Touch controlled musical bell.

john April 7, 2010 4 Comments


This circuit produces a musical tone whenever someone touches the touch point designated as TP in the circuit. The circuit works from two AA cells and produces enough sound.

The circuit uses IC UM 3481 commonly used in musical circuits. The IC contains a ROM with 512 musical notes, tone generator, rhythm generator, modulator, run off control, oscillators, frequency divider and preamplifiers,.  So a very few number of components is  required for this circuit.C1 and R1 act as  the timing components for  the built in oscillator. The transistor Q1 is used for driving the loud speaker. The base of the transistor Q2 is used as the touch point to trigger the musical bell.

Circuit diagram with Parts list.



  • The circuit can be assembled on a general purpose PCB.
  • Use two AA cells in series for powering the circuit.
  • The speaker can be 2 W, 8 Ohm.
  • Padmaja
    August 18, 2014

    will dis project can be done on autocad 2d

  • August 2, 2011


  • Saran
    August 7, 2010

    I have setup this ckt on a breadboard for testing. But touch technique is not working,the music is produced even without the touch.what can i do to make it proper working?

  • pavan
    December 22, 2009

    than q, good application.
    but one question, is there any specific type of material to be used as touch point or any conducting material goes well?

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