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Digital Voltmeter!! on Breadboard

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by remon7, May 23, 2014.

  1. remon7

    remon7 Active Member

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    Now i am working on Digital Voltmeter. Already i bought all components for Digital voltmeter. I am using 7 segment display. In 7 segment display.. i am not understand about DP..also i mention in my attachments also i dont have 470n capacitor but i have 47uf capacitor , can i use it there ?
     

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  2. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    Hello remon7,

    "DP" stands for "Decimal Point". Connect that pin to ground (through a resistor) to light the "dot".

    There is a huge difference between 470nF (0.47uF) and 47uF (it is off by two powers of 10). You will need to find something at least in the range of 470nF.

    Regards,
    Matt
     
  3. remon7

    remon7 Active Member

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    is it DP ?
     

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  4. dave

    Dave New Member

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  5. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    I suggest you google the part number and find the datasheet. It should have the pinout of the device.

    Regards
     
  6. remon7

    remon7 Active Member

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    first things that i use 4.5volts and mention that i did not use 470uf capacitor . without this cap i tried to run , but its not working. i dont know whats happen ? how can i check whole circuit ? means checking all components?
     
  7. remon7

    remon7 Active Member

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    i want to check whole circuit every components .....
     
  8. alec_t

    alec_t Well-Known Member Most Helpful Member

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    If you don't use the specified components in the right way of course it won't work!
    You can't check all the components (individually) unless you know how each component should perform or what its properties should be. That requires reading the relevant datasheets. Google the part numbers and download the (free) datasheets.
     
    • Agree Agree x 1
  9. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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  10. audioguru

    audioguru Well-Known Member Most Helpful Member

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    I think your tangle of long wires and the many rows of contacts on the breadboard will pickup all kinds of interference. A pcb should be used.
    The ICL7107 voltmeter IC is sensitive to interference.
     
    • Agree Agree x 1
  11. tunedwolf

    tunedwolf Well-Known Member

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    I agree, the ICL devices are very twitchy if the board layout is poor.
     
  12. remon7

    remon7 Active Member

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    Yeah finally i have finished my digital voltmeter project, and stuck me. when i plug 4.5volts then it showed me weird number symbol. also when i tried to measure a battery volts then digit symbol also changing, but it does not make any sense , As well as its true that its working, but i could not get where main problem.... ok number 1pic when i used battery for measure. number 2 plug current 4.5volt . without measurements.....normal .. I used ICL7107 somewhere i noticed ICL7106 using for same voltmeter ...so i am using ICL7107. here ICL7106 is not available ..
     

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  13. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    Check your wiring and the datasheet for your display. Are you SURE you used the EXACT parts shown in the schematic? Judging by your previous attempts, I would lean towards "no", in which case of course it won't work. If you did, though, double-check the wiring.
     
  14. remon7

    remon7 Active Member

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    in picture there mention ICL 7106 and ICL 7107. But i am using ICL 7107. any problem ?
     

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  15. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    The 7106 is designed to drive an LCD display, whereas the 7107 is designed to drive an LED display. How about the LED display part numbers? Are they the same as shown in the schematic?

    Could you please post a schematic of YOUR exact setup, with the EXACT part numbers that you are using on your breadboard?
     
  16. remon7

    remon7 Active Member

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    i tried to follow new idea about voltmeter. finally its failed again. in 7 segment display nothing shows me.
     

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  17. remon7

    remon7 Active Member

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    its diagram
     

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  18. remon7

    remon7 Active Member

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    now i have connected with source but reply is just turn on 7segment display dot light. it does not shows any digit. also i tried to measure battery volts. no output :(
     

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  19. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    Photographs of your setup with messy wiring really don't help much, I'm afraid. I need you to tell me EXACTLY what components you used, and compare it with the ones shown in the original schematic.

    Also, try to neaten up your wiring. Chances are that may be causing some of your issues--it's too confusing to follow, and perhaps there's just a single wire out of place.
     
  20. 4pyros

    4pyros Well-Known Member Most Helpful Member

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    You keep jumping all around and never really answer the questions we ask. If you slow down maybe we can help but you keep changing things.
    Did you get the right cap?
    Can you neaten up your wiring?
    May be just hook up the LSB digit for now untill you can get the chip running.
     
  21. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Why don't you use the schematic shown in the datasheet printed by the IC manufacturer instead of using a copy from somewhere that might have errors on it??
     

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