Square to sine converter

Claim 1

An apparatus for converting a square wave signal to a sine wave signal having a predetermined fixed phase shift with respect to the square wave signal, the apparatus comprising: a. means responsive to the square wave signal for shifting the phase of the square wave signal an amount equal to the predetermined fixed phase shift; b. means having an input connected to the shifting means for generating the sine wave signal having the predetermined fixed phaSe shift with respect to the square wave signal; and c. means having inputs responsive to the shifting means and the generating means and an output connected to another input of the generating means for sampling the sine wave signal as a function of the square wave signal to produce a correction signal in response to any change in phase from the predetermined fixed phase shift between the inputs, whereby said correction signal causes the generating means to maintain the predetermined fixed phase shift between the sine wave signal and the square wave signal.

Claim 2

An apparatus for converting a square wave signal to a sine wave signal having a predetermined fixed phase shift with respect to the square wave signal, the apparatus comprising: a. means responsive to the square wave signal for shifting the phase of the square wave signal an amount equal to the predetermined fixed phase shift; b. means having an input connected to the shifting means for generating the sine wave signal having the predetermined fixed phaSe shift with respect to the square wave signal; and c. means having inputs responsive to the shifting means and the generating means and an output connected to another input of the generating means for sampling the sine wave signal as a function of the square wave signal to produce a correction signal in response to any change in phase from the predetermined fixed phase shift between the inputs, whereby said correction signal causes the generating means to maintain the predetermined fixed phase shift between the sine wave signal and the square wave signal.

Claim 3

An apparatus for converting a plurality of input square wave signals having predetermined phase differences therebetween to a plurality of output sine wave signals, said sine wave signals having phase differences therebetween corresponding to the phase differences between the input square wave signals, and further each sine wave signal having a predetermined fixed phase shift with respect to a corresponding input square wave signal, the apparatus comprising: a. a plurality of input circuits, each of said input circuits being responsive to an input square wave signal for shifting the phase of said input square wave signal an amount equal to the predetermined fixed phase shift; b. a plurality of sine wave generators, each of said sine wave generators having an input connected to one of the shifting means and generating an output sine wave signal having the predetermined fixed phase shift with respect to a corresponding input square wave signal; and c. a plurality of sample circuits, each of said sample circuits having inputs responsive to one of the input square wave signals and one of the output sine wave signals and an output connected to another input of a corresponding generating means and sampling the sine wave signal as a function of the input square wave signal to produce a correction signal in response to any deviation in phase from the predetermined fixed phase shift between the inputs whereby said correction signal causes the corresponding generating means to maintain said predetermined fixed phase shift between the one of the output sine wave signals and the one of the input square wave signals.

Claim 4

An apparatus for converting a plurality of input square wave signals having predetermined phase differences therebetween to a plurality of output sine wave signals, said sine wave signals having phase differences therebetween corresponding to the phase differences between the input square wave signals, and further each sine wave signal having a predetermined fixed phase shift with respect to a corresponding input square wave signal, the apparatus comprising: a. a plurality of input circuits, each of said input circuits being responsive to an input square wave signal for shifting the phase of said input square wave signal an amount equal to the predetermined fixed phase shift; b. a plurality of sine wave generators, each of said sine wave generators having an input connected to one of the shifting means and generating an output sine wave signal having the predetermined fixed phase shift with respect to a corresponding input square wave signal; and c. a plurality of sample circuits, each of said sample circuits having inputs responsive to one of the input square wave signals and one of the output sine wave signals and an output connected to another input of a corresponding generating means and sampling the sine wave signal as a function of the input square wave signal to produce a correction signal in response to any deviation in phase from the predetermined fixed phase shift between the inputs whereby said correction signal causes the corresponding generating means to maintain said predetermined fixed phase shift between the one of the output sine wave signals and the one of the input square wave signals.

Claim 6

An apparatus for converting a square wave signal to an output sine wave signal having a 90* phase shift with respect to said square wave signal, the apparatus comprising: a. means responsive to the square wave signal for shifting the phase of the square wave signal ninety degrees; b. means having an input responsive to the shifting means for generating the output sine wave signal ninety degrees out-of-phase with respect to the square wave signal; c. means responsive to the square wave signal and the output sine wave signal for sampling the output sine wave signal as a function of the square wave signal; and d. means responsive to the sampling means and having an output connected to another input of the generating means for producing a correction signal in response to any phase deviation from the 90 degree phase difference between the square wave signal and the output sine wave signal, whereby said correction signal causes the generating means to maintain the 90 degree difference between the square wave signal and the output sine wave signal.

Claim 7

An apparatus for converting a square wave signal to an output sine wave signal having a 90* phase shift with respect to said square wave signal, the apparatus comprising: a. means responsive to the square wave signal for shifting the phase of the square wave signal ninety degrees; b. means having an input responsive to the shifting means for generating the output sine wave signal ninety degrees out-of-phase with respect to the square wave signal; c. means responsive to the square wave signal and the output sine wave signal for sampling the output sine wave signal as a function of the square wave signal; and d. means responsive to the sampling means and having an output connected to another input of the generating means for producing a correction signal in response to any phase deviation from the 90 degree phase difference between the square wave signal and the output sine wave signal, whereby said correction signal causes the generating means to maintain the 90 degree difference between the square wave signal and the output sine wave signal.

Claim 9

An apparatus for converting an input square wave signal to an output sine wave signal 90* out-of-phase with respecT to said input square wave signal, the apparatus comprising: a. means responsive to the input square wave signal for shifting the phase of the input square wave signal 90*; b. means responsive to the shifting means for generating a sine wave signal 90* out-of-phase with respect to the input square wave signal; c. means connected to the generating means for providing the output sine wave signal; d. means having inputs responsive to the input square wave signal and the output sine wave signal for sampling the output sine wave signal as a function of the input square wave signal to produce a correction signal in response to any change in the ninety degrees phase difference between the inputs; e. means connected between the sampling means and the generating means for controlling the phase of the sine wave signal as a function of the correction signal.

Claim 10

An apparatus for converting an input square wave signal to an output sine wave signal 90* out-of-phase with respecT to said input square wave signal, the apparatus comprising: a. means responsive to the input square wave signal for shifting the phase of the input square wave signal 90*; b. means responsive to the shifting means for generating a sine wave signal 90* out-of-phase with respect to the input square wave signal; c. means connected to the generating means for providing the output sine wave signal; d. means having inputs responsive to the input square wave signal and the output sine wave signal for sampling the output sine wave signal as a function of the input square wave signal to produce a correction signal in response to any change in the ninety degrees phase difference between the inputs; e. means connected between the sampling means and the generating means for controlling the phase of the sine wave signal as a function of the correction signal.

Claim 11

An apparatus for converting an input square wave signal to an output sine wave signal ninety degrees out-of-phase with respect to the input square wave signal, the apparatus comprising: a means having first and second inputs for generating the output sine wave signal 90* out-of-phase with respect to the input square wave signal; b. means responsive to the input square wave signal and the output sine wave signal for maintaining the magnitude of the output sine wave signal approximately equal to the magnitude of a predetermined reference signal; c. means connected to the maintaining means and having an output connected to the first input of the generating means for shifting the phase of the input square wave signal 90*; and d. means having inputs responsive to the input square wave signal and the output sine wave signal and an output connected to the second input of the generating means for sampling the output sine wave signal as a function of the input square wave signal to produce a correction signal in response to any deviation from the 90* phase difference between the inputs, whereby said correction signal causes the generating means to maintain the sine wave signal ninety degrees out-of-phase with respect to the input square wave signal.

Claim 12

An apparatus for converting an input square wave signal to an output sine wave signal ninety degrees out-of-phase with respect to the input square wave signal, the apparatus comprising: a means having first and second inputs for generating the output sine wave signal 90* out-of-phase with respect to the input square wave signal; b. means responsive to the input square wave signal and the output sine wave signal for maintaining the magnitude of the output sine wave signal approximately equal to the magnitude of a predetermined reference signal; c. means connected to the maintaining means and having an output connected to the first input of the generating means for shifting the phase of the input square wave signal 90*; and d. means having inputs responsive to the input square wave signal and the output sine wave signal and an output connected to the second input of the generating means for sampling the output sine wave signal as a function of the input square wave signal to produce a correction signal in response to any deviation from the 90* phase difference between the inputs, whereby said correction signal causes the generating means to maintain the sine wave signal ninety degrees out-of-phase with respect to the input square wave signal.

Claim 14

An apparatus for converting an input square wave signal to an output sine wave signal 90* out-of-phase with respect to the input square wave signal, the apparatus comprising: a. a band pass filter responsive to the input square wave signal for generating a sine wave signal 90* out-of-phase with respect to the input square wave signal; b. an amplifier circuit connected to the band pass filter for producing an output sine wave signal 90* out-of-phase with respect to the input square wave signal; c. a peak sample circuit responsive to the input square wave signal and the output sine wave signal for sampling the peak magnitude of the output sine wave signal; d. a differential integrator responsive to the peak sample circuit and the input square wave signal for adjusting the magnitude of the input square wave signal to maintain the magnitude of the output sine wave signal at a predetermined reference magnitude; e. a filter network connected between the differential integrator and the band pass filter for producing a phase shifted signal 90* out-of-phase with respect to the input square wave signal; f. a half-wave sample circuit responsive to the input square wave signal and the output sine wave signal for sampling the output sine wave siGnal over one-half of a period of the input square wave signal; and g. an integrator connected to the half-wave sample circuit for producing a correction signal in response to any deviation from the 90* phase difference between the output sine wave signal and the input square wave signal; and h. a phase control connected between the integrator and the band pass filter for producing a control signal as a function of the correction signal, whereby said control signal causes the band pass filter to maintain the 90* phase difference between the output sine wave signal and the input square wave signal.

Claim 15

An apparatus for converting an input square wave signal to an output sine wave signal 90* out-of-phase with respect to the input square wave signal, the apparatus comprising: a. a band pass filter responsive to the input square wave signal for generating a sine wave signal 90* out-of-phase with respect to the input square wave signal; b. an amplifier circuit connected to the band pass filter for producing an output sine wave signal 90* out-of-phase with respect to the input square wave signal; c. a peak sample circuit responsive to the input square wave signal and the output sine wave signal for sampling the peak magnitude of the output sine wave signal; d. a differential integrator responsive to the peak sample circuit and the input square wave signal for adjusting the magnitude of the input square wave signal to maintain the magnitude of the output sine wave signal at a predetermined reference magnitude; e. a filter network connected between the differential integrator and the band pass filter for producing a phase shifted signal 90* out-of-phase with respect to the input square wave signal; f. a half-wave sample circuit responsive to the input square wave signal and the output sine wave signal for sampling the output sine wave siGnal over one-half of a period of the input square wave signal; and g. an integrator connected to the half-wave sample circuit for producing a correction signal in response to any deviation from the 90* phase difference between the output sine wave signal and the input square wave signal; and h. a phase control connected between the integrator and the band pass filter for producing a control signal as a function of the correction signal, whereby said control signal causes the band pass filter to maintain the 90* phase difference between the output sine wave signal and the input square wave signal.