SU1465560A1 - Spark-safe remote control apparatus - Google Patents

Abstract

FIELD: electrical engineering. used in power supply systems of installations operating in an explosive environment. The goal is to ensure the reliability of the operation of the remote control device. The device contains. receiving unit with intrinsically safe power source (PI) 1 direct current, pulse transformer (t) 2 and output relay (P) 3, control panel with buttons 4.5 control Stop and START, normally open contact 6 of blocking P 10, key element 7, stabilizer 8, direct current voltage and generator 9. At the same time P. 10 is connected to the pulse T I1. When button 5 is pressed, a pulsating current arising in the circuit of the IP 1 when switching with a switch by a key element 7 flows through the primary winding T 11, causing self-induction EMF in the secondary winding to which Р 10 is connected. 9, the pulses enter the circuit of the element 7, which shunts the PI circuit I. The stabilizer 8 maintains a constant voltage of the generator 9 and P 10. The alternating voltage from T 2 goes to the output P 2, which includes the switching device. 1 hp f-ly, 3 ill. i (O F eaten f

Description

fae g

eleven

The invention relates to electrical engineering and can be used in power supply systems for installations operating in an explosive environment, for example, in underground mining of coal deposits, in gas, oil, and chemical fields.

The aim of the invention is to increase the reliability of the device.

Figures 1 and 2 are a functional diagram of the device; FIG. 3 is a schematic diagram of the device.

The intrinsically safe remote control device contains (Fig. A receiving unit with an intrinsically safe power source 1 of direct current, a pulsed transmitter 2 and an output relay 3, as well as a control panel with control buttons Stop 4 and Start 5, for 14) 1 firing contact 6 of the blocking relay, key element 7, stabilizer 8 of constant voltage, generator 9, block relay 10. In the device (Fig 2) there is a blocking element (relay 10 is connected to a pulse transformer 11.

The device works as follows.

When you press button 5 Start, the source voltage is applied to the key element 7 and the voltage regulator 8 with the generator 9 connected to it and the blocking relay 10 The blocking relay 10 locks the button 6 with its contact 5. From the generator output 9. pulses go to the control circuit Key element 7, which, with the generation frequency of the generator 9, shunts the circuit of the intrinsically safe power source 1 with the primary winding of the pulse transformer 2 connected in series

Voltage stabilizer 8 maintains a constant voltage supplying the generator 9 and a blocking relay.

Yu at the moments of failure of the supply voltage, arising from the operation of the key element 7. When the key element 7 is operated, a pulsating current arises in the secondary winding of the pulse transformer 2, in the secondary circuit 1, i.e. alternating voltage, which is fed to the output relay 3, switching on switching

5 0 5

0

from 0

five

apparatus. The device of FIG. 2 works similarly. Its distinctive feature is that when the button 5 is pressed, the pulsating current arising in the power supply circuit 1 when the circuit is switched by the key 7 flows through the primary winding of the pulse transformer 1, causing self-induction in the secondary winding, which is connected to the locking relay 10 with the closing contacts 6.

The above device is intrinsically safe, since it is powered by an intrinsically safe power source, and the remote control circuit does not directly include elements, reducing the useful intrinsically safe power. A short circuit of the control line or its interruption, damage to any element of the device leads to a protective circuit failure. Surfacing the voltage in any practically possible range cannot lead to self-switching, and a decrease in the supply voltage from 0.5 Jn. and even lower does not lead to shutdown. Self-switching is also excluded in case of any interference in the control circuit, due to the complete opening of the circuit by the Start button in the initial state. Even such an unlikely damage complex, such as simultaneously closing the control line outside the control panel and contacting it with an alternating voltage of 1 frequency, does not cause the contactor to turn on automatically, since the effective current in the output circuit of the pulse transformer is determined primarily by the frequency and at small (in comparison with the frequency produced by the generator), the frequency of pulsations in the control circuit will not be sufficient to trigger the output relay of the npHeikkffloro block.

Claims (1)

1. Intrinsically safe remote control device containing an intrinsically safe power source and an executive relay located in a receiving unit connected by a two-wire communication line to a control panel consisting of a generator and sequentially connected buttons gt1 „  Start and Stop This is due to the fact that, in order to increase reliability, it is equipped with a pulse transformer, a DC voltage regulator, a key element and a block relay whose contact is connected parallel to the Start button and the winding is disconnected. the first wire of the two-wire communication line is connected to the primary output of the Stop button, and the second output of the Start button is connected to the inputs of the stabilizer and the key element, the output of which is connected to the control panel One two-wire communication line and to the first output of the generator, to the second output of which the output of the stabilizer is connected, and the control output of the generator is connected to the control input of the key element, and the pulse transformer is located in the receiving unit, the primary winding of which is connected between the first output of the power source and the first wire of the two-wire line and the secondary winding is connected to the executive relay, the second output of the intrinsically safe power source is connected to the second wire of the two-wire line Zi 2, The device according to Claim I., that is, that the first wire of the two-wire communication line is connected to the Stop button via the primary winding of the pulse transformer, the secondary winding of which is connected to the winding of the blocking relay. CfJUB.I "Stop" Pusn L .. fie.Z