DIY Laser Torch

[Hemlock_Mike]

Wlaser --

Those voltage regulators make only fair current regulators. Stick with the LM317 as it's tested and true for constant current.

Mike

 

[Gazoo]

So what about those regulators? And the cap is 47uf and 35V which is what SenKat's driver kit includes.

The cap is OK, the regulators are not. The 7805 can be used as a current regulator but Daedal and I tried it and it sucked...plain and simple.. ;D The LM317T is a good regulator.

BTW, I am using 10uf 16 volt caps. They can be soldered directly to the diode and still fit in the aixiz module.

 

[troop231]

[quote author=troop231 link=1186966870/165#176 date=1199662028]So what about those regulators? And the cap is 47uf and 35V which is what SenKat's driver kit includes.

The cap is OK, the regulators are not. The 7805 can be used as a current regulator but Daedal and I tried it and it sucked...plain and simple.. ;D The LM317T is a good regulator.

BTW, I am using 10uf 16 volt caps. They can be soldered directly to the diode and still fit in the aixiz module.[/quote]

I thought this torch required rather a 47uf instead of 10uf?

 

[Gazoo]

No, it does not. Maybe if you were using a power supply to power the laser, and it was notorious about putting out spikes...but for batteries...naw....

We have beat the discussion of the capacitor to death....lol. I used to recommend the bigger capacitor until I realized it was not necessary to use one that big. In fact I would dare say we could even go smaller than a 10uf....others have. But I will continue to stay with 10uf 16 volt caps for now.

 

[troop231]

Edit: New Diagram below a few posts. ;D

 

[knimrod]

OK, I made a basic diagram of the circuit for this torch as per Daedal's first set of posts. Can someone tell me if this looks right? If something is wrong explain it and I'll fix it, Thanx!  ;D

The polarity of your 1N4001 diode is backwards. The cathode (stripe) of the 1N4001 diode should be connected to the anode (positive side) of the LD.

 

[troop231]

Um, no, before I posted I checked, and Anode=Negative and Cathode=Positive. So it is reversed, therefore correct in my diagram? Hey, is there any other things wrong? Thanks!

 

[knimrod]

Um, no, before I posted I checked, and Anode=Negative and Cathode=Positive. So it is reversed, therefore correct in my diagram? Hey, is there any other things wrong? Thanks!  

Yes, but the stripe on a diode indicates the cathode. In your diagram, the stripe is towards the negative side which would mean it's forward biased. That's not what you want.

 

[troop231]

After reading heavily on here, I thought the Diode was supposed to be oriented that way so it is reverse polarity protected? Can you explain better please or diagram how that works? I'm not to good at electronics. Thanks!

 

[troop231]

Ok, now is this circuit A-OK for some laser driving? Or is there some other stuff wrong? Thanks again!

 

[knimrod]

In a normal diode, current will flow from the anode to the cathode after overcoming a small hurdle (about .6 volts). Current will not flow from the cathode to the anode. So by reverse biasing the diode in parallel with the LD, no current will flow through the diode if the power is hooked up correctly to the pair. On the other hand, if the voltage to the pair is reversed, the diode will be a virtual short circuit, preventing a reverse polarity on the laser diode.

 

[troop231]

So, my updated diagram 2 posts above is now perfect? Right? lol.

 

[knimrod]

It looks good to me though I'm not too sure about the connections to the "original circuit board" not being familiar with exactly what circuit board you have there.

 

[troop231]

The circuit board that is included in the MXDL flashlight. The one daedal used in his posts.

 

[knimrod]

Yes then, it all looks good to me..

 

[troop231]

Ok, I bought all of the components at RadioShack and have now assembled the above diagram I made. Here's the outcome, does it look about right as far as output voltage and ma? Thanks! ;D