I'm back, and I need help! (Please)

Hey, hey, hey, everyone! It's been FOREVER! Yikes! Anyway, I gotz some questions for y'all.

I finally decided to start on my second project (laziness is bad, so work hard kids!), which is a 445nm laser. I'll tell you what I'm using, then I'll tell you what i need to know.

Using:
LM317
1 Ohm, 2W resistor
1N4001 Diode
M140 Laser Diode
3 Element Lens

Need to know:
Which capacitor should I use? 10 or 47 uF/16 or 25 or 35V? (Probably depends on answer to next question)
What power source do I need? What voltage and what mAh should I look for? (AAs or some other batteries, in series or parallel, Li Ion, etc.)

Also, I'm hoping to make this build as small as possible, so does anyone recommend a specific flashlight host or another small enclosure?
And where can I find a decent laser power meter?

I would really appreciate any response you can give me! Thanks!

- Vakker Vinter
(Used to be Didactic Discord, but then I (took an arrow in the knee) thought I was seen as too hyper or n00bish, so I made this account)

1. You don't technically need a cap. If you have to use one I would use a 10uF or 4.7uF ceramic cap.
The voltage rating depends. If it's on the output anything over 6.3V should work fine. If it's on the input make sure the voltage value is higher than your input voltage.

2. It needs to supply 1.25A, and should be greater than 6.5V. I would use two 18650's in series, or 16340's if you want it smaller.

3. Don't have any host recommendations, sorry

4. Check out the Radiant x4 over at illumination supply for a cheap power meter.

As ARG said, check out the Radiant X4. It reads up to 3.5W (I believe) and is probably the cheapest hobbyist lpm.
In regards to a small flashlight host, check out SL for a C6 kit or Mrcrouse for a 501b (plug n burn) kit.

First of all, thanks to both of you for helping me out!
Second, the capacitor is just before the laser diode in the circuit, so would that be, as you say, on the output? Also, will these 18650s fit in a AA holder? And how long will they last before I need to recharge them?

Yup, if it's before the laser diode that's an output cap. Don't forget to short it before hooking up the laser diode.

18650's will not fit in a AA holder. You need 14500's (I think that's the right size) for that.

A couple of good 18650's will last for around 2h of continuous use.

Great! Just one last question...
What would 18650s fit in?

Vakker Vinter said:

Great! Just one last question...
What would 18650s fit in?

Click to expand...

Well if you're just using one 18650 then any of the hosts I mentioned would be fine. If you're using two then you can also buy an extension tube (also from survival laser) for the C6. The tube will allow you to use two 18650s with the C6 OR S4 hosts that Survival Lasers offer

For the C6 extension, would the 18650s be able to be placed in series?

Yeah they are to be placed in series. I'm sure that is the case for all batteries in a flash light host unless I'm just completely wrong here

Awesome! Thank you guys so much for helping me out and being so patient with me! I'll order parts as soon as I can, then I'll show you what I did! Thanks so much!

Hi! I have a couple more questions now that I've done a little browsing... I've looked at the Survival Laser USA site, and the C6 can have three different driver pills. Which one would you recommend? The standard or drilled one?

Also, would the parts for the homemade driver I mentioned in my first post fit in the flashlight? I'm a little concerned that the resistors I bought might be too big as they are ceramic (only ones I could find that met my specifications). Or is that something I need to see when I have the flashlight in front of me?

It should fit into the host if you wire it up nicely (I assume you aren't using a PCB). Use as an example

Also, you won't need a host extender if you just use two 18350 batteries. Seeing as how the driver on SL is only 5 bucks, I would say it would be easier to buy the driver from there, but of course understandable if you don't since the DIY aspect gives you more out of the build

If you are doing a c6 build you can buy drivers from survival laser to suit whatever amperage you want, the 1.25a driver is really cheap and will give you more than 1 watt of output with a 3 element, you can go higher at the expense of a smaller duty cycle.

Basically for a c6 build you need:

-Diode in module and lens
-C6 heatsink (they are like 6 bucks)
-C6 Host (They come with a driver pill, the standard pill has worked fine for me)
-Driver (you could go up to around 1.6a but I recommend 1.25a)
-Some wire and heatshrink to connect the driver to the diode
-SAFETY GLASSES

Also keep in mind that if you get a buck driver you will need 2 lithium cells, the c6 can fit 2 16340's no problem.

Thanks so much! You guys are awesome! I should start receiving parts in a few days, so I'll have this thing done soon (couple weeks)!