Does this signal look OK to you...? (no nudity)

[shobley]

Hi,

I've just added my balanced line driver chips to my highly experimental Arduino DAC - here's the output trace (full differential) for the X axis, when generating a 10 beam fan.

Does this look OK to you? It ranges from +9.2v to -9.6v (this is the differential signal - so it's +/- 10v ptp).

I mean, would you send this to an amp?

The second picture is the output from a Medialas DAC doing the same thing - look how lovely and gentle the transitions are. Would my signal damage the galvo because it jumps directly from one level to another?

Steve

[stanwax]

the return is gentle on the medialas dac for a reason. No scanner will have a step response that matches your return. Can you add a slope to the return in software? I reckon you just to experiment with different slopes and see what yous scanners can handle best.
What software is outputting to the DAC? Is it your own PIC based signal that you talked about some time ago?

Rob

[shobley]

That's what I was afraid of...


Would it help if I were to do and up/down staircase, rather than just an up/return?

I'm not sure if I have enough processor cycles available on the Arduino to do smooth continuous transitions like the Medialas. Fortunately for this project I just need a single axis fan - nothing too fancy.

I'll do some more programming and see what I can do...

[stanwax]

sure you just need to run the ramp in both directions but obviusly on the return you need it to happen in a shorter time span. You can limit th enumber of steps to reduce processing as long as you dont get the intermediate points to dwell.
Or you could do identical ramps in each direction though this may need some trickery to make the beams look the same intensity.

Rob

[shobley]

I tweaked the waveform and got the output to look like this..

So I plucked up the courage and plugged it into an amp - 10 clear beams!!


[And no smoke!]

[stanwax]

wicked.
A picture of it in action would be cool

Rob

[shobley]

In action...

Just before I set the smoke alarm off, and woke my wife...

[allthatwhichis]

This for a harp?

[shobley]

Yes it is...

It's only taken me 22 years to get this far...