Nice box, fits the KISS principle. Why not thin radiata pine instead? Or if you want to spend a little perhaps some meranti? That'd make a sexy laser box.
chido: I´v read this, but why my lasers looks nice with 4 NiMH ?
VillgeIdiot: KISS principle?
When I did it, I just thing in a box to my laser, once I don´t have way to put all into a small 'barrel' with cr123 (with I don´t have too)
I´ll be pleasure with some drive wich runs with 3 NiMH / Alcaline (AAA) - Some ideia? Maybe a booster before the DDL ? I´ll do a 'Joule Thief' to see what happens.
If it works well with 4 NIMHs it'll work better with 6. ;D The thing is that the LM317 takes 3v and it sends the remaining voltage to the LD, the LD will take whatever voltage it needs which is around 3v. (the voltage going to the LD depends on the current it is being driven at) Suppose you're driving the diode at 250mA and it's drawing 2.8v, in total you need at least 5.8v to power the laser. Now let's say the voltage drops to 5.5v, the LM317 will take its 3v, but it will send only 2.5v to the LD which will make the current to drop from 250mA. As the batteries decrease in voltage the LM317 won't provide the LD with the voltage it needs to work and in turn the laser will just keep getting weaker and weaker.
If you use 4 NIMH batteries the driver is only getting 4.8v which is way too low because even if the batteries are charged the driver will start dropping out the moment you power it up. But if you use 6 batteries which equal 7.2v, the batteries will have to drop 1.2v or more before the driver starts to drop out.
chido, before of your answer, I try with 6 Batteries and.. OWW, it´s very nice!
I did a new case with 6 batteries and other LD (I will keep that black box working)
I have a question... Can I put, lets say... 12 volts in this DDL ?
As you said "the LD will take whatever voltage it needs which is around 3v"
The LM317 will get too hot at this voltage, but the LD will not blow, isn´t ?
Other Q. If I put the LD in a aluminium block (3x3x3 cm +-) to dissipate the heat, Can I leave it turned on 'forever' ? I want do a Laser Show and I don´t want be worried with this.
Yes you can put in 12v, the LM317 is good for up to 35v and 1.5A, as long as you don't exceed either of those two it should all work fine, but I recommend you get a heatsink for the LM317 if you're going to use 12v. Like this one.
You can leave it on for ever until it dies as long as you keep the current and temperature down. A 3x3x3 cm aluminum block is not going to be enough if you're going to use it for laser shows.
What kind of LD are you using?
The LD is 8x and/or 16 x. I can´t light matches with collimated beam. But when I use a lens, I match very fast.
The beam goes to very distantes builds.
About voltage... If i put this batterie in the DDL will work nice... won´t bow my LD. Right?
3V goes to DDL, 3volts goes to LD and 6 volts will turn in heat. Right again?
As I never saw an especific power red, I can´t estimate the power :/ Anyway, I´m happy.
Tell me a good dimensions to do the heatsink (block or cilinder of Al).
I don't get it when you say it's an 8x and/or 16x???? Was the DVD burner from which you extracted the diode from an 8x or 16x, it makes a big difference.
The battery should work but I don't know for how long it will power the laser since I don't know its mAh rating.
As for the heatsink. Since you're planning on using this for long periods of time I think an 8 cm long 5 cm tall 5 cm wide aluminum block should be good. Maybe I'm overdoing it but I wouldn't take any chances if I was you.