Sound card DAC tutorial

HIMNL9 said:

(BTW, 12 minus 1,7, multiplied 0,625, gives you 6,43W to dissipate ) .

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Minus 1.25 x 0.625 that is dissipated on resistors.

Should be okay then, but its a fairly large (but odd) heatsink to begin with. I run mine with a much smaller one, but use a 9 volt rail to power the laser diodes (a red and a green at 350 or so mA).

How hot does it get without the fan assisting? Still acceptable?

If you do power the whole thing from a 12 volt rail, i think you will require a fan to cool the projector as a whole anyway. In an enclosed case things get hot easily, and that will degrade the performance of your lasers, even when the transistors are okay.

Without fan it heats up to temperature that burns

I plan to use 2x120mm + 1x80mm fan to pull out heat from case.

Aight - be careful with using fans in a projector though. The airflow will take dust along with it that will end up on your scanners, lasers, dichros and mirrors. It might actually be a good idea to have the fans blow inwards, with some dust filtering before them. If you leave the aperture for the beam open (i.e. not fit a window there) that will make a natural exit for the airflow.

Another solution could be to make some sort of separating wall between the things that get hot and the optical path. This can be as simple as a piece of cardboard or plastic with holes cut out that match the lasers output windows. Doing so, you can cool the parts that get hot but also can get dirty with fans, leaving the optical path clean.

I want to make negative pressure inside case because I don't want heat to accumulate inside.

That is great idea.
I'll separate case part where are electronics from case part where are lasers.

Hey i have one of these in my scanner and its been okay.
But i bought mine off another user and my sound card is not like all of yours its a square not an L, it uses the same drivers but i was wondering if using the older version of the sound card could be giving some bad results.
any thought will try to get a pic later.

If audio chip is the same I really don't see reason to be worried.

The only difference between the square verszion and the L-shaped version is 2 more channels. The L-shaped version has 8 channels. Functionality should be identical.

Make sure you have any surround/sound/processing disabled.

Apart from that, a 8 channel soundcard would be fine, at it would have the additional channels to output audio singal too - though i'm not sure how much use that is

I am in the process of building my first Sound Card DAC / multi-color RRGB laser scanner. I have a +200mw green TTL/analog, 1W 445nm blue and two LOC-815 red diodes. I also purchased a set of SpaceLas PT-30K galvos, C-Media external sound card and a "LaserBoy" correction amp.

The only problem is that Dr. Lava no longer has the complete correction amp kits, just the bare PC boards! After quite a bit of research, and a couple of emails between myself and the doctor, I was able to order all the components online for the bare PC board. In the interest of helping others out, I have compiled a list of everything you will need (plus links) to complete the correction amp...

CORRECTION AMP PARTS:
===================

12 x Resistors 10K Ohm 1/4 Watt
10K Ohm 1/4-Watt Carbon Film Resistor (5-Pack) - RadioShack.com

4 x Capacitors 10µF (Tantalum)
10µF 16V 20% Dipped Tantalum Capacitor - RadioShack.com

3 x TL072 Dual Op-Amps [Part# CED-P-QTL072]
Opentip.com: IC - TL072, Dual Op-Amp

3 x DIP Socket Solder Tail 8-Pin [Part# 517-4808-3000-CP]
4808-3000-CP 3M Electronic Solutions Division IC & Component Sockets

12 x Potentiometers 50K (Inline pins) [Part# 3296W-1-503LF]
3296W-1-503LF Bourns Trimmer Resistors - Multi Turn

1 x LM7905 Regulator [Part# 512-LM7905CT]
LM7905CT Fairchild Semiconductor Linear Regulators - Standard

1 x DC-DC Converter +/-12V [Part# 580-NKA0512SC]
NKA0512SC Murata Power Solutions DC/DC Converters & Regulators


Correction Amp Link:
http://hacylon.case.edu/ebay/laser_diode/LaserBoy_Correction_Amp.php

HOPE THIS HELPS SOMEONE OUT!

VERY good info, thanks! If it's OK with you I'd like to add this information to the OP..

ElektroFreak said:

VERY good info, thanks! If it's OK with you I'd like to add this information to the OP..

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EDIT: Removed "rep" request. I am new to this whole thing so please forgive me...

Asking for rep ? this is a bit like hitting below the belt or sucking the whip cream right out of the can.
I take pride in the fact I have NEVER asked for any rep, all the rep I have recieved is because
someone else gave it to me
If you go around asking people to rep you dose it make you feel good to know some one gave you
something you asked for ? I would much rether have it because some one wanted to give it to me,
it seems to mean so much more that way
Please go read my rep history and find out why people are repped, it's not because they ask for it.
Have a good day !
Pyro...

paulzimm said:

No problem at all - glad to help! You could also "hook a brother up" with a rep point or two

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While I do agree with you Jeff, it's OK.. he earned this one. I often neglect to give rep just because I don't always think about it. This was one of those times..

if i've read corrctly... 1 sound card, and 1 correction amp are needed? or is it one set per galvo equalling 2 sound cards and 2 correction amps?

michael

just one sound card and one correction amp.. they both support 6 signal channels, of which 2 channels control the galvos (1 ch. each) and 3 control the lasers (1 ch. each RGB) which leaves one channel left which isn't used with solid-state lasers.