Comparators & Newbie to electronics

Discussion in 'General Electronics Chat' started by toolman60, Jan 20, 2010.

  1. toolman60

    Thread Starter New Member

    Jan 16, 2010
    22
    0
    I know I have been going about this the wrong way.Is there a way to duplicate the Lm339 in a simulation software?I can put them in the schematic
    but not sure how to make all the connections and make it work properly.I am also trying to duplicate ans simulate a circuit using the LM3914 LED Driver.

    Where I am getting stuck at is when I place 12 339 on the sch. I have 12 components with 5 connections,and I know that I only need 1 gnd and + V to drive the chip,thus I am doing it wrong or using the wrong component.(Thus only 4 components per 339)

    and need also help laying out the 3914 which has 10 comparators in it so that I can simulate it.I am using Tina for the software.If there is another 1 that i need that can be downloaded let me know please that may be better or more user friendly.

    Thanks
     
  2. eng1ne

    Member

    Dec 4, 2009
    97
    3
    Read the data sheet. You must have obtained the 'schematic' your trying to simulate from somewhere.

    I'm not sure I understand what you are requesting, can you post your schematic? Nor am I familiar with Tina, is she capable of schematic capture?

    What is your budget for software?
     
  3. toolman60

    Thread Starter New Member

    Jan 16, 2010
    22
    0
    I have not giving any thoughts to budget for software.Tina will not do capture I dont think anyway.

    Every time i put the Lm 339 on schematic I get 5 pins for 1 comparator.

    Can someone tell me what I am doing wrong.And how to lay it out correctly.

    Thanks
     
  4. eng1ne

    Member

    Dec 4, 2009
    97
    3
    Is this the schematic you have produced? If not, please post the schematic you have produced.
     
  5. toolman60

    Thread Starter New Member

    Jan 16, 2010
    22
    0
    The first thumbnail is what I am trying to reproduce and simulate.
    This is where I am now with the new schematic and trying to simulate it.
    Thanks for trying to help me out
     
    • ICOM.PNG
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  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Tina won't put an entire 339 comparator in the schematic; you have to add each of the four individually. That also means you have to connect the Vcc and GND pins of each comparator to a voltage source and ground.

    With the real component, you will only have to connect one pin to Vcc and another pin to GND. You will also need to connect a 0.1uF capacitor between the two supply pins; this is commonly known as a bypass capacitor.

    If you do not need to use one or more of the comparators in a 339 IC, you should connect their inputs to ground; otherwise you can get strange results.
     
  7. toolman60

    Thread Starter New Member

    Jan 16, 2010
    22
    0
    Thanks Sgt Wookie.

    I will lay that out in the software and try it.If I understand correctly I feed each componet with the V+ and also ground each 1.Then I can just run my Ref V to the other pins thru there resistors.I'LL try that.

    Thanks to all for helping this dummy out.
     
  8. eng1ne

    Member

    Dec 4, 2009
    97
    3
    The way Tina appears to label components seems odd.

    Typically, as the first schematic posted, and as I am familiar, the four comparators that make up the LM339 would be labelled as U1A, U1B, U1C and U1D.

    Note that you have pins 12 and 3 on the top comparator. If Tina is intuitive enough to know these comparators are in one chip (assuming they are), one would have thought it would be intuitive enough to use common Vcc and GND for them all.

    Also note, you haven't connected pin 12 to GND on your schematic.

    The LM339 has 14 pins, your outputs are all pin 15?!
     
  9. toolman60

    Thread Starter New Member

    Jan 16, 2010
    22
    0
    Yes I saw that .I figured there must have been a typo in the netlist somewhere.Thanks for the help I will let you guys know if it works this time in simulation.
     
  10. toolman60

    Thread Starter New Member

    Jan 16, 2010
    22
    0
    Well got it drawn in and it's working (somewhat)
    My +V ref in are so close the 339 is not switching over to the proper transistor to activate relay.I think it is a bug in the software .I am waiting on the rest of parts to be shipped so hope by the first of next week can lay it out on breadboard.

    Thanks all for the help.
     
  11. martinjsto

    New Member

    Jan 28, 2009
    1
    0
    hi toolman, I know this is an old post but I have just installed tina and have come across the same issue.
    did you make a new macro for the lm339, i have tried to recreate it as stated above but my understanding of electronics is limiting my success.
    if you still have the file for your scheematic, could you post here or send to my email. <SNIP>.
    thanks
    Martin
     
    Last edited by a moderator: Feb 5, 2011
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