SU1109710A1 - Function converter of time intervals - Google Patents

Abstract

A FUNCTIONAL TIME INTERVAL CONVERTER containing a time amplitude converter, a resistor, a storage capacitor, a key, a comparator, a reference voltage source and two triggers, the first inputs of which are connected to the input bus, and the time output of the amplitude converter through a resistor is connected to the input of an inverter, which is connected to the input bus, and the output time of the amplitude converter through the resistor is connected to the input of the inverter, which is connected to the input bus; , with the first lining of the storage capacitor and with the first contact of the key, the output of the inverting DC amplifier - with the second lining of the storage terminal The sensor, with the second key contact and the first input of the comparator, the second input of which is connected to the source of the reference voltage, the output of the comparator is connected to the second input of the second trigger, the output of which is connected to the output terminal of the device and to the control input of the key, characterized in that in order to improve the accuracy of the conversion, a one-shot is entered into it, the one-shot input is connected to the device output width, and the output is connected to the second input of the first trigger and the first input is the time of the amplitude converter, the output is Vågå trigger coupled to a second input of the time pre amplitude (L-forming, and the reference voltage source - the third input time amplitude converter.

Description

The invention relates to a measurement technique, (5 in particular, to a pulse device of a measurement technique, intended for the functional conversion of instantaneous values of the intervals between pulses into pulses with durations inversely proportional to these values and can be used in equipment for automatic processing of measurement results of electrical and physical quantities. It is known a device whose operation is based on the use of nonlinear characteristics of semiconductor elements and the implementation conversion of input values to inversely proportional values 1. The disadvantage of this device is low conversion accuracy. The closest to the proposed is a functional time converter containing two 20 flip-flops, two time amplitude converters, two switches, a resistor, a storage capacitor, an inverting DC amplifier, a comparator and a constant voltage source, the first output of the first trigger connected to the input of the first time of the amplitude pre verters, the second output of the first flip-flop is connected to the input of the second time amplitude converter and a control input of the first switch, the contacts of which are connected outputs time amplitude converters. The middle contact of the first switch is connected via a resistor to the input of a DC inverting amplifier, the storage capacitor and the first contact of the second switch are connected to the negative feedback circuit, the second contact of which is connected to the output of the DC inverting amplifier and to the first input of the comparator . The second input of the comparator is connected to a source of reference voltage, the output of the comparator is connected to the second input of the second trigger, the first input of which is connected to the first input of the first trigger and is the input of the device. The output of the second flip-flop is connected to the control input 45 of the second key and is the output of the device 2. The disadvantage of this device is the low conversion accuracy, because during the conversion two amplitude converter times are connected alternately, the same coefficients of which are difficult the time required to switch the converters from min-55 to transform mode. The purpose of the invention is to increase the accuracy of converting a time interval of 10 catches into pulses with durations inversely proportional to the duration of the input pulses. The goal is achieved by the fact that the output of the time of the amplitude converter through the resistor is connected to the input of an inverting amplifier through a resistor, a resistor, a storage capacitor, a key, a comparator, a reference voltage source and two flip-flops. direct current, with the first plate of the storage capacitor and with the first contact of the key, the output of an inverting DC amplifier with the second plate of the storage capacitor, s The first contact of the key and the first input of the comparator, the second input of which is connected to the source of the reference voltage, the output of the comparator is connected to the second input of the second trigger, the output of which is connected to the output bus of the device and to the control input of the key, the one-shot is connected to the output bus of the device, and the output — with the second input of the first trigger and with the first input — the time of the amplitude converter, the output of the first trigger is connected to the second input, the time of the amplitude converter, and the source The third voltage input is the time of the amplitude converter. The introduction of a one-shot with a circuit for connecting elements allows for an increase in the accuracy of the conversion, since this eliminates alternately working time amplitude converters, which introduce additional error due to the nonidentity of the conversion factors and the need for additional time required for converting the converters from the memory to conversion mode. FIG. 1 shows the functionality of the device; in fig. 2 shows the device operation time diagrams. The converter consists of the source i of the reference voltage, the time of the amplitude converter 2, the triggers 3 and 4, the resistor 5, the one-oscillator 6, the storage capacitor 7, the inverting amplifier 8 of direct current, the key 9 and the comparator 10, input 11 and output 12 buses of the device; Time amplitude converter 2 contains a voltage converter 13, a capacitor 14, a switch 15, a storage capacitor 16, an inverting DC amplifier 17 and a control switch 18. The reference voltage supplies from the third input 19, the overwrite signal to the second input 20, the zero signal to the first

input 21. Time amplitude converter has output 22.

The source 1 of the reference voltage is connected to the third input 19 of the time of the ammultidump converter 2 and to the first input of the comparator 10, the input bus 11 of the device is connected to the first input of the trigger 3 and to the first input of the trigger 4. The output of the trigger 3 is connected to the second input 20, the second input of the trigger 4 is connected to the output of the comparator 10, the output of the trigger 4 is connected to the output bus 12 of the device, to the control, to the input of the key 9 and to the input of the one-vibrator 6, the output of which is connected to the first input 21, the time of the amplitude converter 3 and the second input of the trigger 3. Output The time of the amplitude converter 2 is connected to the first contact of the resistor 5, the second contact of which is connected to the input of the inverting amplifier 8 dc, to the first contact of the switch 9 and the first plate of the capacitor 7, the second lining of which is connected to the output of the inverting amplifier 8 dc , with the second contact of the key 9 and with the second input of the comparator 10.

FIG. 2 shows time diagrams at the corresponding points of the functional diagram; a - at the device input, b - at the capacitor 14, c - at the point (output) 22, d - at the output of the inverting amplifier S, d - at the device output, e - at the point (input) 21.

The device works as follows.

When a sequence of pulses arrives at the bus 11 of the output, the time of the amplitude converter 2 forms a sequence of pulses, the amplitudes of which are equal to:

t t - t-Ki-Eo Qi

where is the EQ voltage of source 1 reference

stress;

tj is the duration i of the period of the input pulses (Fig. 2);

KI is the conversion factor of voltage converter 13 — current;

C 1 is the storage capacitor 16 capacity;

O. - the amount of charge on the capacitor 16.

It should also be noted that converter 2 does not have a "dead time," as it goes into memory mode, which occurs on the leading edge of the input pulse, trigger 3 is triggered and key 15 is unwound, capacitor 14 starts to charge and gets charged. equal

Yap-TT) Eu

where ifj is the converter operation time

memory mode.

When the converter 2 goes over into the conversion memory, the key 15 is closed. The charge q is rewritten to the storage capacitor 16 and the latter starts to be charged with a current equal to K-E over time Tj-1 0. i.e. before the next input pulse arrives at the device. Thus, the total charge Q on the capacitor 16 at the moment of arrival at the input of the i-f I device is equal to

Qi KiEo (i: n + Ti-Tn) TiK, Eo.

Trigger 4 also triggers on the leading edge of the input pulse and the switch 9 opens, the voltage at the output of amplifier 8 begins to increase, KOMnapafop 10 triggers after a time equal to the output pulse that can be recorded

r, “, .- R: ii: Eo.

R CfEoCi R-Ci-Ci. 1 v 1

  fjKiElo TiKiEo

where C is the capacitance value of the capacitor 7; k is the resistance value of resistor 5;

K - conversion factor. After the comparator 10 is triggered, the trigger 4 is triggered, using the key 9, zeroes the capacitor 7 and starts the one-shot 6, which keys 18 zeroes the capacitor 16 and returns the trigger 3 to the initial state with the falling edge.

Consequently, at the output of the device, a sequence of pulses of duration is formed, inversely proportional to the periods of the pulse of the input pulses. The device does not require equality of the conversion factors of the individual nodes and does not have a "dead time", which allows for an increase in the accuracy of the conversion.

./

Claims (1)

A FUNCTIONAL TIME INTERVAL CONVERTER comprising a time-amplitude converter, a resistor, a storage capacitor, a key, a comparator, a voltage reference source and two triggers, the first inputs of which are connected to the input bus, and the output of the time-amplitude converter through a resistor is connected to the input of an inverting DC amplifier with the first storage capacitor and with the first key contact, the output of the inverting DC amplifier - with the second lining of the storage capacitor torus, with a second key contact and with the first input of the comparator, the second input of which is connected to the reference voltage source, the output of the comparator is connected to the second input of the second trigger, the output of which is connected to the output bus of the device and to the control input of the key, characterized in that, for the purpose to increase the conversion accuracy, a single-vibrator is introduced into it, the input of the single-vibrator connected to the output bus of the device, and the output to the second input of the first trigger and to the first input of the time-amplitude converter, the output of the first trigger EPA is connected to a second input £ vremyaamplitudnogo converter, and reference source T zheniya The stresses - the third input vremyaamplitudnogo converter. H