A timer is easy-

Look for a mechanical timer that plugs into an electrical outlet, and interrupts the electricity delivery to your item to be shut off. Plug the dehydrator in to it. I found a package at Big Lots last year that had two timers and a flashlight for about $8.00 US. A really cheap solution that can start morning coffee, shut off a crock pot, turn on/off a light, OR time a dehydrator. Try the kitchen supply section or the hardware aisle.

Good Luck!

CamperMom