SU1339459A1 - Device for checking variable reluctance pickups - Google Patents

Abstract

The invention relates to instrumentation engineering and allows for expanding the control functionality. The device contains a constant voltage source 2 and a driver 3. Introduction of a source 5 of the reference voltage, a comparison unit 6, a matching unit 7, a logic unit 8, a pulse generator 9, an initial installation unit 0 increases the type of detectable defects and increases noise immunity by eliminating false positives with a large sensor signal 1 of 1 3.p. f-ly, 2 silt, 1d (L 7 d // 3 it with so 4; SP x

Description

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The invention relates to instrumentation technology and can be used to automatically control induction sensors.

The purpose of the invention is to expand the functionality by increasing the variety of detected defects of the test object and increasing the noise immunity by eliminating false alarms with a large sensor signal.

Fig, 1 shows the block diagram of the device; figure 2 - block diagram of the logic unit.

In Fig. 1, a monitored sensor 1, a constant voltage source 2, a driver 3, a load of the monitored sensor 1, a resistor 4, a voltage source 5 of the reference voltage, a comparison unit 6, a segmental unit 7, a logic unit 8, a pulse generator 9 are indicated. , the initial installation unit 10, the first 11 and the second 12 terminals for connecting to the control object and the communication line 13, the first terminal of the constant voltage source 2 connected to the first terminal of the resistor 4, the second terminal of which is connected to the first terminal I1 to connect to object of contact The second terminal of the constant voltage source a 2 is connected to the common bus, the second terminal 12 for connecting to the control object is connected to the input of the matching unit 7, the output of which is connected to the first input of the comparison unit 6, the second input of which is connected to the output of the source 5 the reference voltage, and the output to the enabling input of the logic unit 8, the counting input of which is connected to the generator output 9 pulses, and the setup input to the output of the unit 10 of the initial installation.

In addition, the device (figure 2) contains 1K-flip-flops 14, RS-flip-flop 15 and the element OR 16, with 1K-flip-flops connected in series, the first input of the element OR 16 is connected to the installation input of the logic unit 8 and the S-input RS -trigger 15, the second input - with the enable input of the logic unit 8 and the R-input of the RS flip-flop 15, and the output - with the R-inputs of the IK- triggers 14, the counting input of the first 1K flip-flop 14 is connected to the counting input of the logic unit 8, 1 entrance

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connected to the inverting output of the RS trigger 1 5.

The device works as follows.

With a good sensor I, the current from the constant voltage source 2 flows around the circuit: resistor 4 - link line 13 - driver. 3, and gives you a high level of voltage drop at the input of matching unit 7. This level is transmitted to the input of comparison unit 6, and since it exceeds the magnitude of the reference voltage, the biological unit 8 is in self-locking mode.

If there is a fault of type Obrish in the sensor circuit 1, the voltage at the input co2 of the block 7 will decrease, therefore,

the voltage at its output will become less than the magnitude of the reference voltage, unit 6 of the comparison will go into a state of logical O at the output, which

25 will trigger the RS-flip-flop 15 in logic block 8, Thus, at the output of the device there will be a signal that there is a fault.

If there is a type fault

2Q AC contact voltage will be lost at the time of the sensor circuit failure. At the output of the matching unit 7, the voltage will also disappear for the time of the sensor circuit failure. The voltage at the second input of the comparison unit 6, coming from the source 5 of the reference voltage, is in (shicin is greater than the voltage coming from matching Q auxiliary unit 7 during the period of sensor circuit failure. Therefore, the output of the comparison unit 6 receives in the form of a logical 0, which removes the logical block 8 from self-blocking and keeps it in the zero state, and a signal is received from the RS flip-flop 15 about a sensor circuit violation.

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When the sensor 1 circuit is restored, the voltage at the output of the matching unit 7 is restored to the nominal level, which exceeds the voltage from the source 5 of the reference voltage, resulting in an output.

In block 6, a signal in the form of a logical level O disappears and a signal appears in the form of a logical

The appearance of a signal with a logic level at the installation inputs of the K-flip-flops 14 of logic block 8 allows counting pulses of the generator 9 pulses by the logic block 8. If before the logic block 8 overflows and, therefore, when it is set to self-blocking, the sensor 1 circuit will break, 6 comparisons show a signal in the form of a logical O, acting on the installation inputs of the flip-flops of logic unit 8, as a result of which it will be reset and held in such a state, while at the output of the comparison unit 6 a signal in the form of a logical Grand O will not disappear. At the same time, the signal about the sensor I circuit is continued.

If at any time the sensor circuit is restored, then at the output of the comparison unit 6 the signal with the logic level O will disappear and the logic unit 8 will begin to accumulate the pulses of the generator 9 pulses. As soon as the logical block 8 overflows, it is set to self-blocking, i.e. becomes insensitive to the pulses of the pulse generator 9. In this case, a sensor fault signal is detected.

The time for filling the logic block 8 with pulses of the generator 9 pulses before it overflows is selected on the basis of the maximum possible interval between violations of the circuit of sensor 1, but no less than 2-3 periods of the frequency of its output signal.

This is necessary in order to ensure reliable and stable operation of the information-measuring systems in which this device will be used after the disappearance of the sensor circuit fault.

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Claims (2)

1. A device for monitoring inductive sensors, containing a constant voltage source, a resistor, first and second terminals for connecting to the test object, the first output of a constant voltage source connected to the first terminal of the resistor, the second terminal of which is connected to the first terminal for connecting the object control, the second output of the constant voltage source is connected to A common bus, characterized in that, in order to expand the functionality and increase noise immunity, a matching unit, a comparison unit, a reference voltage source, a logic unit, an initial installation unit and a pulse generator are inserted into it, and the second terminal for connection to the control object connected to the input of the matching unit, the output of which is connected to the first input of the comparison unit, the second input of which is connected to the output of the voltage source, and the output to the enabling input of the logic unit, th input is connected to the output of the pulse generator, and the setup input - with the output of the initial installation block. 2. The device according to claim.), Characterized in that the logic unit contains n series-connected 1K-flip-flops, an RS-flip-flop and an OR element, with the first input of the OR element connected to the installation the input of the logic unit and the S-input of the RS-flip-flop, the second input - with the enabling input of the logic unit and the R-input of the RS-flip-flop, and the output - with the R-inputs of the 1K-flip-flop, the counting input of the first 1K-flip-flop is connected to the counting input of the logic unit and the I- input is connected to the inverting output of the RS flip-flop. From generator 3 From block 9 From t / cmpoucmSa 6 Editor N.Rogulich Compiled by A. Przhevelsky Tehred L.OliynykCorrector A.Zimokosov Order 4215/34 Circulation 730 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 2