SU1522316A1 - Device for monitoring electromagnet operation - Google Patents

Abstract

The invention relates to instrumentation and automation and can be used to control DC electromagnets under production and operation conditions. The aim of the invention is to increase the reliability of monitoring the current and the response time of the electromagnet. The back edges of the negative polarity pulses, selected and amplified by the amplifier-limiter, trigger a one-shot, forming short pulses. These pulses open the keys connecting the inputs of the second and third amplitude detectors to the outputs of the first amplitude detector and integrator, respectively. At the same time, the current values of voltages, proportional to the amplitudes of local maxima and the time of local minima on the current rise curve, are recorded and stored by the second and third amplitude detectors until the next pulse from the one-shot. As a result, the last voltages recorded by the second and third amplitude detectors will correspond to the response current and the response time of the electromagnet. The accuracy of control in this case does not depend on the nature of the motion of the electromagnet core, which allows the proposed device to be used to control a wide class of electromagnetic mechanisms. 2 Il.

Description

The invention relates to instrumentation engineering and automation and can be used to monitor the parameters of direct current electromagnets under the conditions of production and operation.

The purpose of the invention is to reliably control the current and the response time of the electromagnet.

Fig, a diagram of the device for controlling the operation of the electromagnet; Fig. 2 shows time diagrams explaining the operation of the device.

The device contains a power-1 unit.-I, the output of which through a switch 2 is connected to the winding 3 of the electromagnet and the control resistor 4, connected interconnectingly. NZ

The voltage from the resistor 4 is fed to the input of the differentiating amplifier 5, the output of the amplifier 5 through the ycJliter-limiter 6 is connected to the input of the one-oscillator 7. The first amplitude detector 8 formed by a diode 9, a capacitor 10, a voltage follower 11 with a large input resistance, comparator 12 and key 13, the input is connected to the control resistor D, and the output through the first analog key 14 is connected to the input of the second amplitude detector 15s which is similar to the first amplitude detector 5 8 and is made on a diode {b, capacitor i, follower e 18 voltage, KONmapaTOpe 9 and key 20s Integrator 2J, is made: on the operational amplifier 22, resistor 23, capacitor 24 and key 25, the input through the second analog-key. 26 is connected to the voltage stabilized bus of power supply unit 1; the control input of the switch 26 is connected to the output of switch 2; the output of the integrator 21 is through the third analogue cell 27 connected to the input of the third amplitude detector 2.85 formed by a diode 29, a capacitor 30, and a voltage amplifier 31, a comparator 32 and a key, 33, nulling the inputs of the integrator 21, the first, second and third light detectors 8., 15 and 28 are connected to the device setup bus 34 in the initial state The control inputs of the first 14 to the third 27 analog keys connected to the output of the one-shot 7.

In FIG. -2, the following symbols are taken: i is the tripping current, tav the response time of the electromagnet.

The device works in a consistent manner.

Before starting the ethics test 34, a pulse is supplied to set the device to its initial state. At the same time, the pulse JBj 20;, 25, and 33 are discharged for the duration of the action. Discharge the capacitors lOj Г / ,, 24 and 30g enclosed the most output signals from the detector detectors 8, 15, and 28 and the intragrator 21,

In order to determine the current of operation of the electromagnet and the time of operation, the switch on switch 2 (time t.) Is turned on. As a result, the voltage from the power supply unit 1 (FIG. 2, pos. L) jumps to the winding 3 of the electric

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of the magnet and the control input of the analogue key 26, The current from the electromagnet winding increases according to a certain law (FIG. 2, position 2). As a result of intermittent movement, the current rise curve has several local impulses and local minima. The ICP of the electromagnet is determined by am: the last local maxi glitch), and the response time t pp is the moment of the last local minimum,

The voltage drop across the resistor 4s proportional to the current is differentiated in time by the amplifier 5 (Fig. 2, No.C.).

The limiting amplifier 6 excites and amplifies the pulses of negative polarity, the back of which m at one moment of time t t and t starts the one-shot 7., which at each start forms one short pulse (Fig.2p pos, 4).

The signal from the resistor 4 post-falls also to the input of the amplitude detector 4s At the output of the amplitude detector, the torus 8, a step voltage with a height of 5 and 5 equal to the corresponding local local maves is formed; the signal and the steady-state value of the signal (FIG. 2, pos. 5) .

At the moments of closing the key -: a 14 pulses from a single vibrator 7: and: apg), the output from the amplitude detrusor 8 charges the capacitor 17 gplits of the floor detector 15, E as a result of the absence of the amplitude detector 5 a step voltage is formed (Fig. , po.6.6), the last maximum value of which is equal to the local maximal signal of the signal from the resistor 4, and the successor is proportional to the electromagnet actuation current

At the moment when the key 2 is closed (moment 1;), the voltage from block 1 of the pc-package closes the ana- log key 26 and the integrator's input 25: 1od: - switches to the stabilizing voltage of the power block 1 as a result of - the increase in the integrator 25 output by -g melts according to a linear law (fig. 2). The current value of the voltage E of the intigrator 25 at the moments of closure of the key 27 by pulses from the simultaneous oscillator 7 is remembered by the amplitude detector 28. A graduated output of the amplitude sensor 28 is generated voltage (figure 2, position 8), the last value of which is equal to zheniyu on the integrator at the time of the last local minimum (point t) at current rise in the coil circuit characteristics. The amplitude of this voltage is due to the length of the time interval from time t to time t and corresponds to a certain time scale of the response of the electromagnet.

In order to determine the values of the operation current and the response time during the production and operation of the electromagnet, the voltage at the outputs of the amplitude detectors 15 and 28 is measured with voltmeters, the scales of which are calibrated in units of current and time.

Claims (1)

Invention Formula A device for controlling the operation of an electromagnet, containing a power supply unit, to the output of which, via a switch, terminals for connecting the electromagnet winding and a control resistor, a differentiating amplifier, whose input is connected to a control resistor, and the output terminal of the amplifier, and the first analog switch are connected in parallel first amplitude de2  - R EO I about 15 6 a tector and an integrator connected via a second analog switch to a stabilized power supply voltage bus, and the embedding inputs of the First amplitude detector and integrator are connected to the device installation bus in its initial state, Q in order to increase the current control accuracy and the time of operation of the electromagnet, the second and third amplitude detectors are entered into it, the third a1 | allog key and the single vibrator, the input connected to the output of the specified amplifier, the limiter, and the output to the control the third analog key is controlled and the first analog key is controlled by the information input connected to the output of the first amplitude detector, and the output to the input of the second amplitude detector, the second amplitude detector connected to the installation bus the device to its initial state and to the zero input of the third amplitude detector, the input of which is connected via a third analog key to the integrator output, and the ugfravlny input of the second analog key is connected to the output of the switch, and the input of the first ampouter detector is connected to the control resistor. 20 25 thirty 034 Phi g.1 naSifLiU