Hi everyone,

Just thought I'd post some updates on our progress:

Wound up picking up a used set of Scanpro 30s from Marc (gottaluvlasers) [Thanks so much!] Last month and have been toying around with them since. I've just sent a schematic to the machine shop for the mounting board for all the parts (PSU, galvos, amps, laser) and am waiting on that atm.

Regarding control, there have been a few setbacks. Notably I misread the scanner inputs as 0-5V differential as opposed to the actual -5V to +5V differential inputs, so we have to rebuild the signal amps to accommodate this (or only use one quadrant of the display.)

Right now the signal layout is:
[Microcontroller w/ onboard 0-2.5V DAC] -> [(0,2.5V) -> (-5,+5V) signal amps] -> [Scanner driver board]

The other setback was that the onboard DAC for our particular board is only 10 bits wide as opposed to 16 This means we're going to have to downsample any standard ILDA input files we use. It's possible that we could pick up and external DAC chip but I don't think that's necessary for our applications.

Beyond these things, I had a few questions for everyone:

1. Are the ILDA files set to be drawn with a constant time between points?
E.g. If I have to move from (0,0,0) to (1000,1000,1000), should this take the same amount of time as a move from (0,0,0) to (1,1,1)?

2. How hot are the driver/amp boards supposed to get? Those heatsinks are ridiculously warm.

3. How important are the differential inputs? I ask because our DAC only does 0-2.5V. While we can build 2 parallel amps that convert that to +/-5V and -/+ 5V differential signals, will that be more worthwhile than building a single +/- 10V amp and tying the --input to GND? The cables from the signal-amp output to the drivers are short so I'm not hugely worried about common mode noise being picked up that way... I am worried about converting the 0-2.5V DAC output into two differential signals, though. Won't doing that double the noise from the signal source? (E.g. if the original signal was [signal+noise] and i convert that into [+signal+noise] and [-signal-noise] then when the driver boards do their subtraction, the result is [2*signal + 2*noise].


Thanks as always for your help!

-Josh