Mainly make use of CD4066 to do a switch, the lock which makes use of a 74 LS373s saves function, completing the function of combination lock.That electric circuit implies nine roads to pay road.There are four false codes.While passing a key by the rightness a password, the triode transistor leads, absorbing to match after the electric appliances, making to give out light diode to give out light thus, meaning to have already completed a solution the function of the lock.Because 5 V electric voltages for give out light diode to say too greatly, so add an electric resistance, let it have the cent presses of function.This electric circuit makes use of time that the hurtling of different electric capacity turns on electricity a dissimilarity, controling the sequence of password thus.