SU1614047A2 - Photodetector relay - Google Patents

Abstract

The invention relates to photoelectronic recording devices and can be used in automation systems as photosensors. The aim of the invention is to expand the operational capabilities of the photocell by detecting a pulsed light flux of varying duration. A photo relay provides for the selection of light interference, if the duration of the interference does not exceed the delay time of the single vibrator and ensures the registration of the light flux with a varying duration, due to the introduction of a resistor and the closing contact of the relay element into the device. 2 Il.

Description

The invention relates to photoelectronic recording devices and can be used in automation systems as photosensors for detecting changes in the luminous flux under conditions of light interference.

. The purpose of the invention is to expand the operational capabilities of the photo relay by registering a pulsed light flux of varying duration.

Figure 1 shows the electrical circuit of the proposed photo relay; Fig. 2 shows plots of signals on the corresponding elements explaining the operation of the photo relay.

The photorelay contains a photoresistor (photodetector) 1. Schmidt's trigger 2, the first differentiating circuit, one-shot4, the second differentiating circuit 5. the logic element NO 6, the logic element I 7, the decoupling amplifier 8, the threshold relay element (relay) 9, the level of operation which is equal to the trigger threshold of Schmidt trigger 2, break contacts

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10 relay element 9. capacitors 11- - 13, diodes 14-17, output bus (output pho- torele) 18. resistors 19-21. S contacts 22 of the relay element 9 with a delay for closing, inputs 23 and 24 of the logic element and 7. additional G resistor 25. and transistors 26-30.

In the initial position, the photoresistor 1 is connected via series-connected (Schmidt's trigger 2, assembled on O transistors 26 and 27. differentiating | 1 circuit 3 assembled on the capacitor 11 and sj of the resistor 19. diode 15. one-shot 4. assembled on transistors 28 and 29, differentiating circuit 5. assembled on 1 capacitor 13 and resistor 21, diode 17, fO logical element NOT 6. assembled on transistor 30. to input 23 of logic element AND 7. Another input 24 of logical element And 7 is connected to a collector the transistor 26 of the Schmidt trigger 2 and through The driver 8 is connected to the input of the relay element 9. The closing contacts 22 of which are connected to the electrical circuit between the terminal + of the direct current source and the input of the logic element HE 6, to the opening contact 10 and to the plates of the capacitor circuit of the time delay to return to the initial state of the single vibrator 4 .

The photorelay works as follows.

: At time ti, when the luminous flux changes (Fig. 2) below a certain level, Schmidt trigger 2 and threshold relay element 9 operate. The negative potential of the collector of transistor 26 increases and transistor 27 decreases. In this case, the differentiating circuit 3 forms bipolar bipolar pulses, which through a diode 15 enters the base of the transistor 28 of the single-oscillator 4. When triggering the relay element 9 disconnects its contact 10, which clears the detector 12 of the single-oscillator 4, As a result, an additional electrical circuit 25 is prepared with the help of contacts 22.

I Single Vibrator 4 starts. After the belt delay r, defined by the |; circuit consisting of the resistor 20 and the capacitor 12, the one-vibrator 4 returns to the initial state. The transistor 28 is opened again. In this case, the differentiating chain 13 and 21 forms a diverse - | Short short pulses, the positive part of which is through diode 17 and the logical Element NOT 6 is fed to the input 23 of the logical fKoro element AND 7. Simultaneously with the return to the initial state of the Simultaneous 4, the contacts 22 1 |

Since the negative input voltage from the collector 26 arrives at the other input 24 of the logic element AND 7, then if there are two negative voltages at the inputs 23 and 24 of the logic element And 7, the IHO is turned on. Therefore, at time t2, the output of the photo relay will be formed at the output (output bus) 18 of the photo relay.

If by the time the one-shot 4 returns to the initial state, it is equal to t5 + g, i.e. at the time of the occurrence of a negative voltage at the output is logical

element 6, the negative voltage from the output of the Schmidt trigger is not received, the logic element I7 does not work and the output signal (the initial

5 bus) 18 photo relay no. This means that the Schmidt trigger 2 and the relay 9 operated under the action of light interference, for example, in the time interval ts -1, whose duration is equal to t6 - t5 t less than the specified

10 time delay of the one-shot. 4. Such interference is successfully selected.

If at the moment of time tz + g or t7 + g the luminous flux continues to affect the photo relay, then in the photo relay type always (whatever the duration of this flow), only a short pulse signal is formed at the output of the photo relay (dotted line Ui8 figure 2) of the same duration that

0 indicates a limited functionality of the photocell of the prototype.

To eliminate this disadvantage in the proposed photocell due to the

In contacts 22, a voltage U22 is formed which changes the duration of the output signal Uie in direct dependence on the duration of the input light flux, which allows to extend the range of possible

U change the duration of the light flux at its registration with high accuracy.

It should be noted that, depending on the frequency of occurrence of the luminous flux, the relay 9 can be performed by contactless

5 electronic circuit.

Claims (1)

The formula of the invention of the Photorelay on auth.St. N ° 855779, about tl and - by the fact that, for the purpose of expansion operational capabilities due to the registration of a pulsed luminous flux varying in duration under light interference conditions, a resistor is inserted into it and a threshold element is introduced into the threshold element a closing contact with a closing delay equal to the time when the one-shot returns to its initial state, the resistor and the closing contact of the threshold relay element are connected in series and connected between the input element HE and the positive terminal of the power source, Yu 1 about 1 g t3 and -ts is t. te t