Discriminating fault indication circuit

Claim 2

An indicator circuit for indicating the conduction of a normally nonconductive semiconductor device; said indicator circuit including, in combination: a. a source of rectified DC voltage having first and second terminals which are respectively positive and negative; b. a semiconductor device operable between a conduction and nonconduction condition and normally being in said nonconduction condition; c. a load device connected in series with said voltage source and said semiconductor device; d. first and second diode means having respective first and second leads; said first leads connected to said first and second terminals, respectively, of said voltage source; e. an indicator device having an indicator means movable between first and second indicator positions, and a set coil and a reset coil coupled to said indicator means, whereby energization of said set coil and reset coil operates said indicator means between said first and second indicator positions; f. said second leads of said first and second diodes connected to one another and in series with said set coil and said semiconductor device, whereby conduction of said semiconductor device energizes said set coil; and g. reset circuit means connected to said reset coil; said reset circuit means including switch means, the operation of which energizes said reset coil.

Claim 3

The indicator circuit of claim 1 wherein said load device comprises trip circuit means; and cirCuit interrupter means coupled to said voltage source and to said trip circuit means, whereby operation of said trip circuit means by conduction of said semiconductor device operates said circuit interrupter means.

Claim 4

The indicator circuit of claim 2 which includes energy storage means connected across said voltage source.

Claim 5

The indicator circuit of claim 3 wherein said semiconductor device comprises a controlled rectifier and wherein said energy storage means comprises a capacitor.

Claim 6

An indicator circuit for a multiphase circuit for indicating a fault condition on any of the phases of said circuit; each phase of said multiphase circuit including: a. output voltage means comprising a rectifier circuit having first and second DC terminals for generating an output voltage related to the current in its respective phase; b. a semiconductor device operable between a conduction and nonconduction condition and normally being in said nonconduction condition; c. a multiphase circuit interrupter connected to said multiphase circuit; d. a trip device connected to said interrupter and in series with said semiconductor device; e. respective first and second diode means for each of said phases and each having first and second leads connected to said first and second terminals of said output voltage means of their said respective phase; f. an indicator device for each of said phases; each of said indicator devices having an indicator means movable between first and second indicator positions, and a set coil and a reset coil coupled to said indicator means, whereby energization of said set coil and reset coil operates said indicator means between said first and second indicator positions; g. said second leads of said first and second diodes connected to one another and in series with their respective set coil and said semiconductor device, whereby conduction of said semiconductor device energizes at least one of said set coils, depending on the magnitude of voltage of its respective output voltage means; and h. reset circuit means for each of said reset coils.

Claim 7

An indicator circuit for a multiphase circuit for indicating a fault condition on any of the phases of said circuit; each phase of said multiphase circuit including: a. output voltage means comprising a rectifier circuit having first and second DC terminals for generating an output voltage related to the current in its respective phase; b. a semiconductor device operable between a conduction and nonconduction condition and normally being in said nonconduction condition; c. a multiphase circuit interrupter connected to said multiphase circuit; d. a trip device connected to said interrupter and in series with said semiconductor device; e. respective first and second diode means for each of said phases and each having first and second leads connected to said first and second terminals of said output voltage means of their said respective phase; f. an indicator device for each of said phases; each of said indicator devices having an indicator means movable between first and second indicator positions, and a set coil and a reset coil coupled to said indicator means, whereby energization of said set coil and reset coil operates said indicator means between said first and second indicator positions; g. said second leads of said first and second diodes connected to one another and in series with their respective set coil and said semiconductor device, whereby conduction of said semiconductor device energizes at least one of said set coils, depending on the magnitude of voltage of its respective output voltage means; and h. reset circuit means for each of said reset coils.

Claim 8

The indicator circuit of claim 5 which includes resistor means in series with each of said set coils.

Claim 9

The indicator circuit of claim 5 which includes energy storage means connected across each of said output voltage means.

Claim 10

The indicator circuit of claim 7 wherein said semiconductor device is a controlled rectifier and said energy storage means is a capacitor.