LED Timer Circuit with Buzzer

Discussion in 'The Projects Forum' started by Helikaon, Oct 23, 2014.

  1. Helikaon

    Thread Starter New Member

    Oct 21, 2014
    Hey everyone. Just wondering if someone out there can offer some advice on how to complete a project I am working on. Basically what I am trying to achieve is a countdown timer using an LED set to turn on for a specific time, and once it has turned off, to have a buzzer beep twice only for 1 second beep duration with 1 second intervals between beeps. I will post a schematic of how I am going so far, but my issue is, as I am relatively new to circuit building, I am unsure of what component to use to have a beeper beep twice only for a set duration once the LED turns off. I have wired the LED to light for 10 seconds then turn off using a switch and 555 in monostable, but now I'm stuck on what to use for the next part. I've seen plenty of ideas on how to get a buzzer to beep in astable mode and with a flashing LED etc, but I feel this is slightly different and intriguing.
  2. #12


    Nov 30, 2010
    Love your enthusiasm, but you're about 3 beers short of a six-pack.
    Lay out the block diagram.
    (1) count off 10 seconds (done)
    (2) design a circuit that counts 1 second at a time, on then off
    (3) design a circuit that drives an audio signal to a noise maker during the "on" time of the second timer.
    (4) design a feedback loop that disables the 10 second timer until the other timers are finished.
  3. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    You will need either 2 of the circuits designed in step 2, or a circuit to count up to 2.