RU2307453C1 - Method for selective phase-sensitive demodulation of signal of induction angle indicator and device for realization of said method - Google Patents

Abstract

FIELD: electronic engineering, possible use for transformation of voltage from alternating to constant.

SUBSTANCE: during realization of method of sensitive phase-sensitive demodulation of signal of induction angle indicator, capacitor is charged by if signal of angle indicator during passage of spike value by the signal. Angle indicator is powered by sinusoidal voltage, received from external impulse signal, from which a net of frequencies is received. By addition of frequencies, time interval is created, during which capacitor is charged. Device for realization of method contains capacitor (8), buffer (9), quartz generator (10) of impulses, binary counter (11), generator (12) of sinusoidal voltage, induction indicator (13) of angle, circuit 5AND-NOT (14), analog key (15).

EFFECT: increased precision and interference resistance, ensured change of signal phase.

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Description

The invention relates to the field of electronic technology and can be used to convert AC voltage to DC.

A known method of signal demodulation, implemented in the device described in [1], which consists in charging a capacitor through a diode.

The disadvantage of this method and the implementing device is its low accuracy and noise immunity.

Closest to the claimed is the method implemented in the device described in [2], which consists in charging a capacitor through a diode with subsequent buffering.

The disadvantage of this method is its low noise immunity and the fact that this method does not allow you to feel the phase of the signal.

Closest to the claimed device is a demodulator [2], containing the input and output buffer stages, two diodes, a capacitor.

The disadvantage of this device is that it does not have phase sensitivity and has low noise immunity.

The tasks to which the present invention is directed are obtaining phase-sensitive demodulation, increasing accuracy and noise immunity.

The objectives are achieved by the fact that in the method of selective phase-sensitive demodulation of the signal of the inductive angle sensor, which consists in charging the capacitor, according to the invention, the capacitor is charged with the information signal of the induction angle sensor at the moment when this signal passes its peak value, and the induction angle sensor is fed with a sinusoidal voltage, which is obtained from external pulse signal, from it the grid of frequencies is obtained and by adding the frequencies form the time interval during which they charge the capacitor.

According to the invention, a quartz pulse generator, a binary counter, an induction angle sensor, a sinusoidal voltage generator, a 5I-NOT circuit, an analog key, the control input of which is connected to the output of the circuit, are additionally introduced into the device for selective phase-sensitive demodulation of the signal of the induction angle sensor, containing a capacitor, a buffer, according to the invention 5 AND NOT, the inputs of which are connected to the outputs of the binary counter, the input of which is connected to the output of the quartz pulse generator, the input of the analog key is connected to the signal a coil of an induction angle sensor, the field winding of which is connected to the output of a sinusoidal voltage generator, the input of which is connected to the high-order output of a binary counter, the output of the analog key is connected to one output of the capacitor and the input of the buffer, the output of which is the output of the device, the other output of the capacitor is connected to a common wire .

Significant differences of the proposed method include the fact that the capacitor is charged with the information signal of the induction angle sensor at the moment when this signal passes its peak value, and the induction angle sensor is fed with a sinusoidal voltage, which is obtained from an external pulse signal, and a frequency grid is obtained from it by adding frequencies form a time interval during which the capacitor is charged. With this method of demodulation, the capacitor charge time interval is formed in phase with a sinusoidal voltage when the information signal reaches its peak value, which increases the accuracy and noise immunity of demodulation and provides sensitivity to a change in the phase of the information signal.

Significant differences of the device include the introduction of a binary counter, to the outputs of which a 5I-NOT circuit is connected, which generates pulses by which an analog switch is opened, through which the capacitor is charged with the information signal of the induction angle sensor, which is powered by a sinusoidal voltage generator. Pulses from a quartz oscillator are supplied to the counting input of the binary counter, and pulses from the output of the highest level of the counter are fed to the input of a sinusoidal voltage generator.

This inclusion allows you to open the analog key with a pulse, the phase of which is connected with the phase of the sinusoidal voltage supplying the induction sensor at the moment the information signal reaches its peak value, when the main component of the noise, the quadrature component, is zero, which allows determining the phase of the information signal, increasing the accuracy and noise immunity of demodulation .

The invention is illustrated by drawings. Figure 1 presents a structural diagram explaining the method, figure 2 is a diagram of a device for implementing the method, figure 3 and 4 are timing diagrams explaining the method and device, respectively.

In Fig. 1, an external pulse signal is supplied to the inputs of a sinusoidal signal former 2 and a frequency grid former 3, the outputs of which are connected to the inputs of a frequency addition circuit 4, the output of which is connected to the control input of the time imager 5. Shaper 2 of the sinusoidal voltage is connected to the inductive sensor 6 of the angle, the information output of which is connected to the input of the shaper 5 of the time interval, the output of which is connected to one output of the capacitor 1 and the input of the buffer 7, from the output of which the output signal is taken. The other terminal of the capacitor 1 is connected to a common wire.

The method of selective phase-sensitive demodulation of the signal of the induction angle sensor is as follows.

An external pulse signal (Fig. 3a) is supplied to the input of the sinusoidal voltage generator 2, at the output of which a sinusoidal voltage is generated (Fig. 3b), which feeds the induction angle sensor 6. The same external pulse signal is also fed to the input of the frequency shaper 3, to the outputs of which a frequency addition circuit 4 is connected, at the output of which pulses are generated (Fig.3c), which coincide with the peak value of the sinusoidal voltage (Fig.3b). These pulses are controlled by the shaper 5 of the time interval through which the capacitor 1 is charged with the information signal of the angle induction sensor 6 at the moment it passes its peak value.

When the in-phase value of the information signal of the angle sensor 6 with the output sinusoidal voltage of the driver 2 (Fig. 3e), the voltage across the capacitor 1 will be positive (Fig. 3d), with antiphase - negative (Fig. 3g). A quadrature component is present in the information signal of the induction angle sensor, which has a zero level at the moment the information signal passes the peak value (Fig.3z), therefore, the demodulated value of the quadrature component will also have a zero value, therefore, the proposed method has selectivity and has increased noise immunity. The output voltage from the capacitor 1 is removed through the buffer 7 to exclude the influence of the load.

The device shown in FIG. 2 contains a capacitor 8, a buffer 9, a quartz pulse generator 10, a binary counter 11, a sinusoidal voltage generator 12, an angle induction sensor 13, a 5I-NOT circuit 14, an analog key 15.

A capacitor 8 is connected between the input of the buffer 9 and the common wire, the output of the quartz pulse generator 10 is connected to the input of the binary counter 11, the outputs of which are connected to the inputs of the 5I-NOT circuit 14, the output of which is connected to the control input of the analog switch 15 connected between the signal coil of the induction sensor 13 of the angle and capacitor 8. The input of the sinusoidal voltage generator 12 is connected to the high-order output of the binary counter 11, and the output of the generator 12 is connected to the excitation winding of the angle sensor 13. The output of the buffer 9 is the output of the device.

The device operates as follows.

From the output of the crystal oscillator 10 (Fig. 4a), rectangular pulses are fed to the input of the binary counter 11, at the outputs of which sequences of rectangular pulses (Fig. 4b ... e) are generated, which are fed to the inputs of the 5I-NOT circuit 14, at the output of which pulses (Fig.4zh), and are fed to the control input of the analog switch 15.

From the output of the high-order bit of the binary counter 11, a sequence of rectangular pulses (Fig. 4e) is supplied to the input of a sinusoidal voltage generator 12, at the output of which a sinusoidal voltage is generated (Fig. 4h), the period of which coincides with the period of the input pulse sequence. This sinusoidal voltage feeds the excitation coil of the inductive angle sensor 13, at the output of which an informational sinusoidal voltage is also formed, the amplitude of which is proportional to the angle of rotation of the moving part of the sensor 13, and it can be either in-phase (Fig. 4i) or out of phase (Fig. 4k) relative to the supply voltage, depending on the direction of the rotation angle of the movable part of the angle sensor 13. Since the output pulses of the circuit 14 5I-NOT coincide with the peak values of the information sinusoidal voltage (Fig.4g), they open the analog switch 15 and the capacitor 8 is charged with the peak value of the signal. The time during which the capacitor 8 is charged is formed by the 5I-NOT circuit 14 from the output pulses of the binary counter 11. In the in-phase state of the information and supply voltages (Fig.4z), the output voltage will be positive (Fig.4l), and in antiphase (Fig. 4k) - negative (Fig. 4m). As a rule, the second harmonic or quadrature component is present in the information signal of the induction angle sensor (Fig. 4n), which has a zero value at the moment of formation of the pulse that opens the analog key 15 (Fig. 4g), therefore the proportion of the quadrature component in the demodulated useful signal is insignificant . This ensures the selectivity and noise immunity of the demodulator.

To exclude the influence of the load on the charge of the capacitor 8, a buffer 9 is included between the capacitor 8 and the output of the device.

The proposed method of phase-sensitive demodulation of the induction angle sensor and a device for its implementation were used in the stabilization system of the gyroscopic platform.

Information sources

1. P. Horwitz, W. Hill. The art of circuitry, M. "Mir", 1983, v.1, p.203, Fig.3.35.

2. A.G. Aleksenko, E.A. Kolambet, G.I. Starodub. The use of precision analog microcircuits. M. "Radio communication", 1985, p. 200, fig.5.14a (prototype).

Claims (2)

1. The method of selective phase-sensitive demodulation of the signal of the induction angle sensor, which consists in charging the capacitor, characterized in that the capacitor is charged with the information signal of the induction angle sensor at the moment when this signal passes its peak value, and the induction angle sensor is fed with a sinusoidal voltage, which is obtained from an external pulse signal , a grid of frequencies is obtained from it, and by adding the frequencies, an interval of time is formed during which the capacitor is charged. 2. Device for selective phase-sensitive demodulation of the signal of the induction angle sensor, containing a capacitor, a buffer, characterized in that it is additionally equipped with a quartz pulse generator, a binary counter, an induction angle sensor, a sinusoidal voltage generator, 5I-NOT circuit, an analog key, a control input which is connected to the output of the 5I-NOT circuit, the inputs of which are connected to the outputs of the binary counter, the input of which is connected to the output of the quartz pulse generator, the input of the analog key is connected to the signal the winding of the induction angle sensor, the field winding of which is connected to the output of the sinusoidal voltage generator, the input of which is connected to the high-order output of the binary counter, the output of the analog key is connected to one output of the capacitor and the input of the buffer, the output of which is the output of the device, the other output of the capacitor is connected to the common to the wire.

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