An electromechanical switch havinga hardened memory, said memory having a selectable multi-digit number of a given counting base stored therein, said switch electrically closing when a plurality of sequential switches close simultaneously after a predetermined length of time based upon said number stored therein, said electromechanical switch comprising:
- counter means for producing a combination of unique electrical outputs, each of said outputs of said combination having a plurality of electrical pick-off positions, each output having one electrical pick-off, said electrical pick-off being brush means for transferring electrical signals, the number of said pick-off positions per output being equal to said given counting base used by said counter means, one of said positions per output being a selectable reference position, the number of unique electrical outputs in said combination being defined by B.sup.N where B is said counting base and N is the number of said outputs, said counter means sequencing through said combination, said counter means further comprising a mechanical counter having a plurality of stages, each of said stages having a counter wheel geared thereto, each of said counter wheels being co-axial, each of said counter wheels rotating in angular steps whereby the number of steps per rotation of said counter wheel in each of said stages is equal to said counting base, geneva means actuated by a motor drive to rotate said counter wheels, each of said counter wheels having fixedly attached about a circumference said electrical pick-off, a pick-off of a first stage of said plurality of stages electrically contacting an input trigger circuit being a first circuit of said electrical means, and a pick-off of a last stage of said plurality of stages being in intermittent electrical contact with said memory means;
- memory means for holding one unique combination of electrical outputs, each of said outputs having an electrical contact fixed in one preselected position being one of a plurality of positions available, said memory means having a number of outputs at least equal to the number of outputs from said counter means, said plurality of positions available being equal to said counting base of said counter means, said one preselected position corresponding to one digit of said multi-digit number stored in said memory means, said plurality of sequential switches being at least equal to said number of outputs of said counter means, each sequential switch electrically closing when corresponding outputs of said counter means and said memory have said pick-off and said contact in electrical continuity as defined by said selectable reference position of said counter means and said preselected position of said memory means, said electromechanical switch producing an electrical output signal if and only if all of said sequential switches are in electrical continuity simultaneously;
- said memory means further comprising:
- set/lock means for loading and holding said multi-digit number into said memory means;
- a stepper motor for actuating said set/lock means in response to signals received from said electrical means, said stepper motor being rotatable in both directions;
- a plurality of set disks connected to said set/lock means, each of said set disks being independently rotatable and co-axially located on said set/lock means;
- a plurality of counter set disks, each of said counter set disks being geared to said set disks and co-axially located, each of said counter set disks having fixedly located about a circumference an electrical contact, said counter set disks being co-axially located with said counter wheels of said counter means, the number of said counter set disks being equal to the number of said counter wheels, said counter set disks being alternately located between said counter wheels, each of said counter set disks being in continuous electrical contact with one of two of said adjacent counter wheels excepting a last counter set disk which is in continuous electrical contact with a second circuit of said electrical means, said last counter set disk being adjacent said pick-off of said last stage of said counter means, each of said counter set disks having fixedly located thereon an electrical contact, said electrical contact being intermittently in electrical contact with the other of two of said adjacent counter wheels, and
- reading means for reading digital data stored on said set disks, said digital data being communicated to a computer that controls the movement of said stepper motor through said electrical means, said stepper motor controlling said set/lock means;
- a housing for holding said counter means and said memory means;
- electrical means for controlling said counter means and said memory means.