Recent content by maksar

  1. M

    Heatsink free samples

    Hi! lol  ;D  I think in this case one heatsink will cost me >600$  ;) Did you try to request samples through Internet? Maksar
  2. M

    Heatsink free samples

    Hi! Did anyone got heatsinks as free samples from AavidTermaloy, Wakefield or other company? Maksar
  3. M

    0-30 Vdc Stabilized Power Supply

    Hi! Thanks audioguru. I think this point is clear now  :) Here are the main components I have for the project (5A). By the way, I made PCB by myself. If some one is interested in it, I can post the Ultiboard files. Maksar
  4. M

    0-30 Vdc Stabilized Power Supply

    Hi audioguru! I think you didn't understand me.  :P If the transistors won't fit the heatsink in ambient temperature, I'll cut a little one of it's sides. The cutouts near the "shoulders" of the heatsink are only for providing the room for the transistor and heatsink to enlarge on high...
  5. M

    0-30 Vdc Stabilized Power Supply

    Hi audioguru! Interesting point, I didn't think about this!  :D  But I don't think that this is a big problem. You can make the "shoulders" the shape you want them to be with a dremel. Also you can enlarge the space near the bottom surface of the heatsink, so that 2n3055 will match. Or you can...
  6. M

    0-30 Vdc Stabilized Power Supply

    Hi! Why not to say simply, that we need 4 transistors for 3A project and 5 for 5A project? But still a large heatsink is needed (I probably will buy this one: http://www.semikron.com/internet/ds.jsp?file=648.html) with fan. Or it is posible to use more powerfull transistors with thermal...
  7. M

    0-30 Vdc Stabilized Power Supply

    Hi audioguru! As you can see the standard lengths are 15cm(5.8") and 29cm(11.5"). So it isn't so long and can be easily matched to the case dimensions (case's height and width are fixed and length may be variable for individual needs). Also I don't see problems to mount it as a rear wall, there...
  8. M

    0-30 Vdc Stabilized Power Supply

    Or maybe this one? I tried to show how I see this heatsink in the psu box as a back wall  ::) Maksar
  9. M

    0-30 Vdc Stabilized Power Supply

    Hi! What about this heatsink? http://www.wakefield.com/extrusions/index1.cfm?index3=yes&ext_id=578&c_row=5&ext_ref_num=&ext_type=0&ext_width=7&ext_height= Does this one need fan too? (for 5A project?) I think the upside of the heatsink in the picture should be outside...
  10. M

    Convert 0-30V 3A PSU to 5A or more

    Hi! And one more question.  :) According to the datasheet of 2n3055, after rising of the temperature above 100C the power dissipation falls under ~65W. So in this project 100C for 2n3055s is the max? Maksar
  11. M

    Convert 0-30V 3A PSU to 5A or more

    Hi AUDIOGURU! Thanks for this explanation. I didn't think that it is so simple to calculate and determine the needed heatsink  :o  (After your post I got some reading on this topic). It seems like I'll have to use fan. But does an airflow has big influence on the effective heatsink resistance...
  12. M

    Convert 0-30V 3A PSU to 5A or more

    Hi! Do you think the heatsink 234-2520 on www.rsisrael.com (use search) for each 2n3055 is suitable or it is too big?  ??? Maksar
  13. M

    Convert 0-30V 3A PSU to 5A or more

    Hi! Ok, thanks audioguru. The problem is that I don't have these diodes and my local electronics store don't have them too. So I tried  ;) ;D ;D ;D  But it seems that I'll need to search BZX79C5V6 in the other stores  :-\ By the way, I understand nothing in planes, however, your model doesn't...
  14. M

    Convert 0-30V 3A PSU to 5A or more

    Hi! Can I use zener diode 1N4735A instead of BZX79C5V6? If the answer is yes, which resistances I need? Thanks for the answer. Maksar
  15. M

    Convert 0-30V 3A PSU to 5A or more

    Hi Kain! Good job, your psu looks very good. And you know - ugly planes don't fly.  ;D ;D ;D Can you make some more pictures of your psu? Especially I interested in the bottom side of the board and the case.  :) I begin to build the same psu as well.  8) Maksar
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