SU1541637A2 - Function generator with frequency synchronization - Google Patents

Abstract

The invention relates to devices that generate electrical signals of several forms, both in self-oscillation mode and in synchronization mode by an external periodic signal, and can be used in automation, instrument engineering, computing and information technology. The aim of the invention is to expand the functionality of the device by forming a quadrature sinusoidal signal at an additional output. The goal is achieved by the fact that the device containing the frequency control unit 1, switch 2, integrator 3, relay element 5, first functional converter 4, amplitude stabilization circuit (blocks 6, 7, 8), variable 9 and scale 10-15 resistors , a full-wave rectifier 18, an inverter 19, a switch 26, an adder 25, a second functional converter 24, and four large-scale resistors 20-23 are introduced. Nonlinear conversion of a triangular signal from the output of integrator 3 allows one to obtain a phase-shifted triangular signal with subsequent conversion into a sinusoidal one. 3 il.

Description

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The invention relates to devices that generate electrical signals of several forms in both the auto-oscillation mode and the synchronization mode with an external periodic signal, and is an improvement of the known device according to the author. St. If.

The purpose of the invention is the expansion of functional capabilities due to the formation of an additional quadrature sinusoidal signal at the output. Figure 1 shows a functional electrical diagram of the generator; in Fig. 2 — timing diagrams, according to the operation of individual generator blocks in the frequency synchronization mode; Fig. 3 shows timing diagrams explaining the process of forming the shifted signals on the phase.

A function generator with frequency synchronization contains a frequency control block 1, a switch 2, an integrator 3, a functional converter 4, a relay element 5, an amplitude analyzer 6, an integrating g element 7, a limiting element 8, a non-variable resistor 9, first, second, third, fourth, fifth and sixth large-scale resistors 10–15, bus 16 positive positive voltage, generator synchronization input 17, two-wave rectifier 18, inverter 19, seventh 20, eighth 21, ninth 22 and tenth 23 large-scale leezistors sine nktsionalny converter 24, an adder 25 and || slyuch 26

I The generator operates in several modes.

The mode of free self-oscillations is carried out in the absence of a signal and the input 17 of the generator synchronization. $ closed loop from sequentially switched on switch 2, integrator 3, resistor 11 and relay element 5 are installed stable oscillations, which at the output of integrator 3 have a triangular shape, I at the output of relay element 5 are rectangular. At the output of the first functional converter k, a sinusoidal signal is formed. The amplitude of the triangular signals is equal to the response threshold of the relay element 5 with the hysteresis characteristic. Frequency of free oscillations is determined by the magnitude of the voltage

0

5 o

0

0

five

a variable resistor 9 that is removed from the movable contact, which through the first scale resistor 10 is applied to the input of the frequency control unit 1. The latter converts the input signal into currents through the switch 2 to the input of the integrator 3, resulting in a linear / conversion of the input signal of the frequency control unit 1 into the pulse frequency of several forms. In the free oscillation mode, in order to avoid frequency transients, the scale resistor 1 is disconnected from the input of frequency control unit 1 (using a switch, not shown).

The mode of frequency synchronization is carried out in the presence of a voltage U, 7 of rectangular shape at the output 17. The signal Uj 8) the input of the relay element is the sum of the signals U3 from the output, the integrator's stroke and the signal Uf7. For the convenience of constructing the sum signal, the waveform, U, T, on the time diagrams (Fig. 2) is taken triangular. Consider two possible types of transients when synchronizing a frequency with an external signal.

The first type of transient (Fig. 2a) is possible if the frequency of free oscillations in the generator is lower than the frequency of the external signal. The slope of the triangular voltage U3 at the beginning of the transition process is such that when switching the relay element 5 with the voltage frequency, the amplitude U. is less than specified. At the output of the amplitude analyzer 6, a step voltage Uc of negative polarity is formed, proportional to the amplitude U3. The signal U6 is summed with the positive polarity signal from bus 16, with the result that the signal U7BS is formed at the input of the integrating element proportional to the deviation of the amplitude U5 from a predetermined value. At the output of the integrating element 7, the voltage UT varies linearly in a positive direction. The total signal at the input of the frequency control unit U Ua + Ui7 also increases, which leads to an increase in the slope and amplitude of the signal and. The signal at the integrator output is constant in level when the amplitude U3 is compared with the specified one.

The limiting element 8 limits the level of the output voltage 1C of the integrating element at the beginning of the transition process when the signal at the output of the analyzer 6 of amplitude is 0.

The second type of transient process is possible (Fig. 26) if the frequency of free oscillations of the generator is higher than the frequency of the external signal. The amplitude U3 is higher than the predetermined value, the voltage Ufc is generated at the output of the analyzer 6 amplitude, which, summing up with the bus 16 signal, gives the signal U7 of negative polarity. The output of the integrating element 7 voltage

U ,, changes linearly in a negative direction until the amplitude U3 is equal to the specified one.

The formation of a triangular signal shifted in phase by 90 ° relative to the signal at the output of the integrator 3 is ensured by the fact (FIG. 3) that the triangular signals u3 input to the full-wave rectifier 18 input are converted into triangular signals u BWIf (J and U g, (X fj doubled frequency. To these signals, due to the connection of the outputs of the rectifier 18 through the scale resistors 20 - 23 with the output and input of the inverter 19, are added constant components proportional to the voltage from the bus 16. As a result, the summation of the 25 signals U6b |) f j0 and U in tf considering the inversion, a Ugbtxir signal is generated, which is phase shifted relative to

15 sinusoidal signals, however, the phase relationships of the signals from the outputs of the functional transducers in transients are not disturbed. The proposed construction principle of a two-phase generator allows the reduction of the duration of transients, which is especially important at infra-low frequencies, compared to a synchronized generator, in

25 of which phase or frequency meters are used.

thirty

35

Claims (1)

Invention Formula function generator with frequency synchronization by auto St. No. characterized in that, in order to extend the functionality by forming a quadrature sinusoidal signal at the additional output, a full-wave rectifier, key, adder, inverter, seventh, eighth, ninth and tenth are introduced into it U3 at 90 °. Timing diagrams (FIG. 3) 40 scale resistors and a sine-functional converter, the full-wave rectifier input connected to the integrator output, the direct output of the full-wave rectifier through serially connected shows that transients during synchronization with an external signal can only affect the form of the triangular signal shifted by 90 ° ibb) x .jj. Subsequent conversion of the output signal of the adder into a sinusoidal signal using the second functional converter 24 allows to obtain at the additional output a quadrature sinusoidal signal shifted in phase relative to the signal from the output of the first functional converter by 90 °. Thus, in the proposed device, the synchronization of the frequency by an external signal of a rectangular shape is accomplished by providing a mode of forced oscillations in a self-oscillating circuit consisting of an element 55 The seventh and eighth scale resistors are connected to the inverter output, the input of which is connected to the bus of the positive reference voltage and connected through the ninth and tenth scale resistors connected in series to the inverting output of the full-wave rectifier, the common output of the ninth and tenth resistors is connected to the information input of the key, the output of which is connected to the zero potential bus, and the control input is connected to the output of the relay element, the common conclusions of the seventh Q Compendiums 2, 3, 11 and 5. The amplitude of the triangular signal converted into a sinusoidal signal is invariable by introducing an amplitude stabilization loop. Nonlinear conversion of a triangular signal from the output of integrator 3 allows one to obtain a phase-shifted triangular signal with subsequent conversion into a sinusoidal one. Transients associated with frequency synchronization cause momentary distortion of the output 5 sinusoidal signals, however, the phase relationships of the signals from the outputs of the functional transducers in transients are not disturbed. The proposed principle of building a two-phase generator allows for a reduction in the duration of transient processes, which is especially important at infra-low frequencies, compared to a synchronized generator, in 5 of which phase or frequency meters are used. Invention Formula function generator with frequency synchronization by auto St. No. characterized in that, in order to extend the functionality by forming a quadrature sinusoidal signal at the additional output, a full-wave rectifier, key, adder, inverter, seventh, eighth, ninth and tenth are introduced into it large-scale resistors and a sinus functional converter, with the full-wave rectifier input connected to the integrator output, the direct output of the full-wave rectifier through serially connected The seventh and eighth scale resistors are connected to the inverter output, the input of which is connected to the bus of the positive reference voltage and connected through the ninth and tenth scale resistors connected in series to the inverting output of the full-wave rectifier, the common output of the ninth and tenth resistors is connected to the information input of the key, the output of which is connected to the zero potential bus, and the control input is connected to the output of the relay element, the common conclusions of the seventh and the eighth scale resistors and the ninth and tenth scale resistors are connected respectively to the first and second inputs of the adder, the output of which is connected via a sinus functional converter with an additional output of a quadrature sinusoidal signal of the generator. R - Y s 5Zt7I ZTI Z zry Xx UU UCH z hh .x / Fig1 z hh .x  sT Schig.Z V /