SU503994A1 - Device for connecting an intrinsically safe sensor to the equipment of an intrinsically safe performer - Google Patents

Description

one

This invention relates to a fused electrical equipment.

The known devices for connecting an intrinsically safe sensor to an intrinsically safe equipment, containing an intrinsically safe source, a thyristor trigger with a spark-proof power source, two thyristor mono vibrators, isolation transformers, diodes and resistors, are complex and not reliable enough.

The purpose of the invention is to simplify the design of the device and increase its reliability.

This is achieved by the fact that the intrinsically safe source is loaded on a series circuit of a diode and a resistor shunted by a series circuit of a capacitor, resistor, diode, and the resistor and diode of the last chain are shunted by diodes, the anodes of which form a common point with the cathode of the second one-oscillator thyristor, the control electrode of the thyristor of the first one-shot is connected to the positive terminal of the sensor, and one of the terminals of the winding of the isolation transformer of the first one-shot is directly connected to 5 with a binding clip of an intrinsically safe source.

The drawing shows a schematic diagram of the described device and circuit 10; its connection to the intrinsically safe center: the first sensor and to the spark-proof equipment. In the drawing, the following symbols are used: i. - sensor with intrinsic safety. p mi; and - intrinsically safe source; W 15 device for connecting an intrinsically safe sensor to equipment of spark-proof design; ly - spark source; 6-O, 1-1, 2-2 — lines of communication; 3 and 4 t one-shot thyristors; 5 and 6 - trigger thyristors; 7 - 10 - capacitors; 1114 diodes; 15 and 16 zener diodes; 17 23 - resistors; 24 Vi 25 - isolation transformers; 26 - thyristor of the output circuit of the sensor; 27 - load resistance of the sensor output circuit.

The device works as follows.

In the hover state, the thyristor of the sensor 26 | is closed. The capacitor 8 is charged until the voltage of the intrinsically safe source P. The capacitors 7 and 9 are not charged. In the opening of the thyristor 26, the charge of the capacitors 7 and 9 occurs and at the same time the control current flows through the thyristor 3, the latter opening.

The capacitor 8, discharging through the thyristor 3, generates a pulse of control of the thyristor 5, and a signal appears at the output of the trigger. As soon as the thyristor 26 of the sensor is closed, the power supply and control circuit of the thyristor 3 is de-energized, the thyristor 3 is turned off and the process of charging the capacitor 8 begins. Simultaneously, the resistor 17 is connected. control / thyristor junction 4, 13 discharge. capacitor 7, i.e. The thyristor control transition 4 is supplied with a positive voltage, which turns it on.

The thyristor 4 is opened, and a capacitor 9 is discharged to the primary winding of the transformer 24, which forms a control pulse on the secondary winding, which turns on the thyristor 6 of the trigger. As a result, the thyristor 5 is applied to the switching voltage of the commuting

capacitor 10, and the trigger overturns. - ..

Upon subsequent opening and closing of the sensor thyristor 26, this process is repeated.

Claims (1)

Invention Formula Isolation-free connection device unit sensor to the equipment of intrinsically safe execution. containing an intrinsically safe source, a thyristor trigger with a spark-proof power source, two thyristor single emitters, dividing transformers, diodes and resistors, different from the fact that, in order to simplify and increase reliability, the safety source is loaded on a series circuit of a diode and a resistor shunted by a series circuit of a capacitor; a resistor, a diode, and the resistor and the diode of the last chain are shunted by diodes, the anodes of which form a common point with the cathode of the second thyristor the one-shot, the control electrode of the thyristor of the first one-shot is connected to the positive terminal of the sensor, and one of the terminals of the winding of the separation transformer of the first one-shot is directly connected to the negative terminal of the intrinsically safe source.