Dark Detector On + Timed On (Outdoor Lamp)

Discussion in 'General Electronics Chat' started by kcarring, Mar 8, 2013.

  1. kcarring

    Thread Starter Member

    Jan 22, 2011
    38
    0
    I have been reading a lot of threads here, and elsewhere regarding the use of 4060 IC's, and such for delay timers.

    I have built a circuit that uses a 555 dark detection circuit by Tony Van Roon that I am very happy with.

    [​IMG]

    In day mode, idle, it consumes .1 mA. While supplying the voltage to my mosfet, (running the lamp) - the 55 circuit, itself, uses 6.7 mA.

    So I am happy with those numbers and it behaves perfect.

    My question is this:

    The lamp runs all night. How can I use a 4060 or something to make the lamp only run for 2-6 hrs.

    Thanks
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,019
    3,235
    Use the 4060 as a timer to bring the Reset input low on the 555 at the time-out. You can add a CD4009 inverter to invert the output to give a low to the 555 Reset input.
     
  3. kcarring

    Thread Starter Member

    Jan 22, 2011
    38
    0
    Wouldn't that just start the whole cycle over, the dark detector once again sees that it is still dark, feeds power to the gate, turns on the 4060... ??
     
  4. crutschow

    Expert

    Mar 14, 2008
    13,019
    3,235
    Good point. You need some memory, such as a flip-flop (latch) at the counter output that is set by the counter to keep the light off until it is reset for the next cycle by the light reappearing.
     
  5. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    You can add another 555 monostable between the output of the dark detector and the MOSFET, but I suppose you have thought of that.
     
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