LED Vu meter

Discussion in 'General Electronics Chat' started by frenchie29, Mar 25, 2009.

  1. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
    134
    0
    just built that kit

    http://kitsrus.com/pdf/k89.pdf

    How can I do a quick test on it? I am using a 9volt on it but nothing I would assume that at least 1 led would lid up

    Also I screwed up I reversed the polarity of the battery and the chips go so hot I don't know if I damaged anything or not
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    Can you take clear photos of both sides of the circuit board? Problems are usually spotted quickly that way. Format them to about 1280x900-ish if that size shows enough detail.
     
  3. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    With the power supply polarity backwards then the ICs are destroyed.

    I made a similar one but used a 9V supply. The IC gets too hot with it connected as shown in the bar mode, with a 12V supply and all LEDs lighted. I added a series resistor to all the LEDs to share the heat.
     
  4. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
    134
    0
    What's the difference between the

    LM3914
    LM3915
    LM3916

    I might gonna go get a replacement tomorrow and see if what are the differences between those 3 models
     
  5. bertus

    Administrator

    Apr 5, 2008
    15,647
    2,346
    Hello,

    The difference between the three are:
    LM1914 , linear
    LM3915 , 3 dB steps
    LM3916 , VU meter scale (3 , 2 , 1 , 0 , -1 , -3 , -5 , -7 , - 10 , -20 dB : 3 dB = 10 Volts)

    Greetings,
    Bertus
     
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