Door bell circuit using NE555

jacky January 27, 2014 18 Comments

Description.

The main part of this doorbell circuit are two NE555 timer ICs.When some one presses switch S1 momentarily, the loud speaker sounds a bell tone as long as the time period of the monostable multivibrator built around IC1.

When the switch S1 pressed, IC1 is triggered at its pin 2 and output pin 3 goes high for a time period previously set by the values of POT R4 and POT R5.When the output ofIC1 goes high it resets IC2 and it starts to oscillate to make a bell sound through the speaker.The IC2 is configured as an astable multivibrator whose oscillation frequency can be varied with the help of POT R5.By adjusting the values of R4 & R5, modifications on the tone are possible.

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Circuit diagram with Parts list.

door-bell-circuit-using-ne555.JPG

Notes.

  • The circuit has to assembled on a good quality PCB or common board.
  • The IC1 & IC2 has to be mounted on IC holders.
  • Power the circuit from a 9V battery or 9V DC power supply.
  • Switch S1 is push button switch.
Comments
  • jomon
    September 12, 2017

    Why two potR4 &R5.If only put 1 pot what’s the problem

  • August 30, 2015

    how does ceramic can perform in whole circuit you can,t talk to those capacitor and their role in this circuit

    • sebe
      September 21, 2016

      hi thanks a lot but when I connect ground it doesn’t have sound but if I disconnect it sound

  • August 30, 2015

    how this circuit can work in over you can’t put how it work in full in addition of those capacitor .how it work explain it i need your help very quickly please

  • sindhya
    August 28, 2015

    could you please send me the full details with the procedure of connections clearly??

  • John Titor
    January 22, 2015

    Works fine, I can see that the first 555 in monostable configuration with period variable (changing R4 Value) and the second 555 is Astable config in a range of audible frequencies to human ear

  • Arpan sarkar
    July 22, 2014

    i hav made the smd version of the circuit…and its work really nice..

    • brian
      September 27, 2016

      can u send mi the pcb circuit

  • VIGNESH
    June 17, 2014

    sir what is the meaning of ic holders

    • Seetharaman
      June 17, 2014

      It is an IC socket. It is for inserting the IC into the soldered socket. If you have a problem with the IC you can swap a new one without damaging the PCB by de-soldering and soldering back a new IC.

  • NARAYANA
    January 29, 2014

    HOW TO CONNET THE CIRCUT GIVE EXPLAINTION

    • Seetharaman
      January 31, 2014

      Hi Narayana Assemble circuit on any board. S1 is the Bell Push Switch at the door. Connect it to the circuit it will give nice sound when ever the calling bell door switch is pushed.

  • madhusudan epte
    October 25, 2013

    THIS IS NICE RELIABLE CIRCIUT.I HAVE MADE PROJECT AND ITS WORKING PROPERLY.
    SO U CAN TRUST CIRCIUT DIAGRAM.

    • Praveen
      August 18, 2016

      Can u please explain how to vary potentiometer to control the sound?

  • Clara
    May 1, 2013

    Can you explain what the other resistors and capacitors do?

  • kalyan
    August 8, 2012

    super

  • […] to under $20. Another search quickly brings up door bell circuits such as the links on this page. Door bell circuit using NE555 Although for a doorbell it might be just as quick to buy one from the hardware store. For those […]

    • anjal
      July 23, 2014

      this circuit is good but capacitor c1 & c5 positive terminal so pls tell me c1 & c5 is use seramic ya simple capacitor….
      ya c2 , c3, c4 is siramic capacitor pls ans me and resistor And capacitor work define…..

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