SU809572A1 - Self-excited relay device - Google Patents

Description

(54) AUTOGENERATOR RELAY DEVICE

one

The invention relates to resonant measuring instruments, the output of which has a relay characteristic, and can be used to control various electrical and non-electrical values using inductive or capacitive sensors.

Self-generating devices with an output signal relay characteristic are known, based on the abrupt transition of the continuous generation mode to the intermittent generation mode 1. However, in these devices, the increased sensitivity is limited by the occurring spurious triggers of the relay under the influence of: mechanical and destabilizing factors.

The closest to the present invention is an auto-oscillator relay designed to determine the position of moving objects, which is based on the use of the relay characteristic of the auto-oscillator current component during the transition to the discontinuous generation mode.

torus, assembled according to the capacitive three-point scheme, a relay in the load circuit, as well as a parallel resonant circuit connected to the control circuit of the autogenerator in series with a leakage resistor. The appearance of an object in the sensor field impairs the quality factor of the circuit and reduces the equivalent resistance of the oscillator, and

0 furthermore reduces the frequency of the circuit by introducing reactance into the circuit, thereby reducing the time constant of the oscillating circuit. A change in the frequency of the oscillator also leads to a change in the tuning of the oscillating circuit in the control circuit of the circuit and to a decrease in the total active resistance of the leakage circuit and to an additional decrease in the equivalent resistance of the oscillator. As a result, the time constant of the oscillating circuit decreases more sharply, which causes a transition to a discontinuous mode.

5 generation, switching off the relay and signaling the occurrence of the object 2. switching to the intermittent generation mode, effectively, however, does not ensure the elimination of false alarms, especially with increasing sensitivity. The purpose of the invention is to increase the stability and sensitivity of the device. This goal is achieved by including an inductive sensor included in an oscillator circuit included in an oscillator circuit of an autogenerator performed on a field-effect transistor according to the three-point capacitive circuit, the output circuit of which includes a relay, and an amplitude detector included a resonant circuit, an amplitude detector with a resistive divider at the output, a delay element and two controlled resistors, with shunt capacitors, one of the controlled resistors connected to the source of the field-effect transistor, the second The controlled resistor is connected in series with the resonant circuit in the excitation circuit, and the midpoint of the resistor-splitter amplitude detector is connected via a delay element to the control electrode of the first control resistor, the output of which is connected to the control electrode of the second control resistor, and the input An amplitude detector is connected to an inductive sensor. The drawing shows the principal electrical circuit of the proposed device. The device contains an inductive sensor 1 that reacts to a change in the electrical properties of the controlled medium in the near field of the sensor and includes a control resistor 3 connected to the source circuit of the autogenerator transistor 3 as an element of the oscillatory circuit of the auto-oscillator; control resistor 4, included in the control circuits in series with a parallel resonant circuit 5, 6} amplitude detector 7 with a resistive divider 8, 9; a delay element 10, a relay 11, capacitors 12 and 13, and a variable resistor 14. The device operates as follows. In the absence of an object, or at a given boundary value of the conductive properties of the object in the near zone of the inductive sensor 1, the autogenerator is in continuous oscillation mode. The time constant of the auto-bias circuit in the fixed circuit is less than the time constant of the oscillator circuit of the auto-oscillator. The constant amount of the drain circuit is large and relay 11 is turned on. When an object appears in the sensor 1 field, or when the object increases in electrical conductivity, the quality factor of the oscillating circuit 1, 12, 13 decreases and the frequency of the autogenerator decreases due to introduced reactance, which leads to a change in the setting of circuit 5, b in the control circuit. All this leads to a decrease in the equivalent resistance of the auto-generator and to a decrease in the time constant of the oscillating circuit, which becomes less than the time constant of the auto-bias circuit. Simultaneously with this process, due to a decrease in the quality factor of the circuit 1, 12, 13, the voltage across the load resistor 9 of the amplitude detector 7 also decreases. This voltage acts through the delay element 10 on the controlled resistor 3, the resistance of which increases. An increase in the voltage drop across the resistor 3 acts on the controlled resistor 4, the resistance of which decreases and, accordingly, the total active coop is reduced, E), the motivation in the control circuit. Thus, changes in the resistances of the controlled resistors contribute to a more abrupt emergence and increase of the inequality of the time constant of the auto-bias circuit and the circuit, i.e., they accelerate the transition of the auto-oscillator to the discontinuous generation mode. The transition to intermittent generation leads to a sharp decrease in the current in the source circuit. Relay 11 is turned off and gives a signal about the presence of an object in the nearest area of the sensor floor, or about changes in the electrical properties of the object being monitored. The auto-oscillator relay is tuned by adjusting the time constant of the auto-bias circuit near the transition boundary to the intermittent generation mode. The object's impact on the sensor leads to the occurrence of intermittent generation, and to increase the sensitivity, the setting should be brought closer to the breakdown boundary, however, the sensitivity of the relay is limited due to the occurrence of false positives when exposed to destabilizing factors. The use of passive elements that accelerate the process of transition to intermittent generation, while maintaining the same sensitivity, reduces the number of false positives. The use of control resistors as accelerating elements of the auto-oscillating relay makes it possible to virtually eliminate false-triggers. The setting of the proposed relay from the requirements of maximum sensitivity and the elimination of false scrapping, increases the stability and sensitivity. Availability

Claims (1)

Claim Autogenerating relay ustroy- _f GUSTs comprising an inductive sensor included in an oscillator oscillating circuit formed on the FET, a capacitive scheme trehtochki, in the output circuit of which is incorporated relay, and in the excitation circuit 15 is included a resonant circuit, characterized in that, in order to increase stability and sensitivity, an amplitude detector with a resistive divider at the output, a delay element and two resistor controls, with shunt capacitors, one of the controlled resistor, is introduced into it in is included in the source circuit of the field-effect transistor, the second controlled resistor is connected in series with the resonant circuit in the excitation circuit, and the midpoint of the resistive divider of the amplitude detector is connected through a delay element to the control electrode of the first controlled resistor, the output of which is connected to the control electrode of the second controlled resistor, the input of the amplitude detector is connected to an inductive sensor.