Digital frequency generator for coded interrogation

Claim 2

A command control system for generating a plurality of signal combinations adapted to be connected to a transmitter comprising: control means for providing a coded address signal; an oscillator having an output signal; counter means electrically connected to said oscillator and responsive to said oscillator output signal for providing a plurality of binary signals; first register means serially receiving said coded address signal and providing a first plurality of parallel outputs in response to said control means; gating means responsive to said plurality of binary signals and said first plurality of parallel outputs for generating said plurality of signals of different frequency; first summing means electrically connected to said plurality of signals of different frequency for providing a first summed output signal, said signal being the summation of the individual frequencies of said plurality of signals of different frequency; first averaging means electrically coupled to said first summing means and responsive to said first summed output signal for producing a first averaged output signal with substantially no irregularities therein by dividing said first summed output signal by a predetermined factor; first filter means operatively connected to said first averaged output signal for providing a substantially sinusoidal signal; and amplifier means receiving said sinusoidal signal and providing a modulating signal to the transmitter.

Claim 3

A command control system as recited in claim 1 wherein said control means for providing a coded signal comprises: selection means for selecting a desired code; second register means responsive to said selection means for providing said coded address signal; timing means electrically connected to said register means for producing an output timing signal; clock gate means responsive to said output timing signal and said counter means for providing clock pulses; and electrical means responsive to said clock pulses for transferring said coded address signal to said generator means.

Claim 4

A command control system as recited in claim 2 wherein said first register means further comprises: means for providing a second plurality of parallel outputs in response to said control means; and a second gating means responsive to said plurality of binary signals and second plurality of parallel outputs for generating a second plurality of signals of differing frequency.

Claim 5

A command control system as recited in claim 3 further comprising: second summing means electrically connected to said second plurality of signals for providing a second summed output signal, said signal being the summation of the individual frequencies of said second plurality of signals of different frequency; second averaging means electrically coupled to said second summing means and responsive to said second summed output signal for producing a second averaged output signal with substantially no irregularities therein by dividing said second summed output signal by a predetermined factor; second filter means operatively connected to said second averaging means for providing a second substantially sinusoidal signal; and means coupling said second substantially sinusoidal signal to said amplifier means for providing at the output of said amplifier means a two-tone modulating signal.

Claim 6

A command control system as recited in claim 2 wherein said counter means comprises: a plurality of binary stages serially arranged for providing a plurality of binary signals of differing frequency.

Claim 7

A command control system as recited in claim 5 wherein said first register means comprises: a plurality of binary stages forming a shift register for receiving said coded address signal and providing a plurality of parallel outputs in response to said control means.

Claim 8

A command control system as recited in claim 6 wherein said first averaging means comprises: a plurality of binary stages serially arranged for providing an averaged output signal having a lower frequency than said composite signal and containing substantially no irregularities.

Claim 9

A command control system as recited in claim 7 wherein said first filter means comprises: a plurality of AND gates each having a first input connected to said first averaging means and each having a plurality of other inputs operatively connected to said first register means for providing an output signal; and a plurality of bandpass filters electrically coupled to the outputs of said AND gates for providing a substantially sinusoidal signal for application to said amplifier means.

Claim 10

A command control system as recited in claim 8 wherein said second register means comprises: a plurality of binary stages serially arranged, each stage comprising: a magnetic core; input means operatively connected to said core; output means operatively connected to said core and to the input means of the following stage; a plurality of write-in lines magnetically coupled to selected ones of said stages for establishing said coded address signal.

Claim 11

A command control system as recited in claim 9 wherein said electrical means comprises: a first blocking oscillator having an input electrically connected to said clock gate means and responsive to said clock pulses for producing shift pulse signals for application to said second register means; a second blocking oscillator having an input electrically coupled to the output of said first blocking oscillator and responsive to said shift pulse signals for producing transfer pulse signals for application to said second register means, said shift pulse signals and transfer pulse signals causing said coded address signal of said second register means to be transferred to said first register means in response to said clock pulses.

Claim 12

A digital frequency generator adapted to be connected to a transmitter for control of sonobuoys from an aircraft comprising: an oscillator having an output signal; counter means electrically connected to said oscillator for producing a plurality of binary signals; control means having a plurality of binary stages for providing a coded address signal; register means having a plurality of outputs indicative of said coded signal; timing means operatively connected to said control means for providing an enabling signal; clock gate means having a first input electrically connected to said enabling signal, a second input operatively connected to said counter means and a third input electrically connected to said register means for providing a clock pulse signal; means responsive to said clock pulse signal and coupled to said control means for transferring said coded address signal from said control means to said register means; gating means having a first plurality of inputs connected to said plurality of binary signals and a second plurality of inputs connected to said plurality of outputs from said register means, said gating means providing a plurality of output signals of differing frequency; summing means operatively connected to said gating means for providing a summed signal, said signal being the summation of the Frequencies of said signals of differing frequency; circuit means electrically connected to said summing means for providing a substantially sinusoidal signal; and amplifier means responsive to said sinusoidal signal for transmissions to the sonobuoys.

Claim 13

A digital frequency generator adapted to be connected to a transmitter for control of sonobuoys from an aircraft comprising: an oscillator having an output signal; counter means electrically connected to said oscillator for producing a plurality of binary signals; control means having a plurality of binary stages for providing a coded address signal; register means having a plurality of outputs indicative of said coded signal; timing means operatively connected to said control means for providing an enabling signal; clock gate means having a first input electrically connected to said enabling signal, a second input operatively connected to said counter means and a third input electrically connected to said register means for providing a clock pulse signal; means responsive to said clock pulse signal and coupled to said control means for transferring said coded address signal from said control means to said register means; gating means having a first plurality of inputs connected to said plurality of binary signals and a second plurality of inputs connected to said plurality of outputs from said register means, said gating means providing a plurality of output signals of differing frequency; summing means operatively connected to said gating means for providing a summed signal, said signal being the summation of the Frequencies of said signals of differing frequency; circuit means electrically connected to said summing means for providing a substantially sinusoidal signal; and amplifier means responsive to said sinusoidal signal for transmissions to the sonobuoys.

Claim 14

A digital frequency generator as recited in claim 11 wherein said circuit means comprises: averaging means electrically connected to said summing means for reducing the irregularities in said summed signal; and filter means responsive to the averaged signal and said register means for selecting a bandpass filter in accordance with said coded address signal, said bandpass filter converting said averaged signal to a substantially sinusoidal signal for application to said amplifier means.

Claim 15

A digital frequency generator as recited in claim 12 wherein said counter means comprises: a plurality of binary stages serially arranged for providing a plurality of binary signals of differing frequency.

Claim 16

A command control system as recited in claim 13 wherein said register means comprises: a plurality of binary stages forming a shift register for receiving said coded address signal and providing a plurality of parallel outputs in response to said control means.