SU1404833A1 - Device for checking frequency of mechanical vibrations - Google Patents

Abstract

The invention relates to a measurement technique and can be used to control the frequency of mechanical vibrations. Purpose of the invention

Description

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an increase of 1; a device interval, which is achieved by reducing the number of relays, as well as using a thyristor optocoupler. The device comprises a displacement sensor 1, a constant voltage source, an intermediate relay 4, a time relay 5, a pulse counter 8 and a block circuit 18. The displacement sensor 1 captures the mechanical oscillations of the object being monitored and forms at its output 1

The invention relates to a measurement technique and can be used to control the frequency of mechanical vibrations.

The purpose of the invention is to increase the reliability of the device by reducing the number of relay points.

Figure 1 shows a diagram of a device for controlling the frequency of mechanical vibrations; figure 2 is an example of a variant of the blocking scheme.

The device contains a displacement sensor 1, a thyristor optocoupler 2, a control relay 3, an intermediate relay 4, a time relay 5, containing, in turn, a relay 6 and 7, a pulse counter 8, a time relay disconnecting contact 9, a breakdown contact 10 control relay, open-contact 1 1 intermediate relay, closing contact with delay

12 time switch, make contact

13 of the control relay, the closing contact 14 of the intermediate relay, the transformer 15 and the rectifier 16. The thyristor optocoupler 2 is turned on using a ballast resistor 17. The thyristor optocoupler 2, the control relay 3, the breaking contact 10 of the control relay, the breaking contact 11 of the control relay and the ballast resistor I7 form a lock circuit 18, and a transformer 15

and the rectifier 16t is a source of constant voltage.

The blocking circuit 18 may also be configured in accordance with FIG. 2. However, it includes, as in

pulses whose frequency is equal to the oscillation frequency of the object. The pulses from the output of the displacement sensor 1 are fed to the input of the pulse counter 8, which periodically zeroes. Blocking circuit 18 provides for the counting of pulses during a predetermined time interval, which, in turn, provides a counting result proportional to the frequency of mechanical vibrations. 2 3.p. f-ly, 2 ill.

The first version of the control relay 3, the contact of the intermediate relay 10, as well as the diode 19 and the closing contact 20 of the control relay 3.

The device works as follows.

A constant voltage from the output of the rectifier 16 is supplied to the supply terminals, the displacement sensor I and to the rest of the circuit elements (Fig. 1). As the sensor 1 movement can be used various contactless limit switches, such as type ARC, BVK and other

On the mechanism or element of the mechanism, the oscillation frequency of which is registered, a flag or another element interacting with the movement sensor is set. The design of the interacting element (not shown) is determined by the type of displacement sensor 1. With the approach and departure of the interacting element to the displacement sensor 1 at its output, the polarity of the signal U, changes. When the first pulse of positive polarity appears through contact 10, the voltage U causes the appearance of a corresponding positive signal Uj at the control input of the thyristor optocoupler 2, which opens, and the positive voltage from the output of the rectifier 16 goes through contact 11 to the power input of the thyristor op - tolar in the form of a positive polarity signal U and further to the control winding (total relay 3. The control relay operates. Its contact 10 opens and the contact 13 closes. When contact 10 opens, the control relay The input of the thyristor optocoupler 2 is disconnected from the input signal, but the thyristor continues to remain in the open state, since to close the thyristors of this type, it is necessary to simultaneously satisfy the condition that the current through the power contact is equal to 0. When the contact 13 is closed on the windings of the relay 6 and 7, the positive polarity Ug is applied in. Figure 1 shows an example of the implementation of time relay 5 using two separate relays 6 and 7, which corresponds to the implementation of a circuit using a time relay type VL. Since at the initial moment the contact 14 is open, the pulse counter 8 performs the counting. After a specified time interval, which determines the pulse counting time, contact 9 is opened.

the output of the counter 8 pulses of memory is 25 clock cycles 20. Therefore, the variant of the circuit blocks the recorded value, the torsion definition (figure 2) should be used

pulse frequency. In this case, if the time delay of contact 9 is 1 s, then the counter records the number of pulses with a unit recording coefficient, and the result determines the number of pulses per unit time. If necessary, the result of the account can be adjusted by setting the counter in accordance with its instructions. For example, if the recording duration is more than 1, switching the counter circuit can provide a result with a corresponding dividing ratio.

During the time between the actuations of contacts 9 and 12, no changes occur in the circuit and the measurement result can be visually read from

counter 8 pulses. After a predetermined time delay, contact 12 closes.

The voltage U is applied to the coil of the intermediate relay 4. Contact 11 is opened and contact 14 is closed. Control relay 3 is turned off. Pin 13 opens and turns off time relay 5. The circuit is restored to its original state, since short-term contact of contact 14 occurs, which leads to zeroing of the counter 8 pulses.

The blocking circuit 18 may be configured in accordance with FIG. In this case, when an input occurs

voltage U circuits of positive polarity, a voltage U occurs and, accordingly, the voltage Ug on the winding of the control relay 3. When triggered, it becomes self-blocking via its contact 20. The circuit returns to its initial state upon opening of contact 10 and when an intermediate relay is activated 4.

The choice of one or another variant of the blocking circuit is determined depending on the available hardware base and the range of the measured oscillation frequency, as well as the duration of the pulses at the output of the displacement sensor 1. In order for the interlock circuit 18 to operate, it is necessary that the duration of the pulse Ui be longer than the time required to close the low oscillation frequencies, which is ensured by increasing the duration of the control pulse U,.

Claims (3)

1. A device for controlling the frequency of mechanical vibrations, containing motion sensor, DC voltage source, intermediate relay, time relay, characterized in that, in order to increase reliability, a pulse counter and a blocking circuit are inserted into it, the negative output of a DC voltage source is connected to the displacement sensor and blocking schemes, to the first input the intermediate relay coil and to the common power supply bus of the pulse counter, the positive output of a constant voltage source is connected to the positive power supply input of the blocking circuit, through the time relay contact that closes the time relay contact to the second input of the intermediate relay coil, and the output whom connected to the control input of the blocking circuit AND, through a time delay contact contact to the counting input of the pulse counter, the first input of the relay coil time connected to the first power bus, the second time relay winding input is connected to the second power bus via the closing contact of the blocking circuit, the closing contact of the intermediate relay is connected between the control input of the pulse counter and the common power supply circuit of the pulse counter . 2. The device according to claim 1, characterized in that the blocking circuit comprises a control relay, a thyristor optocoupler and a ballast resistor, the positive power supply input of the blocking circuit is connected via series-connected disconnecting contact of the intermediate relay and the optocoupler thyristor to the first winding input of the control relay, the second the input of the control relay winding and the first input of the ballast resistor are connected to the negative power input of the circuit interlock, the control input of which is connected via a series-connected disconnecting contact of the control turnip and the optocoupler LEDs to the second input of the ballast resistor. 3. A device according to Claim 1, characterized in that the blocking circuit comprises a control relay and a diode, the positive power supply input of the blocking circuit is connected via a serially connected closing relay of the control relay and the breaking contact of the intermediate relay to the first winding input of the control relay, The second input of the control relay coil is connected to the negative power supply input of the blocking circuit, the equalizing input of which is connected through a diode to a common point between the closing contact of the control relay and the break contact intermediate relay. 2