DE1038613B - Ambiguity checker for outputting a signal when several relays of a plurality of functionally related relays simultaneously assume a certain switching state - Google Patents

Description

Certain organs in telephony switching systems contain a large number of relays or equivalent Circuit elements from which, when the organ is working properly, never more than one is in working position. There can also be several such groups of in one organ Relays for which the specified condition applies, can also be present in a telephone switching system several such organs may be present. The proper working of such a group of relays can now be done in the manner be monitored that one determines with the help of a test device whether there is more than one relay at the same time is in the working position, i.e. is excited. If this is the case, a display device is actuated or a signal to report this error is issued. Such a test device can be called an ambiguity checker to name.

Experience has shown that such an ambiguity checker must, so that it works sufficiently reliably, meet various requirements; so he should be insensitive to disturbances, they should monitored relay for the purpose of monitoring, if possible, only a single additional contact need, there should be no special tolerance conditions for the circuit elements of the ambiguity checker must be provided, inter alia. m.

For example, an ambiguity checker can use relays to intermittently fault current received, built up. Such a circuit is shown in FIG. With this circuit certain tolerance conditions for the operating currents of the relay must be observed, which is a Disadvantage of the circuit is. This is explained in more detail on the basis of the following explanations.

In the circuit according to FIG. 1, the potential difference that occurs between two of the contacts which are controlled by the relay to be monitored is evaluated in order to make the display element respond. This circuit has, for example, five relays to be monitored. Each relay controls a test contact. These contacts are located between the corresponding ends and taps of two series circuits of four equal-sized resistors R 11 ... R 14 and R21. .. i? 24. The series connection of the resistors R 11 ... R 14 is fed with the voltage U from a DC voltage source. At the ends of the series connection of the resistors R21. . . A display relay M is connected to i? 24. If only a single test contact is now closed, the relay M receives no current, since there is no voltage between its two connections. If, on the other hand, two test contacts are closed, for example the contacts al and

Ambiguity checker for submission

of a signal when several relays of a plurality of functional at the same time

relays that belong together
assume a certain switching state

Applicant:
Siemens & Halske Aktiengesellschaft,

Berlin and Munich,
Munich 2, Witteisbacherplatz 2

Dipl.-Ing. Karl-Heinz Widdel, Munich,
has been named as the inventor

a2, the one terminal of the relay M via the contact al, the voltage U and the other terminal of the relay M via the resistors R 24, 7223, R22 and via the contact a2, a lower voltage is supplied, so that because of the voltage difference at his Connections the relay M is traversed by current and thus excited. The effective voltage difference in this operating case is less than a quarter of the total voltage U due to the division of the total voltage across the series connection of the resistors. B. al and a5 closed contacts in another case, the relay M receives the undiminished total voltage U. When monitoring five relays so the voltage across the display relay M varies here

from about -j- U to U, i.e. more than four times.

If more than two contacts are actuated by the monitored relays at the same time, the voltage is reduced on the display relay mainly determined by the contacts that are furthest apart.

This circuit has several disadvantages. Even when the circuit is in the rest position, a current flows through the resistors R 11 ... R 14, which current is of the same order of magnitude as the current during operation. In addition, the voltage applied to the display relay fluctuates considerably as a function of the various switching states, which is very disadvantageous for the reliability of the operation of this relay. The fluctuation is greater, the more relays are monitored. You can only monitor a limited number of relays with this circuit.

E09 637/125

For the solution of the problem, which is quite analogous in itself, in which it has to be checked whether more than two at the same time Relays of a group of several relays are in the working position, a circuit is already known (Bell Lab. Record, January 52, Vol. XXX, No. 1, p. 11). With this circuit the monitoring made with the help of a contact pyramid, which is formed from contacts, which of the to be monitored Relays can be controlled. If a larger number of relays is to be monitored, this is here However, it is disadvantageous that many contacts are connected in series and interference because of the addition of the Contact resistance occur. In addition, each monitored relay must have several additional Have contacts. * 5

The circuit according to the invention avoids the disadvantages of the circuits specified above. It is an ambiguity checker that emits a signal if at the same time several relays of a plurality of functionally related relays a certain switching state take in which a test contact assigned to each of the relays is closed. she is characterized in that a daisy chain connection of two transformers is provided, whose in The internal windings of the chain have taps, which in turn are connected to the test contacts are interconnected that the number of turns ratio of any two winding sections of one transformer equals the turns ratio of the corresponding sections of the other Transformer is and that the input of the chain circuit, an alternating voltage is fed to the in the case of simultaneous activation of two or more test contacts, a to the output of the chain circuit the transformer connected to the display unit to respond.

Such an ambiguity checker is shown in FIG. 2 by the chain circuit K1. The primary winding Pl of the transformer Tl is supplied with an alternating voltage. The secondary winding .91 of this transformer has taps and thus as many connections as there are relays to be monitored. The primary winding P 2 of the transformer T 2 has just as many connections. Between the corresponding connections of the two transformers, there are now test contacts α 1 to <i4 of the relays to be awakened, here for example four relays. The display element, here the tube V, is connected to the secondary winding of the transformer T2.

If now two test contacts, z. B. the contacts al and σ2, are closed, the two transfer mators are connected to each other via the contacts such that when the primary winding of the transformer Tl is fed with AC voltage from the secondary winding of the transformer T 2, a certain AC voltage is emitted. Between the taps belonging to the same closed test contact of the secondary winding S1 of the transformer T1 and the primary winding P 2 of the transformer T2 there is inevitably the same voltage in each case, since they are connected to one another. At the two corresponding taps of the transformers T1 and T2, which each belong to one of the now open test contacts a3 and a4, the same voltage is now in each case, which is the same as the number of turns of the corresponding winding sections. Two other test contacts could therefore also be closed without a change in the voltage supplied to the display element. It follows from this that the same voltage occurs in every case at the secondary winding of the transformer T2, if any two test contacts are closed at all. However, more than two test contacts can also be closed. If, on the other hand, only one test contact is closed, no current can flow through the primary winding of transformer T2; the transformer T2 can therefore not deliver any voltage to its secondary winding either.

In the circuit arrangement shown in FIG. 2, several chain circuits for independent groups of relays to be monitored are connected to the display element V. The control electrode S of the display element is connected to the outputs of the chain circuits Kl ... K η via decoupling directional conductors Dl ... Dm. The display element consists of an amplifier tube V which is made conductive by the positive half-waves of the alternating voltage supplied from the outputs of the chain circuit. In this state it causes the display. Thus, with such an ambiguity checker, many groups with numerous relays can be monitored. In the idle state, only the negligibly small no-load currents of the transformers Tl ... TwI flow.

Claims (3)

PATENT CLAIMS: 1. Ambiguity checker for outputting a signal when simultaneously several relays of a plurality of functionally related relays assume a certain switching state in which a test contact assigned to each of the relays is closed, characterized in that a chain circuit (Kl) of two transformers (Tl, T2 ) is provided, whose internal windings (Sl. P2) in the chain have taps, which are connected to one another in sequence via the test contacts (al ) is equal to the number of turns ratio of the corresponding sections of the other transformer (T 2) and that the input of the chain circuit is supplied with an alternating voltage, which in the case of the simultaneous actuation of two or more test contacts (αϊ ... α 4) brings a display element (V) connected to the output of the chain circuit (Kl) of the transformers (Tl, T2) to respond. 2. Ambiguity tester according to claim 1, characterized in that the display element (V) is common to several chain circuits. 3. Ambiguity checker according to claim 2, characterized in that the common display element consists of a tube (V) , the control electrode (S) of which is connected to the outputs of the chain circuits via decoupling conductors (D). Considered publications:
“Bell Laboratory. Record ”, January 1952, p. 11. 1 sheet of drawings 80i 637/125 9.58