Converting to 18650

[Deleted member 8178]

I'm soon getting an Aries-200 which is running off of two C-primaries. I don't like those and want to make a adaptor for one 18650 http://www.dealextreme.com/details.dx/sku.5790

On full charge it'll be at 4.2V so if I add a 1N40xx diode (which one should I use?) the voltage will drop to 3.5V. Still 0.5V too much though.
Laserglow says that the Aries -series use a 1.2W diode pump set to 1W. At 1W the current probably is 1.1A, and 1.2W at 1.3A.

With ohm's law I came up with that if I let the laser run off 3.5V the current should be around 1.28A. Somewhat safe?


Anyone want to add/correct anything? Thanks!

 

[billg519]

You could use a 25500 lithium, this is c-size. These are normally unprotected, so you will have to check the voltage periodically so as not to undervolt the cell and render it useless. As far as the voltage dropping diode goes, use at least a 3A diode, it will be dissipating nearly a watt. (maybe a 1N5408? V[sub]FM[/sub]=1.0V) If you prefer the 18650 protected cell, a quickie adapter could be wrapping one layer of paper around the cell, then around this, wrap 1.5" wide masking tape until the rquired diameter is reached. This can then be slipped onto different 18650's when you change batteries.

 

[Deleted member 8178]

Good advice there . I'll use the 18650-cell as planned, now I wonder if the extra 0.2V (4.2-1) will harm the laser?

Also, can I connect several smaller diodes in parallel to replace one big diode?

 

[Deleted member 8178]

Good advice there . I'll use the 18650-cell as planned, now I wonder if the extra 0.2V (4.2-1) will harm the laser?

Also, can I connect several smaller diodes in parallel to replace one big diode?

I have four 1N4004 diodes, anyone who know if they will work fine?

 

[billg519]

Power may not divide evenly among the four diodes, but this is still worth a try. Should work OK. The extra 0.2 V should not be a problem, as C-alkalines are often over 1.5V when fresh.

 

[Deleted member 8178]

Ok thanks!
The diodes come from the same reel and are unused, so hopefully their characteristics will be more or less identical.

 

[billg519]

Let us know how this turns out. Sounds promising so far.

 

[Kenom]

Ok, I'd like to chime in here and put in my $.02. I did exactly this. However, I did NOT do any secondary modification other than just wiring it up to the driver. While I did see increases of power in the green up to 300mw, the diode died shortly thereafter. I do plan on replacing the existing diode with a 2W and hopefully that will give me enough power to not have to worry about the diode dying from over current/voltage. I can show you the adapter I made for the tube though if your interested.
Peace in!

 

[Deleted member 8178]

I've allready done the diode array and adapter at school, I'll post pics when i get home.

Ok, I'd like to chime in here and put in my $.02.  I did exactly this.  However, I did NOT do any secondary modification other than just wiring it up to the driver.  While I did see increases of power in the green up to 300mw, the diode died shortly thereafter.  I do plan on replacing the existing diode with a 2W and hopefully that will give me enough power to not have to worry about the diode dying from over current/voltage.  I can show you the adapter I made for the tube though if your interested.
Peace in!

Damn that's real a bummer! I've measued the doltage drop, it's .72V, crossed fingers that it will work. Please post your adapter too!

 

[Deleted member 8178]

Note I added a roll of paper to protect the battery. It fits so well that the battery is air cushioned on its way down the tube.

The battery resting onto the internal springs, it can be compressed flush to the edge of the adapter.

The diode array:

A nice rib sandwich lol. I put a aluminium plate on the diodes, might help them to cool to some degree.

Now I await the laser, sigh...

 

[Kenom]

Mine is nothing more than a 1" wooden dowell drilled out in the center large enough for the battery to fit inside.  I then took a true copper rivet, and drove it down through the side that connects to the spring internally and viola!

On another note, Lava is working on a driver for my Kryton Beast and I'm intending to completely remove the existing driver from my aries and instead utilize that. it will be a lot easier regulated and since the crystals in my aries are so beefy, I'm hoping that with a 2W or 3W diode, that I can see an increase of roughly 100-200mw in the end.

Ken

 

[Deleted member 8178]

I got the laser and it is sweet!

I measured the current when running on two slightly used C batteries (1.4V each). The current was 600mA.
With a full 18650 and diode array the current is 660-670mA. Does this seem right? I thought I'd get allot higher current from either :-?. I just bypassed the end cap with my DMM at the 10A setting.

Also I let it run for 5 minutes on the 18650 and diode array, the diodes got kind of hot, but cool enough to touch.

 

[rangedunits]

GwArrr moar pics!!

 

[Deleted member 8178]

I have no moar.

 

[billg519]

This laser is supposed to have a 1.0 - 1.2W 808nm pump diode. Expected operating current would be around 1200 - 1400mA. Can you doublecheck current measurement by using a 0.1 [ch937] resistor in place of the tailcap and measuring mV's across this resistor? (1mV = 10mA)
Nice Laser ! Nice work on the battery sleeve !

 

[Kenom]

do you get any flicker at all in output on yours?  Send it this way and I'll test it's output for ya and graph it. Ahh nevermind your in sweden. I know someone with a Power meter in the netherlands.