SU1073558A1 - Thickness-to-time-interval transducer - Google Patents

Abstract

THERMAL TRANSFORMER IN TIME INTERVAL, containing a magnetic field source connected in series with an induction floor converter, a first key, an integrator, a null organ, and a control circuit and a second key connected to the input of the integrator, the first output of the control circuit is connected to the master the input of the first key, and the second output to the control input of the second key, and is intended for connection to an indicator, characterized in that, in order to improve the accuracy of the conversion, it is equipped with a pilo source The main current, the synchronization input of which is connected to the first output of the control circuit, and the output to the source of a magnetic field, and a second induction transducer fixed relative to the source of the magnetic field and connected to the input of the second key. (L with sd el 00

Description

The invention relates to electromagnetic thickness measurement methods and can be used to determine the thickness of materials and products. An electromechanical thickness-to-time transducer is known, comprising a source of a sinusoidal field, a magnetic field transducer and receiver, a phase shifter, and a mechanical contact system 1. The disadvantage of this device is the low accuracy and reliability of the conversion. The closest in technical essence to the invention is a thickness-to-time transducer that contains a source of a magnetic field, an induction transducer connected in series, a key, a null-organ integration unit, and a control circuit and a second key connected to the input of the integration unit. the output of the control circuit is connected to the control input of the first key, and the second output is connected to the control input of the second key and is intended to be connected to the indicator 2. A disadvantage of the known device L is the low accuracy of monitoring of the instability of the source field. The purpose of the invention is to improve the accuracy of the conversion. The goal is achieved by the fact that the thickness converter in the time interval, containing a source of magnetic field, connected in series an induction field converter, a key, a null-organ integration unit, and a control circuit, and a second key connected to the input of the integrator, the first output of the control circuit is connected To the control input .1.It is the input of the first key, and the second output to the control input - the second key and is intended to poduguchenie to the indicator, equipped with a sawtooth current source, the sync input cat cerned is connected to the first output control circuit, and an output - to a source of magnetic field, and the second inductive transducer rigidly fixed relative to the source of the magnetic field and connected to an input of the second Cl and Uche. FIG. 1 is a block diagram of a converter in a time interval; in fig. 2 - time diagrams and a key state table, where shaded time intervals correspond to a closed, non-shaded - open state of the corresponding key. The converter contains the source 1 of the sawtooth current i (t), the load of which is the source 2 of the magnetic field, the induction converter 3, the winding of which is rigidly fixed relative to the source 2 of the magnetic field. In the operation of the source 2 magnetic field, a second induction transducer 4 field is installed. The thickness-to-time converter also contains two keys 5 and 6, to the input of which induction converters 4 and 3 are connected, and the integration unit 7 connected in series, the null indicator 8 and the control circuit 9. The outputs of the keys 5 and 6 are connected to the input of the integration unit 7, the first output of the control circuit 9 is connected to the control input of the key 5 and the synchronization input of the sawtooth source 1, and the second output of the control circuit 9 is connected to the control input of the key 6 and is intended for connection to the indicator ( in Fig. I not shown). The device works as follows. The source 2 of the magnetic field is placed on one of the surfaces of the object under control (not shown in Fig. 1). An inductive transducer 4 is placed on the opposite surface coaxially with the source 2 of the magnetic field. The source 1 of the sawtooth current forms the sawtooth current i (t) in the source 2 of the magnetic field 2 (Fig. 2a). The operation of the sawtooth current source 1 is synchronized by pulses generated by control circuit 9, the frequency of which is chosen such that the time interval TO meets two conditions: the TO value must be longer than the creature: the disturbed field eddy currents in the non-ferromagnetic control object, which eliminates the effect of electrical conductivity on the accuracy of the thickness conversion in the time interval, the value of Io should be a multiple of the power supply period, which ensures high noise immunity of the converted and At the time of the reverse ho tp, the current i (t) drops to zero, which is maintained in the time interval t to 2TO. At the moment to, at the ends of the windings of the induction converters 2 and 4, EMF pulses EoCt) and fx (t) appear, respectively. At time t (, key 5 closes (key states in Fig. 2e) and the EMF pulse d (1) of negative polarity is integrated by the integration units. At time tj, key 5 opens, and a pi current i (t) appears at the same time. At the time interval ts - tj Ti, the integration block 7 is disconnected from the signal sources and acts as a memory. At the same interval, the EMF reaches a stationary value proportional to the rate of change of current i (t). At time t, key 6 is turned on and input to block 7 integration enters the constant emf about ((Fig. 2c). The output voltage Us (t) (Fig. 2g) of the integration block 7 decreases linearly until tx. When U5 (y becomes equal to zero, the null indicator 8 is activated, which affects the control circuit 9, as a result of which the key 6 opens and the output voltage The operation of the integration block 7 remains equal to zero until the beginning of the next cycle. The interval TX tjj - t is an output information value, depending on the thickness of the product being monitored.

The proposed transducer provides an increase in the accuracy of the thickness measurement and a reduction in unrecoverable scrap.

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Claims (1)

THICKNESS INTERVAL TIME CONVERTER comprising a magnetic field source, an induction field converter connected in series, a first key, an integration unit, a zero-organ, and a control circuit and a second key connected to the input of the integration unit, the first output of the control circuit 'is connected to the control input the first key, and the second output is to the control input of the second key and is intended to be connected to an indicator, characterized in that, in order to increase the conversion accuracy, it is equipped with a sawtooth source th current clock input of which is connected to the first output control circuit, and an output - to a magnetic field source, and the second inductive transducer rigidly fixed relative to the magnetic field source and a second input connected to the License keys SU ,,, 1073558>