Simple turn-on delay

[elizard]

How can I make a simple turn-on delay to delay turning something on for about 20 seconds?
It'll be used in car audio, and basically when the circuit gets power (12v) it'll delay about 20 seconds, and then it'll pass power onto a relay (so low current stuff).

Thanks.

 

[bikejog]

Found this on the net.

http://ourworld.compuserve.com/homepages/Bill_Bowden/page2.htm#delay.gif