SU1767635A1 - Method of forming output signal in contact-free angle transducer - Google Patents

Abstract

Use: automatic control and monitoring systems. Summary of the invention: when forming the output signal in a non-contact angular position sensor, an alternating voltage is applied to one of the input stator windings and a constant voltage to another. As the rotor rotates, the output windings of the stator generate a signal about the frequency of rotation. 1 il. (Ls

Description

The invention relates to the design of elements and systems for automatic control and monitoring and, advantageously, can be used in the development of contactless information electric machines with a gear rotor without winding.

There is a method according to which when energizing alternating current is applied to two input windings, a rotating magnetic flux is created in the sensor magnetic circuit, which induces a signal in the output windings, based on the phase value of which relative to the reference signal the angular position of the rotor relative to the stator is determined. the output signal relative to the reference determines the rotational speed of the rotor. This method is implemented in 1. However, the method cannot be applied in the control, monitoring and electric drives, where the signal from the sensor about the angular position of the rotor relative to the stator and the frequency of rotation of the rotor must be represented as the amplitude of the EMF voltage.

There is another method, according to which a pulsed magnetic flux is created in the sensor magnetic circuit, which induces signals in the output windings. The signals are demodulated and the angular position of the rotor relative to the stator, and the speed of increase (decrease) of linear signals are determined by the moments of the passage of demodulated signals of zero values.

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About XI ABOUT

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the rising (falling) edges of the demodulated trapezoidal output signals determine the rotor rotation frequency. The method is implemented in 2. This method allows to obtain only discrete information about the angular position of the rotor relative to the stator, which limits its scope.

The closest in technical essence to the claimed should be considered a well-known method, which consists in the fact that when an alternating current voltage is applied to the excitation winding, a variable flux generated in the magnetic core of the sensor (pulsating with the mains frequency) induces a signal in the perpendicular output windings, amplitude one component of which is proportional to the sine and cosine of the angle of rotation of the rotor relative to the stator, and the amplitude of its second component (emf of rotation) arising during the rotation of the rotor, p oportsionalna rotational frequency of the rotor 3.

This method can be implemented, for example, in a sensor according to 5, containing, in addition to the excitation winding, a second winding whose axis coincides with the axis of the excitation winding or parallel to it. However, the amplitude of the component of the output signal generated by this method when the rotor rotates the sensor is very small, which limits the scope of application of the method and sensor.

The aim of the invention is to expand the field of application of the method and the angular position sensor by receiving at the output a signal about the rotor speed of the sensor,

For this purpose, a DC voltage is applied to the second input winding of the sensor.

The implementation of the method is considered by the example of the sensor operation in 5, two variants of the circuit diagram of which are shown in FIG.

When AC voltage is applied to the excitation winding B1, B2, the sensor, as in conventional reductosine, also generates an alternating, pulsating with the network frequency, magnetic flux, which in the output windings generates a signal about the angular position of the rotor. In this case, the signal of the two-phase output winding (C1, C2, K1, K2) at fixed positions of the rotor consists only of the transformer emf,

When applied to the excitation winding of the alternating current, and to the second OT, B4, the winding of the direct current voltage in the magnetic cores of the rotor and stator

there will be two magnetic fluxes, alternating and constant. When the rotor rotates due to the pulsation of a constant magnetic flux, a component forms in the output windings

signal (emf rotation) is proportional to the frequency of rotation of the rotor. Since the transformer component of the output signal has the frequency of the excitation voltage

current (mains frequency), and component - emf rotation has a frequency equal to the product of the rotor speed and the number of rotor teeth (the number of electrical reduction of the sensor), which is always significantly less than the network frequency, the separation of the components of the output signal is easily achieved using high and low filters.

By varying the values of the AC and DC voltages applied, it is possible to adjust the level of the components of the output signal of the transformer emf and emf. rotation depending on the conditions of use of the sensor in the object. When serving

same voltage only direct current

the rotor speed signal will

formed in the same way as in synchronous

a generator whose operation is described in 4,

According to the proposed method, the following values of the signal about the rotation frequency at a constant current of 200 mA in the input winding of the sensor were obtained on the sensor samples: the slope is 6 mV-min, the nonlinearity of the characteristic in a given

the frequency range of rotation is not more than 0.15%, the nonlinear distortion factor is about 1%.

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Claims (1)

Invention Formula A method of forming an output signal in a contactless angular position sensor comprising a stator with two input windings, one of which an alternating current voltage, two output windings and a non-winding rotor are supplied, characterized in that, in order to expand the field of application by obtaining a rotational frequency signal at the output, a direct voltage voltage is applied to the second stator input winding. 83Kf I l tis L 64 K2 , t eight -B2 CjUv4vvx C2 -HF1 g K2 / a) / i ;