Help with LED turbo Boost gauge

Discussion in 'General Electronics Chat' started by archieblue, Jan 5, 2011.

  1. archieblue

    Thread Starter New Member

    Nov 8, 2009
    I would like to build a bar/dot LED turbo boost indicator gauge for my car using two LM3914N IC's driving 20 LED's and a MPX4250AP MAP sensor, Can anyone help me with which other components I will need and with circuit design for this project?
    Any help would be much appreciated:)
  2. Jaguarjoe

    Active Member

    Apr 7, 2010
    You will need a rugged 5 volt regulator to power this stuff from an auto's 12 volt system. Something like an LM2930.
    All Electronics has a 20 bar LED display for a few dollars.
    How are you going to calibrate it?
    36 psi is a lot of boost :)
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    What is the application? Is this a street car, or for racing?
  4. archieblue

    Thread Starter New Member

    Nov 8, 2009
    It's for a road car, I would like to build the LED's into the dashboard to make it functional but not intrusive as an aftermarket gauge would be,
    The MAP sensor would have a tube feeding it inside the car, I wish it to indicate vacuum as well as boost hence the choice of MAP sensor, trim pots could be used to adjust the range and it could be accurately calibrated using a manometer or dead weight tester, the physical building of it shouldn't be a problem but it is the circuit requirements and design I am not sure about :confused:
  5. marshallf3

    Well-Known Member

    Jul 26, 2010
    Look up the data sheets on that LM series, everything you'll ever need to know is documented in there.
    Remember they made three variations of the chip.

    I think Digi-Key as well as others still have them but Jameco is also a good source. Both have the bar/graph LED displays as well.
    Mouser has the Adago LED display but I don't think they have the chips as there must be a story to them and NS some time back.
    Last edited: Jan 7, 2011