PL74979B2 - - Google Patents

Description

Priority Application announced: May 30, 1973 Patent description was published: December 20, 1975 74979 KI. 2 Id *, 2 21c, 72 MKP H02h 9/00 of the Patent Office: zv Izsk Mfli 4j U..j, Inventors: Jerzy Seliga, Andrzej Frankowski Authorized by a temporary patent: Industrial Institute for Automation and Measurements, Branch in Lodz, Lodz (Poland The subject of the invention is an electric system of a multi-circuit shunt for intrinsically safe devices limiting the voltage and short-circuit current in many circuits with similar parameters having one common point. So far used to protect against the effects of sparking are protective shunts. designed for each circuit, with each circuit equipped with a separate shunt. The shunts used for these purposes are equipped with non-linear voltage limiting elements, and the individual signal lines contain elements limiting the short-circuit currents of the source and limiting the external short-circuit currents. The object of the invention is to replace a number of the same individual shunts with one protection of all circuits connected to it. This goal was achieved by building an electric shunt system containing separating elements in the number of circuits and a common single or double non-linear voltage limiting element connected by identical electrodes through the common point of the circuits. The opposing electrodes of the separating elements are connected to the individual conductors of the circuits, and the opposite electrodes of the limiting elements to the system reference point. The multi-circuit shunt arrangement according to the invention avoids the use of several or several dozen shunts, while using significantly fewer elements as in the case of individual shunts. Thanks to this, the reliability of the system is increased, the dimensions and weight of the device are smaller, the cost is lower and the manufacturing technology is simpler. The system is particularly suitable for use in digital systems, control systems, and in analogue data recording systems using standardized signals, especially current. The invention will be explained in more detail on the examples of the embodiment shown in the figure in which Fig. 1 shows the anode shunt electrical system, and FIG. 2 the cathode shunt system, FIGS. 3, 4 and 5 show variations of the anode shunt without individual resistors, and FIG. 6 shows a variation of the shunt with two-stage voltage limitation. The circumferential shunt according to the invention has a single or more preferably a double non-linear element Y19Y2, for example a Zener diode to limit the emergency voltage, connected between the common point of the circuits and the system reference point. The individual signal paths 1, 2 ... n of the circuits contain series connected resistors Rj-j-Rj-n limiting the short-circuit current of the source and resistors R2_1 ... R2_n limiting the external short-circuit currents. The individual paths 1, 2 ... n are connected with the elements Y1, Y2 limiting the emergency voltage 74 979ra additional resistors R3-i-R3_n enabling two-stage short-circuit current limitation and two sets of limiting elements Y'v Y2, Y3, Y4 with other limited voltages connected with two signal lines The poly separators xi-i-xi-n and X2-i-X2-n as previously discussed. Fig. 3 - = - 6 shows the variations of anode shunts. The same modifications may be made in the cathode version. PL

Claims (1)

1. Patent claim Electric system of a multi-circuit shunt for intrinsically safe devices in circuits with similar parameters and having one common point, characterized by the fact that it has separating elements (Xi ... Xn) and a common element limiting the voltage with electrodes through the point common (P), while the opposite electrodes of the separating elements (Xi ... ... Xn) are connected to the individual paths (1, 2 ... n), and the opposite electrodes of the voltage limiting element (Yi, Y2) are connected with the reference point (0) of the system. Fig. 4. Fig. 2 through the non-linear spacers Xi ... Xn. The emergency voltage limiting elements Yi and Y2 have differentiation electrodes - anode in the anode shunt (Fig. 1) or cathode electrodes in the cathode shunt (Fig. 2) - connected to the reference point 0 of the system, while the opposite electrodes of elements Yi and Y2 are connected at a common point P of the circuits to the same electrodes of the separating elements Xi.jXn. Opposite electrodes of separating elements Xi..jXn are connected to (individual signal lines 1, 2 ... n. The electric system of the multi-circuit shunt according to the invention can be made in many variants depending on the current and voltage conditions present in the circuits. power supply has a sufficiently limited short-circuit current, it is possible to use a variation without the resistors Ri-i-Ri-n limiting the short-circuit current shown in Fig. 3. If the external circuit resistance is large enough, the shunt variation without the resistors R2-i-is used. R2-n limiting the external short-circuit currents. A variation not containing both the resistors ^ -i-Rj-n and R2-i-R2-n is also possible as shown in Figure 5. Another solution with a two-stage cut limitation is shown in Fig. 6. This system includes Ki.Sid *, Z 21c, 72- 4,979 MICP H02h y o- 2 o-- n o- 0 o- -3i y,?% * Fig. 5 Z o- n ° - * —xy, 1 & * ^ i ^ -2 hl) i * / - / ^ -2 yn o; * i ## HZZ '*, - /, * / - / l * / - 2? 4-, ¦ * / - «¦ *» -. i-2 * i-7 • l 1- I i Ul Y, t 0 o- • * «*? - == * «^ —— $ 2-4 # 2-2 # 2-n READING ROOM Urzedu Palentowf fikklej Iziutf go <» M *, l PL