Newbie needing help. I would like a circuit to control a model train as part of a fund raising project. The layout will have twenty stations and the train will be required to stop at different stations. A section of track at each station will be isolated from the rest but wired together. I would like a random timer to de-energise all the isolated sections. Push button to start and after a delay of approx five seconds the random timer would then de-energise the sections, stopping train at nearest station. Randoms times could be between five and twenty seconds. Can construct circuits but limited knowledge in electronics. Thank you in anticipation of some assistance.