SU1012218A1 - Electric heater testing control device - Google Patents

Abstract

A DEVICE FOR CONTROL OF TESTED ELECTRIC HEATERS, containing a test chamber with electric heaters and a temperature sensor, connected to the output of a single-point regulating automatic potentiometer, a multi-point automatic regulating potentiometer, transformer, by the number of electric heaters, there are 39 holes, and there are 39, and the same area. power thyristor blocks are connected to the corresponding electric heaters, more specifically so that, in order to increase the reliability of the device, a trigger element was introduced into it,, time control unit, first BAN element, discrete signal generating unit, groups of delay elements and BAN elements, first OR element, AND element, switching element, power switching element, reversing motor, NOT element, first, second, third and fourth elements MEMORY, second and third elements BAN, second OR element, block of periodic signals, fishing, and also for each electric heater a group of elements consisting of a starting element, a BANGE element, a power switching element, a MEMORY element, an AND element, a switching element and a reversing motor. A current sensor, a power converter and a constant voltage source, a discrete signal generating unit, the first outputs of which are connected through series-connected corresponding delay elements (L groups and the corresponding BAN group elements are connected to the first inputs of the first OR element, whose output is connected through I the input of the switching element connected to the first reversing motor, the output of which is connected to the first input of the control resistor of the first electric motor The main unit of the discrete signal forming unit through the first element MEMORY is connected to the first input of the first element BANGE, the output of which is connected to the input of the unit to form discrete signals, and the second input to the first input of the power switching element, to the input of the time control unit and with the first output of the trigger element, the second output of which through the element is NOT connected to the first input of the second element MEMORY, the second input connected to the first output of the discrete signal generation unit, and exit from the second inlet

Description

the house of the first MEMORY element, the output of the time control block is connected to the first input of the third MEMORY element, to the first input of the second BANNER element and to the first input of the fourth MEMORY element, the second input of which is connected to the output of the NOT element and the output through the second OR element to the first to the input of the unit of periodic signals and to the first input of the third BANNER element, the output connected to the second input of the switching element, the second input. the first output of the single-point automatic potentiometer, the input connected to the output the temperature sensor house and the second output through the second BANNER element - with the second input of the third MEMORY element, output to; which is connected to the second input of the second OR element; the output of the periodic signal unit is connected to the second input of the first OR element; the inputs of the multipoint regulating automatic potentiometer are connected with the outputs of the respective power converters, and each output through the series-connected elements MEMORY, AND element, switching element and reversing motor - with the first input, respectively etstvuyuschego control resistor, second inputs connected to the output of the DC stabilized power voltage outputs power minute. the ristor blocks are connected to the inputs of the respective power converters, to the inputs of current sensors, the outputs connected to the third inputs of power converters, the second input of each power thyristor unit connected to the first output of the corresponding switching element, the first inputs connected to the output of the transformer connected to the power bus, the second by the input of the switching element is connected through the BANNER element to the output of the corresponding starting element and to the second input of the switching element The element connected to the second inputs of the BANNER element and the element And, the input of the trigger element is connected to the power bus and to the second inputs of the switching elements whose third inputs are connected to the output of the block of periodic signals, and the output of the even element of the MEMORY is connected to the second input of the element BAN.

The invention relates to a test technique and, in particular, to test control devices for silicon carbide silicon heaters for a warranty period.

A device for temperature control, containing an electric heater, power and control thyristors, diodes, fixed and variable resistors, a matching transformer, an electrocontact thermometer, is known.

The operation of the device consists in the fact that when the resistance of the phase-sensitive bridge is changed manually by means of a variable resistor, the output voltage of the control thyristor relative to the phase of the supply voltage and, consequently, its angle, changes at the output of the matching transformer. A current pulse through the control thyristor arrives at the control electrode of the power thyristor, which opens at a certain angle, and the current pulse arrives at the electric heater. When the contact of an electrocontact thermometer is closed, the input circuit of the control electrode is short-circuited, as a result of which the control and power thyristors are closed,

This device has the ability to manually adjust its output voltage, however, it also works on the principle of supplying the electric heater with the maximum voltage, or its complete removal, and this ultimately reduces the quality and reliability of control.

The closest to the proposed technical essence is a program thermostat / 1 torus for a gradient 310 electric furnace, containing a test chamber with electric heaters and a temperature sensor connected to a single-point automatic potentiometer, a multi-point automatic potentiometer, a transformer, control resistors connected. to the corresponding control units and connected through the power thyristor blocks to the electric heaters of the respective zones.  In addition, the thermostat contains program blocks for setting a temperature gradient.  upper, lower and middle zone.  The output of the middle zone temperature setting unit through the measuring unit is connected to the middle zone temperature sensor and to the input of the regulating device, the outputs of which are connected to one input of the three-channel divider, the other inputs of which are connected to the outputs of the program blocks for setting the temperature gradient of the upper and lower zones. in that, according to a given value or program of the temperature of the middle zone, the required temperature conditions are provided both in the middle zone itself and in the upper and lower zones na gradient electric furnace.  In addition, the possibility of software control is provided for both the upper and lower zones using the appropriate program blocks.  In this case, the leading parameter of the process is the temperature of the middle zone, through which the temperature correction of the upper and lower zones 2 is carried out.  However, this device does not contain, based on such a high-precision process, the noise immunity of the program blocks of setting the temperature gradient of the upper and lower, as well as the middle zones.  In addition, the device is characterized by insufficient galvanic separation of the output circuits of the regulating device of the middle zone and the) gram blocks of setting the temperature gradient of the upper and lower zones.  These shortcomings have a negative effect on the quality of the process control that c.  Ultimately, it is not possible to achieve the high accuracy for which the well-known device was created. In addition, turning on the furnace transformer at the output of the power thyristor unit leads to the presence of overvoltage on the power thyristors, which can prematurely destroy them, in turn, affects the reliability of the well-known device, especially during its long-term operation.  The purpose of the invention is to increase the reliability of the device.  The goal is achieved, then, into the device for controlling the exhaustion of the electric heaters,. The test chamber contains electric heaters and a temperature sensor connected by an output to the input of a single-point automatic auto-potentiometer, a multi-point automatic regulating potentiometer, a transformer, by the number of electric heaters the control resistors connected to the first inputs of the corresponding control units, whose outputs through the power thyristor blocks are connected with corresponding electric heaters, introduced lusk element, time control unit, first element BAN, bl to the formation of discrete signals, a group of delay elements and BANNER elements, the first element OR, AND element, switching element, power switching element, reversing motor, element NOT, first, second, third and fourth elements MEMORY, second and third elements BAN, second element OR, a block of periodic signals, as well as for each electric heater a group of elements consisting of a starting element, a BAN, an element, a power switching element, a MEMORY element, an AND element, a switching element and a roar A motor, a current sensor, a power converter and a constant voltage source, a discrete signal generating unit, the first outputs of which are connected to the first inputs of the first element OR, the output of which is connected through the AND element through serially connected delays of the group. with the input of the switching element connected to the first reversible motor, the output of which is connected to the first input of the control resistor of the first the electric heater, the second output of the discrete signal generating unit through the first element MEMORY is connected to the first input of the first BANGE element, the output of which is connected to the input of the discrete signal forming unit, and the second input to the first input of the power switching element, to the time control unit input and to the first output starting element, the second output of which through the element is NOT connected to the first input of the second element MEMORY, the second input connected to the first output of the discrete signal generation unit and the output is with the second input of the first MEMORY element, the output of the time control unit is connected to the first input of the third MEMORY element, to the first input of the second BANNER element and to the first input of the fourth MEMORY element, the second input of which is connected to the output of the HE element, and output through the second element OR - to the first input of the block of periodic signals and to the first input of the third element BANGE, the output connected to the second input of the switching element, BTopbtM input - to the first, the output of a single-point automatic potentiometer, input The second output through the second BANCH element With the second input of the third MEMORY element, the output of which is connected to the second input of the second OR element, the output of the periodic signal unit is connected to the second input of the first element OR, the inputs of the multipoint regulating automatic potentiometer connected to the outputs of the respective power converters, and each output through the successive. MEMORY element, AND element, switching element and reversing motor - with the first input of the corresponding control resistor, second inputs of the constant stabilized voltage source connected to the output, outputs, turns of the power thyristor blocks connected to the inputs of the corresponding power converters , with inputs of current sensors, outputs connected to third inputs of power converters, and the second input of each power thyristor unit is connected to the first output of the corresponding About the switching element, the first inputs of the transformer connected to the output, connected to the power bus, the second input of the switching element is connected through the LETTER 10 186 / element with the output of the corresponding starting element and the second input of the switching element connected to the second inputs of the BANNER element and the And element, the input the trigger element is connected to the power bus and to the second inputs of the switching elements, the third inputs of which are connected to the output of the block of periodic signals, and the output of the fourth element MEMORY under Key to the second input of the item.  FIG.  1 shows a diagram of the device; in fig.  2 illustrates an example of a circuit for generating discrete signals; in fig.  3 diagram of the switching element.  The device contains a starting element 1, block 2 of time control, the first element BAN 3, the block C of forming discrete signals, groups of elements 5-S of the first type, each of which has elements of time and elements BAN, the first element OR 17, element 18 , switching element 19, power switching element 20, reversing motor 21, NOT element 22, first 23, second 2, third 25 and fourth 2b MEMORY elements, single-point regulating automatic potentiometer 27, in time. 28 and the third 29 BENTER elements, the second element OR 30, the source of 31 periodic signals, groups of elements 32-37 of the second type, each of which incorporates the start-up elements ZV-AZ, the elements BAN,.  power switching elements 50-55 elements MEMORY 56-61, elements I B2-B7, switching elements 68-73 and reversing motors, multipoint regulating automatic potentiometer 80, control resistors 81-87, control blocks 88-9, power thyristor blocks 95 101, current sensors 102-107, power converters 108-113, 1 nd temperature sensor, transformer 115, constant stabilized voltage source 116, regulating 117 and test heaters 118-123, test chamber 124.  The discrete signal generating unit 7 contains a BAN 125 element, an AND 126 element, an AND 126 element, a delay element 127 and 128, a MEMORY element 129, a group of elements 130-1t2, each group containing an element M710 MEMORY H3. . . 155, first 156. . .  168, second 169. . . 181 and third 182. .  19 elements BANTS, elements-195. .  207 delay.  All groups, except the first 130, contain the element And 208. . .  219.  In addition, a switch 220, switch blocks 221 are included in the block. . .  223 each of which contains individual switches of outputs of discrete signals 22 ,,. 23 elements OR 236. . . 230, elements AND, MEMORY, NOT and DELAY.  The switching element 19 contains the elements and the banned 2. 5 and a two-channel magnetically controlled element 2A6.  FIG.  1, the outputs O, b, c, d, e of the block L of forming discrete signals and the inputs f, h, k, 1, m, n, p, q, g, s, t and u of the element MEMORY 56-6i are also designated.  Before the device is put into operation, the logical element 1 is absent at the input of the element 22, but is present at the output, as a result of which the first element MEMORY 23 is charged and the second element MEMORY 24 is reset, at the input of which there is no signal 1.    When acting on the trigger element 1, a signal 1 is generated at its output, which passes through the open first element BANGE 3 to the input of the block Formation of discrete signals, launching it into operation.  In addition, the same signal of logical 1 goes to the HE 22 element, as a result of which the signal of logical 1 at its output disappears,. as well as on the time control unit 2, starting it up, and switching the power switching element 20 to the on state, which feeds from its First output network voltage to the power thyristor unit 95 of the control electric heaters 117 and generates a logical signal at its other output 1, arriving at the element And 18.  Translation of the TC into the working state starting elements 38-43.  At the output of these elements, sig is formed by transforming the net voltage. Logic 1 bursts that go through the corresponding open elements BANTS 44-49 to the corresponding power switching elements 50-55, respectively, groups of elements 32-37 of the second type.  These 88 elements are transferred to the on state, supplying power from the furnace transformer IZ through the switching elements to the corresponding power thyristor blocks 96-101 of the tested electric heaters, and also form at their outputs the logic T signals, which go respectively to the elements I 62- 67 corresponding groups of elements 32-37 of the second type.   the absence of voltage electric heaters being tested, which is supplied to them only when the specified temperature is present in the test chamber 124. The multipoint regulating automatic potentiometer 80 forms on its respective outputs the sygnates of logical 1, which are fed to the inputs f, k, m, p, g, and t, respectively, of the MEMORY elements 56-61 of the corresponding groups of second-type RChT elements, resulting in these elements being cocked and At their outputs, the signals of the logical interface II 1 are also formed, which are received from the inputs of the corresponding elements And B2-B7, respectively, of the second type of element groups 32-37.  The presence of the signals of logical 1 on both inputs of elements b2-b7 allows them to form the same signals at their outputs that are fed to one of the inputs of switching ele- gents 68–73 of the corresponding groups of 32–37 second type, as a result of which these elements are prepared for a mode of operation in which Network voltages periodically form at their outputs X, which occurs when a 2k setpoint temperature is reached in the test chamber}.  A single-point automatic potentiometer regulating 27, receiving information from j53T4HKa 114 about the temperature in the test chamber 124, generates in the temperature range from the initial to the preset, for example, a logical 1 signal at its output Z, fed through the open second element BANGE 28 to one of the inputs of the switching element 19, which, having on its other input a signal of a logical 1 from element AND 18, generates a voltage signal at the output, which starts to rotate the reversing motor 21 together with a control resistor 81 fed from a source ka 116 stably constant voltage in a direction in which an increase of the control signal to the control unit 88.  Delay element 9 generates a logical signal 1 at its output, which closes the BLOCK element 13, as a result of which the mains voltage disappears at the output of switching element 1, the reversing motor 21 turns off, jerk 21 is formed at the input of control unit 88 the value of the analog current signal, which after conversion into it and the power tiris. The output unit 95 forms, at the output of the latter, the first value of the voltage applied to the regulating electric heaters 117, which produce the release of thermal energy in the test chamber 12, with which the test begins to heat up. - electric heaters 118-123.  The operation of the block A of generating discrete signals occurs as follows.  .  When a signal is received logical 1 from. of the first element BANNING at the input of the block t, this signal is sent to one of the inputs of element I 126, passes through the open 1 element BANNING 125 to element 127 DELAYS and the other input of element AND 126, as a result of which its output forms a logical 1 signal, which cocks the MEMORY element The NC of the group of elements 130 and -4 through the open first element of the ZDPRET 156 of the same group places the second element BAN 169 into the closed state.  After cocking element MEMORY 1 on. its output generates a signal of logical 1, which is accessed through the open third element BAN 182 of the group of elements 130 and the on switch 220 to the output of the block A of forming discrete signals.  In addition, the signal of logical 1, which is available at the output of the third element BANGE 182 of the group of elements 130.  transfers to the closed state the third element BANGE 183 of the group of elements 131.  After that, after the time specified by DELAY 127, its 18 output generates a logical 1 signal, which cocks MEMORY 129, as a result of which a logical 1 signal is also generated at its output, which enters the input of delay element 128 and converts to closed state element BAN 125, as a result of which the signal of logical 1 at the output, element AND 126 disappears, and ultimately, at the input of the second element, the BAN 1b9 group of elements 130.  After that, the signal of logical 1 from the output of the MEMORY element enters through the open second element BANCH 1b9 of the group of elements 130 to the delay element 195 of the same group, the output of which through a time specified by this element is a signal of logical 1, which is fed to one of the inputs of the AND element 208 of the group of elements 131 and closes the first element of the PROHIBITION 156. V Thereafter, After the time specified by the delay element 128, a logical 1 signal is generated at its output, which resets the MEMORY element 129.  At the same time, the logical 1 signal disappears at its output, the BAN 125 element opens, as a result of which the logical 1 signal is generated again at the output of AND 126 and the corresponding input of AND 108 of a group of elements 131.  The presence of signals of logical 1 on the two inputs of the element AND 208 causes the formation of the same signal on it, as a result of which the element MEMORY of group 1 of elements 131 is cocked, and the open first element BAN 157 of the same group translates into a closed state the second element BAN 170 of elements 131  After the element MEMORY 1k of the group of elements 131 is cocked, a logical 1 signal is generated at its active output, which translates the third element BAN 182 of the group of 130 elements into a closed state, as a result of which the logical 1 signal disappears at its output and output of the discrete signal generating unit k.  The absence of this signal at the output of the third element BANGE 182 of the group of elements 130 brings the third element BANE 183 of the group of elements 131 to the open state, as a result of which the signal logical 1 from the output of the MEMORY element goes to the switch 2kk of the switch block 221. .  After the signal of logical 1 at the output of element And 126 disappears, the second element BANGE 170 of the group of elements 131 is transferred to the open state, and the signal of logical 1 from the output of the MEMORY element Ikk of the same group enters the delay element 196 of the group of elements 131 and after a time given by this element, at its output a signal of logical 1 is formed, which translates into a closed state the first element BAN 157 of the group of elements 131 and enters the element 209 of the group of elements 132 and so on. d.  In a similar way, the control circuit of the platoon of the MEMORY elements of the other groups of elements and the formation of the logical 1 signals at the inputs of the switches of the corresponding switch blocks work.  Depending on which switches in each of the blocks of switches 221.  . . 223 is turned on, the signals of logical 1 pass through the elements OR 236. . 238 to the corresponding outputs a, C o.  Since the signal of logical 1, formed sequentially at the output of each group, excludes the same signal to you:; the previous one. groups, then, obviously, to the corresponding outlets of the block I och g t ojr h. In the case of the formation of discrete signals, only one such sys | passes in the absence of the others.  The selection of any specific signals at the respective outputs of the block k of the formation of discrete signals is carried out using individual switches 224. ,, 235 corresponding blocks of switches 221 ,. ,, 223.   Thus, the source information is specified.  After () the signal of logical 1 is outputted at the output of the delay element 207 of the group of elements 142 and it is fed to one of the inputs of the AND 240 element, the other input of which also receives the signal logs. In other words, a 1 formed at the output of the element And 126, the formation of the same signal at the output of the element And 240 occurs.  This signal collects the element MEMORY 241, at the output of which the output (the block of 1 1812 generation of discrete signals) appears the signal logical 1, with which the second element MEMORY 2C of the device is charged (Fig.  1), after which, at its output, a logical 1 signal is generated, which closes the first BAN 3 element and the II inputs of the BAN 125 and AND 126 elements of the Block k forming discrete signals stops its operation.  The signal, a logical I, which has an MEMORY element at its output, resets all MEMORY elements. . . 155 groups of elements 130. . . As a result, the logical element 1 signal disappears at the inputs and output of the OR element 239, which is also absent at the input of the element NOT, and at its output appears the logical signal 1 which, having passed through the delay element, performs a reset of the MEMORY element 241.  The total time of operation of the described block can be, for example, j calculated for 180 minutes with a discreteness of the occurrence of signals of logical 1 at the outputs of groups of elements 131. . .   in 15 minutes  In addition, to raise the temperature in the chamber, for example, it is necessary to obtain at the output “, b, c and 3 four signals of logical 1,.  whose understanding should be through O, 30, pps r. j i v / jimnv Jot i D «v | W f 90 and 1bO min.  In this case, a signal from the group of elements 130 passes to the output of the SC.  to exit b from the group of elements 132, to exit c from the group of elements 136, to exit E from the group of elements 141.  .  During operation of the block, as soon as a logical 1 signal appears at the output of the MEMORY element 143 of the group of elements 130, the logical 1 signal at the input of the MEMORY 241 element disappears.  After reaching the first value of the voltage regulating electric heaters 117, the logical-i signal 1 disappears at the output of the discrete signal generating unit 4 and this signal disappears at the inputs of the time elements 3 and the BAN 13 of the first type element 5, the logical 1 signal disappears output element 9 time.  After a predetermined period of time, a logical 1 1 signal appears at the output of the cG block of the discrete signal generation unit, while the signals at its outputs fl, c, d and d are absent.  Subsequently, the same signal resets the first element MEMORY 23, which is expressed in the disappearance of the logical 1 signal at its output and the reset input of the second element MEMORY 2k, and also causes the reverse movement of the bodies 21 with the control resistor 81 again which leads to the formation of a second, but greater than the first, voltage value on the regulating electric heaters 117.  The process of heating the test chamber 12 and the test heaters 118-123 is continued.  -In the formation of the second voltage value, the elements of time 10 and the BANNER k groups of elements 6 of the first type take part. In the future signals of logical 1 appear at the outputs c, and then c1, which leads to the formation of the third and fourth voltage values regulating electric heater x 117.  The time elements 10-12 set their time settings, which makes it possible to turn the control resistor 81 at certain angles at which, ultimately, the required values of the voltage on the control electric heaters 117 are achieved.  Further, after reaching the fourth value of the voltage on the regulating electric heaters 117, the set temperature e is reached in the test chamber 124, at which the stabilization mode starts, as well as a gradual increase in the voltage on the tested electric heaters.  118-123 to the value at which a given power is reached.  After performing the necessary operations, the discrete-signal formation unit k generates a logical 1 signal at its output, which cocks the second element of MEMORY 2k, as a result of which a logical 1 signal appears at its output, closing the first BAN 3 element, the output signal does not disappear and the block 4 discrete waveforms are removed from operation.  Reaching the set temperature in the test chamber results in 18. U that the single-point regulating automatic potentiometer 27 generates a logical 1 signal at the output, which passes through the open third element BANCH 29 to the input of the third MEMORY 25 element, coaxes it, as a result the logical 1 signal also appears at its output, then The second ELEY 30 to the input of the source of 3 periodic signals, which is put into operation.  Resistor 81 is controlled by a reversing motor 21, the rotation of the output shaft of which is transmitted to the shaft of the resistor 81 by, for example, a Tpy6ijaToro roller, one end of which is connected to the shaft of the motor 21 and the other to the shaft of the resistor 81.  The presence at the input of the switching element 28, leads to the fact that it closes in the switching element. 19 element BAN and goes to one of the inputs of the element 2.  The signal of logical 1 comes from the output of the element And 18 through the switching element 19 to the other inputs of the element BANNER 2kS and the element And 2kk.  In view of.  the fact that the prohibition element B is closed, the signal of logical 1 is formed at the output of element AND 244 and acts on the corresponding part of one of the channels of the magnetic control element 246.  The power part of this channel operates and transmits the network voltage to the output of the switching element 1E. - If at this input of the switching element 19 there is no logical 1 signal, which arrived earlier from the BAN 28 element, the BAN 245 element and the logical signal are transferred to the Open state. 1 from element 18 passes through switching element 19 and the open element BANE 245 to the control part of another channel, the magnetic control element 246, acting on it.  The power section of this channel triggers and transmits the voltage. network output switching element 19.  Control unit 88 operates on the principle of converting its input analog current signal to a phase-pulse signal acting on an angle. opening thyristors of power unit 95.  .  1510 It is assumed, for example, to use a thyristor voltage regulator, which contains such blocks, as a control unit and a power thyristor unit. Multipoint (multi-channel) control automatic potentiometers KSP-1 or KSP-2, or KCn-i are used as unit 80. |.  In such devices, sensors are polled sequentially and cyclically, comparing their analog signals with the signal of the corresponding sensor, determining the error, amplifying it, and building it with the help of an output logic amplifier.  The occurrence of a logical 1 signal at the output of a single-point regulating automatic potentiometer 27 and the disappearance of such a signal at the other of its output leads to the fact that the switching element 19 is switched to the operation mode, at which short-time network voltage signals appear at its output In the event that short-term periodic signals also appear at the output of the source 31 of periodic signals, which ultimately causes the rotation of the reversing motor 21 together with the control resistor 81 in the direction When a partial decrease occurs. voltage on the regulating electric heaters 11 / This mode of operation occurs until logical signal 1 appears at the output Z of the single-point regulating automatic potentiometer 27, which indicates a decrease in the temperature in the test chamber 124 below the set one.  After that, the switching element 19 switches from the mode of operation, at which at its output simultaneously with the appearance of the signal at the output of the source 31 of periodic signals appear short-term network voltage signals that rotate the reversing motor 21 along with the control resistor 81 a direction in which the voltage on regulating electric heaters 117 partially increases.  Such. the operation mode occurs until the logical 1 signal at the output of the single-point regulating automatic potentiometer 27 disappears, which testifies that the temperature in the test chamber is higher than the set one, then a partial decrease in voltage occurs. Thus, using the described The mode is made to stabilize the set temperature in the test chamber 12 until the end of the test, the time control of which is carried out by the time control unit 2.  From the moment the specified temperature is reached in the test chamber 12, a voltage rise is applied to the tested electric heaters 118-123.  The supply from the source 31 of periodic signals to | atomic signals in logic 1 at the input of the switching elements 68-73, respectively, leads to the fact that short-term periodic signals are also formed at their outputs. mains voltage signals, which begin to periodically rotate reversible motors together with the corresponding control resistors 82-87, fed from a constant voltage source 116 in the direction in which it occurs.  an increase in the voltage at the outputs of the power thyristor blocks 96-101 and the corresponding test electric heaters 118-123.  This mode is produced until the inputs h,, n, q, 5 and U of the corresponding elements of MEMORY 5b-b1 of groups of elements 32-37 of the second type do not receive the signals of logical 1 while the inputs f, k, m, p, g t of the same elements they do not disappear.  Information about the power value is generated in the power converters 108113, each of which receives voltage data on the corresponding electric heater under test and the current from the respective sensors 102-107.  In these converters, information is processed and, in the form of analog voltage signals, enters a multi-point control automatic potentiometer 80.  where it is compared with the electric heater given for each test subject.  If the inputs h, 1, n, q, 5, and U of the corresponding elements of MEMORY 56-61 show the signals of logical 1, coming from the multipoint regulating automatic potentiometer 80, this means that the power on the corresponding and tested electric heaters is higher than the specified one.  In this case, the evolved signals produce a reset of the MEMORY 56-61 elements, as a result of which the logical Vl signals disappear at their outputs and, respectively, at the inputs of the AND 62-67 elements, which are also absent at the inputs of the corresponding elements of the switching elements 68-73 -37 second type.  In this case, intermittent signals appear. periodic signal source 31 causes the output of the switching elements 68-73 to appear periodic network voltage signals, which periodically rotate the corresponding reversing motors together with control resistors 82-87 in the direction in which the analog current currents are partially reduced the signals at the inputs of the respective control units 89-9 and, accordingly, the voltage at the respective test subjects 118-123 until the power level at them becomes lower than the set value.  In this case, logical signals appear at the inputs f, k, m, p, r, and t of the MEMORY 56-61 elements and disappear at the inputs h, 1, n, q, 5 of these elements.  MEMORY elements $ 6 61 are cocked, with the result that logical 1 signals are formed at their outputs, inputs of corresponding elements B2-B7 and their outputs, as well as inputs of corresponding switching elements 68-73 and groups of elements 32-37 of the second type.  Periodically appearing signals of logical 1, coming from the source of 3t periodic signals, form the output voltage of the switching elements 68-73 periodic network voltage signals, which periodically rotate reversing motors with control resistors 82-87 in the direction in which they partially increase both the analog current signals supplied to the inputs of the respective control units 89-9, and the voltage on the respective test electric heaters 118-123, supplied to them, respectively, with-power tees 96–0101 history blocks.  This occurs until the power on the tested electric heaters 118-123 becomes higher than the set point, after which

begins to periodically decrease the voltage and, accordingly, the power removed from the electric heaters being tested.

Thus, after reaching a given power, the process of partially reducing or increasing the voltage on the tested electric heaters 118-123 makes it possible to stabilize the given power on each of them until the end of the tests, after which the time control unit 2 generates a logical signal that closes the third element

BAN 29, resets the third element MEMORY 25 and cocks the fourth element MEMORY 26, at the output of which a signal appears logical 1, passing through the second element 30 to the input of source 31 of periodic signals, which continues to function. At the output of the third element MEMORY 25, the signal logical 1 is absent. Switching switch 19 is switched to a mode in which periodic grid voltage signals appear at its output whenever logical signals 1 periodically arrive at its input, coming from source 31 of periodic signals through the first element OR 17 and element 18 Periodic network voltage signals generated at the output of the switching element 19 periodically rotate the reversing motor 21 and with it the control resistor 81 in the voltage at which, eventually, the voltage periodically decreases. for regulating electric heater x 117 to zero value. After the signal of logic 1 appears at the output of the fourth element MEMORY 26, it closes the elements of the prohibition C-CE of groups of elements 32-37 of the second type, as a result of which the power switching elements 50-55 are switched to the disconnected state which, in turn, leads to a decrease in the voltage of the network from the power thyristor blocks 96-101, Further, due to the absence at the inputs of the elements 62267 of the signals logical 1, previously received from the corresponding power switching elements 50-55 switching elements 68-73 p revod are in opi1910

A sled mode in which the reversible motors 7,7-79 using the source 31 of periodic signals return the corresponding resistors 82-87 to their initial position, after reaching which the starting elements are rendered inoperative,

When the voltage on the regulating heaters 117 reaches zero, the starting element 1. is rendered inoperative, as a result of which the power switching element 20 is switched to the off state, the network voltage is removed from the power thyristor block 95, the output element NO 2 is formed signal of logical 1, which resets the fourth element of MEMORY 26.

The test process is complete.

The technical advantages of the invention in comparison with the known basic object, as which the control device, implemented in a G-3 type electric furnace (,

820

are to improve the quality and reliability of the tests.

In the object, taken as a baseline, as a result of the absence of the possibility of creating the necessary temperature conditions under which a given watt load is reached on the active surface of the tested electric heaters, the quality is reduced

tests, and consequently, the warranty time is underestimated.

In addition, the electric heater control device used in the base object causes a temperature change on their active surface, resulting in a decrease in the service life of the electric heaters.

The economic effect can be obtained by providing the possibility of timely detection of the deficiencies of the technology at the manufacturer of electric heaters in tests, eliminating them, which, ultimately, increases the yield of electric heaters in addition to their planned number. Dmno} .J kgyul29

Claims (1)

. DEVICE FOR CONTROLLING A TEST FOR ELECTRIC HEATERS, containing a test chamber with electric heaters and a temperature sensor, connected to an output with an input of a single-point automatic control potentiometer, a multi-point automatic control potentiometer, a transformer, control resistors connected to the first inputs of the corresponding power control units by the number of electric heaters, outputs the blocks are connected with the corresponding electric heaters, which that, in order to increase the reliability of the device, a start-up element is introduced into it,, a time control unit, the first, a FORBID element, a unit for generating discrete signals, groups of elements - delays and bans, the first OR element, the AND element, the switching element, the power switching element, a reversing motor, the element NOT, the first, second, third and fourth MEMORY elements, the second and third BAN elements, the second OR element, the block of periodic signals, and also for each electric heater, a group of elements consisting of a starting element, a PROHIBIT element, a power switching element, a MEMORY element, an AND element, a switching element and a reversing motor, a current sensor, a power converter and of a constant stabilized voltage source, a discrete signal generation unit, the first outputs of which through the g series connected the corresponding group delay element and the corresponding group PROHIBITION element are connected to the first inputs of the first OR element, whose output through the AND element is connected to the input of the switching element connected to the first a reversible motor, the output of which is connected to the first input of the control resistor of the first electric heater, the second output of the discrete forming unit signal through the first element, MEMORY is connected to the first input of the first element BAN, the output of which is connected to the input of the discrete signal generating unit, and the second input to the first input of the power switching element, to the input of the time control unit and to the first output of the starting element, the second output of which through the element is NOT connected to the first input of the second MEMORY element, the second input connected to the first output of the discrete signal generating unit, and by the output with the second input SU „, 1012218 the house of the first MEMORY element, output d time control unit is connected to the first input of the third element MEMORY, to the first input of the second element BAN and to the first input of the fourth element MEMORY, the second input of which is connected to the output of the element NOT, and the output through the second element OR to the first input of the block of periodic signals and to the first input of the third element is PROHIBITED, the output of the switching element connected to the second input, the second input with the first output of the single-point automatic potentiometer, the input connected to the output of the temperature sensor, and the second output the house through the second element is BANNED - with the second input of the third memory element, the output of which is connected to the second input of the second OR element, the output of the periodic signal block is connected to the second input of the first OR element, the inputs of the multi-point control automatic potentiometer are connected to the outputs of the corresponding power converters, and each output through series-connected elements MEMORY, element AND, a switching element and a reversing motor 1012218 motor - with the first input of the corresponding control resistor, by the inputs of a constant-current constant voltage source connected to the output, the outputs of the power thyristor units are connected to the inputs of the corresponding power converters, to the inputs of the current sensors, the outputs connected to the third inputs of the power converters, the second input of each power thyristor unit connected to the first output of the corresponding switching element, the first the inputs connected to the output of the transformer connected to the power bus, the second input switching element not through the element BAN with the output of the corresponding starting element and with the second input of the switching element connected to the second inputs of the element BAN and element And, the input of the starting element is connected to the power bus and to the second inputs of the switching elements, the third inputs of which are connected to the output of the fm block perio; signal, and the output of the fourth element of MEMORY is connected to the second input of the element BAN.