SU1269039A1 - Converter of instantaneous value of periodic signal to d.c.voltage - Google Patents

Abstract

The invention can be used to measure instantaneous voltages of a periodic waveform of an arbitrary shape. The purpose of the invention is to increase the speed of the converter. It contains a comparator 1, 13 -thrigger 2, a strobe pulse shaper consisting of a block

Description

4 synchronization, 5 delay block and 6 strobe pulses. . The input signal from terminal 7 is fed to the synchronization unit A and to the non-inverting input of comparator 1, the inverting input of which is connected to the output terminal 8 connected to the output of integrator 10. The non-inverting input of integrator 10 (operational amplifier 11 and capacitor 12) is connected to source 9 bias, and On the inverting input of it - the inverting output of the D-flip-flop 2 through a resistor 14. The clock input -T of the flip-flop 2 is connected to the non-inverting you

the gate driver 3 strobe pulses, the inverting of which is connected to the clock input of the reverse register 13 shift. The outputs of the first and last bits of the shift register 13 through the diodes 15 and 17 and the resistors 16 and 18 are connected to the inverting input of the integrator 10. The introduction of the shift register 13, the diodes 15 and 17 and the resistor 18 significantly increases the integration speed in the integrator 10 by increasing the integration speed in the main part of the period, the increase in output voltage. 2 Il.

The invention relates to electrical measuring equipment and can be used to measure instantaneous voltages of periodic signals of arbitrary shape.

The purpose of the invention is to increase the speed of the converter,

FIG. 1 shows a block diagram of a converter; in fig. 2 timing diagrams for converter operation.

The converter of the instantaneous value of a periodic signal into a constant voltage contains a comparator I, the output of which is connected to the data input of the D-flip-flop 2, the strobe-pulse shaper 3. consisting of a synchronization unit 4, the output of which is connected to the input of the delay unit 5, the output of the delay unit 5 is connected to the input of a one-vibrator strobe pulse generator 6. Input 7 of the converter is connected to a non-inverting: input of comparator 1 and to the input of synchronization unit 4. The inverter input of the comparator 1 is connected to the output 8 of the converter. The output of the bias voltage source 9 is connected to the non-inverting input of the integrator 10 5, consisting of an operational amplifier 11, the inverting input of which is connected to its output via a capacitor 12, and the output is connected to the output 8 of the converter. The clock input of the D-flip-flop 2 is connected to a non-rotating output of the strobe pulse generator 6, the inverting output of which is connected to the clock input of the reversing p-bit register

5 13 shifts. DIFFERENT output of D-flip-flop 2 is connected to S-input of register 13. Inverse output of D-flip-flop 2 is connected to data input for right shift DIJ and data input for shift

O to the left T) and input 3 of the register 13. The inverse output of the I) -trigger 2 through the first resistor 14 is connected to the inverting input of the integrator 10. The output of the first bit Q, register 13

15 through the first diode 15 and the second resistor 16 is connected to the inverting input of the integrator 50, and the cathode of the diode 15 is connected to the output of the register 13 The output of the last bit of the Q register

20 13 through the second diode 17 and the third resistor 18 is connected to the inverting input of the integrator 10, and the anode of the diode 17 is connected to the output of the register 13.

, 25 The converter of the instantaneous value of a periodic signal into a constant voltage works as follows.

The input signal u (Fig. 2), the instantaneous values of which are converted into a constant voltage U gj, (Fig. 2fii, from input 7 of the converter goes to the non-inverting input of the comparator 1. To the inverting input

JJ comparator 1 is energized

(Jgj, which is simultaneously applied to the output 8 of the converter and is the output voltage, the value of which is equal to the instantaneous value of the periodic signal at times determined by the position of the strobe pulses. As a result of comparing the signals Ujj and the output of the comparator 1, the corresponding logical signal is formed: signal high level (logical 1) if the voltage at a non-inverting input exceeds the voltage at the inverting input (U g Ug) or a low level signal (logical O) if the inverse relationship Khodnev levels (Ug ayk

At the moment when the G-Trigger 2 of the strobe-pulse front arrives at the clock input from the non-inverting input of the strobe-pulse generator 6 (moments t,, t, ..., t,, Fig. 2a), the result of comparison of the voltages U and and is fixed by the P-trigger 2 and remains unchanged until the next strobe pulse arrives at it. At the time of arrival of the strobe pulse slice (moments t,, t, ..., tl,), the state of the E-trigger 2 is overwritten into register 13. If there is a logical O on the inverting output of the QD-trigger 2, this signal into the register 13 is entered only through input D (to bit Q j and shifts to the left side of register 13 as strobe pulses arrive (in the direction of bit Q,). If there is a logical 1 on the inverting output Q of a D-flip-flop 2, this signal to resistor 13 is entered only through the input Dj, into bit Q, and as it arrives, the strobe pulses shift to the right (in the direction and bit Q). The description of the change in the state of the outputs of the register 13 as the strobe pulses arrive is shown in Fig. 2g, Fig. 26 shows the state of the inverting output Q of the D flip-flop 2. At the same time, it is necessary that the strobe-pulse duration there was no less than the time delay of signal propagation in D-flip-flop 2 and no more than T / n.

The inverting input of the integrator 10 simultaneously receives logical signals from the inverting output D of the trigger 2 and the outputs Q and 0 of the register 13. A voltage that equals the arithmetic average of the logical O and logical 1 is supplied to the non-inverting input of the integrator 10 .

The converter, when applied to the input 7 positive pulses (Fig. 2, with a register size of 13 p 8, operates as follows. Suppose that in the initial state the register bits 13 Q, - Q have information of logical 1, and the bits - information of logical O (first column of digits, fig. 2 d). At time t, the voltage at input 7 exceeds the voltage at output 8. At output Q of D-flip-flop 2, a logical O f f is fixed 21), and through input P of register 13 it is written in bit Og. At the same time, logical O shifts into bit Q of register 13 (the second column of numbers in Fig. 2lJ, the rate of change of the output voltage of the integrator 10 is determined by the total input current through resistors 14, 16 and 18. Since the diodes 15 and 17 are locked, the current through the resistors 16 and 18 do not flow, and the integration speed at the time in question is determined only by the current through resistor 14. A similar picture is observed before the fourth strobe pulse arrives. After time t, logical O shifts into bit Q, diode 15 opens, starts a current flowing through the resistor 16. The rate of change of the output voltage of the integrator 10 is increased. For a reliable operation of the circuit it is necessary that the condition was performed

.i6 p

1 „2 where i | q, (b currents through resistors 14

and 16 respectively. In this case, the rate of change of the output voltage of the integrator 10 is increased n / 2 times, which gives an increase in the speed of the converter almost n / 2 times.

When the input voltage Ugx is exceeded at input 7, the output voltage at the output is 8dT.e. Ug, (moment t), at output Q of D-flip-flop 2 and output (E, register 13 appears logical 1. When this happens, diode 15 closes and the current through resistor 16 stops (1.0). As a result, the decay the output voltage at the output of the integrator 10 and

Claims (1)

Claim A transducer of instantaneous value of a periodic signal to direct voltage, containing a comparator, a non-inverting input of which is connected to the input of the converter, and an inverting input - with its output, a gate-pulse shaper, whose direct output is connected near the inverting input with the clock input of the A trigger, the data input of which is connected to the output of the comparator, an integrator whose inverting input is through the first 5, the resistor is connected to the inverted output of the Г flip-flop, and the output is connected to the output of the converter, a bias voltage source and a second resistor, one of the pins of which is connected to an integrator, characterized in that, in order to improve performance, a reverse shift register is introduced into it , the third resistor and two diodes, 15 an additional inverse output of the strobe generator is connected to the clock input of the shift register; to 5, - the input is the direct output of the D trigger, whose inverse output is connected to the data inputs for left shift and for Whig to the right and to the input of 5 ₀ of the shift register, the outputs of the first and last bits of the shift register two chains consisting of pos25 been consistent connection of the first diode and a second resistor and a second diode and a third resistor respectively connected to the inverting> input of the integrator, the non-inverting 30 input of which connected to a bias voltage source, the first diode being connected by the cathode to the output of the shift register ', and the second diode being turned on in the opposite direction.