How do I eliminate analog Preset.

Discussion in 'General Electronics Chat' started by devilfrmheaven, Jun 12, 2013.

  1. devilfrmheaven

    Thread Starter Member

    Oct 28, 2009
    40
    0
    Hi All,

    I am trying to build an LED dimmer circuit using PWM [​IMG]

    I am looking for a way to eliminate the 50K preset P1 in the circuit. I would like a push button approach can somebody suggest me with a cheap IC.


    Thanks in advance,
    Devil
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,056
    3,245
    P1 controls the duty cycle (don't understand what you mean by "preset"). Are you saying you want some type of incremental approach to controlling the duty cycle with a couple of push buttons?

    Edit: If you need push-button control you could use a digital pot to replace P1. But note that most digital pots have a maximum voltage of 5V so you would need to run the 555 portion of the circuit from 5V. The LEDs could still operate from 12V.
     
    Last edited: Jun 12, 2013
  3. devilfrmheaven

    Thread Starter Member

    Oct 28, 2009
    40
    0
    Yes exactly, I want to eliminate the analog potentiometer with a digital one..
     
  4. crutschow

    Expert

    Mar 14, 2008
    13,056
    3,245
    Then perhaps one like this will work (with the 5V limitation I mentioned in my previous post).
     
  5. devilfrmheaven

    Thread Starter Member

    Oct 28, 2009
    40
    0
    The ICs starting with DS is not available here :( .... Do you have any other suggestion???
     
  6. devilfrmheaven

    Thread Starter Member

    Oct 28, 2009
    40
    0
    I searched for all the ICs below at Cochin and could not get a single one :( is there any other option to get one of these?

    Digital Potentiometer
    AD5206
    AD5220
    AD5228
    AD5263
    AD5290
    AD8400
    DS1267
    DS1809-100
    DS1868
    MAX5160
    MAX5161
    MCP4121
    MCP4131
    TDA7449

    Debouncers
    MCP41100
    LTC6994
     
  7. gerty

    AAC Fanatic!

    Aug 30, 2007
    1,153
    304
    Where is "not available HERE"
     
  8. Ramussons

    Active Member

    May 3, 2013
    557
    92
    Try Ritchie Street, Chennai.

    Ramesh
     
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