First build: Survival Lasers 650nm

Ok...So, I got tired of hunting for a host for my 650nm and I just bought the Black C-6 kit w/ the big, tapered copper heatsink. I'll let you guys know how it goes in my review.

Don't hate me but I'll only have post creation pics! This thing is a beast although I wish I knew how much power it was putting out. With the particular driver I bought, it was designed for 2 3.7v batteries but with just one 3.7 this thing lights matches, pops balloons, melts tape like butter, etc. If it's a 450ma driver, will increasing voltage also increase output?

No increasing the voltage will make the driver heat up more, it wont increase output. If you wanted to do that, you would have to increase the current ie get a new driver, or change the resistors on the existing one. The max recommended current for these drivers is 500 mA, so you are pretty close anyway.

Running it with one battery will reduce the output it will also drastically shorten the run time as the battery voltage sags, but it wont get so warm. I have a similar laser; with one battery I get 150 mW, but with two I get 250 mW. :beer:

Well, that explains why mine doesn't burn better. I've got mine set @ ~475mA and on a single 3.7V. I think I'll test it today in series...

I am very confused about your post.

I bought a 450ma because thats exactly how much power I want going to the diode. You say that adding more voltage would not add more output in my case but you contradict yourself by saying you add another battery (more volts) to get more output.

My only real question is how much of the 450ma its rated for is being utilized with one 18650

hazerkitten said:

I am very confused about your post.

I bought a 450ma because thats exactly how much power I want going to the diode. You say that adding more voltage would not add more output in my case but you contradict yourself by saying you add another battery (more volts) to get more output.

Click to expand...

Its a little more complicated...If you try 3 x batteries you will get the same output as with 2, but your driver will get very hot. 1 fully charged battery is just enough to run a red as the Vdrop of the regulator in Mohs linear is 1.25 V and the Vdrop of the diode is around 2.8 V. So that means your linear only has 4.2 - (2.8 + 1.25) = 0.15 V to play with and struggles to supply power. As the battery potential drops and falls below 4 V it will stop working. Dont quote me on 2.8 V as the exact voltage, it will be around there, but it depends on the diodes IV curve and current drawn. If you use 2 or 3 bats you have enough power and the regulator functions as usual, but the excess voltage is wasted as heat. This only applies to linears, not buck or boost however. :beer:

hazerkitten said:

My only real question is how much of the 450ma its rated for is being utilized with one 18650

Click to expand...

If you want to know that, disconnect the diode and run the driver off 1 battery on a test load.

Grainde,

Thanks for trying to explain that one too me, I just woke up and I'm finding it hard to digest lol.

Disconnecting the diode from the driver wouldnt be fun..

Ok simple answer: Use 2 batteries if you want 450 mA. No using 3 batteries wont help and will not increase the current. If you want a 1 battery solution switch the driver for a buck set at 450 - max 500 mA.

I only suggested disconnecting it, if you wanted to know the exact current your driver provides with only one battery. The easiest way to disconnect it, if you wanted to, would be to snip the wire leads ie dont desolder the diode or driver. That way you can just resolder the wires and you wont risk killing the diode (provided you're careful with static and have discharged the output caps before reconnecting the leads...)..beer:

Due to the size of the c6 it is not possible to fit both 18650 batteries (I am not willing to get an extension tube)

Also, I am not willing to swap out this brand new driver and pill.

I do however have some 123a batteries and when I throw 2 of them in, I can tell NO difference in power..

Please advise,

Haze

How can you tell, do you have an LPM? Visually 200 mW or 300 mW will look similar and unless you have two lasers side by side with the same drivers and identical diodes (known to have identical efficiencies) your opinion would likely be subjective...Chances are you be hard pressed to see a difference anyway!

Normally you can use 2 x 16340's to replace an 18650. CR123A's will work, but their combined voltage is lower and they're generally not rechargeable.:beer:

I understand what you are saying completely.

I was doing my measurement with a fixed focal point of 1 foot burning electrical tape. ~4v was easily as effective at slicing that tape

Yup there wont be much difference 200 mW will burn almost as well as 300. You'll notice a big difference when you get to higher powers though ie 200 mW vs 1 or 2 W! :beer:

Well, when I started reading I got slightly worried and then I saw grainde pop in and clear things up haha.

The thing about linear drivers with a single 18650 cell and an LPC826 is your runtime will not really benefit from the added capacity because once the cell's voltage even starts to drop the laser will start rapidly losing output. A lithium cell's capacity typically runs the whole span between 4.2V and 2.7V as the cell discharges. For the most part you will only stay above 4V for maybe 10% of the total capacity on a really good cell which means almost all of your runtime will be at less than full power and you will very likely deem the cell dead well before it really is. Now with two cells even when you get down to the bottom of the cell's capacity you will still be running at about 6V which is still easily enough to fully power the laser. This means you get full power output all the way down until your cells are completely drained.

I also have a suggestion for replacing DX. The website is called fasttech.com and shipping to the US is consistently half of what DX takes and their prices are almost always lower. Check out this deal on some 16340 cells:
$5.11 UltraFire 16340 3.6V 1000mAh Rechargeable Li-ion Batteries (4-Pack) at FastTech - Worldwide Free Shipping
I use those exact ones and out of about 80 cells I have found 4 duds.

Thanks apex,

You both are absolutely correct and I have noticed that as the voltage gets to 4v she wont turn on.

As this was my first high power laser and also first laser I've ever built, I did make one mistake. After reading and looking around Survival Lasers was the company I decided I wanted to go with. As I'm sure you are aware, they have 2 websites; one for international sales and one for domestic sales. Since they can't sell complete lasers in the USA I decided to piece my own and wanted to replicate this one (Survival Laser R 660nm Parts Bundle - Laser Components Only)

Where I went wrong was that even though that particular laser uses a 500+ma driver, I read on Hightechdealz that the diode would still net ~250-300mw with 380-450ma. Because I do want my laser to last I decided to go with Survivals 450ma driver (DIY 445mA Driver & Pill Module).

Nowhere on that page does it indicate that it is for 405nm but if you go on the international page it does say so. Frustrating as it is, I'm happy that I still have a laser that works but now I've gotta fork out another $35 to get the proper driver (DIY 530mA Driver & Pill Module).

On the upside, I guess I have no choice but to start another build using my existing driver and S06J diode.. should net ~500mw? I've learned a great deal and am having a blast.. thank you ALL for your replies as your answers are spot on.

The first driver you got from SL set to 450mA is designed for any diode that can run at 450mA. The part that you missed was that it is designed to run with two cells instead of one. That driver is a buck driver so AFAIK you will never see full power on one cell even when fully charged (I have never tested this with an LPC specifically). Based on what you stated, you are using a C6 host with that driver which means that you are able to run it with two 16340 cells perfectly. If you want to run that laser right grab some of the cells I linked to above.

I have a S06J laser set to 445mA that with a G2 lens outputs over 800mW. With a standard 3-element lens you can expect somewhere between 500mW and 600mW.

I would suggest getting the correct cells for your LPC laser and then making a second laser instead of tearing the other one apart. You may also want to check out what DTR has to offer here:
https://sites.google.com/site/dtrlpf/home

Apex that made perfect sense. You got a point; tearing down a newly built laser doesn't sound fun. I will definately have to buy some of those batteries.. sounds like they'll do the trick!!

I do need some help however.

I've had this host for about a week and I'm already having problems with the "clicky" button. It still sounds and feels like normal but when I press it, the majority of the time it does not turn on. I have to manipulate the button if you will to get the laser to power on. I do not suspect it is wiring or anything like that.. its clearly the button.

Is there a fix for this?