Complete laser noob... Please help!!!

[mainefungi]

Still sticking with the LM317? Oh well, gotta admire your determination (if not your ability to take good advice).

The max operating temperature for a LM317 is about 125 Deg Celsius (257 F). You can get that information directly from the component's datasheet.

Have you addressed your battery situation yet?

If you are still trying to run this on inferior batteries you are very likely overdrawing your battery. Many batteries have internal protection circuits which automatically cut output when being overdrawn. This could be the pulsing you are seeing; if the battery is cutting out and then recovering... and cutting out again... I drew up a simple 1 Amp LM317 circuit.

I hope you are wired up in a similar fashion. The cap is only needed to smooth out the inrush of current at initial power on. After that the capacitor is seen as an open because this is DC circuit.

 

[jsteg1981]

I did address the battery situation. I bought three 10440s. Three seemed to be too much voltage for the LM317 so I made a dummy cell. With the dummy cell, I was not getting enough current. So now I am using two 10440s and a triple A.

Last night I made a new driver circuit. Same one I have been using. Heatsinked LM317, two 1 ohm 2W resistors in parallel and the 10uF cap. I am not getting a steady 800mA.

I would say it was the LM317. With the three 10440s it ended up hitting the thermal protection phase and shutting down so much that the laser was very faint.

LOL now that I have successfully made the LM317 driver work, once I pay some bills, if I have the cash left this pay period, I will buy a better driver. I just wanted to know I could do it.

What driver is suggested to keep it at 1A and still use the battery setup I have?

 

[jsteg1981]

I am not getting a steady 800mA = I am now getting a steady 800mA.

 

[DrSid]

Oh wow!!! I needed that graph! Thank you sooooo much!

Just keep in mind that it can differ. Every diode is different, some are even 30% better - same current, more light.

 

[mainefungi]

I did address the battery situation. I bought three 10440s. Three seemed to be too much voltage for the LM317 so I made a dummy cell. With the dummy cell, I was not getting enough current. So now I am using two 10440s and a triple A.

WTF? NEVER ever mix litium batteries with standard batteries. You are asking for trouble. Different voltages, different current specs, different drain rates...

:gun:

 

[jsteg1981]

Ok. Well this setup is not going to work then. The LM317 gets too hot with the three 10440s and two do not provide enough current. I hate being a noob sometimes!

 

[jsteg1981]

Also I was not able to find much of anything online about mixing batteries. What can happen?

They are in series... Does that mean that when the AAA discharges, it charges in the opposite polarity? Does that ruin the AAA or ther others?

 

[Th3dArKn3o]

Ok. Well this setup is not going to work then. The LM317 gets too hot with the three 10440s and two do not provide enough current. I hate being a noob sometimes!

Because you don't listen what I and all the other experienced members said !
Buy an blitzbuck driver or DTR has a really good boost driver for an single Li-Io in his shop !
Or if you want to build something on your own consider changing the LM317 with the L200 you can contact me and I will help you with this !

Also I was not able to find much of anything online about mixing batteries. What can happen?

They are in series... Does that mean that when the AAA discharges, it charges in the opposite polarity? Does that ruin the AAA or ther others?

It will ruin the AAA because normal Ni-Mh cells have around 1,2V Cell Voltage
and the Li-io around 3,6V the AAA will quickly discharge and fail !
Also you can damage the lithium as well because of reverse currents