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  • laserist's Avatar
    Today, 12:05
    laserist replied to a thread CYGN-A in The Lounge
    Just connect a 30K resistor between the output of the comparator and the 10K pull up resistor. The 30K resistor will act with the 10K as a voltage divider and give you a virtual ground when the comparator is low.
    99 replies | 5859 view(s)
  • Greg's Avatar
    Today, 11:38
    Greg replied to a thread CYGN-A in The Lounge
    Maybe I could do something with a germanium diode to limit negative excursion and a 5.1V Zener for the other limit.
    99 replies | 5859 view(s)
  • KrisVermeulen's Avatar
    Today, 10:18
    Hello, I have a problem with a setup of 2 6800HP galvo's with Medialas microamps. In the video i drive the galvo's with a static targeted beam but both the galvo's react abnormal. Does anyone have a clue what might be the problem? Thank you for helping me out. https://youtu.be/YYPW_cXKgBE ...
    0 replies | 10 view(s)
  • Greg's Avatar
    Today, 09:25
    Greg replied to a thread CYGN-A in The Lounge
    Not a good solution, but the resistor network shown in the graphic is triggering the inverter. Unfortunately I only have 4 opto-isolators, and nothing much else I need to order at present, but that should be enough to see it working soon.
    99 replies | 5859 view(s)
  • laserist's Avatar
    Today, 07:39
    laserist replied to a thread CYGN-A in The Lounge
    I think a opto-isolator per comparator would salvage the bipolar design.
    99 replies | 5859 view(s)
  • laserist's Avatar
    Today, 07:31
    laserist replied to a thread CYGN-A in The Lounge
    Sorry I'm stupid. We'll have to run the comparators +15 and ground, or do something clever that I haven't thought of yet. Common cathode doesn't accomplish what I wanted when the "cathode" is at -15V Oh well, we needed to be able to offset the input signal in any case.
    99 replies | 5859 view(s)
  • laserist's Avatar
    Yesterday, 11:32
    laserist replied to a thread CYGN-A in The Lounge
    Sorry, you want to run the comparators at +/-15 volts, and pull their outputs up to +5 volts to match your 5V 74LS logic down stream. What we're going for is a whole lot of headroom on the analog input. +/- 2 volts will cover the RYGB output giving RYGBBGYR with no black at all. When you turn the...
    99 replies | 5859 view(s)
  • james's Avatar
    Yesterday, 10:08
    There are some other features in the new development version that are worth mentioning. If you go into the u menu for user interface visual attributes, you can now turn vector rendering on or off. This is the line between two consecutive vertices. With it off all you see are the vertices...
    482 replies | 103647 view(s)
  • Greg's Avatar
    Yesterday, 08:58
    Greg replied to a thread CYGN-A in The Lounge
    I do have 74LS04 hex inverters and LM339 comparators. I'm afraid I'm still a bit confused though. The configuration in the graphic doesn't seem right, with the negative voltages on the inputs of the comparators. Not sure I've understood correctly.
    99 replies | 5859 view(s)
  • james's Avatar
    Yesterday, 07:38
    #math phase_cycle 360.0 #math interval_cycle 1.0 #math start 0.0 #math duration 1.0 math iterations 1000 # x = sin(t * 3) + sin(t * 5) # y = cos(t * 3) + cos(t * 5) # for t = 0 to two_pi
    482 replies | 103647 view(s)
  • lasermaster1977's Avatar
    Yesterday, 07:21
    my bad, for being in a hurry. I meant x=sin(3x) + sin(5x), y=cos(3x) + cos(5x) for x = 0 to 360
    482 replies | 103647 view(s)
  • james's Avatar
    Yesterday, 07:00
    If you generate a frame_set and you want to save it for use later in the script you can store it in an invisible list of frame_sets and recall it later. There are only 2 registers A and B to do math on, but you can store as many frame_sets as your RAM will support. In Win32 your heap is...
    482 replies | 103647 view(s)
  • james's Avatar
    Yesterday, 06:50
    Cool! Thanks! I'll fix that in my cheat-sheet.
    482 replies | 103647 view(s)
  • james's Avatar
    Yesterday, 06:19
    In your example, 3 and 5 are the amplitude. 0 and 90 are phase. It's worth noting that since this all gets scaled to fit inside of short integer space, the actual size of a figure is more or less irrelevant except when compared to other figures in the same space. Offset is also typically...
    482 replies | 103647 view(s)
  • james's Avatar
    Yesterday, 05:47
    If you add two forms that are essentially the same thing that's the same as multiplying one form by 2. It just gets twice as big. If you want to add two frame_sets vertex-to-vertex you make sure they are both in the registers (generate one then generate the other) and call math add This...
    482 replies | 103647 view(s)
  • laserist's Avatar
    Yesterday, 04:05
    laserist replied to a thread CYGN-A in The Lounge
    The LM339 comparators have open collector outputs. You choose a pull up resistor appropriate to the logic family you use. I'm sorry, the inverters I mentioned, sometimes called NOT gates. Example 74LS04 hex inverter.
    99 replies | 5859 view(s)
  • Greg's Avatar
    Yesterday, 02:56
    Greg replied to a thread CYGN-A in The Lounge
    What a great idea. The graphic shows what I think has been described, but a recommended approach to the NOR gates would be helpful. I have HD74LS02 NOR gates which operate 0 to +5V. The square waves from the comparators are +-15V. Should I: 1) use voltage dividers and summing amps to scale and...
    99 replies | 5859 view(s)
  • Greg's Avatar
    Yesterday, 02:36
    Please would you show how to sum two or more circles.
    482 replies | 103647 view(s)
  • dchammonds's Avatar
    04-20-2021, 20:12
    I finally got around to installing MSYS2 on my laptop- I got tired of running downstairs to use the mainframe and a jump drive every time I needed to compile something...*nyancat In msys2_build_notes.txt I had to change the following line from pacman -S --needed base-devel \ to ...
    482 replies | 103647 view(s)
  • james's Avatar
    04-20-2021, 18:32
    Thank you! I love the idea that I can make something substantial out of nothing but thought. I love the fact that I can give it to anyone who wants it and I still have it for myself. I love the fact that people use it all over the world. I love the fact that it has been used by artists...
    482 replies | 103647 view(s)
  • lasermaster1977's Avatar
    04-20-2021, 16:25
    I must correct a statement I made previously. I did NOT get an A in Calculus II (but I was on track to get an A). I dropped all my classes mid-semester to focus full-time on creating laser planetarium shows and the digital/analog electronics that goes with it because the fun, the creativity and...
    482 replies | 103647 view(s)
  • lasermaster1977's Avatar
    04-20-2021, 16:06
    your link was to the 4:02 version, DOAH!
    482 replies | 103647 view(s)
  • james's Avatar
    04-20-2021, 16:05
    Thanks lasermaster1977! Most of what I know about math comes from endlessly messing around with it until it works. I don't have any formal education in math past having bombed out of college Calculus. I never ever did homework in any math class but I always did very well on the tests. So I got...
    482 replies | 103647 view(s)
  • james's Avatar
    04-20-2021, 15:55
    It's the 4:20 version. What do you expect?
    482 replies | 103647 view(s)
  • absolom7691's Avatar
    04-20-2021, 15:08
    Welcome to PL! There are quite a few gents on your side of the pond that would probably be happy to grab a beer at the pub with you. Enjoy your stay here and soak it in. There is a lot of information here and a lot of professionals who literally have decades of experience if not a half a...
    1 replies | 151 view(s)
  • lasermaster1977's Avatar
    04-20-2021, 14:43
    Good catch. It should be https://laserboy.org/code/LB_04_20_2021.zip
    482 replies | 103647 view(s)
  • lasermaster1977's Avatar
    04-20-2021, 14:36
    Consider this: My first trigonometry teacher in college, absolutely new the subject matter it like the back of his hand but conveyed the subject matter in a very math elitist, abstract, hard to understand manner. My grade for the semester was F. My first Calculus I teacher was, unfortunately...
    482 replies | 103647 view(s)
  • dchammonds's Avatar
    04-20-2021, 14:15
    You might want to fix your link to the newest version...
    482 replies | 103647 view(s)
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