SU705366A1 - Frequency and period meter with automatic subrange switching - Google Patents

Description

(54) FREQUENCY MEASURING PERIODOMER WITH AUTOMATIC SWITCHING OF SUB-BANDS

The invention relates to electrical measuring equipment, and can be used to measure quantities converted to the duration or frequency of electric signals.

A signal frequency meter with automatic subband switching is known, using a representation of the measuring information in analog form. The frequency counter contains a scheme for selecting the frequency conversion scale (period) of the measured signal, the integrator, on the output of which the measuring instrument 1 is turned on.

A disadvantage of the known meter is the need for integrating certers for intermediate conversions of discrete signals to direct current voltage.

A frequency meter is known which contains a shift register on series-connected cells with two stable states, a key and a scale selection circuit of the converted frequency (period) of the measured signal 2.

A disadvantage of the known frequency meter with automatic subband switching is the need for a clock pulse generator, which complicates the frequency meter circuit.

The purpose of the invention is to simplify the frequency meter-periodometer.

For this, in a frequency meter containing a shift register on series-connected cells with two stable states, an indicator, a power source, a cell and a block for selecting a frequency conversion scale (period) of the measured signal, the optocouplers are used as the shift register cells associated with the input of the conversion scale selection unit, the output of which is connected with the control input of the key, the output of which is connected to the power supply bus of the shift register cells.

Claims (2)

In a simpler scheme, such a frequency meter-periodometer provides measurement accuracy of the same order as in a similar instrument. This eliminates the need for a clock pulse generator, reducing the number of keys used. To simplify the device can contribute to the formation of the measuring interval of the shift register and indicator in one device. The drawing shows a structural electrical circuit of a frequency periodometer meter with automatic switching of subbands. The frequency and temperature meter contains a shift register 1 on successively connected cells (2-1) - (2-N) with two stable states, which use photodiodes of the photodiode type. , indicator) 3 on LEDs (4-1) (4-N), forming the reference scale of the analog-position type with a light pointer. The shift register 1 simultaneously combines the functions of the indicator and the former of the multivalued Time Measure, Nfo, with which the period TX is correlated, the sequence of the signals under study, or a multiple of the CT, is matched. where K is a factor of multiplicity, for example, 1, 10, 100. The time delay used for switching optronic cells from one state to another is used. Key 5. Block 6 for selecting the frequency conversion scale of the measured signal, which is made on matching logic elements 7-9, whose inputs are connected to the outputs of the distributor 10 and the ruler 11 trigger frequency dividers of the input signals, and the outputs to the inputs of the logic element of the assembly 12 The drawing also shows the terminals 13, 14 of the power supply and the bus of the measured signal 15. The device works as follows. The measured signal TX is fed to the input of a ruler of 11 dividers of the frequency of the block 6 for selecting the scale of the Nin transform of the measured signal. In the initial position, the output of the distributor 10, associated with the input of the coincidence element 7, is in the excited state, i.e. ) in the state of the scientific research institute of logical unit, and the remaining exits in the state of logical zero. In this position, the control input of the key 5 is acted on. The coal voltage impulses of the length SWFx (see the drawing) from the ruler 11. The control pulse time 5 is unlocked and is in the saturation state. Along the front of the control pulse, the process of sequential switching of the optocoupler cells 2-1 to 2-N begins with the simultaneous emitting of the corresponding LEDs 4-1 to 4-N of the indicator 3 until the control pulse duration of the UOT duration key 5. The number of the included LEDs 4-1 to 4-N determines the value of the measured frequency or period Tjt of the input signal. The measurement process is then repeated cyclically. If the duration of the UOT control pulse is such that during the time of its action all the optocouplers will switch. cells 2-1, 2-N, then from the output of the last PTN cell 2N to the input of the distributor 10 of block 6 a pulse is sent which leads to the excitation of its output connected to the input of the coincidence element 8 and to the removal of the excitation from the output coincidence element 7. Thus, an automatic transition to the. second subrange. The selection of the next subband is similar. In the process of sequential switching of the optocoupler cells 2-1 to 2-N, the probabilistic averaging of the instabilities of the on-delay times occurs simultaneously. The adjustment of a given value of Go / for example, during the calibration process, can be done by changing the supply voltage of the opto-cell 2-1 to 2-N. The shift register 1 on the optocouplers is characterized by a high degree of homogeneity of the components used in it and can be manufactured in a miniature version in a single technological cycle. Thus, in the proposed frequency meter, the periodometer can be provided with simpler technical means, the accuracy is the same order as in the similar device. This allows its use in low-cost, wide-range small-sized devices. The invention of the Frequency Periodometer with automatic switching of subbands, containing a shift register on series-connected cells with two stable states, a key, a block for selecting the scale of conversion of the measured signal, an indicator, a power source, and simplification, the shift register cells are made on oYiTpOHax, for example, thyristor, whose inputs are connected to the indicator inputs, the output of the last shift register cell is connected to the input of the scale selector unit and converting the measured signal frequency, which output is connected to a control input of a key, and an output connected to a power kgaocha bus shift register cells. -; Sources of information taken into account in the examination 1. The author's certificate of the USSR, 463927, cl. G 01 R 23/06, 2102.73. 2. Authors certificate of the USSR 374549, cl. G 05 R 23/10, 02JOi7l, Pira; (