SU1716167A1 - Spark-protective separator - Google Patents

Abstract

The invention relates to electrical engineering and can be used in intrinsically safe telephone communication systems in the coal, oil and gas industries. The purpose of the invention is to increase the explosion-proof of the communication line. On the spark-proof side of the device, the calling voltage flows, which, passing through the capacitor, diode bridge 14, accumulates on the capacitor 15 and through-the-resistor 16 ignites the LED of the optron 20. The optocoupler transistor 20 opens and supplies voltage from the source through the resistor 17 to the base of the transistor 21, under the action of which the transistor 21 opens and provides the operation of the relay 7, the contacts of which switch from the DC source 22 to the AC source 10, after which the alternating voltage from the black source Without contacts, limiting resistors and windings of the transformer 2 enters an intrinsically safe line to which a spark-proof telephone is connected. Thus, the intrinsically safe sending of the ringing voltage to this device, acting in time with the incoming spark-induced voltage from the PBX, is provided. 1 il. Yo

Description

The invention relates to electronics and can be used in intrinsically safe telephone communication systems in coal, oil, and gas industries with an explosive atmosphere.

The closest to the proposed is a spark-proof isolating device for intrinsically safe telephone and hands-free communication systems containing a power source with a linear relay, an isolation transformer with a primary winding and a secondary winding, two limiting resistors, a calling relay with contacts, a ring

device, the closing contact of the linear relay capacitor. Through the contact of the linear relay, the primary winding of the isolation transformer is connected to the spark circuit, and the secondary winding is connected opposite the primary and through the limiting resistance and make contacts to the calling device, and through the opening contacts to the power supply, the capacitor is connected between the secondary windings of the transformer.

The disadvantage of the prototype is that the winding of the ring relay is connected via a Zener diode directly into one of the wires of a spark-proof line, which is not available

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bakes the required intrinsically safe intrinsically safe line, since a high-voltage ringing signal from the PBX, or any other dangerous voltage, for example, AC mains voltage, can flow through the spark-hazardous line to the winding of the ring relay, and through its contacts to the spark-proof line.

The purpose of the invention is to increase the explosion-proof of the communication line.

Two capacitors, a diode bridge, four resistors, a transistor optocoupler, a transistor and a second power source are inserted into the device, while the diode bridge is connected to the first wire of the spark-safe communication line and to the second bridge diagonal by one diagonal the second capacitor is turned on, in parallel with which the radiating diode of the transistor optocoupler is connected through the first additional resistor, the collector of which is connected via the third resistor to the positive pole of the second and the power point, and the emitter of the transistor to the base of the inserted transistor and through the second additional resistor to its emitter and the negative pole of the second power source, the base of the transistor of the optocoupler is connected through the fourth additional resistor to the base of the inserted transistor, the collector of which is connected to the positive pole of the second power source.

The drawing shows a spark-proof separation device.

The device contains a power source 1 with a linear relay, an isolation transformer 2 with a primary winding 3 and secondary windings 4, two limiting resistors 5 and 6, a calling relay 7 with contacts 8 and 9, a calling device 10, a closing contact of a linear relay 11, a capacitor 12.

The device includes capacitors 13, 14, a diode bridge 15, resistors 16-19, a transistor optocoupler 20, a transistor 2.1, and a second power source 22.

The positions A and B and A1, B1 denote, respectively, the first and second wires of the intrinsically safe and intrinsically safe communication lines.

The nodes and elements are connected as follows: the primary winding 3 of the isolation transformer 2 is connected via a contact 11 of a linear relay (not shown) to a spark-proof circuit, and the secondary winding 4 of which is turned on opposite to the primary one and through limiting resistances 5, 6 and make contacts 8, 9 - to ringing device 10, and through disconnecting contacts 8.9 - to power supply 1, capacitor 12 is connected between the secondary windings 4 of transformer 2, while diode bridge 15 is connected to the first wire by one diagonal through its first capacitor 13 a spark-safe communication line and directly to the second wire of this line, the second diagonal of the bridge 15 includes the second capacitor 14, in parallel with which through the resistor 16 the radiating diode of the transistor optocoupler 20 is connected, the collector of which is connected via the third resistor 18 to the positive pole of the second power source 22, and the emitter of this transistor is connected to the base of the inserted transistor 21 and through the second additional resistor 17 to its emitter and the negative pole of the second power source 22, the base of the transistor of the optocoupler 20 oedinena through fourth dopollitel- ny base resistor 19c inputted transistor 21 having its collector through the coil ringing relay 7 is connected to the positive pole of the second power source.

The device works as follows.

From the PBX side, the calling voltage flows to the spark-free side of the device, which, passing through the capacitor 13, diode bridge 15, accumulates on the capacitor 14 and through the resistor 16 lights the LED of the optocoupler 20. The optocoupler transistor 20 opens and supplies voltage from source 22 through resistor 18 to the base of the transistor 21, under the action of which the transistor 21 opens and provides the operation of the relay 7, the contacts 8 and 9 of which switch from the direct current source 1 to the alternating current source 10, then the alternating voltage From source 10 through contacts 8, 9, limiting resistors 5, 6 and winding 4 of transformer 2 enters an intrinsically safe line, to which an intrinsically safe telephone set (not shown) is connected. In this way, an intrinsically safe sending of ringing voltage to this unit, acting in time with the incoming spark from the PBX, is ensured. The capacitor 12 provides low attenuation of the device in the speech range. When a subscriber of an intrinsically safe telephone, receiving a call, lifts the handset of the device, a DC circuit from the power source 1 with a built-in linear relay (not shown) is formed through contacts 8 and 9, resistors 5 and 6, winding 4

1716167

transformer 2, intrinsically safe communication line Ai, Bi and telephone set. The linear relay operates and closes its contact 11, thus forms a circuit: PBX, wire of the spark-safe line, contact 11 of the linear relay, winding 3 of the transformer 2, wire in the spark-safe line of the PBX, thereby forming a talk path: spark-safe talk telephone, intrinsically safe A1 lines, VD. windings 4 of transformer 2, capacitor 12, transformer 2, its winding 3, contact 11 of a linear relay, wire A of a spark-proof PBX line, wire B of a spark-proof line.

Resistors 17 and 19, respectively, in the initial state, provide closure of the transistor 21 and the transistor of the optocoupler 20.

The proposed device provides absolute galvanic isolation of the spark-dangerous line from the high-voltage ringing signal, which is fed to the wires A and B from the side of the exchange, thereby increasing the explosion-proof value of the spark-dangerous line.

Claims (1)

Invention Formula An intrinsically safe isolating device containing a power source with a relay, the closing contact of which is connected to the second input of the device through the primary winding of the transformer, the first input of which is connected to the closing contact of the relay, the trigger relay has two switching contacts, the first output of the first secondary winding is connected to the output of the device, and the second to the first capacitor lead, the second lead of which is connected to the first lead of the secondary winding, the second lead of which is the output of the device, and the lead condenser torus through first and second resistors connected to the moving contacts of the ring relay, characterized in that, in order to increase the explosion-proofness, it is equipped with a diode bridge, four additional resistors, transistor optocoupler, additional power supply, transistor, call block and two capacitors, the first output of the first capacitor is connected to the first input of the device, and the second output to the first input of the diode bridge, the second input of which is connected to the input of the device, and the output of the diode bridge through the first An additional resistor is connected to the LED of the optocoupler, whose phototransistor the collector through the second additional resistor is connected to the first output of the additional power source, the second output of which is connected to the common bus, the photo thyristor base of the optocoupler through the third additional resistor connected to . its emitter, to the base of the transistor and through fourth additional resistor - to to the emitter of the transistor and to the common bus, and the collector of the transistor is connected via the coil of the ring relay to the first output of the additional source, the call block is connected to the closing contacts of the ring relay, and the power source to the opening contacts of the ringing relay relay.