Quadrature electronic tachometer

Claim 2

An electronic tachometer for generating a continuous output velocity signal comprising: generating means for generating two continuous and periodic quadrature signals, the slopes of each of said quadrature signals during each cycle containing the intelligence as to the value of the velocity being measured, said two quadrature signals being 90* out of phase with respect to each other; timing means connected to said generating means for generating a plurality of timing signals from said two quadrature signals to control the timing of the electronic tachometer; processing means for generating a plurality of velocity signals from said two quadrature signals and for generating a plurality of comparision signals, said comparison signals being indicative of the relative size between selected ones of said velocity signals; selection means connected to said timing means and said processing means for generating a plurality of selection signals from said comparison signals and timing signals; and combination means for selecting specific portions of each of said velocity signals by gating said velocity signals by said selection signals, said gated portions of said velocity signals being combined to form a continuous output velocity signal.

Claim 3

The electronic tachometer set forth in claim 1 wherein said processing means further comprises a plurality of differentiating means for generating said velocity signals from said quadrature signals.

Claim 4

The electronic tachometer of claim 2 wherein said processing means further comprises a compensating means for each differentiating means for increasing the effective rise time of each said differentiating means.

Claim 5

The electronic tachometer as set forth in claim 3 wherein said compensating means is connected to said timing means for controlling when said compensating means is to provide compensation to said differentiating means.

Claim 6

The electronic tachometer of claim 4 wherein said compensating means provides the compensation for each differentiating means by inputting selective portions of the generated velocity signals from other differentiating means to the differentiating means being compensated.

Claim 7

The electronic tachometer of claim 5 wherein said gating means in said combination means is a field effect transistor.

Claim 8

The electronic tachometer as set forth in claim 1 wherein said gating means in said combination means is a field effect transistor.

Claim 9

The electronic tachometer as set forth in claim 1 further comprisIng an automatic gain control circuit connected to said generating means for generating an automatic gain controlled signal from said two quadrature signals.

Claim 10

The electronic tachometer as set forth in claim 3 further comprising an automatic gain control circuit connected to said generating means for generating an automatic gain controlled signal from said two quadrature signals.

Claim 11

The electronic tachometer as set forth in claim 5 further comprising an automatic gain control circuit connected to said generating means for generating an automatic gain control signal from said two quadrature signals.

Claim 12

The electronic tachometer as set forth in claim 6 further comprising an automatic gain control circuit connected to said generating means for generating an automatic gain control signal from said two quadrature signals.

Claim 13

The electronic tachometer as set forth in claim 7 further comrpising an automatic gain control circuit connected to said generating means for generating an automatic gain control signal from said two quadrature signals.

Claim 14

An electronic tachometer for generating a continuous output velocity signal comprising: generating means for generating two continuous and periodic quadrature signals A and B, the slope of each of said quadrature signals during each cycle containing the intelligence as to the value of the velocity being measured, said two quadrature signals being 90* out of phase with each other; timing means connected to said generating means for receiving quadrature signals A and B and for generating from quadrature signals A and B four quadrature timing signals Q1, Q2, Q3 and Q4, each of said quadrature timing signals representing 90* of the 360* period of said quadrature signals A and B, processing means comprising: differentiating means for generating four velocity signals dA, dA, dB and dB from said quadrature signals A and B, comparison means for generating comparison signal C1 whenever velocity dB is equal to or greater than dA, for generating comparison signal C2 whenever dA is equal to or greater than dB, for generating comparison signal C3 whenever dB is equal to or greater than dA and for generating comparison signal C4 whenever velocity signal dA is equal to or greater than velocity signal dB; selection means connected to said timing means and said processing means for receiving quadrature timing signals Q1, Q2, Q3 and Q4 and comparison signals C1, C2, C3 and C4 and for generating selection signals L1, L2, L3 and L4 from said received signals, where output signal L1 is initiated upon the coincidence of quadrature timing signal Q1 and comparison signal C1 and terminates upon the occurrence of signal L2, where output signal L2 initiates upon the coincidence of quadrature timing signal Q2 and comparison signal C2 and terminates upon the occurrence of output L3, where output signal L3 initiates at the coincidence of quadrature timing signal Q3 and comparison signal C3 and terminates upon the initiation of output signal L4, and finally where output signal L4 initiates at the coincident of quadrature timing signal Q4 and comparator signal C4 and terminates upon the occurrence of output signal L1, combination means connected to said selection means for receiving output signals L1, L2, L3 and L4 for selectively gating velocity signals dB, dA, and dA to form said desired output velocity signal, where output signal L1 selects the portion of velocity signal dB to be used for the output velocity signal, where output signal L2 controls the portion of velocity signal dA to be used in the output velocity signal, where L3 is used to select the portion of velocity signal dB to be used in the output velocity signal and where output signal L4 is used to select a portion of velocity signal dA to be used in the output velocity signal, the continuous outpuT velocity signals being the selected portions of velocity signals dB, dA, dB and dA.

Claim 15

An electronic tachometer for generating a continuous output velocity signal comprising: generating means for generating two continuous and periodic quadrature signals A and B, the slope of each of said quadrature signals during each cycle containing the intelligence as to the value of the velocity being measured, said two quadrature signals being 90* out of phase with each other; timing means connected to said generating means for receiving quadrature signals A and B and for generating from quadrature signals A and B four quadrature timing signals Q1, Q2, Q3 and Q4, each of said quadrature timing signals representing 90* of the 360* period of said quadrature signals A and B, processing means comprising: differentiating means for generating four velocity signals dA, dA, dB and dB from said quadrature signals A and B, comparison means for generating comparison signal C1 whenever velocity dB is equal to or greater than dA, for generating comparison signal C2 whenever dA is equal to or greater than dB, for generating comparison signal C3 whenever dB is equal to or greater than dA and for generating comparison signal C4 whenever velocity signal dA is equal to or greater than velocity signal dB; selection means connected to said timing means and said processing means for receiving quadrature timing signals Q1, Q2, Q3 and Q4 and comparison signals C1, C2, C3 and C4 and for generating selection signals L1, L2, L3 and L4 from said received signals, where output signal L1 is initiated upon the coincidence of quadrature timing signal Q1 and comparison signal C1 and terminates upon the occurrence of signal L2, where output signal L2 initiates upon the coincidence of quadrature timing signal Q2 and comparison signal C2 and terminates upon the occurrence of output L3, where output signal L3 initiates at the coincidence of quadrature timing signal Q3 and comparison signal C3 and terminates upon the initiation of output signal L4, and finally where output signal L4 initiates at the coincident of quadrature timing signal Q4 and comparator signal C4 and terminates upon the occurrence of output signal L1, combination means connected to said selection means for receiving output signals L1, L2, L3 and L4 for selectively gating velocity signals dB, dA, and dA to form said desired output velocity signal, where output signal L1 selects the portion of velocity signal dB to be used for the output velocity signal, where output signal L2 controls the portion of velocity signal dA to be used in the output velocity signal, where L3 is used to select the portion of velocity signal dB to be used in the output velocity signal and where output signal L4 is used to select a portion of velocity signal dA to be used in the output velocity signal, the continuous outpuT velocity signals being the selected portions of velocity signals dB, dA, dB and dA.

Claim 16

The electronic tachometer as set forth in claim 13 wherein the combination means employ field effect transistors whose gate is controlled by output signals L1, L2, L3 and L4 to select the portions of velocity signals dB, dA, dB and dA to form the output velocity signal of the electronic tachometer.

Claim 17

The electronic tachometer as set forth in claim 13 wherein said timing means further generate two compensating timing signals IA and IB from said two quadrature signals A and B; and said processing means is connected to said timing means to receive two compensating timing signals, IA and IB, said compensating timing signals IA and IB condidtioning gating means for selecting specific portions of each of said velocity signals dA, dB, dA and dB, said selected portions of said velocity signals dA, dB, dA and dB being connected to said differentiating means for improving the effective rise time of the generated velocity signals dA, dB, dA and dB so as to improve the effective high frequency of said differentiating means.

Claim 18

The electronic tachometer as set forth in claim 13 wherein the electronic tachometer further comprises; automatic gain control means connected to said generating means for receiving said quadrature signals A and B, absolute value detector and compensating means for obtaining the instantaneous absolute value of quadrature signals A and B, said absolute value and compensating means further introducing the non-linearities into the absolute value generated for quadrature signals A and B by introducing non-linearities into the absolute values for quadrature signals A and B as the absolute values of A and B approach a zero value, said non-linearities introduced being equal to the non-linearities existing in the absolute values generated for each quadrature signal A and B about each peak value of absolute value A and B such that the absolute value signals A and B when added together would produce a signal equal to a constant; summation means for adding the absolute values generated by absolute value detector and compensator for quadrature input signals A and B and for substracting that summation from a reference voltage to produce an automatic gain control error signal which is used to sense variations in the amplitude of the generated quadrature signals A and B from a designed specified value.

Claim 19

The electronic tachometer as set forth in claim 14 wherein the electronic tachometer further comprises: automatic gain control means connected to said generating means for receiving said quadrature signals A and B, amplitude value detector and compensating means for obtaining the instantaneous absolute value of quadrature signals A and B, said absolute value and compensating means further introducing the non-linearities into the absolute value generated for quadrature signals A and B by introducing non-linearities into the absolute values for quadrature singals A and B as the absolute values of A and B approach a zero value, said non-linearities introduced being equal to the non-linearities existing in the absolute values generated for each quadrature signal A and B about each peak value of absolute value A and B such that the absolute value signals A and B when added together would produce a signal equal to a constant; summation means for adding the absolute values generated by absolute value detector and compensator for quadrature input signals A and B and for subtracting that summation from a reference voltage to produce an automatic gain control error signal which is used to sense variations in the amplitude of the generated quadrature signals A and B from a designed specified value.