Remote Controlled Door (RCD)
Parts of this idea are being used for other purpose but here it is.
Suppose you are in you bedroom or working on something interesting and you don't want to be interrupted when suddenly someone knocks on your door.
The idea is to build or assemble from already present device a transmitter and reciever than can control the lock in the door thru a powerful magnet coil (or an alreday present mechanism can be found i the market-by mechanism i do mean the hole door mechanism).
The block diagram or sequence goes like this.
3)switch (could be a sucession of a transistor and a timer to make sure the signal is present for enough time)
4)12v, 9v, 6v realy to control the coil mounted on the door or the door mechanism it self.
5)... (if any other steps required).
Apart from the bedroom door the device can be used mounted on any door whether the main gates or any another (don't know if the wireless accessed car work following the same or similar principle).
Reward: a prototype of the device would be given to the most helpful prs, post, comment(s).