Abstract: A switching arrangement for a telecommunication switching system having test and seizing circuits is disclosed in which test switching means for bounce-free contact operation require a seizing current rise delayed by switching means in the seizing circuit. The improvement comprises a transistor for establishing the seizing current, a testing resistor disposed in series with the transistor and an RC network associated with the transistor. The potential across a control electrode of the transistor which is determined by the charging voltage of said associated RC network defines a control current. The potential renders the transistor increasingly conductive to current in accordance with a charging process setting in at the start of a test and seizing operation.

Abstract: A telecommunication switching arrangement is described wherein those switching elements that are idle are marked at a given test point with a free or idle potential, and those which are currently in use, or busy, are marked by an absence of the foregoing potential. The condition indicated at the test point is sensed by test switches on a preceding switching element which, using a test and seizing circuit, attempts to seize the switching element in question. When a switching element is busy, it is guarded by a potential differing from the idle potential. In the course of a connection release and while an inhibited test and seizure circuit is opened, seizure attempts on the opening seizure circuit are prevented. A current monitoring device recognizes a decrease in current flow as a release and opens the seizing circuit until the switching element in question is completely released.

Abstract: A telecommunication switching arrangement is described wherein each seizable switching component, i.e., a component in an idle condition, is so marked by application of an idle potential to a test point by means of a seizing circuit in that switching component. The busy condition is indicated by the absence of the aforementioned potential. The condition of the switching component is sensed by a test switching device having an internal impedance corresponding to that of a preceding switching component. The latter device accomplishes its task by completing a test and seizure circuit including the aforementioned test point. If a switching component being tested is already seized by another switching component, it will have been blocked by a blocking circuit in the other switching component.