Magnetic synchro angle resolver

Claim 2

Apparatus for extracting a sinusoidal component at a given frequency from a complex wave including a predominent submultiple component at one half said given frequency and components at harmonics of said given frequency, comprising: means presenting a signal equal to but out of phase with the submultiple component of said complex signal; a summing amplifier responsive to said complex signal and to said out of phase signal, for presenting a refined signal equivalent to said complex Signal with substantially all of said submultiple component removed; means presenting a reference signal at said given frequency; and balanced demodulator means responsive to said refined signal and said double frequency signal for presenting a third signal equivalent of said complex signal with all of said submultiple component removed, with all even harmonics removed, and with all odd harmonics deminished by amounts related to the harmonic order.

Claim 3

Apparatus for processing a pair of signals derived in a harmonic generating type of magnetic synchro generator and including components related to the position of the rotor thereof, comprising: means including a pair of respective balanced demodulators for extracting from said complex signal waveform signals comprising substantially only the second harmonic component thereof; and means for resolving said pair of signals to provide a signal manifestation indication of the rotary position of said rotor.

Claim 4

Apparatus for processing a pair of signals derived in a harmonic generating type of magnetic synchro generator and including components related to the position of the rotor thereof, comprising: means including a pair of respective balanced demodulators for extracting from said complex signal waveform signals comprising substantially only the second harmonic component thereof; and means for resolving said pair of signals to provide a signal manifestation indication of the rotary position of said rotor.

Claim 5

Apparatus for providing a signal manifestation of the angular position of a rotor of a second harmonic generating type of magnetic synchro which is driven by a source of alternating current line voltage, said synchro providing a pair of complex signal waveforms including components of line voltage, components at the second harmonic of line voltage, the phase relationship of which is a function of the rotary position of the rotor in said synchro, and components of higher ordered harmonics of said line voltage, comprising: inverter means responsive to the source of line voltage for developing a signal out of phase therewith; a pair of summing amplifiers connected to said inverter means and responsive to said pair of complex signals for subtracting substantially all of the line voltage components from said pair of complex signals; balanced demodulator means connected and responsive to said summing amplifiers for developing a pair of signals comprising essentially only the second harmonic and diminished amounts of odd higher ordered harmonics of said complex signals; filter means responsive to each of said balanced demodulator means for filtering the odd harmonic components from said complex wave.

Claim 6

Apparatus for providing a signal manifestation of the angular position of a rotor of a second harmonic generating type of magnetic synchro which is driven by a source of alternating current line voltage, said synchro providing a pair of complex signal waveforms including components of line voltage, components at the second harmonic of line voltage, the phase relationship of which is a function of the rotary position of the rotor in said synchro, and components of higher ordered harmonics of said line voltage, comprising: inverter means responsive to the source of line voltage for developing a signal out of phase therewith; a pair of summing amplifiers connected to said inverter means and responsive to said pair of complex signals for subtracting substantially all of the line voltage components from said pair of complex signals; balanced demodulator means connected and responsive to said summing amplifiers for developing a pair of signals comprising essentially only the second harmonic and diminished amounts of odd higher ordered harmonics of said complex signals; filter means responsive to each of said balanced demodulator means for filtering the odd harmonic components from said complex wave.

Claim 7

Apparatus according to claim 3 further comprising: means responsive to said filter means for developing signals which are the function of the sum and the difference of said filtered complex waveforms; means developing a signal indicative of the magnitude of said sum signal exceeding the magnitude of said difference signal; an A to D converter having a signal input and a reference input for providing a digital manifestation of the ratio of the magnitude of a signal at said signal input to the magnitude of a signal at said reference input; and means responsive to said relative magnitude signal for passing said sum and difference signals to the reference and signal inputs of said A to D converter, respectively, and for passing said sum and difference signals to said signal and reference inputs of said A to D converter, respectively in response to the absence of said relative magnitude signal.

Claim 8

Apparatus according to claim 4 further comprising: means developing a signal indicative of the sign of said sum signal and a signal indicative of the sign of the difference signal, said sign signal, said magnitude signal and the output of said A to D converter comprising a signal manifestation of the angular position of said rotor.

Claim 9

Apparatus for determining a phase angle from a pair of signals which comprise bipolar quadrature related functions of said angle, comprising: means responsive to the absolute value of the magnitude of said two signals for developing a cross signal in response to a first one of said function signals having an absolute magnitude greater than the second one of said function signals; an analog to digital converter having a signal input and a reference input, said analog to digital converter providing a digital manifeStation of the ratio of the magnitude of a signal applied to said signal input to the magnitude of a signal applied to said reference input; nd means responsive to said first signal to connect said first signal to said signal input of said A to D converter and said second signal to said reference input of said A to D converter, and responsive in the absence of said one signal for connecting said first signal to the reference input of said A to D converter and said second signal to the signal input to said A to D converter.

Claim 10

Apparatus for determining a phase angle from a pair of signals which comprise bipolar quadrature related functions of said angle, comprising: means responsive to the absolute value of the magnitude of said two signals for developing a cross signal in response to a first one of said function signals having an absolute magnitude greater than the second one of said function signals; an analog to digital converter having a signal input and a reference input, said analog to digital converter providing a digital manifeStation of the ratio of the magnitude of a signal applied to said signal input to the magnitude of a signal applied to said reference input; nd means responsive to said first signal to connect said first signal to said signal input of said A to D converter and said second signal to said reference input of said A to D converter, and responsive in the absence of said one signal for connecting said first signal to the reference input of said A to D converter and said second signal to the signal input to said A to D converter.

Claim 11

Apparatus in accordance with claim 5 additionally comprising: means responsive to each of said first and second signals for generating a related sign signal dependent on the instantaneous sign thereof, said cross signal, said sign signals and the output of said A to D converter comprising a signal manifestation of said phase angle.

Claim 12

Apparatus for developing a signal manifestation of an angle, theta , from a pair of signals A, B developed from a magnetic synchro driven by a source of line voltage of amplitude V sinusoidally varying at a rate w said signals A, B being represented as A 2/3 V sin wt + E sin ( theta -120) sin 2 wt + (higher harmonics) B 1/3 V sin wt + E sin ( theta -60) sin 2 wt + (higher harmonics) where E equals the peak voltage of the second harmonic of the line voltage, said apparatus comprising: first means responsive to said signals A, B and to the source of line voltage to remove substantially all of the line voltage component from said signals A, B to develop a pair of respectively relating signals C and D as C E sin ( theta -120) sin 2 wt + (residual wt and harmonics) D E sin ( theta -60) sin 2 wt + (residual wt and harmonics); second means responsive to the line voltage source and to said first means for synchronously rectifying said signals C and D at twice the line frequency so as to develop a pair of related signals F, G as follows F E sin ( theta -120) + (odd harmonics) G E sin ( theta -60) + (odd harmonics); third means responsive to said second means for taking the weighted sum and the difference of said signals F and G so as to develop a pair of respective signals H and J as H F+G/ Square Root 3 - E cos theta J F-G - E sin theta ; fourth means responsive to said third means for developing a signal X when in response to H being negative, a signal Y in response to J being negative, and a signal Z in response to J being greater in absolute magnitude than H; and fifth means including an analog to digital converter having a signal input and a reference input for developing a digital word manifestation of the ratio of the magnitude of a signal on the signal input to the magnitude of the signal on the reference input, said means including means for applying the absolute value of said signal H to said reference input and the absolute magnitude of said signal J to said signal input in response to the presence of said signal Z, and applying said signals H and J conversely to said signal and reference inputs, respectively, in response to the absence of said signal Z, the output manifestation of said analog to digital converter comprising the low order portion and said signals X, Y and Z comprising the respectively highest ordered portions of a digital output word signal manifestation of said angle theta .

Claim 13

Apparatus for developing a signal manifestation of an angle, theta , from a pair of signals A, B developed from a magnetic synchro driven by a source of line voltage of amplitude V sinusoidally varying at a rate w said signals A, B being represented as A 2/3 V sin wt + E sin ( theta -120) sin 2 wt + (higher harmonics) B 1/3 V sin wt + E sin ( theta -60) sin 2 wt + (higher harmonics) where E equals the peak voltage of the second harmonic of the line voltage, said apparatus comprising: first means responsive to said signals A, B and to the source of line voltage to remove substantially all of the line voltage component from said signals A, B to develop a pair of respectively relating signals C and D as C E sin ( theta -120) sin 2 wt + (residual wt and harmonics) D E sin ( theta -60) sin 2 wt + (residual wt and harmonics); second means responsive to the line voltage source and to said first means for synchronously rectifying said signals C and D at twice the line frequency so as to develop a pair of related signals F, G as follows F E sin ( theta -120) + (odd harmonics) G E sin ( theta -60) + (odd harmonics); third means responsive to said second means for taking the weighted sum and the difference of said signals F and G so as to develop a pair of respective signals H and J as H F+G/ Square Root 3 - E cos theta J F-G - E sin theta ; fourth means responsive to said third means for developing a signal X when in response to H being negative, a signal Y in response to J being negative, and a signal Z in response to J being greater in absolute magnitude than H; and fifth means including an analog to digital converter having a signal input and a reference input for developing a digital word manifestation of the ratio of the magnitude of a signal on the signal input to the magnitude of the signal on the reference input, said means including means for applying the absolute value of said signal H to said reference input and the absolute magnitude of said signal J to said signal input in response to the presence of said signal Z, and applying said signals H and J conversely to said signal and reference inputs, respectively, in response to the absence of said signal Z, the output manifestation of said analog to digital converter comprising the low order portion and said signals X, Y and Z comprising the respectively highest ordered portions of a digital output word signal manifestation of said angle theta .