SU836600A1 - Digital frequency meter - Google Patents

Description

The invention relates to measuring and computing technology and can be used in complex information measuring systems for highly accurate measurement of frequency signals. A digital frequency meter is known, comprising an input pulse shaper, counters, a reference frequency generator, a selector, a control unit and a memory register 1. A disadvantage of the known device is the low accuracy of gfi measuring low frequency signals. Closest to the proposed device, there is a pulse shaper, a crystal oscillator, a dividing unit, a control unit, a main pulse counter, a main memory register, a correction unit, and an indicator 2. A disadvantage of the known device is the dependence of the accuracy of frequency measurement with its help on the duration of the measurement time interval, which increases as the measured frequency rises with low-frequency signals. The purpose of the present invention is to improve the accuracy of frequency measurement. This goal is achieved by the fact that, in a digital frequency meter containing a pulse feeder, an indicator whose first input is connected to the main memory register, the first input of the latter is connected to the main pulse counter, the first input of which is connected to the output of the encapsulation unit, and also the comparison unit codes and serially connected crystal oscillator, dividing unit and control unit, the output of which is connected to the input of the correction unit, to the second input of the main pulse counter and to the second input of the main memory register, in neg a frequency multiplier, an indication switching unit, an additional pulse counter connected in series, an additional memory register and a code comparison unit, whose output is connected to the input of the indication switching unit and to the first input of the frequency multiplier, the second input of which is connected to the output of the pulse generator and to the first input are entered additional

the pulse pulse, the second input of the coordinate is connected to the output of the control unit 1A 0SH1. At the same time, the output of the multiplier is partly connected to the third input of the pulse counter, the second aeloe of the memory register register is scheddled to the control unit, and the output of the switch of the display indications is combined with the second indication of the indicator 5 a.

Ya P1 "Goge is represented by structuressshe is a schematic device diagram.

.In 1, the socket contains quartz 1, block 2 divisions, block 3 and 3), correction block 4, form 5 pulses, 6 sasTOTKi multiplier, blue counter 7, additional counter 8, block 9 comparable codes, main register 10 pomags, Shift register 11, SJTOK 12 toggle indices K m and M neschikator 13.

The device works as follows. The measured frequency f iiocaa of the driver of 5 pulses is ps simultaneously at the inputs of two identical counters 7 and 8, and (and at counter 7, the pulses are fed through frequency multiplier 6, and at the input of counter 8 without. Counter 8 is used to automatically select the coefficient of multiply | USE the multiplier, and the counter 7 is for calculating the number of units, and the ratio of the multiplier is set by the code 8, which is written to the memory register 11. The number code PML When counted by the counter, less than 10, a 1 st signal appears at the first output of block 9 of code comparison, sets in the cleverly cleared ratio of 10. When the code number is greater than 10 and o is smaller. 100, a single pulse appears on the second the output of the code comparison device, and the multiplication factor is set to 10. - 10x the code of the number of pulses greater than 16. The multiplication factor is set to 1. From the same outputs of the code comparison device, the signals are fed to the automatic peracter and the position commented in and {shakat 7rv 13.

} Inform € W1. The number of pulses of the measured frequency fx multiplied by that OR OR OTHER coefficient is recorded by the counter 7 and is stored in the register 10 of the memory. 1new tiHf (the total number of counters 7 and 8 in memory registers 19 and 11 is solved by the signals of control unit 3). The counters are also reset at the same time by control signals, and the correction in the form of additions

(subtracting) one pulse is performed only in the counter 7 by means of the correction unit 4. By introducing a frequency multiplier with a variable multiplication factor, the frequency measurement accuracy on all subbands is the same and can be estimated as follows:

f

-)

dr ±

 11.1 I-. - ". - ..I

: W4

JT L

SG - relative error

Where

frequency measurement; exemplary time interval for filling the counter

N - V multiplication factor; frequency crystal oscillator;

quartz oscillator error.

Claims (1)

1. Authors Certificate of the USSR 0 B 266940, cl. G 01 R 23/10, 1970. 2, Gutnikov B.C. and others. Specialized digital frequency meter for work with measuring frequency converters. CSP, W 5, 5 1977, s, 22-24 (prototype).