Abstract: This invention is an electronic apparatus which is capable of creating a sequence of conditions for responding to signals. This apparatus, after certain lapsed times, creates a condition and which condition, is of a definite time duration. When the apparatus is in this condition, a signal can be introduced to the apparatus to change the state of the apparatus and also the output signal from the apparatus. Such an apparatus can be used as an electronic combination lock or can be used as a screening device to prevent an individual with a slow reflex from changing the state of the apparatus and the output signal of the apparatus. For example, the apparatus can be used in conjunction with the ignition of an automobile; and, if an intoxicated individual with a slow reflex tries to operate the apparatus, the intoxicated individual will not be able to change the state of the apparatus and the output signal of the apparatus.