battery powered programmable timer

Discussion in 'General Electronics Chat' started by jg2monte, Jan 31, 2011.

  1. jg2monte

    Thread Starter New Member

    Jan 31, 2011
    what would be required to develop a battery powered programable time switch . it would operate a typical home air freshener . looking for programable mode of operation between every 30 to 120 minutes with a pulse on during a 12 hour period and then a total rest period for the remaining 12 hours
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    For that duration, and for the price, a small microcontroller, such as the PIC 12F683 (8 pin) would work great.

    Do you know any programming languages? Startup cost for uC's is about $40 for the programmer and a couple ICs, but they allow design of advanced and complex projects with very minimal hardware. $35 for the programmer, $1-$9 for additional chips, typically under $5 ea though.

    If you don't want to go the uC route, the solution would best be solved by a slow clock (square wave oscillator), clocking a counter/divider to get the delay you'd like. The hardware would involve a few more ICs and passive components, but your basic idea could be done as well.

    What is your experience level with electronics/soldering/logic/etc?
  3. Potato Pudding

    Well-Known Member

    Jun 11, 2010
    Use one or two 4541 programmable timers.

    They are standard parts made by several different manufacturers.

    Check out the datasheets and if you are still not sure, ask for help.