Connecting multiple LM3914's

Discussion in 'General Electronics Chat' started by Iaoel, Nov 13, 2013.

  1. Iaoel

    Thread Starter New Member

    May 10, 2012
    :)hello i want to express this thread further i want to know how can I connect the 3 pieces of lm3914 on to make a equalizer look LED sorry im Noob Thanks btw I dun speak english well a schematic diagram will do well so i can know how to connect it Thanks again
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012

    The currents in the Leds are set by the ref current on pin 7 set by R1, this current is 10 times the value , 7 to 13 mA in each led, (see page 9 datasheet)

    to cascade them in series see page 18 datasheet, just make sure the first IC is the ref lo to ground and connect its ref hi to the next ref lo and so on , the last IC has the ref adjust set to the desired level from 1.2V to 12V.
  3. bertus


    Apr 5, 2008
  4. Iaoel

    Thread Starter New Member

    May 10, 2012
    thank you bros
  5. GopherT

    AAC Fanatic!

    Nov 23, 2012
    Simply connecting multiple lm3914 together will only allow a voltage to be divided into 20, 30 or 40 segments instead of 10.

    If you want a multi-band equalizer display, you will need a circuit that pulls out the relative power of different frequency bands in an audio signal.

    You can use the following ship to separate the signal into seven frequency bands. There are some issues with this chip - only one output that must bu multiplexed back to your array of LM3914 chips.