Usb Dac

[MechEng3]

I have the easylase DAC and have always been dissapointed that the analog outputs never reached the full 5 volts for modulation. This is strange to me because the TTL jumper ,when moved to such setting, will deliver close enough to 5 v to get the lasers to blank......privided they are TTL units. I am in search of another DAC that is USB compatable as to retain the use of the laptop for show output and design work.....not to mention ease of total components to move or store. I have other issues standing against this one now and I would like to find something to replace it with. Any help other than modifying this one?

[DZ]

I have the easylase DAC and have always been dissapointed that the analog outputs never reached the full 5 volts for modulation. This is strange to me because the TTL jumper ,when moved to such setting, will deliver close enough to 5 v to get the lasers to blank......privided they are TTL units. I am in search of another DAC that is USB compatable as to retain the use of the laptop for show output and design work.....not to mention ease of total components to move or store. I have other issues standing against this one now and I would like to find something to replace it with. Any help other than modifying this one?

You could always build a little pre-amp between your dac and the projector using tl082cp ic's Would be simple to build and use pots so it would be easy to adjust.

David

[dave]

I have the easylase DAC and have always been dissapointed that the analog outputs never reached the full 5 volts for modulation. This is strange to me because the TTL jumper ,when moved to such setting, will deliver close enough to 5 v to get the lasers to blank......privided they are TTL units. I am in search of another DAC that is USB compatable as to retain the use of the laptop for show output and design work.....not to mention ease of total components to move or store. I have other issues standing against this one now and I would like to find something to replace it with. Any help other than modifying this one?

Are you checking with a cro?

[MechEng3]

Are you checking with a cro?

It has been tested by me and Marconi. We have the same results...well close enough. Yadda mentioned it would be possible to remove the resistors on the output side of the DAC chips to achieve the desired results.....I am still looking for a viable solution......
The tl 082 sounds like a great idea as long as any output from there would without any doubt be clamped at 5 volts.

[Zoof]

Did you check with Joachim on this because my Easylase is a little over 5V on the modulation outputs? What voltage are use using to power te card?

[Laser Ben]

Aprox. how much do these cards cost?

[cruch]

Easylase card cost about 250-300usd. Something like that.

[allthatwhichis]

Isn't it a box, not a card?

[cruch]

it can be both

[stanwax]

I recently bought easylase bare board and have just measured mine using a Tek TDS 210 and I get 5.00v at the top. If anything mine does not go to zero. The range seems to be from about 0.05v to 5.00V so some fine control at the lower end is missing but I certainly am not gonna worry about that ammount.

Have you measured the output with the lasers disconected ie are they loading the output in any way ? Where are you measuring - on the laser input, on the easylase output connector, or on the board itself? Where are you earthing the scope? are you using a scope? cos if you are using a multimeter you will never read a true value as its not a DC signal or an ac signal a MM could get its head round.

The power going into the board should not cause too much of a problem as easylase has its own dc to dc convertors on board so unless the input volts are seriously low it should be able to work. The op amp output stages use a split 12v supply which is generated from the 9v or so coming in. Mine is powered by a 7.5v wall wart - cos thats what I had spare and it works a treat.

Rob