RU212274U1 - PHASE-SENSITIVE AC TO DC VOLTAGE CONVERTER - Google Patents

Abstract

The utility model relates to electrical measuring technology and automation and can be used for phase-sensitive measurement and conversion of AC to DC signals in feedback circuits of servo systems, in phase-locked loop devices and phase-sensitive rectification circuits. The device contains an inverter, a controlled phase shifter, a comparator, a frequency-voltage converter, a single vibrator, an integrator with reset, an adder and a driving signal source, the output of the comparator is connected to the input of the frequency-voltage converter, the output of which is connected to the input of the integrator with reset, the output of the driving signal source connected to the second input of the adder, the output of which is connected to the control input of the controlled phase shifter, the output of which is connected to the output of the measuring transducer, the reference voltage input is connected to the input of the comparator, the output of which is connected to the reset input of the integrator with reset, the output of which is connected to the first input of the adder, and the input of the measuring transducer is connected through an inverter to the input of the controlled phase shifter. The technical result of the claimed utility model is to expand the functionality of the measuring transducer by providing phase sensitivity. 3 ill.

Description

The utility model relates to electrical measuring technology and automation and can be used for phase-sensitive measurement and conversion of AC to DC signals in feedback circuits of servo systems, in phase-locked loop devices and phase-sensitive rectification circuits.

Known measuring converter AC to DC [Patent for PM No. 163230 RF, IPC G01R 19/22, publ. 07/10/2016], containing a phase shifter, the first and second quadrators, an adder and a square root extraction unit, the converter input is connected to the inputs of the first quadrator and the phase shifter, the output of which is connected to the input of the second quadrator, and the outputs of the first and second quadrators are connected respectively to the first and second inputs of the summing device, the output of which is connected to the output of the converter through the square root extraction unit.

The disadvantage of this converter is that, along with high speed and accuracy, its scope is limited only to measuring power frequency voltage, since the phase mixer provides a phase shift of 90 ° only at this frequency. At other frequencies, the converter does not perform its function, since its output voltage will have a significant variable component, commensurate with the constant.

The closest analogue to the proposed utility model is an AC-to-DC measuring converter [Patent for PM No. 168459 RF, IPC G01R 19/22, publ. February 3, 2017], containing two quadrators, a differentiator, a division unit, an adder, a square root extraction unit, a comparator and a frequency-voltage converter, the input of the measuring transducer is connected to the input of the first quadrator, and the outputs of the first and second quadrators are connected, respectively, to the first and to the second inputs of the adder, the output of which is connected to the output of the measuring transducer through the square root extraction unit, a differentiator, a dividing unit, a comparator and a frequency-voltage converter are additionally introduced, the input of which is connected to the output of the comparator, the input of which is connected to the input of the measuring transducer and the input of the differentiator, the output of which is connected to the first input of the division block, the output of which is connected to the input of the second quadrator, and the output of the frequency-voltage converter is connected to the second input of the division block.

This technical solution was chosen as a prototype.

The disadvantage of this converter is that the device is not sensitive to changes in the phase of the input voltage.

The technical result of the claimed utility model is to expand the functionality of the measuring transducer by providing phase sensitivity.

The specified technical result is achieved by the fact that in a known measuring AC-to-DC voltage converter, containing a comparator, a frequency-voltage converter and an adder, and the output of the comparator is connected to the input of the frequency-voltage converter, an inverter, a controlled phase shifter, a single vibrator, an integrator with reset and driving signal source, the output of which is connected to the second input of the adder, the output of which is connected to the control input of the controlled phase shifter, the output of which is connected to the output of the measuring transducer, and the synchronization input is connected to the input of the comparator, the output of which is connected to the reset input of the integrator with reset, the output of which is connected with the first input of the adder, the output of the frequency-voltage converter is connected to the input of the integrator with reset, and the input of the measuring transducer is connected through the inverter to the input of the controlled phase shifter.

The essential differences of the proposed phase-sensitive measuring transducer are the introduction of an inverter, a controlled phase shifter, a single vibrator, an integrator with a reset and a driving signal source, as well as the organization of new connections between the elements of the device. The combination of elements and connections between them ensure the achievement of a positive effect - expanding the functionality of the measuring transducer by providing phase sensitivity.

The essence of the utility model is illustrated by drawings. In FIG. 1 shows a functional diagram of a phase-sensitive measuring transducer; in fig. 2 - time diagrams of voltages u _in , u ₁ , u _op , u ₂ , u ₄ , u ₅ , u ₇ and U _out ; figure 3 - phase characteristic of the converter

The phase-sensitive measuring transducer (Fig. 1) contains an inverter 1, a controlled phase shifter 2, a comparator 3, a frequency-voltage converter 4, a single vibrator 5, a reset integrator 6, an adder 7, and a driving signal source 8.

Phase-sensitive measuring transducer works as follows. The input sinusoidal voltage u _in =U _{m in} sin(ωt+Ψ _in ) with a frequency ω=2πƒ is fed to the input of the measuring transducer. At the same time, the input of the comparator 3 is supplied with a reference sinusoidal voltage u _op =U _{m op} sinωt with the same frequency ω=2πƒ. The inverter 1 shifts the phase of the input voltage _u in 180°, so that the voltage u _in and u ₁ are in antiphase (Fig. 2). Voltage u ₁ is applied to the input of the controlled phase shifter 2:

u ₁ \u003d U _{m in} sin ( _ωt + Ψ in + 180 °),

where U _{m in} - the amplitude of the input voltage u _in ;

_{Ψ in} - initial phase of the input voltage u _in .

The comparator 3 converts the sinusoidal reference voltage u _op into a rectangular voltage u ₂ (Fig. 2), which is fed to the inputs of the frequency-voltage converter 4 and the single vibrator 5.

On the fronts of the voltage pulses u ₂ , a single vibrator 5 is launched and narrow pulses u _{4 of} a fixed duration with a frequency ω are formed at its output, which are fed to the reset input of the integrator with reset 6. At the same time, the frequency-voltage converter 4 converts the frequency of these pulses into a constant voltage U ₃ positive polarity value:

where K _pchn - the transfer coefficient of the converter frequency-voltage 4;

ƒ - input voltage frequency;

ƒ _max - maximum operating frequency of the input voltage of the converter.

In this case, the value of _Kpn is selected from the condition for obtaining the maximum output voltage U ₃ \u003d 10 V at ƒ _max , i.e. K _pn =10/ƒ _max .

The output voltage U ₃ of the frequency-voltage converter 4 is fed to the input of the integrator with reset 6.

At the output of the integrator with reset 6, a sawtooth voltage u _{5 of} negative polarity is formed with a frequency ƒ of the input voltage of the converter, the amplitude of which is determined by the formula:

where U _5m - the amplitude of the output voltage of the integrator with reset 6;

T - input voltage period u _in ;

ƒ - input voltage frequency u _in ;

R is the resistance of the integrator resistor with reset 6;

C - capacitance of the integrator capacitor with reset 6.

Thus, when choosing the integration constant RC of the integrator with reset 6 equal to RC=1/ƒ _max , the amplitude of its output voltage does not depend on the frequency of the reference voltage u _op in the entire operating frequency range.

The output voltage u _{5 of} the integrator with reset 6 is added in the adder 7 with the bias voltage u ₆ =U _cm =5 V from the source of the driving signal 8, as a result of which an alternating sawtooth voltage u ₇ with an amplitude of 5 V is formed at the output of the adder 7. This voltage is applied to control input of controlled phase shifter 2.

Controlled phase shifter 2 allows you to linearly change the phase cp of the input signal from -180° to +180° when changing the control voltage from -5 V to +5 V (Fig. 2). This sawtooth control voltage, acting on the controlled phase shifter 2, changes the phase ϕ of its input signal from -180° to +180° with a frequency ƒ of the input voltage u _in (Fig. 2).

As a result, the output voltage u _out is formed at the output of the controlled phase shifter 2 and at the output of the measuring transducer:

u _out =U _{m in} sin( _ωt +Ψ in +180°+ϕ)=U _{m in} sin{( _ωt +Ψ in +180°+(180°-ωt)}=

\ _{u003d U m in} sin (Ψ _in ).

It can be seen from the obtained expression that the value of the output voltage u _out of the measuring transducer depends on the amplitude of the input voltage U _{m in} and on its initial phase _{Ψ in} , that is, the circuit has phase sensitivity. The resulting expression is the equation of the phase characteristic, the form of which is shown in Fig. 3. The phase response is a sinusoidal curve. In FIG. 3 as an example shows the time diagrams of voltages at the initial phase of the input voltage Ψ _in = -90° (in the time interval from t=0 to t=t ₁ ), with _{Ψ in} = 0° (in the time interval from t=t ₁ to t=t ₂ ), at _{Ψ in} =+90° (in the time interval t>t ₂ ).

Thus, the use of an inverter, a controlled phase shifter, a single vibrator, an integrator with a reset, and a driving signal source in the measuring transducer makes it possible to achieve the required technical result - expanding the functionality of the measuring transducer by providing phase sensitivity.

In the practical implementation of the proposed measuring converter as an inverter 1, you can use a conventional inverting amplifier on an operational amplifier. Controlled phase shifter 2 can be made according to the scheme (Patent for PM No. 206198 of the Russian Federation, G01R 19/22. Controlled phase shifter, publ. 08/30/2021). Comparator 3 can be performed on the K554CA3 chip. As a frequency-voltage converter 4, you can use a converter on the KR1108PP1 chip. Single vibrator 5 can be performed on the K561AG1 chip. An integrator with reset 6 can be performed on an operational amplifier (op-amp) according to the scheme (V.G. Gusev, Yu.M. Gusev. Electronics and microprocessor technology. - M .: Higher school, 2005. - p. 459, fig. 6.18, c). Adder 7 is a non-inverting adder on the op-amp. The source of the setting signal 8 is a conventional source of stable voltage.

Claims (1)

A phase-sensitive AC-to-DC measuring converter, containing a comparator, a frequency-voltage converter and an adder, and the output of the comparator is connected to the input of the frequency-voltage converter, characterized in that it additionally includes a controlled phase shifter, a single vibrator, an integrator with a reset and a source of a setting signal, the output of which is connected to the second input of the adder, the output of which is connected to the control input of the controlled phase shifter, the output of which is connected to the output of the measuring transducer, and the reference voltage input is connected to the input of the comparator, the output of which is connected to the reset input of the integrator with reset, the output of which is connected to the first input adder, the output of the frequency-voltage converter is connected to the input of the integrator with reset, and the input of the measuring transducer is connected through the inverter to the input of the controlled phase shifter.

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