help please!

Discussion in 'Homework Help' started by JJ9, Apr 20, 2009.

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  1. JJ9

    Thread Starter New Member

    Apr 20, 2009
    hi everyone

    what type of circuit would be needed for an alarm clock that began to sound 30mins before wake up time. the sound/music would gradually increase in volume.
    hope it makes sense..i am talking about progressive alarm clocks..but i want to know about the sound part not the light..

    what elecronic component(s) would be needed? What component could be incorporated into an exisiting analogue/digital alarm clock circuit?
    are there any exisiting circuits with explainations of how they work on the net?
    any information would be useful so i knwowhat to search for..

    i dont need to make this clock..i just need information/explanations

    help would be much appreciated!:)
  2. PRS

    Well-Known Member

    Aug 24, 2008
    You have so much more freedom when you design yourself than when you use pre-existing circuits. The latter are not always tailored to your need. Having said that, I take it you want to make a clock radio turn on 30 minutes before you have to get up and gradually increase the volume in order to wake you up gradually?

    So, using the existing trigger for the alarm clock and setting it 1/2 hour before you wake up, the volume needs to be gradually increased to max? There are many ways to skin a cat. One approach would be to use a 555 timer to pulse a counter that in turn turned up the voltage of a DAC whose output controlled the volume of the audio amplifier.
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    This has been posted all over. Enough, already.
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