Electric ovens are pretty good dehydrators for items that are not too sensitive to the temperature. I have successfully dehydrated various meats, including beef jerky, in an electric oven, but I wouldn’t use it for more heat sensitive items, such as mushrooms or herbs.
Most of the meats can be dehydrated by frying them with little or no fat, and placing them onto an oven tray lined with baking paper. With beef jerky, things are done a bit differently. First thing to do is to protect the oven from the dripping marinade by placing a piece of aluminum foil to the bottom of the oven. Then it is time to stick wooden cocktail sticks through the end of each of the meat strips, and hang them through an oven rack. The rack should then be placed in the oven so that the meat strips hang freely in the air.
Controlling the temperature and the air flow in a conventional electric oven is a bit of a problem. I have usually left the oven door slightly open by placing a wooden or metal spoon between the door and the frame of the oven, and setting the temperature to as low as possible (usually about 50 C (120F)). Dehydrating using an oven takes longer time and consumes a bit more energy than using a real dehydrator, but other than that, an oven can do the job pretty well.