GB923744A - Improvements in automatic defect signalling systems - Google Patents

Abstract

923,744. Protective arrangements. COMPAGNIE DE CONSTRUCTION DE GROS MATERIEL ELECTRO-MECANIQUE. April 18, 1961 [May 24, 1960], No. 14045/61. Class 38 (5). [Also in Group XXXVIII] In a system in which one or more of p different faults may occur, each fault, when it occurs causing an associated fault indicating line to be marked, means are provided for recording and indicating the order in which the first n faults occur. As described, the order in which the first two of p fault-indicating lines 1, 2 ... p, Fig. 1, are marked is recorded and indicated. Each fault indicating line, e.g. p, has three bi-stable storage devices Mp1, Mp2, Mp3, associated with it. These storage devices are so arranged in column as shown, that if any device, e.g. Mp1 in the first column (extreme right-hand column) is " on a column conductor Y 1 Y 1 <SP>1</SP> is earthed, via a diode Pp1, thereby preventing any other storage device in that column being turned " on." Similarly, any device " on " in the second column prevents any other device being turned on in that column by earthing a column conductor Y 2 Y 2 1. In operation, each storage device is first reset by applying a negative pulse to every row conductor. The first fault that then occurs marks its associated line, e.g. p, which causes the third storage device Mp3 to be turned " on." This in turn applies a negative pulse via an R-C coupling to the adjacent storage device Mp2 which goes " on," and similarly this storage device turns on the first storage device Mp 1. The turning " on " of device Mp1 however turns " off " the previous device Mp2. Thus, finally the result of the first fault-indicating pulse is that storage devices Mp3 and Mp1 are both " on " and an output is taken from device Mpl to an indicator (Fig. 2, not shown). The next fault-indicating pulse that occurs attempts to cause a similar sequence of events. However, since the first column is now blocked by the earthing of column conductor Y 1 Y 1 <SP>1</SP>, the second storage device is unable to turn the first storage device " on " and so it remains on. Thus, the second fault-indicating pulse causes its associated second and third storage devices to go " on." Any subsequent fault-indicating devices are then effective only to turn on their third storage devices. Thus the circuit described indicates which faults were the first two to occur, and also any subsequent faults but not their order of occurrence. The circuit can easily be extended to identify the first n faults. The actual visual indication of a fault is effected by lamps (Fig. 2, not shown), there being one lamp for each fault-indicating line 1, 2... p, the lamps being controlled so as to flash in distinctive ways to indicate whether a fault is the first, second or subsequent fault. Specification 923,743 is referred to.