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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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    How can i control polarity for 7660 IC?
     
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  2. remon7

    remon7 Active Member

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    schematic diagram .......................
     

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  3. 4pyros

    4pyros Well-Known Member Most Helpful Member

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    Your wiring looks alot better.
    Can you check the power to the chip?
    Pin 1 is positive and pin 26 should be negative.
    Seems that chip needs 5 volts or more supply voltage.
    You may need more than 4.5 volts to get it to work!!!
     
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  4. dave

    Dave New Member

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  5. remon7

    remon7 Active Member

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    Present situation !!!!
     

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  6. remon7

    remon7 Active Member

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    yeah today i will apply 5volts...
     
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  7. remon7

    remon7 Active Member

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    26 number pin for negative now ...
     
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  8. remon7

    remon7 Active Member

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    Its 26number pin to ground !!!
     

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  9. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    remon7, I was asking for two lists: One of the components you used, and one of the components specified by the schematic. You gave me the one of the components you used, but not of the ones required by the schematic. Or am I missing something?
     
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  10. 4pyros

    4pyros Well-Known Member Most Helpful Member

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    No it needs to be negative 5 volts, thats what the 7660 chip is for.
    You must fix this for it to work!!!
     
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  11. 4pyros

    4pyros Well-Known Member Most Helpful Member

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    He re-posted the schematic.
     
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  12. remon7

    remon7 Active Member

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    Today i went to lab and applied 5volts but results in 7 segment display its not stable and not accurate !!!!
     

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  13. remon7

    remon7 Active Member

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    I gave you right list where i mentioned which i used and which are not. with name and quantity ....

    1x - 220 Ohm Resistor
    1x - 10K Resistor
    1x - 15K Resistor
    1x - 47K Resistor
    1x - 100K Resistor
    1x - 1M Resistor
    1x 10K Pot
    1x - 100pF Capacitor <<<< I am using 101K it looks like green tablet. <<<<Look this notes <<<<
    1x - 10n Capacitor<<<< I am using 103J it looks like green rectangular tablet.<<<<Look this notes <<<<
    1x - 100n Capacitor<<<<I am using 104K it looks like Yellow rectangular tablet<<<<Look this notes <<<<
    1x - 220n Capacitor<<I am using 224J it looks like Yellow rectangular tablet<<<<Look this notes <<<<
    1x - 470n Capacitor<<I am using 474J it looks like Gray rectangular tablet<<<<Look this notes <<<<
    2x - 10uF Capacitor <<<<<I am using 10uf volts 63volts 2 piece and 1 piece 10uf 16volt. <<<just use 2 piece.<<<<Look this notes <<<<
    3x - 1N4148 Diode
    1x - ICL7107 IC
    1x - 7660 IC
    2x - MAN6910 2-digit LED 7-segment Display
     
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  14. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

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    Yes, but I didn't want to go through the entire schematic and compare each and every part with the part in his list.

    Ah, my apologies remon7. I did not realize you had combined the two lists. At first glance all the components you used should work. Make sure you fix the voltage issue that 4pyros pointed out though. It won't work if you don't supply the -5v in the right place.
     
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  15. chemelec

    chemelec Well-Known Member

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    In the Schematic you put on Post #42, the 10uF Capacitor between Pins 5 & 3/Gnd, is in BACKWARDS.
    The Positive of this Cap should go to pin 3/Gnd.
    The Negative of this cap should go to Pin 5.
     
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  16. remon7

    remon7 Active Member

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    its amazing maybe its working well. To be honest when i am working on this project that's time i was thinking that many people(Engineer )<DerStrom8, chemelec, 4pyros>with me. helping me about advice, planning, ideas. That's why i did not lose my hope. Rather its increased after reading your messages. Look my digital voltmeter >>
    unfortunately its not work well maybe its on right track..Need more Help ....yeah Derstrom8 i used -5 part with 5volt supply negative part and positive +5volt positive end and ground still ground there is no charge . u noticed that in this video first LED Display was off i dont know even when i connected for measuring volts then first LED just on showing me number 1 digit. just it...so tell me next procedure ....
     

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  17. chemelec

    chemelec Well-Known Member

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    What is the Voltage your Measuring?

    Without a Voltage Divider on the Input, Maximum voltage measurement may only be 0.199 Volts.
    (199 Millivolts.)
     
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  18. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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    1st LED total off MAY be OK with Leading Zero Blanking.

    Again, a reminder - what is your input at this time. Initially I would short the inputs.
     
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  19. remon7

    remon7 Active Member

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    Input means measuring voltage is 3volt maybe .......again at home i used 4.5volt for supply but ic wants 5volts. usually in campus lab i used 5volts from power supply ....But its working great at home means in 4.5volts...
    Thanks
     
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  20. remon7

    remon7 Active Member

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    >>>>>It includes a 3.5-digit LED display with a negative voltage indicator. It measures DC voltages from 0 to 199.9V with a resolution of 0.1V. The voltmeter is based on single ICL7107 chip and may be fitted on a small 3cm x 7cm printed circuit board. The circuit should be supplied with a 5V voltage supply and consumes only around 25mA.<<<<<< please look this website i followed this website ideas >>>http://projectlistinfo.blogspot.com/2013/01/how-to-make-digital-voltmeter.html it says 0 to 199volts.
     
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  21. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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    No, initially make the measured voltage ZERO by shorting the inputs. No voltage to the + and - inputs. Attempt to read 000 first.
     
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