US 4,394,647 AGranted

Voltage monitoring arrangement for ORed power diodes

AssigneeBell Telephone Laboratories, Incorporated

InventorGilbert A. Van Dine

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Abstract

Each power diode in an ORed direct-current power distribution system has connected thereacross, between the respective load and source terminals of the power diode, a series connection of respective first and second light-emitting diodes (LEDs) with the LEDs being similarly poled with respect to their common connection, with the power diode and the first LED being oppositely poled with respect to the power diode load terminal, with a resistance connected between the common LED connection and the power supply return. A resistance-LED arrangement is also provided in parallel with each nonindicating fuse. The ON (fully conducting--showing detectable visible light) and OFF (not fully conducting--not showing detectable visible light) patterns of the LEDs, both under the condition of normal voltage on each power bus and under the condition where the relative voltage between buses is varied slightly, can be used for circuit failure diagnostics.

Claims20

Dependent claims

A voltage monitoring arrangement for a direct-current power distribution system wherein a plurality of separate power sources supply power in parallel to a common load through separate two-terminal power diodes similarly poled for unidirectional current conduction therethrough between the source terminals of the power diodes and the common load terminals of the power diodes and wherein the sources and the load have a common power supply return characterized in that at least one power diode is provided with voltage monitoring circuitry comprising:

(A) a first two-terminal current conducting circuit adapted to be fully conducting only in response to a prescribed first minimum amount of direct-current voltage across its terminals and to be negligibly conducting for lesser or reversed-polarity voltages;
(B) a second two-terminal current conducting circuit adapted to be fully conducting only in response to a prescribed second minimum amount of direct-current voltage across its terminals and negligibly conducting for lesser or reversed-polarity voltages;
and
(C) a two-terminal, direct-current impedance;
(D) one terminal of each of the first circuit being connected to a common circuit node, the corresponding terminal of said second circuit being connected to the same common node;
and one of said terminals of said impedance being connected to said common circuit node;
(E) the other terminals of the respective first circuit, second circuit, and impedance being connected respectively to the load terminal of the power diode, to the source terminal of the power diode, and to the common return;
and,
(F) the impedance being of such value as to limit to prescribed maxima the fully conducting amounts of current through the first and second circuits.

6 more elements

A voltage monitoring arrangement for a direct-current power distribution system wherein a plurality of separate power sources supply power in parallel to a common load through separate two-terminal power diodes similarly poled for unidirectional current conduction therethrough between the source terminals of the power diodes and the common load terminals of the power diodes and wherein the sources and the load have a common power supply return characterized in that each of said power diodes is provided with voltage monitoring circuitry comprising:

(A) a first two-terminal current conducting circuit adapted to be fully conducting only in response to a prescribed first minimum amount of direct-current voltage across its terminals;
(B) a second two-terminal current conducting circuit adapted to be fully conducting only in response to a prescribed second minimum amount of direct-current voltage across its terminals;
and,
(C) a two-terminal, direct-current impedance;
(D) corresponding terminals of each of the first and second circuits, and one terminal of the impedance being connected together to define a common circuit node;
(E) the other terminals of the respective first circuit, second circuit, and impedance being connected respectively to the load terminal of the power diode, to the source terminal of the power diode, and to the common return;
(F) the impedance being of such value as to limit to prescribed maxima the fully conducting amounts of current through the first and second circuits;
each of said power diodes, first circuit, and second circuit having respective fully conducting voltages thereacross of V.sub.PD, V.sub.CD1, V.sub.CD2 related so that said respective first circuit and said second circuit have maximum respective voltages v.sub.CD1 and v.sub.CD2 thereacross during nonconduction thereof, and a voltage is supplied to said last terminal of said last mentioned power diode;
and being related so that V.sub.CD2 -V.sub.PD is less that or equal to v.sub.CD1, and V.sub.BN being said voltage supplied to said source terminal of one of said power diodes and said voltage supplied to said source terminal of another one of said power diodes being V.sub.BN -V.sub.R where V.sub.R is a voltage reduction;
and being related so that for each said voltage monitoring circuitry V.sub.PD +V.sub.CD1 -V.sub.R is less than or equal to v.sub.CD2.

7 more elements

A voltage monitoring arrangement for a direct-current power distribution system wherein a plurality of separate power sources supply power at the same amount and polarlity of direct-current potential in parallel to a common load through separate two-terminal power diodes similarly poled for unidirectional current conduction therethrough between the source terminals of the power diodes and the common load terminals of the power diodes, wherein eachh power diode has a direct-current voltage drop thereacross of V.sub.PD when fully conducting, wherein the sources and the load have a common power supply return, and a voltage V is supplied to a source terminal of each said power diode characterized in that at least one power diode is provided with voltage monitoring circuitry comprising:

(A) a first two-terminal current conducting circuit having
(1) a direct-current voltage drop thereacross of V.sub.CD1 when fully conducting
(2) and a maximum direct-current voltage drop thereacross of not more than v.sub.CD1 when negligibly conducting;
(B) a second two-terminal current conducting circuit having
(1) a direct-current voltage drop thereacross of V.sub.CD2 when fully conducting
(2) and a direct-current voltage drop thereacross of not more than v.sub.CD2 when negligibly conducting;
(C) a two-terminal, direct-current impedance;
(D) one terminal of each of the first circuit, the corresponding terminal of the second circuit, and the impedance being connected together to define a common circuit node;
(E) the other terminal of the respective first circuit, second circuit, and impedance being connected respectively to the load terminal of the power diode, to the source terminal of the power diode, and to the common return;
(F) the impedance being of such value as to limit to prescribed maximum the fully conducting amounts of current through the first and second circuits;
and V.sub.PD, V.sub.CD1, v.sub.CD1, V.sub.CD2, and v.sub.CD2 being related so that
(1) V.sub.CD2 minus V.sub.PD is not greater than v.sub.CD1 ;
and
(2) V.sub.PD plus V.sub.CD1 minus V.sub.R is not greater than v.sub.CD2 where V.sub.R is a reduction in said voltage direct-current voltage V supplied to said source terminal of said power diode.

11 more elements

Dependencies are inferred from the claim text.