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!