Ringing controller
AssigneeCatena Networks, Inc.
InventorS. Donald McGinn
Life of this patent
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Abstract
In a telecommunications system, a switching device selectively applies one of two different voltage supplies to a common node. A first of the voltage supplies is coupled to the common node by a first switch and a second of the voltage supplies is coupled to the common node by a second switch. The switching device includes the following elements. A difference detector detects a difference between the first and second voltage supplies. A control circuit selectively enables one of the first and second switches and disables the other of the first and second switches, for switching between the first and second voltage supplies in response to the difference detector. The control circuit performs the switching between the first and second voltage supplies when the detected difference falls below a predetermined threshold.
Claims18
In a telecommunications system, a switching device for selectively applying one of two different voltage supplies to a common node, a first of said two different voltage supplies being coupled to said common node by a first switch and a second of said two different voltage supplies being coupled to said common node by a second switch, said switching device comprising:
- a difference detector that detects a difference between said first and second voltage supplies;
- and
- a control circuit that selectively enables one of said first and second switches and disables another of said first and second switches for switching between said first and second voltage supplies in response to said difference detector,
- wherein said control circuit enables switching between said first and second voltage supplies when said difference falls below a predetermined threshold.
In a telecommunications system, a ringing controller for selectively applying one of two different voltage supplies to a transmission loop, a first of said two different voltage supplies being a battery supply and a second of said two different voltage supplies being a ringing supply, said ringing controller comprising:
- a first switch that couples said battery supply to said transmission loop;
- a second switch that couples said ringing supply to said transmission loop;
- a difference detector means for detecting a difference between said first and second voltage supplies;
- and
- a control means for selectively enabling one of said first and second switches and disabling another of said first and second switches for switching between said first and second voltage supplies in response to said difference detector means,
- wherein said control means enables switching between said first and second voltage supplies when said difference falls below a predetermined threshold.
In a telecommunications system, a method of selectively applying one of two different voltage supplies to a common node, a first of said voltage supplies being coupled to said common node by a first switch and a second of said voltage supplies being coupled to said common node by a second switch, said method comprising the steps of:
- detecting a difference between said first voltage supply and said second voltage supply;
- and
- selectively enabling one of said first and second switches and disabling another of said first and second switches for switching between said first and second voltage supplies in response to said difference,
- wherein switching between said first and second voltage supplies occurs when said difference falls below a predetermined threshold.
Dependencies are inferred from the claim text.