DE759054C - Circuit arrangement for the lighting lamps of the instrument dials of control panel measuring devices - Google Patents

Description

Circuit arrangement for the lighting lamps of the instrumentation. - Scales of control panel measuring devices Measuring instruments are used in control rooms, test stands and the like used to monitor the individual system parts during operation. if It is also required that he watch, so it can easily happen that, keeper the measuring instruments constantly over especially when a very large number of measuring instruments is present, it is overlooked that the measured value has reached a critical level, itself thus, for example, approaches a value that must not be exceeded. Would If the switchman determines this in good time, he could still take countermeasures hit to a further increase in the measurement. value to prevent, and so the inadmissible Eliminate the condition before the automatic protective devices intervene.

To the switch attendant in an extraordinarily obvious way on time to draw attention to the achievement of a critical measured value, it is known when reaching particularly important measured values, e.g. B. the maximum permissible measured values, the lighting lamps for the scales of the measuring instruments in one from to light up in different ways than normal lighting. This particular lighting can, for example, be a flashing light or lighting done by a special color. Since this is the measuring instrument through a special lighting is marked, the L # Ieß- # vert one straight has reached the allowable value, the attendant's attention is drawn straight to it steered this instrument so that he got the reading of this instrument in time can observe and be faithful to appropriate measures.

The invention relates to a circuit arrangement for the lighting lamps the instrument dials of switchboard measuring devices, which in a known manner at Reaching a maximum permissible measured value in a lighting system that differs from normal be made to light up in a distinctive way. In addition, at the same time with an acoustic alarm is activated when the lighting is changed. According to the Invention, a hand-operated acknowledgment button is provided by actuating it the acoustic alarm and the special lighting are switched off when the Time of acknowledgment the measured value has reached a permissible level again, while the The acoustic alarm is only switched off if at the time of the acknowledgment the measured value is still above the permissible level. So both signal states remain persist until an acknowledgment is received. With this acknowledgment, the switch attendant forced to become aware of the fact that the permissible measured value has been exceeded gain weight. However, it is not possible for the switchman to activate the visual alarm again to disappear before the measured value does not fall below the limit value again has decreased. This means that the switch attendant is constantly informed that the Fault condition still exists.

In the drawing, an embodiment of the invention is on hand a measuring device for electrical currents explained. However, it is just as good possible, the invention in connection with other measuring devices, which a water level or measure a speed or another technical-physical quantity, to use.

In the figure, R, S, T represents a three-phase network from which via the Current transformer S'Li <'and the measuring instrument M measured the current in phase T. will. The measuring instrument M has two lamps L1 and I_, to illuminate the instrument scale, which are normally tiber the contacts., in the rest position of the battery voltage be fed here. A relay PS is connected in parallel to the measuring instrument, which at a certain current value, which should be the critical current value, comes to respond.

If this is the case, the relay CS closes its contact iis and thus makes relay I_ respond. Relay E switches on at contact ei Horn H on and on contact e. the supply circuit of lamps L1 and L. is switched over, so that these lamps are now fed via the flashing rail B1. The flashing rail is connected to the positive pole of the power source via the self-interrupter LT and receives current pulses via the self-interrupter.

To have the security that the switchman from reaching has taken note of the critical 1 reading is still an output circuit provided, in which the relay E closes a self-holding circuit via the contact e3. The horn alarm and the flashing of the measuring instrument can only be switched off when the exit button 0 is pressed. If this key is pressed, and exists During this time the critical measured value is still available, although the right contact the Q key opens the circuit of relay E, but this is at the contact iis Circuit is still closed in parallel to this, the relay E does not fall yet and the measuring instrument continues to flash. By closing the left contact of button Q, relay A is activated brought because contact e4 is closed. The R £ la1S A closes at contact a1 a self-holding circle, and at the contact a. it opens the circuit of the horn H. It If the horn is turned off, the measuring instrument will continue to flash exist until the switch attendant reduces the current in lines R, S, T to a lower one Has brought value. Only then does the relay US open its contact iis again. if Now the exit button Q is pressed for the second time, the self-holding circuit is established of relay E is interrupted and the entire circuit is returned to the rest position return; guided.

If the first press of the acknowledgment key Q is the current in the network R, S, T are already lower than the critical value, so by pressing once the acknowledgment key Q both the acoustic alarm and the flashing of the measuring instrument eliminated; because by pressing the Q key the relay F. drops out and thereby the circuit is immediately brought to the rest position.

Instead of the relay ÜS, which at a certain current value to the Response comes, you can (read relay E also from the measuring instrument by a mechanically, affect optically, magnetically or electrically operated switching devices. Will With the measuring instrument, for example, water levels are measured, so you can switch on of relay E depending on the position of the float or on the position of the measuring instrument. The same applies to other measured values.

The invention can also be used in an advantageous manner in the case of luminous or dummy circuit diagrams to represent electrical power distribution networks are used in which In addition to the measuring instruments, there are other illuminated symbols. are there yourself Opposite these symbols there is a glowing or flashing one in a special color I will mark the reading instrument better.

Claims (2)

PATENT CLAIMS.-i. Circuit arrangement for the lighting lamps of the instrument scales of control panel measuring devices, which when reaching the highest permissible Measured values in a manner different from normal lighting to illuminate be brought, in which, at the same time as the lighting changes, an acoustic Alarm is set in action, characterized in that by means of a manually operated Acknowledgment button the acoustic alarm and the special lighting are switched off, if at the time of the acknowledgment the I-1st measured value has a permissible level again, that against it the acoustic alarm is only switched off by the acknowledgment button, if at present the acknowledgment the measured value is still above the permissible level. 2. Circuit arrangement according to claim i, characterized in that the acknowledgment button is in the rest position a self-holding circuit for one that switches on the alarm and the special lighting Relay prepared and in the working position the circuit for one only the alarm The switching-off relay closes if at the same time there is also a contact of the alarm and the special lighting switching relay is closed. For demarcation of the subject matter of the invention from the prior art are the following in the grant procedure Documents considered: USA.-Patent 1Tr. i 572 536; British Patent No. 45.1.855.