A voltage monitoring circuit for simultaneously detecting excessive excursions of a plurality of primary voltage source

Claim 2

A voltage monitoring circuit for simultaneously detecting excessive excursions of any one of a plurality of primary voltage sources comprising a bridge circuit network having a first, a second, a third and a fourth junction, said first and second junctions respectively connected to a first and a second primary voltage source, a first and a second transistor each having a base, an emitter and a collector element, the base elements of each of said first and second transistors respectively connected to said third and fourth junctions of said bridge circuit network, a third primary voltage source commonly connected to the junction created by the common connection of the emitter elements of said first and said second transistors a third transistor also having a base, an emitter and a collector element connected via its emitter element to said first transistor circuit, a fourth transistor having a base, an emitter and a collector element connected via its base element to said second transistor, a common output junction created by a connection between the collector elements of said third and fourth transistors and a controlled switching means connected to said common junction to provide an output signal when any one of said first, said second, and said third primary voltage sources exceeds a predetermined allowable excursion and causes the termination of conduction in either said first or said second transistor, to respectively initiate conduction of said third or said fourth transistor, the initiation of conduction in either said third or said fourth transistors causing initiation of conduction in said controlled switching means.

Claim 3

The voltage monitoring circuit as set forth in claim 1, wherein said first and said second transistor circuits, each comprise a transistor one of which is a PNP and the other an NPN type, and said transistors are connected together in a complementary manner.

Claim 4

The voltage monitoring circuit as set forth in claim 1 wherein said third transistor is connected in a common base arrangement.

Claim 5

The voltage monitoring circuit as set forth in claim 1 wherein said controlled switching means is a silicon rectifier.

Claim 6

A voltage monitoring circuit for simultaneously detecting excessive excursions of any one of a plurality of primary voltage sources comprising a bridge circuit network having a first, a second, a third and a fourth junction, said first and second junctions connected to a first and a second primary voltage source, a first and a second transistor switching circuit connected to said third and fourth junctions of said bridge circuit, a third primary voltage source commonly connected to said first and second transistor switching circuit, a third and a fourth transistor switching circuit respectively connected to said first and second switching circuits, and a controlled switching output circuit commonly connected to said third and fourth transistor switching circuits, said first and said second switching circuits having appropriate voltage levels connected thereto from said first and second primary voltage source via said bridge network and said third primary voltage source for maintaining each of them in a normally closed condition, said third and said fourth switching circuits and said controlled switching output circuit connected to appropriate voltage levels for maintaining each of them in a normally open condition, wherein magnitude level variations of any one of said first, said second or said third primary voltage sources outside of a predetermined allowable range causes said first or said second normally closed transistor switching circuits to switch to an open condition and subsequently to switch said third or said fourth normally open transistor switching circuits and said controlled switching output circuit to a closed condition.

Claim 7

A voltage monitoring circuit for simultaneously detecting excessive excursions of any one of a plurality of primary voltage sources comprising a bridge circuit network having a first, a second, a third and a fourth junction, said first and second junctions connected to a first and a second primary voltage source, a first and a second transistor switching circuit connected to said third and fourth junctions of said bridge circuit, a third primary voltage source commonly connected to said first and second transistor switching circuit, a third and a fourth transistor switching circuit respectively connected to said first and second switching circuits, and a controlled switching output circuit commonly connected to said third and fourth transistor switching circuits, said first and said second switching circuits having appropriate voltage levels connected thereto from said first and second primary voltage source via said bridge network and said third primary voltage source for maintaining each of them in a normally closed condition, said third and said fourth switching circuits and said controlled switching output circuit connected to appropriate voltage levels for maintaining each of them in a normally open condition, wherein magnitude level variations of any one of said first, said second or said third primary voltage sources outside of a predetermined allowable range causes said first or said second normally closed transistor switching circuits to switch to an open condition and subsequently to switch said third or said fourth normally open transistor switching circuits and said controlled switching output circuit to a closed condition.

Claim 8

The voltage monitoring circuit as set forth in claim 5 wherein an auxiliary power source is included to supply operating voltage levels to said first, said second, said third and said fourth transistor switching circuits as well as to said controlled switching output circuit.

Claim 9

The voltage monitoring circuit as set forth in claim 5 wherein the transistors of said first and said second transistor switching circuits respectively comprise a first and a second transistor, one of which is a PNP type and the other an NPN type, connected together in a complementary fashion, and said third primary power source is connected to the common junction of the emitters of both of said transistors.

Claim 10

The voltage monitoring circuit as set forth in claim 5 wherein said bridge network circuit includes a first zener diode serially connected with said first primary voltage source, a second zener diode serially connected with said second primary voltage source and a resistive bridge network connected between said first and said second zener diodes,

Claim 11

The voltage monitoring circuit as set forth in claim 8 wherein a PNP and an NPN transistor are respectively connected to opposite arms of said resistive bridge network and said PNP and NPN transistors are connected together in a complementary manner.

Claim 12

The voltage monitoring circuit as set forth in claim 8 wherein said first and second zener diodes are connected between a first and a second primary voltage source and a first set of opposite arms of said resistive bridge network, a PNP and an NPN transistor are respectively connected to the second set of opposite arms of said bridge network and said PNP and said NPN transistors are connected together in a complementary manner with their emitters commonly connected together and to a third primary voltage source.