Sony SLD1236VL minimag

[kaunak]

I ordered a Sony SLD1236VL 16x laser from stonetek a few days ago and I installed it in a mini mag flash light. There was about 2.5-3 volts going to it and it works ok but it cant light a match coloured black and it can barely burn through a black garbage bag. I would guess it is around 20-30 mW. Could the diode be damaged? I really dont know what it could be other than that :-?

 

[Hemlock_Mike]

Hate to ask the same old question. How many mA are you getting to the diode? Diodes don't draw voltage -- they draw current.

Mike

 

[MB500]

Try focusing it if you haven't. The dot size can be pretty huge at the aperture when its focused for distance.

 

[kaunak]

yea i know about mA but I don't know how to get the right current to go through the diode. Im using a mini mag which I would guess draws about 150-200 mA at least? It uses 2 AA batteries which is about 3 volts if that helps.

 

[chido]

Don't use a minimag, all that does is connect the diode straight to the batteries which can kill it instantly or significantlly shroten its lifespan. Go build your self a proper laser.
I recommend you look at this thread for building a laser out of a dorcy flashlight which already has a driver and this video walkthrough.

 

[tone1132]

"I installed it in a mini mag flash light" otherwise known as a mini-mag mod.
^I think thats the problem.

 

[kaunak]

the mini mag isn't the problem, the current/diode is. Ive seen many people make mini mag mods where they output at least 150mw. Mine is about 30-40? Ive also tried the diode in another mini mag with the same power.

 

[chido]

If you have your diode in a minimag you're dumping all the power from the batteries into it, there's no way of controlling the current unless you solder a resistor to it.
By connecting it straight up to the batteries the diode won't last too long. If you want it to live a long and happy life, then you have to build a driver for it, or make a laser out of a dorcy flashlight which already has a driver, check post #4.

BTW, how do you know how many mW your diode is putting out?

 

[kaunak]

Its underpowered to what it should be for a mini mag mod. I could guess its around 30-40? It takes around 10-15 seconds to burn a full hole thought a black garbage bag.

 

[tone1132]

Thats WEEAAK!!! do it right, with a driver, or a dorcy mod. c'mon!

 

[chido]

Its underpowered to what it should be for a mini mag mod. I could guess its around 30-40? It takes around 10-15 seconds to burn a full hole thought a black garbage bag.

You can't guess how many mW a laser is putting out, you need a laser power meter. If it's still burning then it shouldn't be weak since you're not using a driver to limit the current going to the diode and all the power from the batteries is going straight to it. Are you sure you're focussing it right?

 

[MB500]

I ran my stonetek diode with a voltage regulator at 2.85 volts. I am only sourcing about 98mA when it is first turned on. It can still light a match instantly and cut tape very fast. I think it was safe to use a voltage regulator when my current was so low.

 

[chido]

You need a current regulator to run a diode, not a voltage regulator. The diode will take whatever voltage it needs so you don't need to regulate voltage, only current.
Only 98mA!!!! Your diode is underpowered, is it one of the new JL-54 diodes or one of the old ones?

 

[Scriabin]

You need a current regulator to run a diode, not a voltage regulator. The diode will take whatever voltage it needs so you don't need to regulate voltage, only current.
Only 98mA!!!! Your diode is underpowered, is it one of the new JL-54 diodes or one of the old ones?

What are the differences between the old and new diodes? I have 3 diodes "JL-54 ", I have mounted one of them in a died green laser pointer with nice results, but seems that a CR2 battery it is not enough, and the output is quite weak.

Later I'll build a better driver with LM317...I want to run it at 200 mA, with a big heatsink..

 

[rog8811]

Its underpowered to what it should be for a mini mag mod. I could guess its around 30-40? It takes around 10-15 seconds to burn a full hole thought a black garbage bag.

If you do not control the current all the excess current and volts will be turned into heat by the LD, which makes it less efficient....which causes it to heat up more....which causes it to die.....

It isn't a secret on this forum, a regulated laser diode is a happy laser diode...short cuts in this hobby only end in frustration and large holes in your bank balance.

Regards rog8811

 

[MB500]

You need a current regulator to run a diode, not a voltage regulator. The diode will take whatever voltage it needs so you don't need to regulate voltage, only current.
Only 98mA!!!! Your diode is underpowered, is it one of the new JL-54 diodes or one of the old ones?

Ya, I was fairly inexperienced so I just decided to use a low voltage regulator so the current couldn't go too high. I left it on for 4 minutes and it only hit around 102mA. I did it maybe 4 months ago so I'm not sure which diode it is.