SU471670A1 - Switch - Google Patents

Description

one

The invention is intended for use primarily as a terminal in drive control circuits for moving objects, such as coal plows, mine lifts, where cable damage is possible.

Known switches, in which the contacts of the sensors included in the current-carrying branch of the actuator in series with it or in parallel. In the nerve case, the executive relay is energized when the sensor contacts are closed, in the second case it is open. In the first case, the relay is disconnected by opening the sensor contact, in the second case by shunting the relay coil with the contact, while to avoid a short-circuit of the supply voltage in series with the bypass contact and the relay coil, a resistor is turned on.

There is a known AGE limit switch, which is used in elevator control systems. The switch is an actuator and a magnetic sensor with a magnetically controlled release contact. When the control element approaches the sensing element of the sensor, the magnetically controlled contact opens, causing the electromagnetic relay to trip.

coil which is connected in series with the contact.

In the circuit where the sensor contact is connected in series with the emergency relay, the short circuit between the actuator and the sensor prevents the relay from tripping when the sensor contact opens. In a circuit where the actuating relay is shunted by a sensor contact, the relay is not turned off when

wire breakage. As a result of damage to the communication line, the mechanism controlled by the actuator will not stop at a given point on the way, but will continue to move, which can lead to an accident with serious consequences.

The aim of the invention is to increase reliability by providing a protective disconnection of an additional device in case of breakage or short circuit of wires connecting

actuator with sensor.

This is achieved by the fact that the executive elements are connected to a high-resistance power source through the output of the control key, the key input is bounded by a sensor contact and a resistor, which is located in the sensor unit. The control key can be performed, for example, on a transistor, a tisistor, an electron tube, etc.

Such an implementation of the proposed switch ensures the sanitation of its actuators, damage to the communication line between the actuator and the sensor, since the current in the control switch input circuit is stopped when the communication line is broken, the actuators are de-energized, and the connection is disconnected from the actuator the relay is bypass through an open transistor and a diode.

The drawing shows the pin-pin diagram of the proposed switch.

The switch consists of a sensor 1 and an actuator with a control circuit 2. The sensor contains a magneto-controlled contact 3 and a resistor 4 connected in parallel with the contact.

An electromagnetic relay 5 is used as an actuator. Transistors 6 and 7, resistors 8–11, capacitor 12, diodes 13 and 14, and pin 15 of electromagnetic relay 5 are used to create a delay relay. An actuator with a control circuit is connected to a high-impedance power source 16 through the control key 17. Sensor 1 is connected to the input of the key 17.

The key is assembled on transistor 18, resistors 19, 20, and diodes 21, 22. The base of transistor 18 is connected to the midpoint of a power supply divider, one arm of which is a resistor 20, the other is series-connected resistors 19 and 4. Resistors are so selected that a negative potential is created on the base of the transistor, the transistor is normally open. The switch works as follows. When a power supply is present, transistors 6, 7 and 18 are open, relay 5 is turned on, its contact 15 is open, capacitor 12 is charged (but the circuits: plus power supply, circuit elements 21, 18, 6, 7, 12, I, 10 and 13, minus the power source). When the plow approaches the end of the lava, the magnetically controlled contact 4 is briefly interrupted. A diode 22 bypasses the actuator (relay 5 and transistor 6) through the diode 22, the relay 5 disappears and gives a signal to stop the plow. After falling away

the relay closes its contact 15 and through a resistor 9, a power source 16, a contact 15, a resistor 11 discharges a capacitor 12, creating a locking positive potential of 5 PA bases of transistors 7 and 6. Transistors 7 and 6 are closed, and the electromagnetic relay remains off during the discharge time of the capacitor. During this time there is a blank runout of the plow and its automatic reversal. At the end of the capacitor discharge, transistors 7 and 6 open, the relay turns on, and the circuit goes back to its original state. When a wire breaks connecting the sensor

15 1 with the input of the key 17, on the base of the transistor 18 appears positive with respect to the emitter, the transistor is closed, the transistor closes and the relay 5 drops off and gives a signal to stop the plow.

0 Closing the wires connecting sensor 1 with other circuit elements is similar to closing contacts 3. This also eliminates relay 5 and gives a signal to stop the plow.

5 If a disconnecting contact is used in the sensor, connected in series with a resistor 4, then after the sensor has triggered, the contact will open the negative bias circuit to the base and the transistor will close

0 will cause the electromagnetic relay to fall off. The same will happen if there is a break in the wires connecting the sensor with the key and the element control circuit. When the wires are closed, the actuator is sensed (relay 5

5 and the transistor 6), the relay disappears and also gives a signal to stop the plow.

Subject invention

0 A switch containing a contact sensor, an actuator with a control circuit and a power source, characterized in that, in order to improve reliability, a control key, such as a diode transistor, is inserted into the control circuit, and the actuator is connected to the power source key and bypass through the input of the control key contact and the sensor resistor.

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