I need a curcuit board designed and a list of components needed so that I can build the circuit myself. I have very little electronic component knowledge and no curcuit building knowledge. This information must be presented to me in an understandable way. The curcuit needing to be built is relatively simple. I need a curcuit that can connect to a motor and reverse the polarity of the motor via a timer, such that the motor shaft moves clockwise when the polarity is not reversed, and after a specfic time has elapsed, the motor reverses polarity and the shaft moves counter-clockwise. This design is simillar to that of a curcuit in a garage door opener, however, instead of opening and closing with a button, it opens and closes via a timer.