Reading DC Amperes

Discussion in 'General Electronics Chat' started by bumba000, Oct 29, 2015.

  1. bumba000

    Thread Starter Member

    Oct 7, 2015
    72
    2
    Hi All,
    So I have (with much help) created a DC boost circuit discussed here http://forum.allaboutcircuits.com/threads/dc-buck-boost.116393.

    This is my circuit
    [​IMG]

    So I have two multimeters. I have a UEI brand DM383B and also a GE2524. Both have settings and probe locations for measuring DC amperes of up to 10A. I understand that I should disconnect the positive connection from supply to load. Connect my meter's positive probe to the now available supply positive and then the negative meter probe to the positive load lead. Leaving the negative supply to negative load as is (fully connected with nothing between). I get a zero on both meters and the load does not become active. What in the world is going on?

    Thank You, John
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Post the data sheet for the ammeter
     
  3. crutschow

    Expert

    Mar 14, 2008
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    Are you using the 10A current input terminal to the multimeter?
     
  4. bumba000

    Thread Starter Member

    Oct 7, 2015
    72
    2
    I forgot to mention; yes, I am using the appropriate 10A meter terminal and have the dial set to DCA 10A.
    http://www.ueitest.com/sites/default/files/product-resources/DM383B Manual.pdf

    I have just tested a small DC motor using my lab power supply. Connecting the motor directly to the supply and the motor works well. Remove positive and add the meter in series and the motor does not work at all and I get no reading on the meter.
     
  5. gerty

    AAC Fanatic!

    Aug 30, 2007
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    Sounds like your meter fuse is blown
     
  6. recklessrog

    Member

    May 23, 2013
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    I could well be that the meter fuse is blown, but first go back a little, is the red positive lead in the 10A socket, and the black negative lead in the com socket with the setting knob set to DC 10A?
     
  7. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    It has already been said.

    Is the Red meter lead in the A spigot?
    Is the internal 10A fuse blown?
     
  8. bumba000

    Thread Starter Member

    Oct 7, 2015
    72
    2
    Yeah, I am using the meter properly I just have this amazing knack for overlooking the completely obvious. Both fuses in the GE meter were blown and just the larger fuse in the UEI meter was blown. They be measuring amps now!

    Thank you very much, John
     
    RichardO likes this.
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