LED Driver/Controller

Discussion in 'The Projects Forum' started by idioticcreation, Jan 4, 2011.

  1. idioticcreation

    Thread Starter New Member

    May 16, 2009
    Hello, I am trying to find some help on this project that I am currently working on. A brief description of what I am trying to achieve is a circuit that can control and power 6 LEDs off of 4 CR2032 batteries.

    Some basic design guidelines are to use surface mount components in order to keep the pcb and its components overall height as low as possible.

    I planned on pairing the CR2032 batteries in parallel to achieve a source of ~6 Volts DC.
    The LEDs I will be using are 5mm and I would like to have them running ~4-5 Volts @ 24mA.

    I'm also trying to control the LEDs so that they have two different modes:
    -Constant on
    -Strobe (tracer effect)

    I'd like to group the LEDs so that 4 of them can be controlled by 1 switch, and the other 2 to be controlled by their own switch. By controlling, I mean switching between off, constant on, and strobe.

    I was thinking that a DPDT slide switch could be used to change through the different modes for each set of LEDs to keep it simpler than using a tactile momentary push button switch.

    Any help is appreciated, and if there is any other information that I need to post please let me know.
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    That a lot of hardware under the hood for something you want to keep small.

    Are you wanting discrete IC's or can you go with a micro controller?

    It will be the 'small' size you have imagined if you use a micro, but the learning curve could be problem?

    Tell us more about what you have in mind, exactly. PWM with a 555; direct current limit control with a 317? Both?
  3. idioticcreation

    Thread Starter New Member

    May 16, 2009
    It was my mistake when I referred to this project as small. I would say I want to keep it as small as possible, the batteries being the largest component, but I am definitely trying to stay within 45 x 40 mm perimeter. The LEDs also will not take up any room on the board because they will not be mounted on the pcb.

    I am open to either discrete IC's or a micro controller, but cost does definitely come into play considering I really only want the LEDs to have the functions on/strobe/off.

    At first I was considering just keeping it simple and just making the LEDs a simple on/off by using a switch and current limiting resistor, but having a strobe option would be very appealing to me. The problem arises that I don't have enough knowledge to design a circuit that could do such a thing. I am proficient enough to assemble the circuit and follow instructions as I have the basic tools and experience, but I am currently dumbstruck when it involves using IC's.
    Last edited: Jan 4, 2011