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Gazoo

Gazoo

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Glad to know the open can was a successful harvest and did not rot..lol

The other LD is infrared..it will burn and all, but is dangerous unless you have goggles for it. I throw those diodes in the trash.

I can't answer your questions about the batteries because I do not know exactly what you have. Another option is to use 6 AA nimh batteries to power both circuits.
 





jayrob

jayrob

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Gazoo said:
Glad to know the open can was a successful harvest and did nit rot..lol

The other LD is infrared..it will burn and all, but is dangerous unless you have goggles for it. I throw those diodes in the trash.

I can't answer your questions about the batteries because I do not know exactly what you have.  Another option is to use 6 AA nimh batteries to power both circuits.
Click to expand...

Well....I guess I have some experimenting to do. 6 AAs will take up more room than 4 cr123s, but I'm sure they will have more capacity. I'm thinking I might try pairing up two sets of cr123s and then hook the 6 volt sets up parallel so that I can use one switch to power the LD driver as well as the peltier...Gazoo, I know you have tested battery current and know about electronics (I don't know anything about electronics - I am learning as I go), I am wondering how fast the peltier will discharge batteries...Can I just look at current? I mean, I know that an MXDL using 2 cr123s running an LD at 325mA has good battery capacity (batteries last). Am I correct in thinking that the peltier will have the same draw on the batteries if I run it at the same current?
Jay
 
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a_pyro_is

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Just a thought, but maybe it's time to ask a mod to move the '112D Open-can harvest guide' portion of this thread to a new thread so that it may more easily be found when the next guy goes searching.
 
Gazoo

Gazoo

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Jayrob,
You are correct about the current draw. However the peltier will draw more current with less voltage than the LD. This is because it has a much higher resistance. For example the voltage applied to the peltier using the AMC7135 is 1.7 volts..where as the voltage applied to the LD is 2.8 volts. Each is receiving 350ma's of current.

As far as the batteries you will run into problems using regular Lithium CR123's unless you use 3 in series with each circuit..this would be a total of 6. Or you could make a combination of cells, in series/parallel, and make a pack to power the whole thing. This would be better as the batteries would drain equally. If you are using Lithium Ion RCR123's, then you do not want to use more than two in series for each circuit. The regulators get too hot running at 12 volts. The thermal protection of the regulators will kick in, and the current will slowly drop.

I still think the best solution is to use 6 AA Nimh batteries.
 
jayrob

jayrob

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Just a thought, but maybe it's time to ask a mod to move the '112D Open-can harvest guide' portion of this thread to a new thread so that it may more easily be found when the next guy goes searching.
Click to expand...
a_pyro_is, I agree...this thread some how went off into the open can laser project! Great stuff from Gazoo here...

Gazoo said:
Jayrob,
You are correct about the current draw. However the peltier will draw more current with less voltage than the LD. This is because it has a much higher resistance. For example the voltage applied to the peltier using the AMC7135 is 1.7 volts..where as the voltage applied to the LD is 2.8 volts. Each is receiving 350ma's of current.

As far as the batteries you will run into problems using regular Lithium CR123's unless you use 3 in series with each circuit..this would be a total of 6. Or you could make a combination of cells, in series/parallel, and make a pack to power the whole thing. This would be better as the batteries would drain equally. If you are using Lithium Ion RCR123's, then you do not want to use more than two in series for each circuit. The regulators get too hot running at 12 volts. The thermal protection of the regulators will kick in, and the current will slowly drop.

I still think the best solution is to use 6 AA Nimh batteries.
Click to expand...

Ok...thanks Gazoo. I know I'll figure out some things when I start experimenting. It's just that I have a bunch of the 3 volt lithium batteries and would some how like to use 4 of them. I can set 4 of them up in a 6 volt pack and then just turn the 6 volt current down on the peltier side I would think?? Just thinking out loud...You said that the peltier cools good using the AMC driver at 1.7 volts and 350mA current. So, is my thinking correct that I can get the same cooling with less current in a 6 volt system?
Jay
 
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a_pyro_is

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jayrob said:
a_pyro_is, I agree...this thread some how went off into the open can laser project! Great stuff from Gazoo here...
Click to expand...

They don't call him 'The Great Gazoo' for nothin'.
 
Gazoo

Gazoo

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Jatrob,
You will find the regulator dropping out as soon as the CR123's begin to sag...and it will be almost instant. I am not as concerned with this with the peltier...you could probably go as low as 4 or 5 volts with the batteries before the 317 regulator begins to drop out... assuming you are driving it with 350ma's which would be appx. 1.7 volts

Others have found that two CR123's do not provide enough voltage to power SenKats diode...the 317 drops out. And actually the open can diode takes more voltage and current than the SenKat diode to achieve the same output. The open can is very similar to the Graph Daedal posted of the Phaser diodes.

All I can suggest is to Keep an eye on the voltage between the output and adjust of the 317. If it goes below 1.25 volts, then the regulator is dropping out.

The LM317 will be regulating the current to the peltier...if you apply 1.7 volts to the peltier, the current will be the same as if you were driving it with the 7135 using 3 nimh batteries....~350ma's. Point being the 317 requires more input voltage to do the same job as the 7135, and therefore is much less efficient.
 
jayrob

jayrob

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Gazoo said:
Jatrob,
You will find the regulator dropping out as soon as the CR123's begin to sag...and it will be almost instant. I am not as concerned with this with the peltier...you could probably go as low as 4 or 5 volts with the batteries before the 317 regulator begins to drop out... assuming you are driving it with 350ma's which would be appx. 1.7 volts

Others have found that two CR123's do not provide enough voltage to power SenKats diode...the 317 drops out. And actually the open can diode takes more voltage and current than the SenKat diode to achieve the same output. The open can is very similar to the Graph Daedal posted of the Phaser diodes.

All I can suggest is to Keep an eye on the voltage between the output and adjust of the 317. If it goes below 1.25 volts, then the regulator is dropping out.

The LM317 will be regulating the current to the peltier...if you apply 1.7 volts to the peltier, the current will be the same as if you were driving it with the 7135 using 3 nimh batteries....~350ma's. Point being the 317 requires more input voltage to do the same job as the 7135, and therefore is much less efficient.
Click to expand...

Well, with all of this information, I have a good start with this project...I can try 4 cr123s in a 6 volt pack, or 4 rcr123s in a 7.2 volt pack, and if that doesn't work, I'll try the AAs and maybe the AMC7135s...
Thanks Gazoo...I'll show you what I come up with...
Jay
 
H

Hikari_V

Guest
Happy new year, I am new to this forum but not to lasers, I am somewhat new to building diode based laser pointers.

I would appreciate someone telling me how to properly remove these open faced diodes from their housings from an LG 20x DVD writer. :eek: :eek:
Thanks for all the information you can supply
 
jayrob

jayrob

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I would appreciate someone telling me how to properly remove these open faced diodes from their housings from an LG 20x DVD writer.
Thanks for all the information you can supply
Click to expand...

Well, take a look at page 3 of this thread to see how to remove an open can diode from a Pioneer 112D. I would imagine that it would be similar with your DVD...
Jay
 
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