SU1237986A1 - Device for measuring oscillation period - Google Patents

Abstract

The invention relates to the field of electrical and radio measurements and can be used as a precision periodometer. The purpose of the invention is to increase the accuracy of measurements in a wide range, by measuring with analog means the intervals at the beginning and end of the period for converting the measured values into a digital code and then summing up the measurement results of the integer and fractional parts. To achieve this goal, a device containing a reference generator i, the first and second drivers 7 and 8, counter 3, trigger 6, and integrator 1I, first and second current generators 9 and 10, key 2, adder 4, analog-digital the transducer 12 and the delay line 5. The operation of the device is explained in time diagrams in the description of the invention. 2 Il. W 1su with 00 o

Description

one

The invention relates to electrical and radio measurements and can be used as a precision periodometer.

The purpose of the invention is to increase the measurement accuracy in a wide range by measuring with analog means the intervals at the beginning and end of the period for converting the measured values into a digital code and then summing up the measurement results of the integer and fractional parts.

FIG. 1 shows the structure diagram: the devices of FIG. 2 - time diagrams of his work.

The device consists of a reference generator 1, a key 2, a counter 3, an adder 4, a delay line 5, a trigger 6, the first and second drivers 7 and 8, the first and second current generators 9 and 0, the integrator 11 and the A / D converter 12.

The generator 1 is connected to the first inputs of the drivers 7 and 8 and to the successively connected to the key 2, the counter 3 and the adder 4, the first output of the trigger 6 is connected to the second input of the key 2, and through the driver 7 and the current generator 9 to the first integrator input P, and the second trigger output 6 through the driver 8 and the current generator 10 is connected to the second input of the integrator 11 "The output of the latter through the ADC 12 is connected to the second input of the adder 4. The input of line 5 is connected to the output of the trimmer 8, and the output - to the reset inputs of the counter 3 and integrator 11. Trigger Input 6 is connected to the input, and the output of the adder 4 - with the output bus device,

FIG. Figure 2 shows the time diagrams of the device operation: voltage at the device input (2a), at the output of generator 1 (2 &), trigger

6 (2B), shaper 7. (2 g) shaper 8 (2 O and integrator 11 (2e).

The device works as follows.

Before starting the measurement, the counter 3, the trigger 6 and the integrator 11 are in the initial state. At the beginning of the measured period T, flip-flop 6 (2a, 2b) overturns. The signal from its output starts the driver

7 and unlocks key 2. Signal reference generator 1 (28) with a period

Tr enters counter 3, which begins to fill. Upon the arrival of the third pulse T (counting from the beginning of TX) to the driver 7, it is turned off (21). Thus, the pulse duration t, obtained in the first pulse driver 7, is within (2 T, 3 T). At the end of the measured period

trigger 6 returns to its original state, and the signal from its first output locks key 2. At counter 3, during T passes K pulses characterizing Tu: T, CT, at the same time, the signal from the second output of trigger 6 starts the driver 8, turning off on the arrival of the second (calculated from the end T of the pulse T. Thus, the duration of the t-pulse,

obtained in the former 8 is in the range of (T, 2Td), and the measured period is determined by the formula

T, (K-l), - t

The signals from drivers 7 and 8 open during their operation current generators (respectively 9 and 10), the first of which increases and the second reduces the voltage on integrator 11 (2e). If the currents of both current generators 9 and 10 are the same in magnitude, then after the end of the pulse t, the voltage at the output of the integrator 11 will be proportional. In ADC 12, the magnitude of this voltage is digitized. Since it is within (0.2Td), the code from the output

The A / D converter 12 is folded in the adder 4 with the code from counter 3, and the resulting value code Tu is fed to the output bus.

Since after the end of Tj in the counter 3 the number K1 must be written, then the initial state is taken to be the state of the counter 3, equal to P-1, where P is the capacity of the counter 3, Setting this state, as well as resetting the integrator 11

before each measurement pulse from the output of the imaging unit 8, delayed in line 5.

Claims (1)

Invention Formula A device for measuring the period of oscillation, containing the reference gene A rator whose output is connected to the first input of the first shaper is the second shaper, counter, trigger and integrator, about ayushchy 6 so that, in order to improve measurement accuracy in a wide range, the first and second generators are introduced into it current, key, adder, analog-to-digital converter (ADC) and delay line, the output of the reference generator is connected to the first input of the second driver and the pulse input of the key, the potential input of which is connected by the second input of the first driver and the first trigger output, the second V J 7V 379864 the output of which is connected to the second input of the second driver, the output of the key is connected to the counter input of the counter, the bit outputs of which are connected to the inputs of the first term of the adder, the inputs of the second term are connected to the ADC outputs, and the outputs of the first and The second FORJO worlds through the first and second current generators are connected to the first and second inputs of the integrator, the output of which is connected to the input of the ADC, the input of the delay line is connected to the second-form house, and the output is reset egratora ischetchika. Well il-t, -f2