Apparatus for determining the sequence of circuit discontinuities in a sealing circuit for a power output device

Claim 2

A fault-finding circuit for determining which of several series connected contact that are wired to a potential source opens first in a sealing circuit for a power output device, said circuit comprising: a plurality of switches, visual indicator means, means connecting each switch to one visual indicator such that closing of the switch will energize its associated indicator, means initially maintaining one side of each switch at a first potential, means initially maintaining the other side of each switch at a second potential, each of the switches includes a switch-triggering means, a conductor connecting each triggering means to one side of one of the contacts that are to be monitored, the contacts when closed maintaining the triggering means at a potential that will prevent its associated switch from conducting and the opening of one of the contacts changing the potential of at least one triggering means sufficiently to cause its switch to become conducting thereby energizing its associated indicator whereby when one of said contacts opens, the potential of those triggering means between the open contact and the potential source will be changed to make their associated switches conduct and the opening of said contact preventing the potential source from energizing the triggering means of any of the switches remote from said potential source from the switch that is conducting.

Claim 3

A fault-finding apparatus for determining the opening sequence of a plurality of contacts connected to a power supply means in a sealing circuit for a power output device, said apparatus comprising a plurality of switches, each switch containing a cathode, an anode and a gate, an indicator connected in series with each switch, said power supply means being connected to each of the switches to initially maintain each anode at a first potential and cathode at a second potential, said indicators connected to each switch such that each indicator will be energized only when its associated switch is in the ''''on'''' condition, leads for connecting each anode and cathode of the switches across the monitored electric power circuit, leads for connecting each gate to one side of each of the contacts being monitored, the opening of one of the contacts will cause the gate of the associated switch to be connected through the power output device to the cathode thus causing the switch to become conducting and after a contact opens only those switches having their gates connected to the anode through the power output device thereof will be turned ''''on'''' and those which remain connected to the cathode remain in an ''''OFF'''' condition whereby when one of said contacts opens, the potential of those gates between the open contact and the potential source will be changed to make their associated switches conduct and the opening of said contact preventing the potential source from energizing the gates of any of the switches remote from said potential source from the switch that the switch that is conducting.

Claim 4

A fault-finding apparatus for determining the opening sequence of a plurality of contacts connected to a power supply means in a sealing circuit for a power output device, said apparatus comprising a plurality of switches, each switch containing a cathode, an anode and a gate, an indicator connected in series with each switch, said power supply means being connected to each of the switches to initially maintain each anode at a first potential and cathode at a second potential, said indicators connected to each switch such that each indicator will be energized only when its associated switch is in the ''''on'''' condition, leads for connecting each anode and cathode of the switches across the monitored electric power circuit, leads for connecting each gate to one side of each of the contacts being monitored, the opening of one of the contacts will cause the gate of the associated switch to be connected through the power output device to the cathode thus causing the switch to become conducting and after a contact opens only those switches having their gates connected to the anode through the power output device thereof will be turned ''''on'''' and those which remain connected to the cathode remain in an ''''OFF'''' condition whereby when one of said contacts opens, the potential of those gates between the open contact and the potential source will be changed to make their associated switches conduct and the opening of said contact preventing the potential source from energizing the gates of any of the switches remote from said potential source from the switch that the switch that is conducting.

Claim 5

The apparatus of claim 1 wherein each switch comprises a silicon controlled rectifier.

Claim 6

The apparatus of claim 1 wherein a power supply is connected across the main power line being monitored and the switches are connected in parallel across the power supply.

Claim 7

The apparatus of claim 1 wherein the means connecting the gate of each of the thyristors to the circuit being monitored comprises a releasable connector.

Claim 8

The apparatus of claim 1 wherein each of the switches comprises a thyristor having a cathode, an anode and a gate and each of the contacts is connected to the gate through a capacitor for blocking DC currents.