the ttl ground , catweazle scanner ground are connected to pins 14 & 15 . Do you mean connect the scanner x & y ground to the same point ?Originally Posted by stupidsexyflanders
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the ttl ground , catweazle scanner ground are connected to pins 14 & 15 . Do you mean connect the scanner x & y ground to the same point ?
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The DAC is made by Nu Light
Senior Member
grounds
no the scan set power supply to ground
it called star grounding , solves lots of problem with noise,and ground loops causing prolems
so disconnect all your grounds then for example ( take laser power supply ground to the star point and then to the laser ground) do that to scan set power and modulation input as well using same ground point ,
this is how pangolin recomend the ground system in a projector should be.
and it works to solved all sorts of problems for me
When God said “Let there be light” he surely must have meant perfectly coherent light.
Good luck...
I can say where, but I am sure this pin out set up is part of your problem...
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I can say where, but I am sure this pin out set up is part of your problem...
Thing is , it works fine with the lambda pro module . Its only since changing the module i have had issues. The Pin out is as per Nu-Light Manual. Any help is very grateful. I think the blanking issue is why i cannot get a decent test pattern . It leaves beam trails.
Senior Member
grounds
ok just try this as i said laserwave has a differental input on the modulation
so connect your laser supply ground to modulation - and your dac 0v ground
if that dont work
then try your laser with a couple of 1.5v batterys on the modulation just to see if it even works ??
When God said “Let there be light” he surely must have meant perfectly coherent light.
Whoa, tails, or it doesn't blank at all? Can we get a picture of that test pattern?
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Whoa, tails, or it doesn't blank at all? Can we get a picture of that test pattern?
It doesnt blank. Ok tried this last night. Module is set to negative TTL . Scanner dc ground & module dc ground connected to DAC pins 14 & 15 (pins 14-19 are all linked grounds in the DAC) . If i connect to the dac , even with the dac unpowered & not connected to pc the beam comes on. If i disconnect the dac ,beam goes off . If i remove the ground wire from the ttl input on the module , it dims & starts to modulate . If i connect up the lambda pro same way everything works fine. As i dont have a manual for the laserwave module , can anyone tell me what the other switch is for on the psu . Is it mode or analog polarity. Thanks
update , with nothing connected to the laser psu the ttl `input` gives me constant 5.33 volts. Thats the problem.
Last edited by stupidsexyflanders; 03-08-2011 at 23:28.
Senior Member
Are you saying that you have 5v output from the laser driver?
If you have selected TTL- then that should happen.
TTL- requires the DAC to ground this signal to switch the laser off.
TTL+ requires the DAC to provide 5v (well about 2.5v or more) to switch the laser on.
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i have 5.33 volts on both + and - ttl setting. Yes from the laser driver/ Doc what is the other switch for and which setting should it be on as it also has some influence on things
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