SU363957A1 - ALL-UNION - Google Patents

Description

one

The invention relates to the field of hof-tic magnetic research, namely to converting the output signal of a sensor of a nuclear precession magnetometer into a digital code.

Known sod-precessional magnetometers with 3vieKTpoHnbiMn counters operate on the principle of counting the number of periods of the reference frequency over a period of a certain number of periods of nuclear precession, containing a generator of the reference frequency, a coincidence circuit, counters and a register. One of the counters recalculates a given number of nuclear precession periods and forms a time interval during which the frequency of the reference generator passes through the coincidence circuit to another counter. At the end of this time interval, the digital code from the last counter is rewritten into the output register. The number recorded on this register is the digital code for the duration of the nuclear precession period.

To obtain an output in units of magnetic field intensity, i.e., inversely proportional to the duration of the nuclear precession period, known division devices are used that contain an adder, shift registers, comparison circuits and registers for storing the results of intermediate operations. However, the known dividing devices are bulky and complex. The goal of the “inventor” is to simplify and increase the reliability of the device for converting the output information of the sensor of a trans-precessional magnetometer into a digital code. The goal is achieved by the fact that in the proposed device the period counter of the reference frequency is reversible and connected to the nuclear precession period counter and to the coincidence circuit through the switch. The sign bit of the reversible counter is connected to the output register, the second input of which is connected to the switch.

Using a reversible counter and switch, they implement the well-known division method without restoring the remainder, and the NA divider is stored and inserted into the reversible counter by repeatedly repeating the process of measuring the duration of a certain number of nuclear precession periods.

The block diagram of the conversion device is shown in the drawing.

The scheme / coincidence is connected to the generator 2 of the reference frequency and to the counter 3 periods of nuclear precession, the input of which is connected to the output of a nuclear-precessional magnetically sensitive sensor (MHD). The coincidence circuit and the counter of the number of nuclear precession periods are connected to the inputs of switch 4, one group of outputs of which is connected to the counting inputs of the first i bits of the reversible counter 5, the second group of outputs is connected to the main inputs of the output register 6, which is also connected to the sign bit of the reverse counter 5 .

The conversion device works in the following way.

During each cycle of operation of the sludge prenatal magnetometer, the sensor working substance is polarized and the nuclear precession frequency is converted, and the frequency conversion is performed within one cycle. The process of frequency conversion begins with the installation of meters in the initial state. The counter 3 periods of nuclear precession is set to the zero state, and a certain number is written to the reversing counter 5. This number depends on the coefficient of proportionality between the magnitude of the magnetic field and the nuclear precession frequency, on a given number of nuclear precession periods, during which the number of periods of the reference frequency is calculated, and on the reference frequency. The sign bit of the reversible counter 5 is set to the zero state. The conversion device operates in separate ticks, during each of which one digit of the result is determined. In each cycle, the counter 3 recalculates a given number of nuclear precession periods and forms a time interval equal to the duration of a given number of nuclear precession periods. The output signal from the output of counter 3 to the coincidence circuit 1 arrives, and the pulses from the generator of the reference frequency pass through the coincidence circuit to switch 4 and further to the input of the highest (rth) from the group of lower-order bits of the reversible counter 5. Switching on the reversible counter 5 The addition or subtraction is determined by the state of the sign bit (G) of this counter. In the zero state of the sign bit, counter 5 works on subtraction, and in the case of one, on addition.

Since the sign bit of the reversible counter 5 is set to the zero state before the conversion, the number of impulses of the reference frequency generator that came during the predetermined number of core precession periods is subtracted from the number recorded before the conversion. After the end of the subtraction through the switch 4, one is entered into the high bit of the output register 6, if the sign bit of the reversible counter 5 is in the zero state, and zero, if in the one state. Before the next cycle begins, the output of the switch 4 is connected to the counting input of the next lower (i-1) -th bit of the reversible counter 5, the reversible counter being switched on for addition or subtraction, as described above.

In the second and subsequent cycles from the number remaining in the reversible counter after the previous clock cycle, the number of pulses of the reference frequency generator is added to it during the passage of a specified number of core precession periods; by filling up the subtraction or addition to the next to the highest and subsequent lower bits of the output register 6, zero or one is written depending on the state

the sign bit of the reversible counter 5. Before the start of each clock cycle, the output of the switch 4 is connected to the counting input of the next low bit of the reversing counter 5. After determining the state of the least significant bit of the output register 6, the nuclear precession frequency conversion process ends.

The described sequence of operations, including shifting the divider before subtraction (addition), changing the type of operation (subtraction or addition), and determining the result digit depending on the sign of the result of the operation in a given clock cycle, is a division algorithm without restoring the remainder. The use to implement this method of dividing the reversible counter and switch and the representation of the divider in the pulse code allows us to construct a simple and reliable device for converting the output information of the sensor of the nuclear precession magnetometer into a digital code. The output is proportional to the magnitude of the intensity of the floor.

Subject invention

A device for converting the output information of a nuclear precessional magnetometer sensor into a digital code comprising a nuclear precession period counter, a reference frequency generator, a coincidence circuit connected to a nuclear precession period counter and a reference frequency generator, a reference frequency period counter, and different that, in order to increase the reliability of the device, the counter

the periods of the reference frequency are reversible and connected to the counter of the periods of nuclear precession and to the coincidence circuit via a switch that is connected to the output register connected to the sign bit of the reversible counter.

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