Apparatus for determining the location of a failure in a series relay circuit and the type of failure

Claim 2

Monitoring structure for a plurality of relay contacts connected in series between a first and second conductor, which first and second conductors are connected to the opposite terminals of a source of electrical energy, comprising separate means, associated with each series connected relay for indicating initial closing of each of the series-connected contacts, connected between the conductors and to one side of the monitored series-connected contact associated therewith, each said separate means comprising a first circuit including first resistance means, a first diode and a first neon light connected in series with each other between the first and second conductors, said resistance means preventing initial illumination of the light due to the electrical signal between the first and second conductors but permitting continued illumination of the light due to the electrical signal between the first and second conductors after initial illumination thereof, and a second circuit including second resistance means, said first neon light and a second diode connected in series with each other and between the one side of the associated contact and the second conductor for initially illuminating the first light on closing of the contact associated therewith and all of the series connected contacts between the associated contact and the first conductor.

Claim 3

Structure as set forth in claim 1 and further comprising separate means, associated with each of the series-connected contacts for indicating the first contact of the series-connected contacts which opens after the series-connected contacts have all closed, connected between the first and second conductors and to the one side of the associated contact comprising a third circuit including third resistance means, a second neon bulb and a third diode connected in series between the first and second conductors, which third resistance means is sufficient to prevent initial illumination of the neon bulb due to the electric signal between the first and second conductors and is insufficient to prevent continued illumination of the second neon bulb due to the electric signal between the first and second conductors after initial illumination of the neon bulb, and a fourth circuit including fourth resistance means, the second neon bulb, a fourth diode and a separate relay contact connected in series between the first conductor and the one side of the associated series-connected contact, and relay coil means, for closing the separate relay contact on completing a circuit through the series-connected contacts, connected between the series-connected contacts and the second conductor.

Claim 4

Structure as set forth in claim 2, wherein the means for closing the separate relay contact fUrther includes a holding contact in series with the series-connected contacts between the series-connected contacts and the first relay coil means for closing the separate contact and a second relay coil for maintaining the holding contact in a closed condition connected in parallel with the means for closing the separate relay contact having a dropout time with respect to the holding relay contact which is longer than the dropout time of the first relay coil with respect to the separate contact to insure lighting of all of the second neon lights in monitoring circuits subsequent to the initial contact in the series-connected contacts which has opened.

Claim 5

Monitoring structure for a plurality of relay contacts connected in series between a first and second conductor, which first and second conductors are connected to the opposite terminals of a source of electrical energy, comprising separate means, associated with each of the series-connected contacts for indicating the first contact of the series-connected contacts which opens after the series-connected contacts have all closed, connected between the first and second conductors and to one side of the associated contact comprising a first circuit including first resistance means, a neon bulb and a first diode connected in series between the first and second conductors, which first resistance means is sufficient to prevent initial illumination of the neon bulb due to the electric signal between the first and second conductors and is insufficient to prevent continued illumination of the neon bulb due to the electric signal between the first and second conductors after initial illumination of the neon bulb, and a second circuit including second resistance means, the neon bulb, a second diode and a separate relay contact connected in series between the first conductor and the one side of the associated series-connected contact, and relay coil means, for closing the separate relay contact on completing a circuit through the series-connected contacts circuit, connected between the series-connected contacts and the second conductor.

Claim 6

Monitoring structure for a plurality of relay contacts connected in series between a first and second conductor, which first and second conductors are connected to the opposite terminals of a source of electrical energy, comprising separate means, associated with each of the series-connected contacts for indicating the first contact of the series-connected contacts which opens after the series-connected contacts have all closed, connected between the first and second conductors and to one side of the associated contact comprising a first circuit including first resistance means, a neon bulb and a first diode connected in series between the first and second conductors, which first resistance means is sufficient to prevent initial illumination of the neon bulb due to the electric signal between the first and second conductors and is insufficient to prevent continued illumination of the neon bulb due to the electric signal between the first and second conductors after initial illumination of the neon bulb, and a second circuit including second resistance means, the neon bulb, a second diode and a separate relay contact connected in series between the first conductor and the one side of the associated series-connected contact, and relay coil means, for closing the separate relay contact on completing a circuit through the series-connected contacts circuit, connected between the series-connected contacts and the second conductor.