Search:

Type: Posts; User: bmandl

Page 1 of 9 1 2 3 4

Search: Search took 0.01 seconds.

  1. Replies
    17
    Views
    2,211

    Closed: Re: Smps transformer windings

    Not pulses. It oscilates like some kind of sinuse (it's not sinuse) with frequency of 1Hz. But I am doing measurements with AC disconnected, because my oscilloscope is grounded. I don't know if it's...
  2. Replies
    17
    Views
    2,211

    Closed: Re: Smps transformer windings

    Which diodes exactly? I have a service manual, but I don't know if I can post it here. I can tell you the name of the model and you can google service manual. It's quite accessible: PHILIPS MCM3150....
  3. Replies
    17
    Views
    2,211

    Closed: Re: Smps transformer windings

    I am constantly getting voltage on VDD pin (17V - 10V peak to peak) in 1s intervals.
  4. Replies
    17
    Views
    2,211

    Closed: Re: Smps transformer windings

    Hm, I replaced IC3 and Q16 and I still don't get any output on gate pin of IC3. I get some sort of square waveform on VDD pin (5V 200ms inpuls every second). I tryed to put 3V to FB pin and still no...
  5. Replies
    17
    Views
    2,211

    Closed: Re: Smps transformer windings

    Datasheet:...
  6. Replies
    17
    Views
    2,211

    Closed: Re: Smps transformer windings

    So at first, IC3 is powered from high voltage of rectifier bridge for start-up, then it starts to oscillate and voltage is induced in auxiliary winding. Then it's supplied from there. Is it possible,...
  7. Replies
    17
    Views
    2,211

    Closed: Smps transformer windings

    Hello guys,
    I am looking at schematic of a SMPS for some audio system and I can't figure out, how the heck does that high frequency transformer work... I don't understand the winding for supplying...
  8. Replies
    0
    Views
    794

    Closed: Local PLC database system

    Hello guys,
    I don't know if I am in the right forum, but please move topic if that is so.
    I would like to ask you guys for ideas and suggestions. What would be the best industrial solution to...
  9. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    Exactly how would resistors in each string equalize currents through leds? I am talking about configuration with constant current power supply and multiple parallel strings of series leds with series...
  10. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    I guess, I'll really have to omit the protection and maybe just use some current mirror to equalize currents. I hope that non of the leds dies, or at least just one string.
  11. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    I would use different transistor.
  12. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    Why would Q3 explode?
  13. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    I think I came to a solution. I will use current mirror with aditional bypass transistor, which can whitstand 6A of current in case, no string is connected, so all the current passes throuhgh this...
  14. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    I have a constant current supply ready for this led matrix.

    If one led fails, the current doesn't flow through this string. So current has to flow through remaining strings, because I have...
  15. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    Klaus, i am afraid, that these Chinese leds won't stand any temperature drifts and over-currents. So, I would like to make some kind "bullet-proof" design, analog circuit preferred. Could 4...
  16. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    I just have 6A constant current supply, so I can't test with lower current. I have constant voltage supply with current regulation thou. But it is useless here. But what if some day one led in one...
  17. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    I am building LCD based 3d DLP printer.
    So, what do you say about mentioned ICs from texas instruments? Would it be better to build my own circuit with transistors?
  18. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    No, heat sink will be additionally cooled with 4 fans, 2 from every side (two for inlet air, two for outlet air). Why would I need liquid hydrogen? Leds won't blind anybody, because this will be a...
  19. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    @FvM, after you mentioned uniform currents, I started to investigate in this direction. The problem is, if one led in any string fails, all leds will be over driven without protection, and eventually...
  20. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    Unfortunately, I don't have any datasheet for these leds, because I bought them from a Chinese seller. So I guess I'll have to try.
  21. Replies
    27
    Views
    3,608

    Closed: Re: High power led matrix connection

    I think that 545mA would be enough, as luminosity doesn't change that much in this range, correct? But what happens with voltage on individual leds, when connected this way? Wouldn't voltage be too...
  22. Replies
    27
    Views
    3,608

    Closed: High power led matrix connection

    Hy guys.
    I need your help. I am building a high power led matrix and I need advice on how to connect individual leds. I have a 260x160mm heat sink, where I will mount star PCB leds. PCBs are 20mm...
  23. Replies
    5
    Views
    1,789

    [SOLVED]Closed: Re: MPLINK '.udata' can not fit the section

    And of course, some strange things were happening, because DATABANK actually means start of RAM and wherever in my program I was manipulating with location 0x2 (PCL), the program ran away (it makes...
  24. Replies
    5
    Views
    1,789

    [SOLVED]Closed: Re: MPLINK '.udata' can not fit the section

    Nope. I tryed it like that:
    UDATA
    temp res 1

    CODE
    main
    but same error. It deffinetly has something to do with linker and udata section.

    - - - Updated - - -
  25. Replies
    5
    Views
    1,789

    [SOLVED]Closed: Re: MPLINK '.udata' can not fit the section

    These are just warnings, they are not relevant. The linker error is the problem:
Results 1 to 25 of 210
Page 1 of 9 1 2 3 4