help Blow it not working

Discussion in 'General Electronics Chat' started by mani_ps2, Jun 28, 2008.

  1. mani_ps2

    Thread Starter New Member

    Jun 28, 2008
    1
    0
    i assembled the "blow it" programmer as in "board.jpg" in the ZIP file downloaded from http://www.geocities.com/dinceraydin/8051/.

    and when blowing in real mode it shows as blowing even if the 89c2051 is not inserted in the socket.

    this version uses BC548 instead of BC547. I have no idea to resolve this problem, can anybody help me. thanks in advance
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
    Hello,

    I do not have any practical experience with this, but in my oppinion the BC547 and BC548
    only differ in maximum voltage.
    Perhaps the HFE (gain) of the transistor is to low.
    There is nothing said about the HFE of the transistor, an C type has a higher HFE than the B or A types.
    See datasheet.

    Greetings,
    Bertus
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    All the transistors are doing is pulling a line to ground. Almost any NPN transistor with a beta of 100 or above should do as well as the type shown.
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    The "Blow-It" board and software is rather simplistic. It has no provisions to check whether or not you've actually installed the uC to program; it simply sends the commands to the board.
     
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