I think I was goign down this route before. I have these timers but I don't remember what I was going to do with them:
http://www.mouser.com/ProductDetail/Texas-Instruments/NE556N/?qs=gb35HGp1gQKUkn%252b6zgU6RA%3d%3d&gclid=CPeurI_E08QCFQgxaQodYFIA2w
http://www.mouser.com/ProductDetail/Texas-Instruments/NE555P/?qs=rkhjVJ6%2f3EIf4CWgjIKuKQ%3d%3d&gclid=CNLc8qXE08QCFYNAaQodqDUAvg