and get a nice ~1400mW. A diode as expensive as the 7475 shouldn't be abused ayways. :yh:

BobMc · Sep 20, 2016

Sta said:
Don't push the 7475 over 2.4A, you risk shortening its life. I keep mine set right at 2.4A and get a nice ~1400mW. A diode as expensive as the 7475 shouldn't be abused ayways. :yh:

I've got a 7475 running at about 2.4-5 amps she's doing about 1400-500. Would like to build a pocket one and push the diode to the very max. Realize it might cut the life expectancy but I'd like to give it a go and she how she beams. By pocket I mean a host that will fit in your pocket. Will be using the same host as my post of my first build, I really like that host.

DTR · Sep 21, 2016

BobMc said:
I'm planning on a build with a ndg7475, dtr's tests say that it can run up to 2.8 amps

Just to be clear I list 2.4A as the max suggested running current on the NDG7475. See the recommended current at the top of the sales page.
https://sites.google.com/site/dtrlpf/home/diodes/ndg-1w-520nm

The testing does take the diode to and past the point of foldback so you can see where the curve drops off but the last tested current is not an endorsement of where you can reliably run the diode. To get a full curve it is necessary to test past the peak of efficiency.:beer:

BobMc · Sep 21, 2016

DTR said:
Just to be clear I list 2.4A as the max suggested running current on the NDG7475. See the recommended current at the top of the sales page.
https://sites.google.com/site/dtrlpf/home/diodes/ndg-1w-520nm

The testing does take the diode to and past the point of foldback so you can see where the curve drops off but the last tested current is not an endorsement of where you can reliably run the diode. To get a full curve it is necessary to test past the peak of efficiency.:beer:

I'm confused??? according to your testing the 7475 keep building till 2.8 amps putting out 1.554 watts. Am I missing something here? I am new to this hobby but was wondering where exactly the peak would be. Am I not reading the pictures correctly? I realize 2.4 amps is recommended and safer, but if it's still building than it's not at the peak. What am I not seeing or understanding??? thanks

DTR · Sep 21, 2016

What is key in the power test is the efficiency mW out per mA in and when you get to the point of diminishing returns where the efficiency starts to drop off sharply(foldback) that is a dangerous area to run the diode. Past 2.4A you are getting less and less return for the same increases in power which will result is a less stable output as heat builds up quickly and if it can not be removed from the diode quick enough this bottleneck of heat will cause a rapid drop in power output and quicken the rate of degradation shortening the life of the diode.

BobMc · Sep 21, 2016

DTR said:
What is key in the power test is the efficiency mW out per mA in and when you get to the point of diminishing returns where the efficiency starts to drop off sharply(foldback) that is a dangerous area to run the diode. Past 2.4A you are getting less and less return for the same increases in power which will result is a less stable output as heat builds up quickly and if it can not be removed from the diode quick enough this bottleneck of heat will cause a rapid drop in power output and quicken the rate of degradation shortening the life of the diode.

Ok, now that explains things a lot! gotcha.Thanks, ok will be ordering a 7475 with a copper module with a halfback and a g2 lens here shortly thanks for the help !! really!

Pman · Sep 21, 2016

You also have more of a possibility of it blowing on startup surge but it's all part of the "game". I have no idea what you would gain with a 520nm by pushing into foldback. If you were talking about a 462 or 465nm diode it would be more meaningful especially with the 07E. What I'm saying is why would you want a 520nm to be higher in wavelength.
Good for you on choosing what I would consider to be the best high power 520nm diode Bob. If you dont have an 07E yet you are in for a treat if you go that route next. Now that's a great diode 5hats worth driving at different outputs. Not only is it really powerful if that's something you are after but it's also very bright and beautiful and not as expensive but to be fair, that 520nm cost a fortune when DTR first started selling it so you are getting quite the bargain with it compared to what a lot of us paid

Happy building and be sure to share it with us

While you are at it you should get another lens to help tame the divergence as it's not much more $ and you grow to appreciate good divergence.

BobMc · Sep 21, 2016

Pman said:
You also have more of a possibility of it blowing on startup surge but it's all part of the "game". I have no idea what you would gain with a 520nm by pushing into foldback. If you were talking about a 462 or 465nm diode it would be more meaningful especially with the 07E. What I'm saying is why would you want a 520nm to be higher in wavelength.
Good for you on choosing what I would consider to be the best high power 520nm diode Bob. If you dont have an 07E yet you are in for a treat if you go that route next. Now that's a great diode 5hats worth driving at different outputs. Not only is it really powerful if that's something you are after but it's also very bright and beautiful and not as expensive but to be fair, that 520nm cost a fortune when DTR first started selling it so you are getting quite the bargain with it compared to what a lot of us paid
Happy building and be sure to share it with us While you are at it you should get another lens to help tame the divergence as it's not much more $ and you grow to appreciate good divergence.

Thanks Pman, I just ordered a ndg7475 witha g2 in a 12mm module with a half back from dtr. I don't have a 07e build but I have an 06 build, that's the diode in my "first build" post. How much difference is there between an 06 and a 07e?. Also I ordered a g2 lens with the 7475, which lens would you recommend ? I talked to dtr he explained the "why" not to overdrive a diode, it's information that I needed. So I'm going to have the driver set at 2.4 amps.Thanks:::::::::::::: Edit: I just looked on dtr's website and couldn't find an 07e found an 06 and a 08,is the 08 the new version?

DTR · Sep 21, 2016

It is on the way.:beer:

Here is the NUBM07
https://sites.google.com/site/dtrlpf/home/diodes/nubm07e-465nm-laser-diode

BobMc · Sep 21, 2016

DTR said:
It is on the way.:beer:

Here is the NUBM07
https://sites.google.com/site/dtrlpf/home/diodes/nubm07e-465nm-laser-diode

Thanks, and I might just have found my next build!!!!!

Pman · Sep 22, 2016

As far as difference I would say night and day. When you get into all the blues from 445nm-465nm there is a very visible difference between them and I consider the 07E to be the standout of the group. The 07 can be anything from a lighter blue to almost teal depending upon luck of the draw on where your particular diode is on the spectrum and how it reacts to being pushed beyond manufacturers data sheet. DTR doesn't bin his diodes so you never know what you are going to get.
I currently own 3 07E builds from 4.5-5.5A and I found that my 5A one actually has more green in it than the 5.5A one. If you want just a great sky blue don't push it too hard and run it from 4-4.5A. Once you get beyond 4.5A depending upon the diode the color starts to look different than a sky blue. Personally I'm tempted to change the driver on the 5A one to a 5.5A and see just how far that one will push with more green. This is something I wouldn't tell someone else to do unless they can handle a potential diode loss. What's more interesting is to get one first and not push it and then build another and see what it will do. I will likely be buying another one as I have a project that I'll be working on with someone else using them once the parts all come together.

Take a look here at the 5A 07E build I made and pay particular attention to the beam shots after it got darker as the teal color is starting to really show. Look at the comparison shots and you will get a better idea how the color changes. It's more than the camera shows but you get the general idea. I will say that the wavelength difference looks better on my phone than my netbook so if you have more than one way to look at the pics its better to try more than one.
http://laserpointerforums.com/f65/5w-07e-471nm-build-98461.html

BobMc · Sep 23, 2016

Pman said:
As far as difference I would say night and day. When you get into all the blues from 445nm-465nm there is a very visible difference between them and I consider the 07E to be the standout of the group. The 07 can be anything from a lighter blue to almost teal depending upon luck of the draw on where your particular diode is on the spectrum and how it reacts to being pushed beyond manufacturers data sheet. DTR doesn't bin his diodes so you never know what you are going to get.
I currently own 3 07E builds from 4.5-5.5A and I found that my 5A one actually has more green in it than the 5.5A one. If you want just a great sky blue don't push it too hard and run it from 4-4.5A. Once you get beyond 4.5A depending upon the diode the color starts to look different than a sky blue. Personally I'm tempted to change the driver on the 5A one to a 5.5A and see just how far that one will push with more green. This is something I wouldn't tell someone else to do unless they can handle a potential diode loss. What's more interesting is to get one first and not push it and then build another and see what it will do. I will likely be buying another one as I have a project that I'll be working on with someone else using them once the parts all come together.

Take a look here at the 5A 07E build I made and pay particular attention to the beam shots after it got darker as the teal color is starting to really show. Look at the comparison shots and you will get a better idea how the color changes. It's more than the camera shows but you get the general idea. I will say that the wavelength difference looks better on my phone than my netbook so if you have more than one way to look at the pics its better to try more than one.
http://laserpointerforums.com/f65/5w-07e-471nm-build-98461.html

Wow! There's a lot of color difference ! Makes me think about getting a 07 and seeing if I can wire in a potentiometer to be able to change current/color on the fly. Got me thinking Pman!! Thank's I love it!&#55357;&#56397;

badboybilly · Oct 2, 2016

Hi Bob
I think you will like the divergence on the high power green diode better with Jordan,s
2 element AR coated lens than the G2,
I realise you already purchased the G2 but with the multimode greens that rectangle splash around the line-ribbon is very noticeable with the G2. I personally like the 2ellements output much better with a little power loss, You should try one with your next purchase and let me know if you agree.

ndg7475 build question?

BobMc

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