Repertory telephone dialler utilizing binary storage of digit valves

Claim 2

An electric impulse transmitter for a telephone instrument, said transmitter cOmprising a cyclic dynamic store including at least one binary shift register, which store is capable of storing a plurality of binary coded values in respective time positions in the cycle thereof, input and output cyclic distributors each including a respective binary shift register, means responsive to timing signals from the input distributor to enter in successive time positions in the store binary coded digit values representing a telephone number to be signalled, output means responsive to timing signals from the output distributor, and impulsing means controlled by said output means to supply a succession of trains of impulses that are respectively characteristic of the binary coded digit values entered in the store.

Claim 3

An electric impulse transmitter in accordance with claim 1 wherein all three shift registers utilize metal oxide semiconductor transistors.

Claim 4

An electric impulse transmitter in accordance with claim 1 wherein each shift register is formed as at least a part of an integrated circuit.

Claim 5

An electric impulse transmitter in accordance with claim 1 includes a pushbutton mechanism by means of which the binary coded values of a telephone number to be called are derived.

Claim 6

An electric impulse transmitter for a telephone instrument comprising a cyclic dynamic store including at least one binary shift register which is stepped by clock pulses, input and output cyclic distributors each including a respective binary shift register which each provide a timing pulse once per cycle thereof, the cycle times of the store and said distributors being equal, means responsive to an input signal and a timing signal from said input distributor to set the state of one of the stages of said store register, during at least one clock pulse period in a cycle of the register, whereby in operation at least one binary value relating to each decimal digit value of a telephone number to be signalled is written into said store, means temporarily to change the effective length of said shift register in said input distributor by one or more stages when a decimal digit value is written into said store whereby said store and said input distributor are stepped differentially, output means responsive to a timing pulse from said output distributor and to the state of a stage of said store register, at least during one clock pulse period, impulsing means controlled by said output means, and means temporarily to change the effective length of said register in said output distributor, by one or more stages, under the control of said output means whereby said store and said output distributor are stepped differentially, the arrangement being such that said impulsing means supplies a plurality of trains of impulses that are respectively characteristic of a plurality of decimal digit values written into said store.

Claim 7

An electric impulse transmitter for a telephone instrument comprising a cyclic dynamic store including at least one binary shift register which is stepped by clock pulses, input and output cyclic distributors each including a respective binary shift register which each provide a timing pulse once per cycle thereof, the cycle times of the store and said distributors being equal, means responsive to an input signal and a timing signal from said input distributor to set the state of one of the stages of said store register, during at least one clock pulse period in a cycle of the register, whereby in operation at least one binary value relating to each decimal digit value of a telephone number to be signalled is written into said store, means temporarily to change the effective length of said shift register in said input distributor by one or more stages when a decimal digit value is written into said store whereby said store and said input distributor are stepped differentially, output means responsive to a timing pulse from said output distributor and to the state of a stage of said store register, at least during one clock pulse period, impulsing means controlled by said output means, and means temporarily to change the effective length of said register in said output distributor, by one or more stages, under the control of said output means whereby said store and said output distributor are stepped differentially, the arrangement being such that said impulsing means supplies a plurality of trains of impulses that are respectively characteristic of a plurality of decimal digit values written into said store.

Claim 8

An electric impulse transmitter in accordance with claim 5 wherein said store comprises four similar shift registers through which are stepped in parallel four binary values relating to each decimal digit value written into said store.

Claim 9

An electric impulse transmitter in accordance with claim 6 wherein said store comprises logic circuits arranged to return to the inputs of said four shift registers, upon the occurrence of each impulse from said impulsing means, binary values, in respect of the digit value being read from said store, which represent a digit value one less than that appearing at the outputs of said four registers, whereby said digit value is progressively counted down to zero and said impulsing means supplies a train of impulses characteristic of that digit value.

Claim 10

An electrical impulse transmitter in accordance with claim 5 wherein said store comprises one binary shift register the four binary values relating to a decimal digit value being written in succession into said binary shift register and subsequently being transfered on readout to set a four-stage binary counter, this counter being progressively reset to zero by impulses from said impulsinG means to provide a train of impulses characteristic of that digit value.

Claim 11

An electric impulse transmitter in accordance with claim 5 wherein said shift registers utilize metal oxide semiconductor transistors.

Claim 12

An electric impulse transmitter in accordance with claim 5 wherein each shift register is formed as at least a part of an integrated circuit.

Claim 13

An electric impulse transmitter for a telephone instrument, said transmitter comprising a cyclic dynamic store including at least one binary shift register, which store is capable of storing a plurality of binary coded values in respective time positions in the cycle thereof, distributor means to derive cyclic input and output timing signals respectively once per cycle of the storage shift register, means responsive to input timing signals from the distributor means to enter in successive time positions in the store binary coded digit values representing a telephone number to be signalled, output means responsive to output timing signals from the distributor means, and impulsing means controlled by said output means to supply a succession of trains of impulses that are respectively characteristic of the binary coded digit values entered in the store.

Claim 14

An electric impulse transmitter for a telephone instrument, said transmitter comprising a cyclic dynamic store including at least one binary shift register, which store is capable of storing a plurality of binary coded values in respective time positions in the cycle thereof, distributor means to derive cyclic input and output timing signals respectively once per cycle of the storage shift register, means responsive to input timing signals from the distributor means to enter in successive time positions in the store binary coded digit values representing a telephone number to be signalled, output means responsive to output timing signals from the distributor means, and impulsing means controlled by said output means to supply a succession of trains of impulses that are respectively characteristic of the binary coded digit values entered in the store.