SU1376111A1 - Device for counting moving articles - Google Patents

Abstract

The invention relates to the technical means of automated systems, process control systems and is intended to count moving products. The aim of the invention is to increase the reliability of the device. The device contains sources of light 1.2, photodetectors 3,4, shapers of 5.6 pulses, element NOT 9, trigger 10, element II, threshold elements 12.17, indicators 13.21, maximum voltage selector 16, amplifiers 14, 15, a pulse generator 19, a switch 18, a counter 20. The device makes it possible to determine the limit value of the pollution of optical channels. This increases the reliability of the results of the account and eliminates the need for diagnostic work during operation. I il. (L

Description

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The invention relates to technical means of automated process control systems and is intended to count moving products.

The purpose of the invention is to increase the reliability of the device by preventing the malfunctioning as a result of the untimely detection of contamination of its optical channel and simplifying its operation due to the elimination of the need for its regular inspection.

The drawing shows the functional diagram of the device.

The device contains the first 1 and second 2 light sources, the first 3 and the second 4 photodetectors, the first 5 and the second 6 pulse shapers, each of which is made of repeater 7 and threshold element 8, element 9, trigger JO, element 11, the first threshold element 12, first indicator 13, first 14 and second 15 amplifiers, maximum voltage selector 16, second threshold element 1 7, key 18, pulse generator 19, counter 20, second indicator 21 for monitoring optical channel contamination.

The device works as follows.

In the initial state, when there is no object in the zone of operation of the counting device and the optical channel of the device is not polluted, there is no voltage at the outputs of the first and second photoreceivers (logical zero signal), therefore, at the outputs of the first 5 and second 6 drivers, the signal is a logical zero, so the output of the element 11 is also a signal of a logical zero. The presence of a logical zero at the output of the element 11 causes the signal of a logical zero at the output of the threshold element 12. At the same time, the signals of the logical zero name at the outputs of amplifiers 14 and 15 and at the output of the second threshold element 17. The signal of the logical zero is fed to the control input of the key 18, as a result the key is closed and does not transmit pulses from the output of the generator 19 to the counting input of the counter 20. From the output of the second threshold element, a logic zero signal is applied to the installation input to the zero state of the counter 20. The signal to

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the second indicator 21 dp of the optical channel contamination monitoring is absent, since the counter 20 is set to the zero state.

Moving counting objects interrupt the light rays that fall on the first 3 and second 4 photodetectors. At the same time, the voltage of the logical unit appears at their outputs at the moments of complete overlap of the light objects by the counting objects. The appearance at the outputs of the photodetectors of a voltage of a logical unit causes the appearance of a logical unit at the outputs of the first 5 and second 6 drivers. At the output of the element 11, pulsed signals are formed, in terms of frequency and duty ratio corresponding to the transit time of the counting objects in the range of the counting device. At the output of the first threshold element 12, signals are generated that arrive at the indicator 13. Simultaneously, pulses with the frequency of following the counting objects are formed at the outputs of the first 14 and second 15 amplifiers, at the output of the maximum voltage selector 16 and the second threshold element 17. of the counting object in the zone of operation of the counting device, the electronic key is opened by sending a signal of a logical unit to its control input from the second threshold element 17. The pulses from the I9 generator begin to pass through Without a key 18, the counter 20 is countable. The signal of the logical unit from the output of the second threshold element 17 is also fed to the input to the zero setting of the counter 20, enabling the counting.

A signal at the input of the optical channel pollution indicator appears when the counter 20 counts a predetermined number of pulses, determined by its division ratio, which is selected depending on the time the counting objects are in the range of the counting device. The division factor of the counter 20 is selected so that during normal movement of the counting objects in the selected pulse frequency from the generator 19, the signal at the input of the indicator 21 for monitoring the pollution of the optical channel does not appear, since when each object leaves the operating area of the counting device

CHICK 20 is set to zero by a logical zero signal from the output of the second threshold element 17, and when the next object enters the device’s area of operation, the counter 20 starts counting the pulses from the generator with zero.

In the case of contamination of the optical channel of the device, for example, under the action of gradually settling dust, the voltage at the outputs of photodetectors

3 and 4 gradually increase as their illumination by sources I and 2 of light gradually decreases with pollution. Accordingly, the voltage rises at the outputs of the first 14

and second 15 amps. Due to the variation in the electrical parameters of the photodetectors, and also because of the possibility of uneven sedimentation of dust, the voltage at the outputs of the amplifiers 14 and 15 may differ somewhat.

At the output of the maximum voltage selector 16, there will be a voltage corresponding to a more polluted optical channel. In the case of equality of input signals at the output of the selector 16 will be a signal equal to the input. The threshold for triggering the second threshold element I7 is selected below the threshold for triggering threshold element 8; therefore, a logical unit signal appears at its output when the voltage at the outputs of the photodetectors 3 and

4 is not enough to ensure that the signals of a logical unit are formed at the outputs of the threshold element 8 and, respectively, at the outputs of the first 5 and second 6 drivers. The appearance of a logical unit at the output of the second threshold element 17 leads to the opening of the key 18 and the counting by the counter 20. The pulses from the generator 19 begin to flow to the counter 20, at the output of which the signal of the logical unit appears after the counter input 20 the number of pulses arrives.

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equal to the established division ratio. The appearance of a logical unit at the output of the counter triggers the indicator 21 to monitor the pollution of the optical channel. At the same time, the counting device still remains operable, and the operation of the indicator informs the service personnel of the need to clean the optical channel of the counting device.

Claims (1)

Invention Formula A device for counting moving articles, containing the first and second light sources mounted opposite the first and second photodetectors, respectively, the output of the first of which is connected to the first input of the trigger and to the input of the HE element, the output of which is connected to the first input of the AND element, the output of the second photodetector through the second pulse shaper is connected to the second input of the trigger, the output of which is connected to the second input of the element I, the output of which through the first threshold element Connected to the input of the first indicator, characterized in that, in order to increase reliability and simplify operation of the device, the first and second amplifiers, the maximum voltage selector, the second threshold element, the second indicator, the pulse generator, the key and the counter, the first and The second photodetectors are connected respectively via the first and second amplifiers to the inputs of the maximum voltage selector, the output of which is connected via the second threshold element to the control input of the switch and to the installation input at the counter, the output of which is connected to the input of the second indicator, the output of the pulse generator is connected via a switch to the counting INPUT of the counter.