1. Welcome to our site! Electro Tech is an online community (with over 100,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Circuit schematic for LED tachometer?

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by wsemajb, Jun 17, 2010.

  1. wsemajb

    wsemajb Member

    Joined:
    May 4, 2007
    Messages:
    42
    Likes:
    0
    My circuit/electronics skills are pretty limited to following schematics and building a circuit directly from them.

    I'm trying to find a circuit to get me 99 percent of the way toward interfacing the following two items for indicating ml/min water flow...

    http://img.diytrade.com/cdimg/163371/3406791/0/1174985167/MS_Mini_flow_sensor.jpg
    15 LED Circular & Linear Bargraphs - LEDtronics - 12991

    I'd like the bargraph to register 0 - 2000 ml/min. With straight up (middle) bar indicating 1000ml/min

    I realize that this is essentially an LED bargraph tachometer reading pulses from a hall effect switch.
    Since RPM measurement with hall switches is such a common task, I'm hoping that there exists
    some schematic involving the following ICs to accomplish this with little additional conditioning
    or (hopefully no) programing.

    LM2917 freq/volt converter IC
    LM3914/15/16/17 LED driver ICs

    Would the following page be of use to me?

    LM2917N, LM3914, Tachometer, PCB


    Thanks so much.

    Brad
     
    Last edited: Jun 17, 2010
  2. wsemajb

    wsemajb Member

    Joined:
    May 4, 2007
    Messages:
    42
    Likes:
    0
    Am I wrong in approaching this as a tachometer?
     
  3. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

    Joined:
    Jan 4, 2007
    Messages:
    19,924
    Likes:
    533
    Location:
    England.
  4. Reloadron

    Reloadron Well-Known Member

    Joined:
    Dec 23, 2009
    Messages:
    6,113
    Likes:
    197
    Location:
    Cleveland, Ohio USA

    Hi Eric

    Maybe it is me but the Link no workie, workie?

    Ron
     
  5. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

    Joined:
    Jan 4, 2007
    Messages:
    19,924
    Likes:
    533
    Location:
    England.
    Last edited: Jun 18, 2010

Share This Page