SU1252487A1 - Apparatus for remote control of working-face machine - Google Patents

Description

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And: the process is related to the remote control of tobacco machines and mechanisms and can be used in mine switching equipment, for example, when controlling magnetic actuators via a two-wire communication line in an explosive environment and the need to comply with the intrinsic safety of control circuits, and also used in the remote control schemes of mining machines and complexes, which, when excavating mine workings, operate under conditions of significant supply cable line and high energy end load, which creates significant difficulties for limiting voltage fluctuations in the network, and a high degree of automation makes it difficult to technical implementation of circuit solutions for three-wire communication lines in cramped mining conditions.

The purpose of the invention is to increase the reliability and security of control.

The drawing shows a schematic diagram of the device.

The device consists of a receiving relay 2 placed at the executive point of the supply transformer 1, reacting to the constant current component with a closing contact 3 and a time-breaking contact A, the second diode 5, a communication line 6 located at the command point of the opening 7 a stop button, closing 8 and disconnecting 9 contacts of the start button, end diode 10, current limiting resistor 11 and thermistor I2 with a negative temperature coefficient of resistance.

The device works as follows.

In the initial position with the transformer 1 turned on, two parallel chains are connected to its secondary winding. The receiving relay 2 is included in one chain, the second is the disconnection contacts 7 of the stop button, the current limiting resistor 11, the starting button 9 disconnecting to (-) push button 9, which bypasses the thermal resistor 12 and the rachmky contact 4 of the receiving relay 2. Availability second load chain 25

52 /) 87J

line 6 is connected to the variable component of the current, which eliminates the probability of spontaneous VC;

5 When the start button is pressed by opening the contact 9, the thermistor 12 is opened and the circuit current bypassing the circuit is bridged. Hbrfi resistor II - thermistor 12

 through the closing contact 8 of the start button and the diode 10. At the moment the start button is pressed and the thermistor 12 is bridged, the latter has a high initial impedance, the magnitude 5 of which is taken on the basis of ensuring that the coca value passes through the receiving relay 2, in the direction opposite to the polarity of the diode 10, sufficient to enable it. Receiver relay 2 is turned on: its contact 3 is closed and time-delayed contact 4 is opened.

When the start button is held in the on state, the resistance of the thermistor 12 is reduced to a few ohms, thereby maintaining the receiving relay 2 in the on state when the start button is released, when the likelihood of a brief simultaneous break of the contacts 8 and 9 occurs. relay 2 in the on state occurs due to the presence of a parallel

35 chains: disconnecting contacts 7 stop buttons - current-limiting resistor 1I - disconnecting contact 9. start buttons - line 6 - diode 5 - closing contact 3.

0 In this case, the occurrence of an emergency situation, for example, contact failure, wire breakage, etc., leads to the fact that the probability of switching on the device is eliminated before

5 faults. The presence of reliable self-switching protection permits the selection of the resistance of the current-limiting resistor only from the condition that the receiving current relay passes in the direction opposite to the polarity of the end diode, sufficient to hold the relay in the on state, thereby virtually eliminating the likelihood

55 s, 9 inadvertent disconnection of the downhole machine with a short-term decrease in the mains voltage.

thirty

Claims (1)

BOTTOM REMOTE CONTROL DEVICE containing a receiving relay mounted on the secondary winding of the supply transformer and connected by a two-wire communication line with an end diode connected at the command point via the make contact of the start button and the make contact of the stop button, the make contact of the start button has an additional disconnect contact, and a current limiting resistor connected at one end to the opening contact of the stop button and the first output of the closing contact of the start button, from characterized in that, in order to increase the reliability and safety of control, it is additionally equipped with a thermistor with a negative temperature coefficient of resistance and a second diode, and the receiving relay is equipped with an additional contact closing and disconnecting time delay contact, while the current-limiting resistor is connected to the first output by the other end a thermistor with a negative temperature coefficient of resistance directly, and with its second output and the anode of the end diode - through the opening contact start button, the anode terminal of the diode is connected to the first terminal of the interrupter contact with time delay relay receiver connected in series into a two-wire communication line, and the cathode of the second diode anode is * through the receiving relay make contact connected to a second terminal of the interrupter with an exposure time of contact receiving relay. I 252487