Digital system and method for generating analog control signals

Claim 2

In a method utilizing digital storage means, signal processing circuitry and a digital-to-analog converter for generating an analog control signal having an amplitude which varies with time according to a predetermined waveform, the steps of: storing a plurality of amplitude signals representative of the changes in amplitude between predetermined points in the analog waveform, storing a plurality of time signals representative of the time intervals between the predetermined points, providing pulses at rates corresponding to successive ones of the stored amplitude signals, counting the pulses and providing an output pulse each time the count reaches a number corresponding to one of the stored time signals, converting the output pules to an analog output signal which advances in stepwise fashion along line segments interconnecting the predetermined points, storing a jump signal indicative of the occurrence of an instantaneous change in the amplitude of the analog signal and converting one of the stored amplitude signals directly to analog form to provide the output signal in response to the jump signal.

Claim 3

The method of claim 1 wherein the amplitude and time signals are stored at separately addressable locations in a single memory device and the amplitude signals for each line segment are stored in and auxiliary store prior to addressing the memory location where the time signals for the segment are stored.

Claim 4

The method of claim 1 wherein the first named pulses are provided by generating clock pulses at a predetermined rate and delivering N pulses in response to each clock pulse, where N corresponds to the change in amplitude represented by each of the amplitude signals.

Claim 5

The method of claim 1 wherein the output pulses are counted to provide a digital signal having a parallel format and the last named signal is converted to analog form to provide the analog signal.

Claim 6

The method of claim 4 wherein signals corresponding to the polarities of the slopes of the line segments are stored and the output pulse count is incremented and decremented in accordance with the polarity signals.

Claim 7

In a system for generating an analog control signal having an amplitude which varies with time according to a predetermined waveform: digital memory means for storing amplitude and time signals respectively representative of changes in amplitude and time between predetermined points in the analog waveform, means for providing pulses at rates corresponding to successive ones of the stored amplitude signals, counter means responsive to the pulses for delivering an output pulse each time the count reaches a level corresponding to one of the stored signals, digital-to-analog converter means responsive to the output pulses for delivering an analog output signal which advances in a stepwise fashion along line segments interconnecting the predetermined points, means for storing a jump signal indicative of the occurrence of an instantaneous change in the amplitude of the analog signal, means for applying the amplitude signals to preset inputs of the counter means, and means for conditioning the counter to transfer the amplitude signals from the preset inputs directly to the output lines of the counter means in response to the jump signal.

Claim 8

In a system for generating an analog control signal having an amplitude which varies with time according to a predetermined waveform: digital memory means for storing amplitude and time signals respectively representative of changes in amplitude and time between predetermined points in the analog waveform, means for providing pulses at rates corresponding to successive ones of the stored amplitude signals, counter means responsive to the pulses for delivering an output pulse each time the count reaches a level corresponding to one of the stored signals, digital-to-analog converter means responsive to the output pulses for delivering an analog output signal which advances in a stepwise fashion along line segments interconnecting the predetermined points, means for storing a jump signal indicative of the occurrence of an instantaneous change in the amplitude of the analog signal, means for applying the amplitude signals to preset inputs of the counter means, and means for conditioning the counter to transfer the amplitude signals from the preset inputs directly to the output lines of the counter means in response to the jump signal.

Claim 9

The system of claim 6 wherein the memory means comprises a read-only-memory.

Claim 10

The system of claim 6 wherein the means for providing pulses comprises a rate multiplier responsive to clock pulses occurring at a predetermined rate and to the amplitude signals for delivering pulses at a rate corresponding to the product of the predetermined rate and a number represented by each of the amplitude signals.

Claim 11

The system of claim 6 wherein the digital-to-analog converter means comprises a digital counter responsive to the output pulses and a digital-to-analog converter connected to the output lines of the counter.

Claim 12

The system of claim 9 further including means for storing polarity signals corresponding to the polarities of the slopes of the line segments and means for conditioning the counter to count up or down in accordance with the polarity signals.

Claim 13

The system of claim 6 wherein the amplitude and time signals are stored at separately addressable locations in the memory means, together with means for successively addressing the amplitude and time signals for each line sigment, and auxiliary storage means for temporarily storing the amplitude signals while the time signals are addressed.

Claim 14

In a system for generating an analog control signal having an amplitude which varies with time according to a predetermined waveform: digital memory means for storing amplitude and time signals respectively representative of changes in amplitude and time between predetermined points in the analog waveform, a source of pulses occurring at a predetermined rate, rate multiplier means responsive to the pulses and to the amplitude signals for delivering pulses at rates corresponding to the product of the predetermined rate and numbers represented by the amplitude signals, means for dividing the pulses from the multiplier means by numbers corresponding to the time signals to provide output pulses defining stepped line segments interconnecting the predetermined points of the output waveform, digital counting means responsive to the output pulses, digital-to-analog converter means connected to the outputs of the counting means for delivering an analog output signal corresponding to the stepped line segments, means for storing jump signals indicative of the occurrence of instantaneous changes in the amplitude of the analog waveform, means for applying the amplitude signals to preset inputs of the counting means, and means responsive to the jump signals for conditioning the counting means to transfer the amplitude signals directly from the preset inputs to the outputs of the counting means.

Claim 15

In a system for generating an analog control signal having an amplitude which varies with time according to a predetermined waveform: digital memory means for storing amplitude and time signals respectively representative of changes in amplitude and time between predetermined points in the analog waveform, a source of pulses occurring at a predetermined rate, rate multiplier means responsive to the pulses and to the amplitude signals for delivering pulses at rates corresponding to the product of the predetermined rate and numbers represented by the amplitude signals, means for dividing the pulses from the multiplier means by numbers corresponding to the time signals to provide output pulses defining stepped line segments interconnecting the predetermined points of the output waveform, digital counting means responsive to the output pulses, digital-to-analog converter means connected to the outputs of the counting means for delivering an analog output signal corresponding to the stepped line segments, means for storing jump signals indicative of the occurrence of instantaneous changes in the amplitude of the analog waveform, means for applying the amplitude signals to preset inputs of the counting means, and means responsive to the jump signals for conditioning the counting means to transfer the amplitude signals directly from the preset inputs to the outputs of the counting means.

Claim 16

The system of claim 12 wherein the amplitude and time signals are stored at separately addressable locations in the memory means and auxiliary storage means is included for storing the amplitude signals for one segment while the time signals for said segment are addressed.

Claim 17

The system of claim 12 further including means for storing signals corresponding to the polarities of the slopes of the line segments, and means for conditioning the counting means to count up or down in accordance with the polarity signals.