SU1494020A1 - Relay amplifier - Google Patents

Abstract

The invention relates to computing and can be used in systems of automatic control of technological processes. The purpose of the invention is to improve accuracy. The amplifier contains the first 1 and second 2 isolation transformers, input buses 3 and 4, the first 5 and second 6 current-limiting resistors, the generator 7 of periodic rectangular voltage, the first 8 and second 9 large-scale unipolar amplifiers, the adder 10, the first 11 and the second 12 comparators, smoothing capacitor 13, first 14 and second 15 switches and output bus 16. The introduction of additional elements eliminates the dead zone characteristic of the known device and also significantly improves the linearity of the static What characteristics of the amplifier. 2 Il.

Description

The invention relates to computing and can be used in systems of automatic control of technological processes.

The purpose of the invention is to improve the accuracy of the relay amplifier

FIG. 1 shows a block diagram of a relay amplifier; FIG. 2 shows time diagrams explaining the operation of a relay amplifier.

The relay amplifier contains the first isolation transformer I with the first 1-1; the second 1-2 and third I-3 windings, the second separation transformer 2 with the first 2-1, the second 2-2 and the third 2-3 windings, the first 3 and second 4 input buses, the first 5 and second 6 current-limiting resistors, generator 7 of periodic rectangular voltage, first 8 and second 9 large-scale unipolar amplifiers, 1 O adder, first II and second 12 comparators, smoothing capacitor 13, first 14 and second 15 switches and output bus 16.

Relay amplifier works to

blowing way.

When the power supply of the relay amplifier is turned on, a series of periodic pulses (Fig. 2a) appears at the output of a generator of a rectangular-shaped periodic voltage (Fig. 2a), which are connected to winding resistors 5 and 6 connected in series with current-limiting resistors 5 and 6. 1 -2 and 2-2.

Under the action of this voltage across the windings of transformers 1 and 2, a current begins to gerotech, the rate of change of which is low when the magnetic conductors are not idle (Eny. If the magnetic conductors are high, the current changes to its maximum value instantaneously, then remain constant to us.

With the indicated changes in current, windings 1–3 and 2–3 lead to emf, which is different from zero for unsaturated magnetic conductors, and is equal to zero when they are observed.

Suppose the input signal is zero (Fig. 2 b), then the emf induced in windings 1-3 and 2-3 will be equal. and since these windings are included in the opposite direction, the emf induced in them will be subtracted and their difference

5 0 5

0

five

0

five

five

0

will be equal to zero (Fig. 2c), and, consequently, the voltage at the output of the relay of the amplifier also equals zero (Fig. 2)

Suppose the input signal is different from zero and, for example, positive (Fig. 2 b). Then, in the first half-period of the change in the output voltage of the generator 7, one transformer will be Saturated earlier, and the other later than when the input signal is zero. In the second half-period, the process of fastening the magnetic cores occurs the other way around.

As a result, the law of change over time in emf in volumes 1–3 and 2-3 will change. In this case, obviously, the average value at the output of both windings is 1-3 and 2-3 bu; years is zero (Fig. 2c).

The difference signal (e, -e) from the second Bjogod, an oomot 2-3 arrives simultaneously on the first 8 and second 9 large-scale unipolar amplifiers and the first comparator 1 I.

The scale amplifiers B and 9 are circuit-implemented: so that the output of the amplifier 8 can only be a positive polarity signal, and the output of the {body 9) is negative, and the gains of the amplifiers 8 and 9 are equal.

Thus, at the output of the amplifier 8 there is a positive part of the difference signal (e, -), the EMF of windings 1-3 and 2-3 multiplied by the gain factor, and at the output of the amplifier 9 is negative (Fig. 2c, d id )

Over the entire period of time when the signal (e, - e) is positive, the output signal of comparator 11 is maximum in amplitude and is also positive. In the period of time when the signal (e, - e) is negative, the signal and, is maximum in a time and is also negative (Fig. 2 c and e).

Thus, when the differential signal (e, - e) arrives at the input of the comparator 1I, at the output of the comparator 11, a sequence of pulses of opposite polarity and maximum amplitude is formed. Using a smoothing capacitor 13, the middle component (Fig. 2e) is selected from this sequence of opposite-polarity pulses, which varies in amplitude but is constant in sign, i.e. is negative when i „is positive and positive. when i is negative. This signal is fed to the input of the second comparator 12, which goes into one of two established states, namely, if i is positive, then at the output of the second comparator 12 a signal of maximum amplitude of negative polarity (in this case, switch 14 is closed, and switch 15 is open ), if ig is negative, then the output of the second comparator I2 is a signal of maximum positive amplitude (in this case, switch 14 is open and switch 15 is closed),

Since switch 14 is closed and switch 15 is open (1p positel1, the output signal of the first large-scale unipolar amplifier 8 goes through the switch 14 to the potential-zero bus, and the output signal of the second large-scale unipolar amplifier 9 (negative polarity) goes to the second an input of an adder 10 having an inverting characteristic, with the result that a sequence of pulses of positive polarity is formed at its output and, therefore, on the output bus 17 of the relay amplifier.

To change the polarity of the input signal, the algorithm of operation of the relay amplifier is similar to the one described above with an accuracy of the sign (Fig. 2a – Fig. 2g), i.e. a positive voltage is generated on the capacitor 13, as a result of which the output of the comparator I2 is the maximum positive signal, the switch 14 is open, and the switch 15 is closed. The output signal from the second scale amplifier 9 through the switch 15 is fed to the zero potential potential, and the output of the first scale amplifier 8 is fed to the first input of the adder 10, as a result of which a sequence of negative polarity pulses is formed at the output of the relay amplifier.

m

14Ч4020

F o

rmula of invention

Relay amplifier containing the first and second dividing

transformers with three windings each, the first outputs of the first windings of the isolation transformers are combined, the second outputs of the first windings of the isolation transformers are input buses of the relay amplifier, the first terminals of the second windings of the isolation transformers are connected to the first terminals

the first and second current-limiting resistors, respectively, the second terminals of which are connected to the first output terminal of the generator of a periodic voltage of rectangular form, the second output terminal of which is connected to the second terminals of the second windings of the isolation transformers, the first terminals of the third windings of the isolation transformers are combined, and - due to the fact that, in order to improve the precision of the amplifier, the first and second large-scale unipolar amplifiers, an adder, the first and second com Arathor, the first and second switches, a smoothing capacitor, the second terminal of the third winding of the first isolating transformer connected

connected to the zero potential bus, the second output of the third winding of the second isolation transformer is connected to the inputs of the first and second large-scale unipolar amplifiers and to the input of the first comparator, the output of which is connected to the second output of the smoothing capacitor and to the input of the second comparator The output of which is connected to the control inputs of the first and second switches, the outputs of which are connected to the zero potential bus, and the information inputs are connected to the output The first and second large-scale unipolar amplifiers and, respectively, to the first and second inputs of the adder, the output of which is the output of the relay amplifier.

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Claims (1)

SUMMARY OF THE INVENTION A relay amplifier comprising, _with first and second isolation transformers, with three windings each, the first terminals of the first windings of isolation transformers are combined, the second terminals of the first windings of isolation transformers are input buses of the relay amplifier, the first terminals of the second windings of isolation transformers are connected to the first terminals 15 the first and second current-limiting resistors, respectively, whose second terminals are connected to the first output terminal of the generator Rectangular voltage of a rectangular shape, the second output terminal of which is connected to the second terminals of the second windings of isolation transformers, the first terminals of the third windings of isolation transformers are combined, which means that, in order to improve the accuracy of the amplifier, it the first and second large-scale unipolar amplifiers, an integrator, first and second comparators, first and second switches, a smoothing capacitor were introduced, the second terminal of the third winding of the first isolation transformer connected to the first terminal of the smoothing capacitor and connected to the zero potential bus, the second terminal of the third winding of the second isolation transformer is connected to the inputs of the first and second large-scale unipolar amplifiers and to the input of the first comparator, the output of which is connected to the second terminal of the smoothing capacitor and the input of the second comparator, the output of which is connected to the control inputs of the first and second switches, the outputs of which are connected to the bus of zero potential, and the information inputs are connected 50 to the outputs of the first and second large-scale unipolar amplifiers and, respectively, to the first and second inputs of the adder, the output of which is the output of the relay amplifier. < ι f · e _g e _r s h U ** IX- _ S> h S S4 “9 t I? g-lx U-12 t 1 t Ί ΙΓ 1 U-10 S / b G IS G J U,!, Li t Figure 2