Page 6 of 14 FirstFirst ... 2345678910 ... LastLast
Results 51 to 60 of 134

Thread: CYGN-A

  1. #51
    Join Date
    Mar 2010
    Posts
    581

    Default

    Happy to report that the real 4QMMs arrived, and the first test of the SPGN looks like it is spiral generating. Output from a CYGN-A and a ramp from an HP function generator gives me a Laserium flashback where the image is growing out from the center while unwinding itself at the same rate from the outer edge. I love this effect. Lots to calibrate and explore.
    Attached Thumbnails Attached Thumbnails SPGN_first_results.jpg  


  2. #52
    Join Date
    Mar 2010
    Posts
    581

    Default

    Most of the circuitry of the SPGN is related to controlling the BB4302 ramp generator, and the digital switching of analog signals. The crux of the whole business is the amplitude modulation of the input signals using analog multipliers.

    The attached graphic shows a circuit I found that I believe is supposed to provide Z axis rotation. Beside it is my attempted implementation of this circuit, but it only produces distortion and RF noise. Thoughts regarding how to get this circuit to function as a 2D vector rotator are welcome.
    Attached Thumbnails Attached Thumbnails SPGN_simplified.png  

    AD633_rotator_not_working.png  


  3. #53
    Join Date
    Jun 2009
    Location
    St. Louis, MO
    Posts
    1,199

    Default

    Click image for larger version. 

Name:	IMG_20210322_070449482.jpg 
Views:	5 
Size:	1.91 MB 
ID:	57750

    I'm not sure what you got there, but it's not a z axis rotator. I drew the above a long time ago, but never built i.
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  4. #54
    Join Date
    Mar 2010
    Posts
    581

    Default

    Zeiss letterhead - cool. Here's the wiring diagram I build that from. Omitting the output amplifier, I'm getting a small distorted figure near the negative limit on one axis and centered on the other. Input is a circle. Changing the voltage on the sin and cos inputs produces something that sort of looks like rotation or phase shift of the distorted figure.
    Attached Thumbnails Attached Thumbnails AD633_Z_rotate_not_working2.jpg  


  5. #55
    Join Date
    Jun 2009
    Location
    St. Louis, MO
    Posts
    1,199

    Default

    Pin 6 should be grounded . I assume you have +/- 15V to pins 8 & 5.
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  6. #56
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Quote Originally Posted by Greg View Post
    Most of the circuitry of the SPGN is related to controlling the BB4302 ramp generator, and the digital switching of analog signals. The crux of the whole business is the amplitude modulation of the input signals using analog multipliers.

    The attached graphic shows a circuit I found that I believe is supposed to provide Z axis rotation. Beside it is my attempted implementation of this circuit, but it only produces distortion and RF noise. Thoughts regarding how to get this circuit to function as a 2D vector rotator are welcome.

    As drawn, it works in "theory" for a +/- 90' Rotation. In reality, the internal op-amp needs to be used and it is very noisy and unstable. BTDTGTS.
    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  7. #57
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Quote Originally Posted by mixedgas View Post
    As drawn, it works in "theory" for a +/- 90' Rotation. In reality, the internal op-amp needs to be used and it is very noisy and unstable. BTDTGTS.
    Steve
    I'll email you a real rotator schematic that is known to work later tonight.

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  8. #58
    Join Date
    Jun 2009
    Location
    St. Louis, MO
    Posts
    1,199

    Default

    The board I'm sending has two rotation circuits built with AD532s...
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  9. #59
    Join Date
    Mar 2010
    Posts
    581

    Default

    Pin 6 grounded... I should have seen that. My build of your AD633 based rotator is now working. Next test is the continuous turn sine cosine De Jur potentiometer from the Magic Mountain console as source of the sin and cos voltages. Do these signals normally come from a joystick?

    Thanks Steve, for discerning the low down on the 2 quadrant rotator I posted previously. I have a couple of pages you either sent or posted a while back. Coordinate Converter by Arthur Mayer, using the AD7533.
    Last edited by Greg; 03-22-2021 at 13:47.

  10. #60
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Quote Originally Posted by Greg View Post
    Pin 6 grounded... I should have seen that. My build of your AD633 based rotator is now working. Next test is the continuous turn sine cosine De Jur potentiometer from the Magic Mountain console as source of the sin and cos voltages. Do these signals normally come from a joystick?

    Thanks Steve, for discerning the low down on the 2 quadrant rotator I posted previously. I have a couple of pages you either sent or posted a while back. Coordinate Converter by Arthur Mayer, using the AD7533.

    The CC works but you have to have the correct CMOS switches. Some of the more modern parts are positive swing only and latch up on the negative cycle.

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •