SU970253A1

SU970253A1 - Digital frequency meter

Info

Publication number: SU970253A1
Application number: SU813279100A
Authority: SU
Inventors: Геннадий Михайлович Косач; Валерий Иванович Селищев; Василий Михайлович Худобин
Original assignee: Предприятие П/Я А-3251
Priority date: 1981-02-20
Filing date: 1981-02-20
Publication date: 1982-10-30

Description

Изобретение относитс к созданию цифровых частотомеров, примен емых дл измерени электрических и неэлектрических величин, предварительно преобразованных в частоту,The invention relates to the creation of digital frequency meters used to measure electrical and non-electric quantities, previously converted to frequency,

Известны цифровые частотомеры, которые по частотному диапазону могут быть разделены на высокочастотные и низкочастотные, содержащие . генераторы, селекторы, делитель и индикатор 1.Known digital frequency meters, which in the frequency range can be divided into high frequency and low frequency, containing. generators, selectors, divider and indicator 1.

Недостатком данных устройств вл етс то, что относительна погреш-i Юность, измерени частоты возрастает при уменьшении измер емой частоты и уменьшении времени измерени .The disadvantage of these devices is that the relative error i-Youth, frequency measurement increases with decreasing measured frequency and decreasing measurement time.

Из известных устройств наиболее блиёким к предлагаемому по своей технической сущности вл етс устрой ство, содержащее последовательно соединенные генератор талонной частоты , делитель базы времени, формирователь строб- импульса, селектор и основной блок счетных декад, а также усилитель-формирователь, выход которого подключен к второму входу селектора и индикатор 2.Of the known devices, the device which is most closely related to the proposed technical entity is a device containing serially connected clock frequency generator, time base divider, strobe pulse generator, selector and main unit of counting decades, as well as a booster amplifier whose output is connected to the second input selector and indicator 2.

Недостаток известного устройства - низка точность измерени .A disadvantage of the known device is low measurement accuracy.

Цель изобретени - повышение точности измерени .The purpose of the invention is to improve the measurement accuracy.

Поставленна цель достигаетс тем, что в цифровой частотомер, содержащий последовательно соединенные генератор эталонной частоты, делитель базы времени, фо иирователь строб-импульса, селектор и основной блок счетных декад, а также усили10 тель-формирователь, выход которого подключен к второму входу селектора и индикатор, введены последовательно соединенные селектор эталонной частоты, дополнительный блок счет15 ных декад и арифметический блок, выход которого подключен к входу индикатора, при этом второй вход ари | 1етического блока соединен с выходом основного блока счетных декад, выход усилител -формировател подключен к первому входу селектора эталонной частоты, второй вход которого соединен с выходом формировател строб-импульса, а выход гене25 ратора эталонной частоты подключен к третьему входу селектора эталонной частоты.The goal is achieved by the fact that a digital frequency meter containing a series-connected reference frequency generator, a time base divider, a strobe pulse generator, a selector and the main unit of counting decades, as well as a driver driver, the output of which is connected to the second input of the selector and the indicator , a serially connected reference frequency selector, an additional block of counting decade and an arithmetic unit, the output of which is connected to the indicator input, are introduced, with the second input ari | This unit is connected to the output of the main block of counting decades, the output of the amplifier maker is connected to the first input of the reference frequency selector, the second input of which is connected to the output of the strobe pulse generator, and the output of the reference frequency generator is connected to the third input of the reference frequency selector.

Claims

The drawing shows a structural diagram of the proposed frequency meter. The digital frequency meter contains a block of 1 us or t barely formed by the body,. the selector 2, the strobe pulse shaper 3, the time base divider 4, the reference frequency generator 5, the indicator b main unit of 7 counting decades, the reference frequency selector 8, the additional block of 9 counting decades and the arithmetic unit 10, the frequency meter works as follows. The measured oscillations fx are amplified and formed by a block 1 of amplifier shapers and passed through a selector 2 to block 7. Select 2 is opened by a strobe pulse generated by the pulse shaper 3 from the pulse signals received from the time base divider 4. The reference frequency from the generator through the selector 8 enters the block. The selector 8 opens upon receipt of a strobe pulse from the generator 3 and the first post-strobe pulse signal from block 1 of the shaping amplifiers. After the end of time, unit 7 displays the number of counts of the measured frequency. The selector 8 is closed upon the arrival of the next pulse after the end of the counting time. Block 9 displays the updated counting time corresponding to an integer number of periods of the measured frequency. The numerical values of blocks 7 and 9 are fed to the arithmetic unit 10, where the measured frequency is calculated by the formula: where N is the number of pulses of a block of 7 counting decades; N is the number of pulses of the block count of 9 counting decades; f- is the reference frequency from oscillator 5. The calculated value of the measured frequency enters indicator 6. Due to the fact that the measured frequency value is calculated from the counting decades and the known reference frequency, the basic relative error of the instrument will not increase with decreasing f X and T. Thus, the use of the proposed digital frequency meter can significantly improve the accuracy of frequency measurement. DETAILED DESCRIPTION OF THE INVENTION A digital frequency meter comprising a series-connected reference frequency generator, a time base divider, a strobe pulse shaper, a selector and a main unit of counting decades, and a shaper amplifier whose output is connected to the second input of the selector, and an indicator that includes by the fact that, in order to improve the measurement accuracy, the reference frequency selector, an additional block of counting decades and an arithmetic unit, the output of which is connected to the indicator input, are introduced into it , the second input of the arithmetic unit is connected to the output of the main block of counting decades, the output of the amplifier-mapper is connected to the first input of the reference frequency selector, the second input of which is connected to the output of the formate-i l strobe, and the output of the reference frequency generator is connected to the third input selector frequency reference. Sources of information taken into account in the examination 1. Digital measuring devices. Directory. Leningrad branch. Energy, 1971, with. 109.

2. Electronic-counting frequency meter 4-3 32, Technical specification, operating instructions, album 1, part 1, 1978.