SU1741159A1 - Scanning amplifier - Google Patents

Abstract

The invention relates to amplifying devices with PWM modulation and can be used in a computer. The purpose of the invention is to improve the accuracy of the development of the amplifier. The device includes an adder 1, an integrator 2, relay elements 3, 4, a switch 5, an inverter 6, an EXCLUSIVE or 7 element one-shot 8, an input 9 and an output 10 terminal. 3 il.

Description

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The invention relates to amplifying devices with pulse-width modulation and can be used in computers,

Known scanning amplifier (RU), which contains an integrator, relay elements, the equivalence function block.

However, this device has a significant dynamic error,

The closest to the proposed RP is a device containing an adder, an integrator, a relay unit, a key, an inverter, and a one-shot.

A disadvantage of the known device is the low accuracy of operation due to the non-identical parameters of integrator zeroing pulses generated on the leading and trailing edges of the output signal.

The purpose of the invention is to increase the accuracy of the work of the reactor

The goal is achieved by the fact that in a switchgear containing a series-connected adder, an integrator with a reset and the first relay element, the output of which is. which is the output of the amplifier, is connected via a key element to another input of the adder, a one-shot whose output is connected to the reset input of the integrator and through the inverting input of the key element, a second relay element and an EXCLUSIVE OR element are entered, the first and second inputs of which are connected respectively to the outputs the first and second relay elements, the output is connected to the input of the one-shot. and the input of the relay element is connected to the output of the integrator.

The essential difference between the proposed technical solution is the identity of the parameters of the integrator reset pulses generated on both the leading and trailing edges of the output signal of the switchgear.

FIG. 1 shows the functional scheme of the switchgear; in fig. 2 - characteristics of its elements; in fig. 3 - time diagrams of signals

The RU includes an adder 1. an integrator 2, a first 3 and a second 4 relay elements, a key 5, an inverter 6, an element 7 of the function EXCLUSIVE OR. one-shot 8. input 9 and output 10 terminals.

The adder 1 is made with a single transmission coefficient for each of the inputs. Integrator 2 implements the transfer

function W (p) where T is constant

time, and has an input of setting zero initial conditions, which is produced by applying a signal 1 to it (Fig. 2a). Relay elements 3 and 4 have a non-inverting hysteresis loop, and their output signal varies discretely within ± A. The key 5 goes into the closed state when an O signal is applied to its input. The signal at the output of the inverter 6 has a level opposite to the input voltage level (Fig. 2c). Element 7 generates a signal 1 at the output if the characters of the input signals do not match (Fig. 2d). A single vibrator 8 is designed to form a pulse of stable duration synchronously with the falling edge of the input action (Fig. 2e).

FIG. 3 marked: Y2 (t) - the output signal of the integrator 2; Ya (t) is the output signal of the first relay element 3; ) - the output signal of the second relay element 4; Y (t) - output pulses of the element EXCLUSIVE OR 7; Ye (t) - pulses at the output of the one-shot 8; tu is the duration of the output pulses of the one-shot 8: ± bi are the switching thresholds of the relay element 3; ± b2 are the switching thresholds of the relay element 4.

The principle of RU operation is as follows.

Blocks 1, 2, 3, and 5 form a self-oscillating stage designed to convert the input voltage into a frequency-pulse-frequency signal. In the absence of voltage at the output of the one-shot 8, the output signal of the inverter 6 is 1, the key 5 is open and the output of the relay element 3 is connected to the input of the adder 1. The voltage at the output of the integrator 2 rises linearly until then. until successive switching of the second 4 and first 3 relay elements (Fig. 3a) occurs. The ambiguity zone of the relay element 4 is inside the ambiguity zone of the relay element 3. In the general case, the switching thresholds of unit 4 may be asymmetric with respect to zero RF (as shown in Fig. 3a). As a result, a signal is generated at the output of block 7 (FIG. 36), the trailing edge of which coincides with the instants of time for changing the sign of the pulses at the output of the switchgear (Fig. 3a). This makes it possible to exclude from the RU circuitry a second one-shot, which is part of a known RP, and thus eliminate the device operation error that occurs due to the non-identical parameters of the time of the driving chains of one-shot.

When the one-shot 8 is started (Fig. Sv), the key 5 goes into the open state, disconnecting the output of the relay element 3 from the input of the adder 1. At the same time, the zero initial conditions of the integrator 2 are set (Fig. 3a).

If there is an input signal (signal diagrams are not driven) in one of the self-oscillation half-periods, the rate of change of the output voltage of the integrator 2 is determined by the sum of the input signals of the adder 1, and in the other half-period - by the difference of these signals. As a result, at the output of the switchgear a pulse flow is formed, the average value of which is proportional to the level of the input action.

Thus, the proposed device makes it possible to eliminate the error of a known reactor occurring due to non-identical parameters of zero integrator pulses.

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Claims (1)

The invention A deployment amplifier containing a series-connected adder, an integrator with a reset, the first relay element whose output, which is the output of the amplifier, is connected via a key element to another input of the adder, a single vibrator, the output of which is connected to the reset input of the integrator and through an inverter with a control the input of a key element, characterized in that, in order to improve the accuracy in operation, a second relay element and an element EXPERIMENT OR has been introduced into it, the first and second inputs of which are connected The outputs are respectively to the outputs of the first and second relay elements, the output is connected to the input of the one-vibrator, and the input of the second relay element is connected to the output of the integrator. a B about phage 3 UzF /