Control and holding circuit for relay matrices
AssigneeTelefonaktiebolaget L M Ericsson
InventorsRoyne Gunnar Hjortendal, Jons Kurt Alvar Olsson
Life of this patent
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Abstract
In a relay matrix there are provided a plurality of control and holding circuits for selecting which of the relays are to be energized. The control and holding circuits which are associated with groups of relays include two-state devices which are triggered into a conductive state at the coincidence of a control signal and a minimum value control current and remain in that state after the termination of the control signal until the control current falls below the minimum value.
Claims11
A matrix switch comprising a matrix of relays arrayed in groups, each of said relays having signal transfer contact means and an energizing means with first and second terminals, a plurality of first signal transfer terminal means, each of said first signal transfer terminal means being connected in parallel to the signal transfer contact means of one of the relays in each of said groups of relays, a plurality of second signal transfer terminal means, each of said second signal transfer terminal means being connected in parallel to the signal transfer contacts of fall of the relays in a different group of said groups of relays, a plurality of first control current terminals, each of said first control current terminals being connected in parallel to the first terminal of the energizing means of one of the relays in each of said groups of relays, a plurality of second control current terminals, a plurality of control and holding circuits each associated with a different one of said groups of relays, each of said control and holding circuits having a control signal input for receiving a marking signal, and first and second control current transfer means, each of said control and holding circuits having switching means connecting said first and second control current transfer means and rendered conductive when a marking signal is received at its control signal input and at least a given current is available for flowing from one to the other of its control current transfer means and is rendered non-conductive thereafter when the available current is less than said given current, means for connecting first control current transfer means of each of said control and holding circuits in parallel to the second terminals of the energizing means for each relay in the associated group, means connecting the second control current transfer means of each of said control and holding circuits to a different one of said second control current terminals, means for selectively applying marking signals to the control signal inputs of said control and holding circuits, and means for selectively applying sources of current with a controllable amplitude across said first and second control current terminals.
Dependencies are inferred from the claim text.