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DVD-RW Laser...How to know what mA to push to?

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I am going to make a DVD-RW laser torch. I am also going to use Daedals circuit for it. I will put a ammeter in line when adjusting the 100 ohm pot. How do I know what the highest mA the laser will take? I do not want to risk burning the LD out because I am short on money and it took me a while to locate this used DVD-RW drive (got it for free though). Thanks
 





Gazoo

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Need to know the make and model number of the drive.
 
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Ok, I am going to pick it up today, I will post back later. Thanks

BTW
I am planning on powering this with a 9V, I don't think that will create too much exess heat on the regulator. I am doing this because they are cheaper than the 3V cells and I already have a 10 pack of them. Now I just need to figure out how to get it to fit in a flashlight body :)

Already ordered the mount from Aixiz
 

Gazoo

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You will be lucky to get 10 minutes of runtime with a 9 volt Alkaline battery, even going easy on the diode and with short duty cycles. I am going to post the link to the energizer data sheet. Note the Milliamp-Hours Capacity chart.

http://data.energizer.com/PDFs/522.pdf

Eventually you will want to get a 6 volt pack made up of rechargeable batteries.. ;)
 
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For sure -- 250 to 300 mA will wipe a 9 volt cell FAST !!
Look on Dealextreme for LiIon cells too.

Mike
 
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hmm, maybe I need to rethink, I did not think the mAh would be that low.

The body I want to use is a mini mag...(2 AAs)
 
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OH -- I thought you were using 9 volt batteries.  I think there are numerous posts here on how to use a minimag light.
By the way -- is it a 16x, 18x, or a 20x ?? This can make a difference in drive current.

Mike
 

Gazoo

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DKAudio said:
hmm, maybe I need to rethink, I did not think the mAh would be that low.

The body I want to use is a mini mag...(2 AAs)

Now I am confused. You did say you wanted to power it with a 9V battery, and that you had a 10 pack of them. Then you go on to say you want to put all of this in a 2AA minimag, is this correct? I am assuming you want to use the minimag to house everything except the 9 volt battery.

If you want to use a minimag with a pair of AA's, which is a good idea, you will not be able to use Daedal's circuit. You will still need a resistor in series with the diode, and put a capacitor across the diode. While this is better than nothing, it will not provide as much protection as Daedal's circuit does.
 

Things

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just be careful with Li-Ion batteries, they love exploding when they get punctured or overcharged, or heated too much! :D :D
 
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I still think the original question is a good one. I'm building Daedal's circuit, and I understand that you start with the pot on max. resistance, then dial it down until the LD begins to lase. Then what? How far past the minimum lasing resistance should you go? Too far, and you'll shorten the LD life (or zap it). Not far enough, and you're leaving burning power on the table.
 
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Well, forget that I said anything...
I went to pick up the DVD-RW my friend had and it turned out to be a CD-RW and DVD-ROM.  GRRR

I will have to get one some other way.  

My plan was to use my mini mag body for the project.  I don't know what I can use to power it though since Gazoo said Daedal's circuit won't fit with it.

Back to square 1, any tips/suggestions would be appreciated. Like I mentioned before, I already ordered the mount from Aixiz.

Thanks
 

ericab

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DKAudio said:
Well, forget that I said anything...
I went to pick up the DVD-RW my friend had and it turned out to be a CD-RW and DVD-ROM. GRRR

I will have to get one some other way.

My plan was to use my mini mag body for the project. I don't know what I can use to power it though since Gazoo said Daedal's circuit won't fit with it.

Back to square 1, any tips/suggestions would be appreciated. Like I mentioned before, I already ordered the mount from Aixiz.

Thanks

i have a good tip/suggestion....

dont use a minimag... seriously...

check this out:

http://www.laserpointerforums.com/forums/YaBB.pl?num=1186966870

not only does it look good, but it fits daedals circut.

conclusion:

minimag = :mad:

-eric
 

Gazoo

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wilheldp said:
I still think the original question is a good one. I'm building Daedal's circuit, and I understand that you start with the pot on max. resistance, then dial it down until the LD begins to lase. Then what? How far past the minimum lasing resistance should you go? Too far, and you'll shorten the LD life (or zap it). Not far enough, and you're leaving burning power on the table.

It is a good question, but there was no way to answer the original question without knowing the make and model of the drive. Even with this information it would be a rough guess since we would not have the specs of the diode. Unless someone had experience with his particular DVD drive, which I was hoping for and would have searched for it.

So we either need the spec sheet, or at a minimum someone that has run the same DVD diode through the paces to get an idea of how much the diode can be pushed.
 
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DKAudio said:
Ok, I am going to pick it up today, I will post back later.  Thanks

BTW
I am planning on powering this with a 9V, I don't think that will create too much exess heat on the regulator.  I am doing this because they are cheaper than the 3V cells and I already have a 10 pack of them.  Now I just need to figure out how to get it to fit in a flashlight body :)

Already ordered the mount from Aixiz

That will also heat up the LM317 quite a bit. Perhaps not out of operating spec, but its gunna get pretty warm. Heatsinking would be a good idea.
 
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Gazoo said:
It is a good question, but there was no way to answer the original question without knowing the make and model of the drive. Even with this information it would be a rough guess since we would not have the specs of the diode.  Unless someone had experience with his particular DVD drive, which I was hoping for and would have searched for it.

So we either need the spec sheet, or at a minimum someone that has run the same DVD diode through the paces to get an idea of how much the diode can be pushed.
OK, since the OP's plan fell through, let's drive this discussion towards the Sony GB laser diodes.
 
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wilheldp said:
[quote author=Gazoo link=1188324298/0#12 date=1188361798]
It is a good question, but there was no way to answer the original question without knowing the make and model of the drive. Even with this information it would be a rough guess since we would not have the specs of the diode.  Unless someone had experience with his particular DVD drive, which I was hoping for and would have searched for it.

So we either need the spec sheet, or at a minimum someone that has run the same DVD diode through the paces to get an idea of how much the diode can be pushed.
OK, since the OP's plan fell through, let's drive this discussion towards the Sony GB laser diodes.[/quote]

Yeah, that is a good idea. I think I am just going to have to spend the $18 and get one.
 




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