Noob: LED Car Heater Display

Discussion in 'The Projects Forum' started by phil2580, Jun 27, 2011.

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  1. phil2580

    Thread Starter New Member

    Jun 27, 2011

    I'm looking to change the heater temp dial in my car to an LED-based one.

    My idea is to attach a potentiometer to the dial to control 4x Blue and 4x Red LEDs. When the heater is at its coldest, I want the blue LEDs lit, and the Reds turned off. As the Dial is rotated (and thus the resistance of the pot is increased), I want the blue LEDs to fade and the reds to brighten.

    Can this be done just using a pot, or do I need a more complicated circuit to handle it all?


  2. wayneh


    Sep 9, 2010
    Welcome to the AAC forum.

    This is more complicated than you think, but doable. What you're describing is essentially a bargraph voltage display, and there is a special IC for doing exactly that. I believe it's a LM3914. Your challenge will be to determine the voltage "breaks", what the knob is doing and where you want your display to change.
  3. Wendy


    Mar 24, 2008
    I am truly sorry, but the Terms of Service (TOS) has a clause that forbids automotive modifications. You will find a link to the TOS at the bottom of this page. We have a list of alternate sites for these kinds of projects.

    Member selected automotive forums

    When a mod notices this thread I suspect it will be closed.
  4. bertus


    Apr 5, 2008

    I am closing this thread as it violates AAC policy and/or safety issues.

    6. Restricted topics. The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:

    • Any kind of over-unity devices and systems
    • Automotive modifications
    • Devices designed to electrocute or shock another person
    • LEDs to mains
    • Phone jammers
    • Rail guns and high-energy projectile devices
    • Transformer-less power supplies
    This comes from our Tos:
    Terms of Service
    There will be enough sites where automotive questions can be discussed :
    Member selected automotive forums

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