SU690628A2 - Optronic change-over switch - Google Patents

Description

(54) OPTOELECTRONIC SWITCH

The invention relates to the field of telegraph and measurement technology and can be used in devices designed for receiving and recording the duration of the spike of a single field of signals. Known optoelectronic switch p aut. St. No. 499669, containing an input LED optically connected to the photodiode, an auxiliary LED connected optically to the photodiode, the first and second transistor switches, an inverter, a delay circuit, two variable resistors (1}. A disadvantage of the known device is its low immunity. “The goal is to reduce the noise immunity.” To do this, an optoelectronic switch containing input and auxiliary LEDs optically connected with the corresponding photodiodes, the first and second transistor switches, the collector The first switch of the key through the inverter n the delay circuit is connected to the base of the transistor of the second key, introduced an additional delay circuit, an additional inverter, power supply, and the delay circuit through the additional delay circuit connected to the input of the additional inverter n the input of the first element And, the other input connected to the output of the inverter, and the output to the trigger input, while its other input is connected to the output of the second element I, whose inputs are connected respectively to the input of the inverter and the output of an additional the vertor. FIG. 1 shows a structural electrical circuit of the device; in fig. 2 - a diagram of his work. An optoelectronic switch contains an input LED optically connected to a photodiode 2 connected in the reverse direction between the power supply bus 3 and the input circuit of the first transistor switch 4, an auxiliary LED 5 connected in series with variable resistors 6 and 7 between the power supply bus 3 and the bus 8 and optically coupled to the photodiode 9 connected between the input circuit of the transistor switch 4 and the common bus 8, the second transistor switch 10, the output of which is connected

The cathode of the LED 5 is connected to the variable resistor 7, and the input is via the delay circuit II connected to the output of the inverter 12, an additional delay circuit 13 connected between the output of the delay circuit 11 and the connection point of the additional inputpopa 14 to one of the inputs of the first element 15 , the second input of which is connected to the output of the inverter 12, the trigger 16, one of the inputs of which is connected to the output of the element And 15, and the second input to the output of the second element And 17, one of the inputs of which is connected to the output of the transistor switch 4, and the second entrance - to the exit at the inverter 14. The received signals are applied to input 18, output terminal 19 is.

The device works as follows. In the absence of a spsal at the input of the optoelectronic switch, transistor switch 4 is closed, the inverter 12 is open, and the output of the delay circuit 11 is a shy voltage level. In this case, the transistor switch 10 is closed, and a current flowing through the LED 5 is determined by the values of two series-connected resistors 6 and 7, which determines the lower registration level of the signal Ij fkg. 2a), the output of the delay circuit 13 is a low voltage level, and the output of the inverter 14 is high. As a result, a low voltage level arrives at both inputs of the AND 15 element, so a high voltage level will be output at its output. At this time, the input element And the 17 comes a high voltage level, so at its output there will be a low voltage level. As a result, the trigger 16 is set to a state in which the output voltage 19 is low (Fig. 2g).

When the signal arrives at the input of the optoelectronic switch and the registration level Ij is exceeded, the transistor switch 4 is opened and the inverter 12 is closed. At the same time, the output voltage And 15 shows a low voltage level (Fig. 2e). At a time -c equal to the delay time of the leading edge of the signal by the delay circuit 11 after the inverter 12 is closed, a high voltage level arrives at the input of the transistor switch 10, as a result of which the transistor switch 10 opens. The current through the LED 5 will now be determined by the value of the variable resistor 6 and correspond to the registration level D 2 After a delay time equal to the leading edge delay time of delay circuit 13, after the appearance of the upper voltage level at the output of the delay circuit 11, the output of the delay circuit 13 also the upper level of the voltage appears. This leads to the fact that with the release of the element

And 17 at the input of the trigger 16 begins to receive a high voltage level (Fig. 2e), since both the inputs of the element And 17 low voltage levels. The trigger 16 is set to a state in which a high level of voltage is output at the output 19 (Fig. 2g).

When the amplitude of the signal decreases below level 2 (Fig. 2a), the transistor switch 4 and the inverter opener 12 are closed. At the same time, the output level of the And 17 element shows a low voltage level (Fig. 2d). After a time Γ ″) the delay time {of the falling edge of the delay circuit 11 after the open; 12; the input of the transistor switch 10 receives a low voltage level, as a result of which the transistor switch 10 closes. In this case, the level of the register will correspond to Ii.4epe3 delay time j j. Equals the delay time of the falling edge OJeI during delay 13 (Fig. 2c, d), after reaching the next level at the output of the delay circuit 11, at the output of the delay circuit 13 also low voltage level. This leads to the fact that from the output of the element 15 to the input of the trigger 16 a high voltage level flows (fig. 2e), since both inputs of the element 15 have low voltage levels. The trigger 16 is set to a state where the output level 19 is low. From the diagrams of the operation of the optoelectronic switch, it follows that the signals at the output 19 are delayed by the CoD time, which ensures a high accuracy of the registration of signals with significant distortions of their fronts.

When the input 18 of the optoelectronic interference switch (Fig. 2a, signal HI), having a duration commensurate with the duration of the useful signal, and the amplitude Ittg J, the transistor switch 4 is opened. After time T, the power switch 10 is released, resulting in a recording level ; optoelectronic switch becomes Ij. After a time t - t j, a low level arrives at the input of the element And 17. voltage, however, at the input of the element And 17 low level will not be, because through BpeiWHt. the transistor switch 4 will be locked due to the fact that Inj 1a. Therefore, the state of the element I 17 does not change, and the trigger 16 will retain its previous state. Thus, an interference of the form 1P (Fig. 2a). The optoele strongh 1m switch will not be registered.

An optoelectronic switch 0 works similarly when a useful signal is damaged by splitting, the depth of which does not reach the minimum level of registration G (Fig. 2a,

signal II). Such fragmentation will not be registered by an optoelectronic switch.

If the duration of interference or crushing, acting on the input of the optoelectronic switch, is less than the time - GG, their amplitude and depth can be any that does not change the condition of the trigger 16. Let the input of the optoelectronic switch be affected by an interference of 3ni with a duration Tc. -% s (Fig. 2a). When the level Ij reaches the disturbance, the transistor switch 4 opens and the inverter 12 closes. After time T. 4, the lower voltage level will arrive at the right input of the AND 17, but by this time the interference will stop - (tn), and I 17 will not will have no matching voltage levels at its input, therefore its state will not change, and, therefore, the state of trigger 16 will not change either,

Similarly, an optoelectronic switch operates when a signal is damaged by crushing with a duration of C r + C and a depth equal to the amplitude of the signal 1. Such a crushing also does not cause a change in the state of trigger 16.

Thus, the proposed optoelectronic switch is resistant to the effects of interference (shotleish), which have significant amplitudes (depths), and the density, while 5 this ensures a high nausea of registration of useful signals.

Claims (1)

The invention of the Optoelectronic switch on the author. St. 0 N4996695 characterized in that, in order to improve noise immunity, an additional delay circuit, an additional inverter / elements And and a trigger are introduced into it, and the output of the delay circuit is connected via an additional delay circuit to the input of the additional inverter and the input of the first element And, the other input of which connected to the output of the inverter, and the output to the trigger input, while another its input is connected to the output of the second element I, the inputs of which j are connected respectively to the input of the inverter and the output of the additional cable. Sources of information taken into consideration by experts 5 j I, Copyright svdedelstvo.SSSR№499669, cl. H 03 K 17/78. 05.20.74. 690628