Page 3 of 3 FirstFirst 123
Results 21 to 26 of 26

Thread: vacuum tube smsp

  1. #21
    .... Silvio's Avatar
    Join Date
    Apr 2015
    Location
    Malta
    Posts
    694
    Blog Entries
    9
    Have you tried winding the 64 turn in bifilar fashion? Are you using a layer of tape between each winding. Are you leaving 4mm margin space at the bobbin cheeks? I think your winding is arching and shorting out due to the high voltage.

    Are you using a snubber in the primary? any spikes in the primary will be amplified in the secondary winding and the voltage here may rise more than a 1000v. If your insulation is not correct the secondary winding may arc and short out.

    When trying out the transformer put a small load on the output. This will help control any excess voltage spikes generating very high voltages. Try to never start the transformer with the secondary high voltage open.

    Lastly use new enameled copper wire. see that it is in good condition. Use mylar tape for insulation and not something else.

    Good luck

  2. #22
    I did not know if I needed to put a small load on the high voltage secondary test.
    I would like to adjust one more output voltage.
    We expected the output voltage to change when the input voltage of PWM changed, but it did not change much
    I want to know how to change the secondary voltage.

  3. #23
    .... Silvio's Avatar
    Join Date
    Apr 2015
    Location
    Malta
    Posts
    694
    Blog Entries
    9
    If you are opting for regulation keep in mind that this is done in the primary winding. If you have more than one secondary than all the secondary voltages vary together. Having such a high output voltage it would be some what difficult in a way to control from the high to the low voltage as the margin of error will be quite large due to that the control voltage will be more or less 2.5v and the output being around 400v.

    I guess you have to choose another winding with a lower voltage to do this. You will have to use an output inductor with the winding that is being sensed. This is important otherwise it will not regulate properly. You must also have a minimum load with the output when using regulation.

    If you are expecting the output to change you must load it a little so that the excess charge on the capacitors will fall down accordingly. If you are still getting a higher voltage than needed than you have to adjust the winding turns. You can use the formula

    155v / primary turns = volt per turn. Here you will be close to the wanted voltage.

    Regards

  4. #24
    I am trying to adjust the secondary voltage.
    Even in normal smps, there is VR for fine tuning
    Try to vary the voltage by about 10 to 20%

  5. #25
    This is an OTL tube amp.
    The secondary voltage is 150V, -150V.
    Change this voltage.
    Adjusting the voltage of the sg3525 no1 pin changes the PWM pulse width.

    When the pulse width changes, the voltage must also change accordingly, but it does not change much.
    I want to know how the voltage is controlled.

    OTL-1.jpgOTL-2.jpgOTL-전원부.jpg

  6. #26
    .... Silvio's Avatar
    Join Date
    Apr 2015
    Location
    Malta
    Posts
    694
    Blog Entries
    9
    I can see you make a nice job there. I would rather see some oscilloscope shots showing how the pulse width is changing.
    The voltage is controlled by changing the pulse width. However the output must be loaded to see the voltage change. A narrow pulse will give a low voltage and a wider pulse will give higher voltage.

    We like to see a schematic of your setup to see what you actually did. You can draw it up by hand and take a photo of it.

Similar Threads

  1. Tube amp SMPS
    By miniman82 in forum diysmps
    Replies: 24
    Last Post: 02-28-2017, 04:56 PM
  2. Vacuum Tube SMPS
    By printer2 in forum diysmps
    Replies: 21
    Last Post: 05-13-2016, 03:29 AM
  3. Tube SWPS
    By sdman in forum Switching Power Supplies Informations
    Replies: 0
    Last Post: 03-24-2014, 05:42 PM
  4. Power Supply for X-Ray Tube
    By S0syk in forum diysmps
    Replies: 0
    Last Post: 07-30-2013, 12:45 PM
  5. My Tube amp by L6L
    By cakum in forum Tubes & Valves
    Replies: 5
    Last Post: 04-06-2013, 11:55 AM

Posting Permissions

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