Which 405nm diode

Hey all,

I bought a pocket mini build many years ago now and a diode to go with it. Unfortunately it turned out that the diodes people thought they were getting were incorrect and couldn't handle the 190ma i had the driver set for. After waiting months to get that build and then having it die on me I tossed the host aside and forgot about it.

I've pulled it out recently thinking about throwing a diode in it. It's a pocket mini with copper heatsink and a nice glass lens if I remember correctly. Using whatever popular buck/boost board was available at the time they I had set to 190ma when I ordered it. Unfortunately I don't know the exact procedure to change this (I suspect hooking up the leads to a large resistor and measuring the current flow and adjusting from there would allow me to change the output).

Now I am looking for a diode to use with this little host. There isn't a huge heat capacity in this host, just a copper ring dropped in. I am thinking of going for something that I could use with 190ma or if there is a guide to adjust the output perhaps a little larger as long as the heat would be manageable.

Which diode in the 200-350ma range would be good and who is supplying them these days?

What do you mean by 200-350? mW or operating current in mA? A great place to get your diodes is from your good ol' pal DTR, he sells 14x and 16x 405nm diodes. I'm not actually sure of their lasing threshold, and I can't check because I think his site is down at the moment.

200-350ma

I'm set at 190ma now but I think this driver should go higher. I feel like it was some version of the flex boost/buck that seems to still be popular. I started the build for this back in 2009. I don't think my pocket mini could really handle much more power than 300ma. It does have the copper insert but I don't recall the recommended power spec for it.

https://sites.google.com/site/dtrlpf/home/diodes/bdr-209-405nm-16x-diodes
At 300mA you should get almost 500mW, and 200mA should give you around 300mW. I say gopher it, best of luck

Thanks for the help. Being out of the loop here for 6 years left me with quite a gap of what to buy and where to get it. I may look into other wavelengths as he has quite a selection on his site!

Many thanks

No problem, any time Good to see someone back into the hobby after such a gap

Just a quick update and question.

I bought the 16x and confirmed that the driver I have is the flex v5. With the v5 it looks to support up to 5.5v. According to this chart here the max I could run the diode at and keeping with 5.5v of the flexdrive is about 200ma.

Am I correct in the way I have read that chart? If so I guess I will keep my driver at 190 and expect about 300mw output. I have seen threads where DTR mentions running a flex at 750ma which would be somewhere in the 6.6v+ range. This seems to be on the edge of what the flex manual rule of thumb says

"A good rule of thumb is that: (Vout (Volts) * Iout (Amps) ) / Vin (Volts) < 1.2 "

The manual also states "75-400mA buck/boost 5V out"

As these drivers have been in use for quite some time now is there a more definite and proven guideline as to how far they can be pushed?

I'm sorry, I don't know diddly about drivers and electrical components, but I know you're reading that graph right, and if your drivers set at 190mA you will get around 300mW. This is the best I can do, if someone else could provide knowledge I don't have that'd be great. Best of luck mugenski!

Mugenski said:

Just a quick update and question.

I bought the 16x and confirmed that the driver I have is the flex v5. With the v5 it looks to support up to 5.5v. According to this chart here the max I could run the diode at and keeping with 5.5v of the flexdrive is about 200ma.

Am I correct in the way I have read that chart? If so I guess I will keep my driver at 190 and expect about 300mw output. I have seen threads where DTR mentions running a flex at 750ma which would be somewhere in the 6.6v+ range. This seems to be on the edge of what the flex manual rule of thumb says

"A good rule of thumb is that: (Vout (Volts) * Iout (Amps) ) / Vin (Volts) < 1.2 "

The manual also states "75-400mA buck/boost 5V out"

As these drivers have been in use for quite some time now is there a more definite and proven guideline as to how far they can be pushed?

Click to expand...

Actually if you bought it from me with the driver in the last 6 months they are all X-boost's. Lazeerer states 6.5V max input on these but I would suggest keeping it 6V and under to be safe as you are pretty close to the forward voltage of the diode there and the load must be higher voltage than the power source.

Here is the thread with specs on the driver.
http://laserpointerforums.com/f67/x-boost-v7-mini-super-mini-8mmx11-5mm-1-8a-laser-driver-76532.html

Unfortunately the driver is a flex v5 that I bought about 6 years ago from Jayrob. I'm guessing to be safe I should really only drive it at 200ma unless people have done testing otherwise.

Thumbs up on taking bitcoin by the way

DTR said:

Actually if you bought it from me with the driver in the last 6 months they are all X-boost's. Lazeerer states 6.5V max input on these but I would suggest keeping it 6V and under to be safe as you are pretty close to the forward voltage of the diode there and the load must be higher voltage than the power source.

Here is the thread with specs on the driver.
http://laserpointerforums.com/f67/x-boost-v7-mini-super-mini-8mmx11-5mm-1-8a-laser-driver-76532.html

Click to expand...

And whoa, DTR, you're three posts away from being a class 4 laser! Congrats!

Well I received the diode but it looks like it's smaller than the older bluray diode I tried to use 6 years ago. Not sure how I will mount this now.

Tested the driver, works fine running on old LED i have around so nothing wrong there. I will see if I can get a smaller heatsink made perhaps.

You should contact Jayrob if you are really set on using that host and driver. He has so many choices and I wouldn't want you to sink a ton of money into making what you have work or possibly damaging your diode.

I would get a NDV4542 from o-like. 200mW 405nm diode with a max input of 250mA. Can't go wrong as they are only $9.20! Link: NICHIA 405nm 200mW CW Violet Laser Diode LD NDV4542 [OL-4542B] - $9.20 : Zen Cart!, The Art of E-commerce

I tried to order some of those diodes to play with but the website kept timing out on me.

I have one of DTR 16x diodes. Anyone have an image or can tell me which are positive and negative? I keep getting conflicting information from google.