(19)
(11) EP 0 104 865 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
27.12.1984 Bulletin 1984/52

(43) Date of publication A2:
04.04.1984 Bulletin 1984/14

(21) Application number: 83305506

(22) Date of filing: 20.09.1983
(84) Designated Contracting States:
CH DE FR IT LI SE

(30) Priority: 28.09.1982 GB 8227635

(71) Applicant: Morrison, John Malcolm
 ()

(72) Inventor:
  • Morrison, John Malcolm
     ()

   


(54) Code confirmation circuit


(57) A code confirmation circuit includes input means comprising a number of switches (KI to Kn) each representing a different code value. A counter (CT) has a number of outputs energisable in sequence from a datum state and each representing a different code value. Circuit means interconnect the switches and the outputs of the counter such that the operation of a switch having the same code value as the energised counter output causes an amplifier (A1) to clock the counter (CT) so as to energise the next counter output in sequence. Resetting means comprising a second amplifier (A2) are responsive to the operation of an incorrect switch to cause the counter to be reset. The energisation of the last counter output in the sequence indicates the correct sequence of operation of the switches.






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