sound card help

[jamilm9]

First i'm not sure if this is the right section to post this so if you want mods can move this. To make a sound card dac you need a oscilloscope right? Because i don't have one would anyone be able to make one for me for the cost of parts plus a bit. btw i'm not ready for this yet so i didn't put it in the bst secion. This is the best dac for under $100 right. Finally i was seeing some people say that a eorror sound could blow a scanner. Any way to fix that.(5v zenzers) Thanks.

[mixedgas]

First i'm not sure if this is the right section to post this so if you want mods can move this. To make a sound card dac you need a oscilloscope right? Because i don't have one would anyone be able to make one for me for the cost of parts plus a bit. btw i'm not ready for this yet so i didn't put it in the bst secion. This is the best dac for under $100 right. Finally i was seeing some people say that a eorror sound could blow a scanner. Any way to fix that.(5v zenzers) Thanks.

You don't need a scope if you have a voltmeter and DR Lava's test file. I'm sure he'll post here in a few hours.

All control systems can blow scanners. The sound card dac guys often send each other ILDA files that are poorly designed that stress the scanners, that is where the bad reputation comes from. Good artwork won't blow the scanners with the soundcard dacs. Good artwork is easy to do.
Programs are available that will optimize the art work for the sound card. ILD SOS is one example.

You just need to find the right people to hang out with, and they are here on PL.

I have a sound card dac, and once the offset is adjusted with a voltmeter, before scanning, they are fine. You only need to adjust once, unless you change something in the system hardware.

Steve

[jamilm9]

i don't understand what i have to do with all the pots on the op amp board

[mixedgas]

i don't understand what i have to do with all the pots on the op amp board

The board is a level shifter.

OK, the signal from the sound card dac is 0-2.5 Volts for audio signals. We need different signal levels for standard lasers and galvos.

Laser signals for most systems are 0-5 volts for color and +/- 5 Volts for the galvos. If you do not have the board, you only get half the deflection and it only goes up and right, no down and left. The board has adjustable gain pots, so now you can amplify the signals to 5 volts for color (gain of two) and 10V for the X-Y, a (gain of about 4) Now you need to make the 10 into +/- 5 volts, so a offset pot for that channel is set to add a constant -5 volts

So for your color signals, you hook a voltmeter and load a test pattern image and set the offset pot so when there is no color, ie a all blank image is loaded, you get 0 volts. Then you load a test image that is max white, and adjust each color signal for 5 volts, and you go back and forth between the two images untill you have 0-5 by adjusting both the gain and offset pots for a given color. Next you adjust the gain and offset pots for X and Y using a special test pattern so you have -5 and +5 for the galvos, then you can hook the galvos up. DrLAVA here works on the cards and Keeperx can help you as well.

You need a Lasermedia and ILDA test pattern as well as one from DrLava, the ILD and LM patterns come with laserboy and can be downloaded from the PL FTP site, There is one more you need that I dont know the name of, that is sound card dac specific.

If you have a electronics friend who owns a oscilloscope, it is even easier, your friend can do this in about two minutes. With a voltmeter it only takes about 5.

I hope this helps.
Steve

[keeperx]

each channel has 2 pots. one for offset and the other for gain

offset is to set each channel at 0v DC when nothing is playing. the gain is to set the max output for each channel.

color channels max out at 5v DC when playing a white dot wave... and the XY channels max out at 5v AC when playing a full screen circle.

there are a few different ways to tune the card. its BEST to have a scope but not necessary...