SU734827A1 - Inductive change-over switch - Google Patents

Description

(54) INDUCTIVE SWITCH

I

The invention relates to the field of instrumentation technology and can be used, in particular, in devices controlling the traveling positions of the working bodies of mechanisms.

The inductive switch is known, which contains movable ferromagnetic measles, an inductive sensor to which the primary winding of a saturating magnetic element is connected, the secondary winding of which is connected to the control electrode of the thyristor, which together with the relay winding is connected to the AC source 1.

However, such a device has a large phase shift of the output pulses.

An inductive switch is also known. It contains an inductive sensor with a movable ferromagnetic core and a winding connected by a first output to the first terminal of an alternating voltage source, and a second through a capacitor in parallel to which are connected in series the windings of a drossel and a pulse transformer, in which the first output winding through the first diode is connected to the control electrode

the main thyristor, the anode of which is connected to a positive power source, the cathode is connected to the second output of the output winding of the pulse transformer via a relay winding, in parallel to which an RC circuit is connected,

 the control electrode of the additional thyristor is connected to the cathode of the second diode, and the zener diode 2.

However, this device has a low reliability.

10 An object of the invention is to increase reliability.

To do this, a third diode is additionally introduced into the inductive switch, the cathodes of the second and third diodes are connected, and the anodes are connected to

15 corresponding to the first and third pins of the winding parts of the inductive sensor, the cathode of the additional thyristor is connected to the middle output of the serial RC circuit and the cathode of the Zener diode, the anode of which

JQ is connected to the fourth terminal of the winding part of the inductive sensor, and the anode of the additional thyristor is connected to the power supply through the closing contact of the relay.

The drawing shows the principle electrical circuit of the proposed structure.

The device contains a ferromagnetic measles 1, an inductive sensor 2, a capacitor 3 resonant to the inductive sensor, an agitational element 4 with a primary winding magnetic element 5 with a primary and a secondary winding, a diode 6 connected to the correcting electrode of the primary thyristor 7, a relay winding, 8 and a closing contact relay 8, capacitor 10 and resistor II RC circuits, diodes 12, 13 and zener diode 14, connected to the control electrode of the additional thyristor 15. The closing contact 9 is included in the gap of the anode of the additional thyristor 15 and the positive source a, DC. The thyristor cathode is 15. connected to the middle output of the RC circuit. The inductive sensor 2 and the resonant capacitor 3 are tuned to resonance with the bark 1 removed. The primary winding of the magnetic element 4 has a number of turns several times greater than the number of turns of the primary winding of the magnetic element 5 in order to get a distinct jump in the appearance of and. the disappearance of the voltage. Both primary windings of magnetic elements 4 and 5 are connected in series with each other and parallel to resonant capacitor 3 and constitute a parallel ferroresonance circuit. Anodes of two diodes 12 and 13 are connected to the terminals of the winding section of inductive sensor 2, which consists of two identical sections. whose cathodes are connected together and connected to the control electrode of the thyristor 15. The midpoint of both sections is connected via the zener diode 14 to the cathode of the thyristor 15. The zener diode 14 serves to cut off the residual pulses supplied from sections, windings, subject to the presence of controlled pulses on the main thyristor 7.

When core 1 is inserted into the inductor coil 2, the voltage on the resonant capacitor 3 of the parallel ferroresonance circuit is small, the cores of the magnetic elements 4 and 5 are not saturated, the controlled current pulses in the secondary winding of the magnetic element 5 are absent, the thyristor 7 is off, the relay 8 is turned off de-energized.

When removing the core from the coil of the inductive sensor 2, the effective value of the voltage on the capacitor gradually increases to the saturation voltage of the primary winding of the magnetic element 4.

At the moment of saturation, a trigger voltage jump of the parallel ferroresonance circuit occurs to a stable value at which magnetic electrons 4 and 5 produce controlled current pulses in the secondary winding of the magnetic element 5

A positive controlled pulse through the diode 6 is supplied to the control electrode of the thyristor 7 and turns it on.

The relay 8 is turned on and, with its closing contact 9, connects the anode of the additional thyristor 15 to the DC source. The capacitor 10 is charged to the magnitude of the DC voltage source. .: .., .. ,, /

In the state of removing the core 1 from the inductive sensor 2, the relay 8 is permanently and permanently powered by the current of the direct current source. In this case, the pulses arriving at the control electrode of the thyristor 7, after turning on the thyristor 7, do not affect the further operation of the circuit.

With the introduction of the core 1 e coil of the inductive sensor 2, the control pulses in the secondary winding of the magnetic element 5 disappear during the trigger jump of the disconnection of the parallel ferroresonance circuit. The jumper disconnect jump corresponds to a decrease in the voltage jump at the input of the parallel ferroresonance circuit (junction on the capacitor 3) and an increase in the voltage jump on the winding of the inductive sensor 3.

After a certain period of time after the disappearance of the pulses from the sections of the winding part of the inductive sensor 2, a voltage pulse is applied to the controlled electrode, an additional thyristor 15, through diodes 12 and 13. The additional thyristor 15 is turned on.

When the additional thyristor 15 is opened, the entire voltage of the capacitor 10 is applied to the transition of the cathode-anode of the main thyristor 7, as a result of which the thyristor 7 is closed. The capacitor 10 ne1: (Discharger. Closing the thyristor 7 leads to de-energizing and disconnecting relay 8 and opening the closing contact 9. When contact 9 is open, the capacitor 10 is completely discharged. When the I core is inserted into sensor 2, the circuit is brought to its initial de-energized state.

Claims (2)

1. USSR author's certificate No. 289433, cl. G 08 C 9/04, 1964. 2. USSR author's certificate No. 536720, cl. G 08, C 9/04, 1975 (prototype).