SU1170422A1 - Device for tolerance checking of voltage - Google Patents

Abstract

A DEVICE FOR ADMISSION MONITORING VOLTAGE, containing series-connected threshold elements of the upper and lower voltage levels, the inputs of which are connected to the input buses, characterized in that, in order to increase reliability by providing self-monitoring, two frequency dividers, four formers, are introduced into it, two amplifiers, two storage capacitors, an OR element, a control relay, two auxiliary and two separation diodes and a trigger, the outputs of which through the corresponding series Foreign amplifiers and storage capacitors are connected to the anodes of the auxiliary diodes and to the two inputs of the OR element, whose output is connected to the control relay winding, while the cathodes of the auxiliary diodes are connected to the zero potential bus, and the outputs of the threshold elements of the upper and lower voltage levels are connected to trigger inputs respectively, through the first driver and serially connected first frequency divider and the second driver, the output of which is connected to the installation input of the second de Ithel frequency input coupled to the output of the third formirova (L-body, and output - with an input of the fourth formers, which outputs through the separating diodes connected to the inputs of the upstream threshold voltage level. Yu GS

Description

The invention relates to a pulse technique and can be used in the construction of analysis devices.

The aim of the invention is to increase reliability by providing self-monitoring mode.

FIG. 1 shows a functional diagram of the device; in fig. 2 - time diagrams of operation (a - threshold elements of the upper and lower voltage levels when the control voltage Ujt changes, b - devices when the controlled voltage U changes across the whole range).

The device for voltage tolerance control contains input buses 1 and 2 connected to the information inputs of threshold elements 3 and 4 of the upper and lower voltage levels, the outputs of which are connected respectively to the inputs of the first driver 5 and the first divider 6, the output connected through the second driver 7 to the installation input of the second divider 8, the input connected to the output of the third driver 9, and the output from the fourth driver 10, and to the first input of the controlling trigger 11, the second input of which en with the output of the first driver 5, and its outputs are connected to the inputs of amplifiers 12 and 13, the outputs connected respectively to the storage capacitors 14 and 15 to the inputs of the OR 16 element, the output of which is connected to the winding of the control relay 17, while the inputs of the OR 16 element are connected to a zero potential bus through auxiliary diodes 18 and 19, and the first and second outputs of the fourth driver 10 are connected respectively to the first inputs of the threshold elements 3 and 4 of the upper and lower voltage levels through isolation diodes 20 and 21, pr In the fourth mapper 10, the input is connected to one plate of the capacitor 22, the second plate of which is connected to a zero potential terminal through a resistor 23 and directly to the base of the transistor 24, into the collector circuit of which a transformer 25 is connected, the secondary windings of which are connected to the outputs of the fourth driver 10 , and a resistor 26 connected between the inputs of the threshold element 3 of the upper voltage level, provides the setting of the switching threshold of the threshold element 3, while the threshold elements 3 and 4 can be in Full on-optocouplers inverters 27 and 28.

The device for tolerance control voltage with self-control works as follows.

The controlled voltage, Ujt, from input lines 1 and 2 goes to threshold elements 3 and 4, where it is compared with threshold voltages Ui of the lower and U2 upper tolerances (Fig. 2a, plot a). With

the value of the monitored voltage Ui at the output of the threshold elements 4 and 3 there are respectively zero and unit potentials, when 5 the monitored voltage reaches the value of the output of the threshold elements 4 and 3, zero potentials appear (Fig. 2a, plots a - b)

Suppose that the dividers 6 and 8 in the initial state are in the zero state, i.e. there are zero potentials at their outputs, and the value of the controlled voltage U is within, then at the output of the threshold element 4, for example Based on the inverter optocoupler 28, zero pulses (Fig. 26, plot b) appear, filling the first divider 6, made, for example, on the basis of a binary counter with a conversion factor of sixteen. With eight pulses

0, at the output of the first divider 6, a positive voltage drop (0/1) occurs (Fig. 26, plot d), under the action of which a short potential potential occurs at the output of the second driver 7 (Fig. 26, plot d), which sets the trigger 11 into the unit state (Fig. 26, plot c), and the divisor 8 is in the zero state (Fig. 26, plot e). In this case, the storage capacitor 15 starts charging from the amplifier 13, through the auxiliary diode 19, and

The storage capacitor 14 begins to discharge through amplifier 12 and element OR 16 into control relay 17 (Fig. 26, plot and). The second divider 8, made, for example, on the basis of a counter with a conversion factor of ten, is filled with clock pulses, for example, with a follow-up period of 0.02 s coming from the imaging unit 9, whose input is connected to the mains supply. When the tenth clocking pulse arrives, a positive difference appears at the output of the divider 8 (after 0.2 s)

voltage (Fig. 26, plot e) acting on the input of the fourth driver 10, made, for example, in the form of a differentiating circuit from a capacitor 22 and a resistor 23 and a transistor 24 with a transformer 25 in the output (collector) circuit.

As a result, a pulse is generated at the outputs of the driver 10, acting through the separating diodes 20 and 21 at the inputs of the threshold element 3 (made, for example, on the basis of an optocoupler-inverter 27 with a shunt input of the last resistor 26, which sets the threshold for switching on the threshold element 3) that leads to a short-term appearance of a zero pulse at the output of the threshold element 3 (Fig. 26, plot c), a single pulse at the output of the first generator 5 (Fig. 26, plot g) and the installation of a controlling trigger 11 at zero all over

state (Fig. 26, plot c), i.e., thus checking the operability of the upper tolerance channel. In this case, the control relay 17 begins to receive power from the storage capacitor 15 (the capacitor 14 begins to recharge).

After 0.32 seconds (the period of filling the first divider 6), a positive voltage drop occurs at the output of the first divider 6, which ultimately leads to the overturning of the controlling trigger 11 in a single state. Further, the operation of the device is repeated.

Thus, in the case when the controlled voltage U does not exceed the upper tolerance voltage U2, the controlling trigger 11 periodically changes its state, thus ensuring the health of the upper tolerance channel.

In the case when the value of the monitored voltage exceeds the upper tolerance voltage U2, the operation of the device proceeds essentially the same as the one described above. The only difference is that a zero pulse arises from the effect of each positive half-wave of the monitored voltage at the output of the threshold element 3 (Fig. 26, plot g), acting through the first driver 5 at the input

setting in the zero state of the controlling trigger 11, i.e., this trigger is constantly kept in the zero state. Storage capacitor 15 is discharged and the control relay is turned off. At the instants of time (after 0.32 s), when the first divider 6 is filled, a single pulse appears briefly at the output of the second shaper 7, setting the controlling trigger AND into a single state, however, after a very short time (almost instantly which is determined by the non-simultaneity of switching on the threshold elements due to the difference in voltage Ui and Ug (Fig. 2a, plot a-b) returns to the zero state (fkg. 26, plot and). Consequently, the accumulative

5, the capacitor 15 does not have time to charge (in this case, the charging time of the storage capacitors 15 and 14 is approximately 0.1 s) and the control relay 17 remains in the off state.

Thus, in the case when the controlled voltage U exceeds the voltage Ug of the upper tolerance, the controlling trigger 11 practically remains in one state.

Thus, the failure of any element of the device leads to de-energization of the control relay, thus ensuring reliable operation of the device.

Claims (1)

DEVICE FOR PERMISSION VOLTAGE CONTROL, containing series-connected threshold elements of upper and lower voltage levels, the inputs of which are connected to input buses, characterized in that, in order to increase reliability by providing a self-monitoring mode, two frequency dividers, four shapers, two are introduced into it an amplifier, two storage capacitors, an OR element, a control relay, two auxiliary and two isolation diodes and a trigger, the outputs of which are connected in series through the corresponding Amplifiers and storage capacitors are connected to the anodes of the auxiliary diodes and to the two inputs of the OR element, the output of which is connected to the winding of the control relay; when this is done, the cathodes of the auxiliary diodes are connected to the bus of zero potential supply, and the outputs of the threshold elements of the upper and lower voltage levels are connected to trigger inputs, respectively, through the first driver and in series connected the first frequency divider and the second driver, the output of which is connected to the installation input of the second divider Toty, an input connected to the output of the third driver, and output - with an input of the fourth driver, which outputs through a separating diodes connected to the inputs of the upper voltage level of the threshold element. Fig · ;!