Hello friends....
Friends I have used Analogue alarm clock in the place of timer circuit because It have very good accuracy and can also be set.I have tested this alarm clock and I have got that it rangs very accurately on the set interval.
This is very simple alarm clock which is common in every houses which works on 1.2 volt pensil cell.. But friends, I have very small place and this alarm clock circuit can't fit properly because of size...... so i want to convert this analogue alarm clock to some other circuit. And this circuit should work as same as this analogue alarm clocks works and we can also vary it's time.And one thing more it should be very accurate as same as alarm clock..
Your timer circuit will need a quartz oscillator (or similar) for accuracy, counter chips, decoder/logic chips, a four-digit display, a keypad for input, a battery holder and a casing. Quite an undertaking just to re-invent the wheel. IMHO you won't be able to build one smaller than the readily-available alarm clocks.