100MW PORTABLE UNIT

[greenlazer]

Hello to all....sorry about the stirring of the of the pot so to speak. The thread is closed and all is going to be OK. I have a 100mw unit that I think can be made portable. I plan to take a NiMh 14.2 [2800mah]vdc pack and feed it to a voltage inverter to get 110 vac., then to the regulated and filtered supply to the dpss assembly. It is fan cooled. All parts are new so far.I have fabricated a nice case or housing for this device.Complete with keyed safety and all warning labels. Should be very nice as well as unique! My question is....is this possible?????Or am I wanting something that is not possible. Would like to have for outdoor shows...like on the side of a house. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/cool.gif /ubbthreads/images/graemlins/icon23.gif /ubbthreads/images/graemlins/ooo.gif /ubbthreads/images/graemlins/help.gif

 

[Raccoon]

converting from DC to AC to DC again isn't very effecient.

 

[greenlazer]

I was told that the dc voltage has to be extremely clean. the power unit as supplied is current regulated and very complex in its own right. I feel if I don't use it , I will take a chance on frying this new unit $$$$$$$ !! /ubbthreads/images/graemlins/banghead.gif /ubbthreads/images/graemlins/banghead.gif

 

[Bengal]

I dont know how clean your laser voltage has to be, but a linear regulator like a lm 317 or similar ic can provide a very clean dc voltage, it can also be configured as a current limiter or constant current source.

taking the route from dc to ac to dc , especially the way you described is wasteful.

Batteries , believe it or not are the most "clean" source of voltage available.

run thru a regulator to prevent overvoltage can be a very suitable power supply.
might not be long lasting....

 

[enLIGHTenment]

Laser diodes are extremely picky about power. Hooking an LM317 to a laser diode will destroy it immediately. DC-AC-DC is the best way to go short of buying a DC powered laser such as a 315M.

Note that it is illegal to use a >5mw class IIIb laser for a public show without a permit.

 

[Kreso_Bukvic]

From what voltage your unit operates?
I remember on som forum some guy made module portable but cannot remember where.. It wascalled new project and we are all involved or so.

 

[Goldmagnet]

I dont think Bengal was talking about hooking up a 317 to the diode, but to the existing power supply, on the DC side.

That just cuts out the ineffeciencys in the conversion, and as Bengal states is the cleanest solution.

 

[Guliver]

Actually...the LM-317 can serve as a very good current regulator for driving diode's.
Its a very simple circuit, I've driven many a diode with them.
The hard part is figuring out what resistor to use.
But that's not what he was suggesting.
The LM-317 will clean up the dirty dc and clean it up quite a bit.

 

[trident]

greenlazer can you post a pic of your custom case? Also, what did you pay for your 100mw unit?

 

[greenlazer]

Hello to all and thanks for sharing an interest. I have to work on saturday, but will continue the final assembly of the unit that night. I plan to use the dc/ac/dc power for now as I have all the components on hand in new condition.I have a little soldering left and final fitment of internals. Should weigh around 5 lds.I will post pix as soon as I can showing "under the hood" and action.

 

[greenlazer]

I will have the wife gather the info and costs on all parts and post soon with pix.

 

[Kingjamez]

[ QUOTE ]
enLIGHTenment said:
Laser diodes are extremely picky about power. Hooking an LM317 to a laser diode will destroy it immediately. DC-AC-DC is the best way to go.

[/ QUOTE ]

Yeah, that is not correct. I use LM317's in a current limiting arrangement up to 3amps all the time. Combined with a battery they are probably the simplest, easiest, and most reliable way of powering any laser diode. I'm looking at a laser right now that I power with a LM317. Any green laser that is 300mW or less should be able to be powered by a (well heat sinked) LM317

 

[bootleg2go]

I agree with Bengal and Kingjamez, The cleanest power source there is is a battery (pure DC, no noise/ripple or anything) and an LM317 is the perfect regulator, and very inexpensive. Don't go from DC to AC then back to DC, that will just add weight size and complexity where you don't need it and the resulting power will not be as clean.
Remember it is illegal to use anything over 5mw in power outdoors unless you have a variance and permit. In fact if your planning on getting some galvos setup to project a laser show, 5mw is plenty for projecting onto a surface and making shapes/animations. In fact 100mw will be too bright for people to watch comfortably if projected on a wall or something.

good luck
Jack

 

[Goldmagnet]

Hey enLIGHTenment I have just had a look at your home page.

You are pretty weird, you scare me, you are probabbly right on anything you say.

Regards

Gold

 

[Raccoon]

[ QUOTE ]
The LM-317 will clean up the dirty dc and clean it up quite a bit.

[/ QUOTE ]

I'm sorry, but what are you talking about?
How can someone have "dirty dc" from a battery pack of NiMHs?!

The reason the original poster wanted to use a DC to AC inverter was because his laser unit comes with an AC wall plug (which is transformed back into DC). Yes, this would be a simpleton solution that doesn't involve butchering your laser, but it is still highly ineffecient and clunky.

The ACTUAL solution is to throw away the AC power cord and butcher the unit-- providing it the DC current DIRECTLY from the batteries. Warranty Voided! /ubbthreads/images/graemlins/grin.gif

 

[Guliver]

The use of ac inverters even run from batteries contain square-waves (the dirt /ubbthreads/images/graemlins/icon15.gif ) as well as the ac which will quickly cause problems..especially to transformers. The square-waves will saturate the transformers causing premature death. /ubbthreads/images/graemlins/frown.gif
And possibly cause the following circuits to be unstable.
The LM-317 regulator with the proper use of bypass caps on its input and output can clean-up dirty supply lines.
Hope That Helps !!! /ubbthreads/images/graemlins/smile.gif

 

[greenlazer]

Ok Folks... i measured output of ac/dc module and it was 1.88vdc. unloaded volts were @ 4.88vdc. I applied 1.6vdc@500maH and nothing. I then applied 3.0vdc and the sound of a capacitor charging was audible ....then nothing. The original supply was employed and nothing.I think it is dead!!!!!!OUCH!!!!!!!!!!!

 

[greenlazer]

OK as suggested ....ac/dc power module has output of 1.8vdc @ 400maH. I cut the cable and applied 1.5 vdc and nothing @ 400maH. I then applied 3vdc at same current and it sounded like a capacitor charging ..then nothing.I then replaced all connections to the original supply and now nothing. DEAD!!!!!!!!! ----$$$$$ /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/help.gif /ubbthreads/images/graemlins/help.gif /ubbthreads/images/graemlins/help.gif /ubbthreads/images/graemlins/help.gif /ubbthreads/images/graemlins/ooo.gif

 

[Kingjamez]

What does a chargeing capacitor sound like ???

-Jim

 

[bootleg2go]

I was going to ask the same thing, I've been heavily involved in electronics for over 25 years and I've never heard a capacitor charging. They will make a very large POP when they explode do to reverse polarity or old age. I suspect if you heard anything, it was not a capacitor at all, but maybe the sound of something inside the laser head itself frying.

Jack