Variable waveform synthesizer using digital circuitry

Claim 2

A variable waveform synthesizer for accepting a digital pulse train of a predetermined period and constructing therefrom a variety of multi-valued waveform approximations comprising: counting means for receiving the digital pulse train and sequentially assuming in response thereto N separate and distinct digital states; pulse generating means responsive to the digital pulse train for generating a digital pulse stream of pulses each of the pulses of the digital pulse stream being less than the predetermined period of the digital pulse train, the pulse generating means including means for varying the width of the pulses; decoding means responsive to the counting means for decoding at most N digital states and including at most N individual outputs, each decoder output activated in a predetermined order in response to the digital states assumed by the counting means; combining means responsive to the pulse generating means and the decoding means outputs and having a number of combining means outputs in one-to-one relation with each of the decoder means outputs so that the width of the pulses output from the combining means will be determined by the coincidence between the pulse generator output and the decoder outputs; and synthesizing means for accepting the outputs of the combining means and generating therefrom a pulse of a predetermined amplitude for each activated decoder output and including output means responsive to said pulses for constructing therefrom a multi-valued waveform approximation.

Claim 3

The waveform synthesizer of claim 1, wherein the synthesizing means comprises: means responsive to at least one of each of the decoder outputs for generating a predetermined amount of current such that as each said decoder output becomes activated in response to its respective binary state sequentially assumed by the binary counting means a corresponding and predetermined amount of current is generated; and means connecting the current generating means and the output means for receiving the currents generated to create pulses therefrom.

Claim 4

The variable waveform synthesizer of claim 1, wherein: the number of digital states sequentially attained by the binary counter is ten; and the number of outputs from the decoding means is 10.

Claim 5

The variable waveform synthesizer of claim 1, wherein the output means comprises: integrating means responsive to said pulses for constructing therefrom the multi-valued waveform approximation.

Claim 6

A variable waveform synthesizer for generating a variety of analog waveform approximations comprising: first pulse generating means for generating a digital pulse train of a predetermined period, T, the first generating means including means for varying the repetition rate of said pulse train; second pulse generating means responsive to said first pulse generating means for generating a pulse having a pulse width less than T for each pulse contained in the digital pulse train, the second pulse generating means including means for varying the pulse width of the pulses generated thereby; binary counter means responsive to the first pulse generating means and capable of sequentially attaining N separate and distinct digital states; decoding means responsive to said binary counter for decoding each of the digital states attained by the binary counter, said decoding means having at most N individual outputs each of which activated in response to one and only one of the N states attained by the binary counter means; combining means responsive to the decoding means outputs and the second pulse generating means and having at most N combining means outputs activated by coincidence between the decoding means outputs and the second pulse generating means; a plurality of constant current sources responsive to the combining means outputs such that when a combining means output is activated the current source coupled thereto is placed in a conducting state causing a current to flow therefrom, each of the current sources including means for varying the current provided thereby; and output means for receiving and combining the current produced by the current sources and synthesizing therefrom the analog waveform approximation, the output means including integrating means for shaping the analog waveform approximation.

Claim 7

A variable waveform synthesizer for generating a variety of analog waveform approximations comprising: first pulse generating means for generating a digital pulse train of a predetermined period, T, the first generating means including means for varying the repetition rate of said pulse train; second pulse generating means responsive to said first pulse generating means for generating a pulse having a pulse width less than T for each pulse contained in the digital pulse train, the second pulse generating means including means for varying the pulse width of the pulses generated thereby; binary counter means responsive to the first pulse generating means and capable of sequentially attaining N separate and distinct digital states; decoding means responsive to said binary counter for decoding each of the digital states attained by the binary counter, said decoding means having at most N individual outputs each of which activated in response to one and only one of the N states attained by the binary counter means; combining means responsive to the decoding means outputs and the second pulse generating means and having at most N combining means outputs activated by coincidence between the decoding means outputs and the second pulse generating means; a plurality of constant current sources responsive to the combining means outputs such that when a combining means output is activated the current source coupled thereto is placed in a conducting state causing a current to flow therefrom, each of the current sources including means for varying the current provided thereby; and output means for receiving and combining the current produced by the current sources and synthesizing therefrom the analog waveform approximation, the output means including integrating means for shaping the analog waveform approximation.

Claim 8

The variable waveform synthesizer of claim 5, wherein N equals 10.

Claim 9

The variable waveform synthesizer of claim 1, wherein the synthesizing means includes a plurality of current sources responsive to activation of each combining means output to place the current source coupled thereto in a current conducting state.