Redundant over-voltage protection/power distribution system for telecommunication systems

• US 10,291,019 B2
• Filed: 04/28/2016
• Issued: 05/14/2019
• Est. Priority Date: 05/07/2015
• Status: Active Grant

• Current Assignee: John Mezzalingua Associates, Llc
• Original Assignee: John Mezzalingua Associates, Llc
• Inventors: Chawgo, Shawn M.
• Primary Examiner(s): Bauer, Scott
• Application Number:
  US15/141,081
• Publication Number:
  US 20160329703A1
• Time in Patent Office: 1,111 Days
• CPC Class Codes: H02H 3/05 with means for increasing reliability, e.g. redundancy arrangements for logic circuits H03K19/003
• CPC Class Codes: H02H 9/041 using a short-circuiting device

Abstract

A redundant over-voltage protection/power distribution system for a macro/distributed antenna telecommunications system. The overvoltage protection system includes first and second surge protection devices each having one end electrically connected to the power cable upstream of an RRU and a second end electrically connected to ground. The first and second surge protection devices issuing an alert signal when one of the devices is in a failed condition and changing state to provide the RRUs with uninterrupted power for continuous operation of the telecommunications system when one of the surge protection devices has failed.

Claims

1. In a telecommunication system subject to lightning strikes and having a power cable supplying electrical power to at least one Remote Radio Unit, an overvoltage protection system, comprises:

first and second surge protection devices each having one end electrically connected to the power cable upstream of the Remote Radio Unit, and a second end electrically connected to ground,

the first and second surge protection devices each having an operative state and an inoperative state, at least one of the surge protection devices having a monitoring circuit operative to issue an end-of-life signal when the surge protection device has changed state from an operative to an inoperative state; and

a relay connecting to at least one of the surge protection devices and operative to change its state from an inoperative state to an operative state;

wherein, in a first operating mode, the first surge protection device is in an operative state and the second surge protection device is in an inoperative state, and,

wherein, in a second operating mode, the relay changes the state of the second surge protection device from an inoperative state to an operative state in response to an end-of-life signal issued by the first surge protection device;

the second surge protection device providing continued operation of the telecommunications system following the change in state of the first surge protection device from an operative to an inoperative state

wherein a cue is issued that the first overvoltage protection device has reached an end-of-life condition and

wherein each surge protection device employs a variable resistivity ohmic component responsive to a low voltage potential and to a high voltage potential, the ohmic component having a high resistivity when exposed to the low voltage potential and a low resistivity when exposed to the high voltage potential and

wherein the second surge protection device is replaced following a prescribed time of use following the issuance of the cue.

2. The overvoltage protection system of claim 1 wherein the relay is configured to disconnect the first surge protection device from the power cable and wherein in the second operating mode the relay enables second surge protection device in response to the end-of-life signal.

3. The overvoltage protection system of claim 2 wherein each of the surge protection devices are Metal Oxide Varistors (MOVs).

4. The overvoltage protection system of claim 3 wherein the at least one surge protection device employs a meltable metal to complete a circuit to initiate the end-of-life signal.

5. A redundant power distribution device for a telecommunication system comprising:

a first varistor having a variable resistivity ohmic component therein responsive to a low voltage potential and to a high voltage potential, the ohmic component having a high resistivity when exposed to the low voltage potential and a low resistivity when exposed to the high voltage potential;

the first varistor connected at one end to an electric node upstream of a circuit to be protected from an overvoltage and at a second end to electrical ground, the first varistor having an end-of-life sensing circuit;

a second varistor having a variable resistivity ohmic component therein responsive to low and high voltage potentials, the ohmic component having a high resistivity when exposed to the low voltage potential and a low resistivity when exposed to the high voltage potential;

the second varistor having one end connected to electrical ground;

a relay operative to connect the other end of the second varistor to the electrical node upstream of the circuit to be protected;

wherein upon sensing an end-of-life condition a first cue is issued indicative of the end-of-life condition of the first varistor and the relay is energized to connect the other end of the second varistor to the electrical node upstream of the circuit to be protected, thereby enabling continued operation of the telecommunication system while providing a second cue that redundant protection is no longer available; and

,

wherein the second varistor is replaced following a prescribed time of use following the issuance of the first cue.

6. The redundant power distribution system of claim 5 wherein the first and second metal oxide varistors include a ceramic mass of zinc oxide in a matrix of metal oxides from the group of:

bismuth, cobalt, and manganese.

7. A telecommunication system comprising:

a plurality of remote units connecting a master unit to a plurality of telecommunications antennas, each of the remote units including;

overvoltage protection devices connected to each of the remote units and operative to protect each remote unit from an overvoltage condition, one of the overvoltage protection devices initially in an operative state and the other in an inoperative state, the overvoltage protection device issuing an alert signal when a voltage monitoring circuit therein detects a failed condition, and

a relay, responsive to the alert signal, to change the state of the inoperative overvoltage protection device to an operative state

wherein a cue is issued that a first overvoltage protection device has failed; and

wherein a second overvoltage protection device is replaced following a prescribed time of use following the issuance of the cue.

8. The telecommunication system of claim 7 wherein the change in operating state provides continued overvoltage protection for each of the remote units when one of the overvoltage protection devices becomes inoperative.

9. The telecommunication system of claim 7 wherein the relay disconnects the first overvoltage protection device from a power cable and enables the second overvoltage protection devices.

10. The telecommunication system of claim 7 wherein each of the overprotection devices are Metal Oxide Varistors (MOVs).

11. The telecommunication system of 9 wherein the at least overvoltage protection device employs a meltable metal to initiate a failed condition signal.

12. A telecommunication system having power and data cables for supplying power and data, respectively, to at least one Remote Radio Unit from a base transceiver unit (BTU) and a source of power, comprising:

first and second surge protection devices each having one end electrically connected to the power cable upstream of the RRU, and a second end electrically connected to ground,

the first and second surge protection devices each having an operative state and an inoperative state, at least one of the surge protection devices having a monitoring circuit operative to issue an end-of-life signal when the surge protection device has changed state from an operative to an inoperative state; and

a relay connecting to at least one of the surge protection devices and operative to change its state from an inoperative state to an operative state;

a connector having first and second ends each having a plurality of power pins and fiber optic data connectors, the first end operative to transmit power from the power source and exchange data with the BTU, the second end operative to transmit power and exchange data with the RRU, the first end of the connector keyed with the second end of the connector;

wherein, in a first operating mode, the first surge protection device is in an operative state and the second surge protection device is in an inoperative state and,

wherein, in a second operating mode, the relay changes the state of at least one of the protection devices from an inoperative state to an operative state in response to the end-of-life signal,

the second surge protection device providing continued surge protection of the telecommunications system following the change in state of the first surge protection device

wherein a cue is issued that the first surge protection device has reached an end-of-life condition and

wherein the second surge protection device is serviced following a prescribed time of use following the issuance of the cue.