LED blink and off

Discussion in 'The Projects Forum' started by spec07, Jun 30, 2015.

  1. spec07

    Thread Starter New Member

    Jun 29, 2015
    4
    0
    Hi guys,

    I have a current project which requires me to light up 7 LEDs in series using a on/off switch, blink for 5 secs (timing can be more) and turn off.

    Is there any available circuit similar to this application? It has to be mobile as well, I'm thinking of powering the circuit with a typical 9V battery. Not sure if it is enough.

    Any idea?
     
  2. #12

    Expert

    Nov 30, 2010
    16,330
    6,818
    Tell more. Do you want: 1,2,3,4,5,6,7 blink blink blink...off?
    or: 7 x on, blink blink blink...off?
    or something else?
     
  3. spec07

    Thread Starter New Member

    Jun 29, 2015
    4
    0
    I need all LEDs to be blink at the same time and off. -> 7 x on, blink blink blink...off
     
  4. #12

    Expert

    Nov 30, 2010
    16,330
    6,818
    What color?

    It starts with an LM556 chip. One timer counts off 5 seconds and the second one does the blinking. 9 volts won't run more than 2 or 3 LEDs in a series string, so we need to know what color to get the current right.
     
  5. #12

    Expert

    Nov 30, 2010
    16,330
    6,818
    How good are you at designing stuff? It's going to be a combination of bits from these:
     
  6. spec07

    Thread Starter New Member

    Jun 29, 2015
    4
    0
    I am not too good in designing circuit to be honest, am only 14 this year and this seems to be too tough for me. I am hopeful to get a full circuit solution if possible. This circuit would have to be portable though. Will two 9V battery in series which sums up to be 18V be sufficient to power 7 LEDs? LEDs I am thinking to use will be white as it requires to be bright to be seen during day time.

    Sorry for asking so much and thank you for your reply.
     
    Last edited: Jul 1, 2015
  7. AnalogKid

    Distinguished Member

    Aug 1, 2013
    4,544
    1,251
    This is what I posted on ETO for the same topic:

    This also can be done with a single NAND gate, or a combination of gates. Here are two schematics to show this. The functions are the same as the two-555 approach: an ON timer, enabling an oscillator, driving the LEDs.
    Here is a calculator for the oscillator and the ON timer:
    http://talkingelectronics.com/pay/BEC-2/Page49.html

    ak
     
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