Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
229 words
Lamp failure detector for monitoring at least one pilot lamp arranged to show the state of a transducer, said detector comprising at least one lamp to be monitored; switching means connected to said lamp for controlling the magnitude of a signal current flowing through said lamp between two levels, one level being sufficient to visibly light the lamp and another level insufficient to visibly light the lamp; control means for sensing the level of current flow through said lamp and for generating a control signal when current flow through said lamp is interrupted; failure sensing means comprising a transistor having a base connected to said control means for receiving said control signal; indicator means comprising an audible alarm device connected to the collector of said transistor for providing an indication when current flow is interrupted in said lamp and a signal is received at said base of said transistor; ring-back means connected to said collector of said transistor; and movable contact means for switching said audible alarm device to said collector of said transistor and to ring-back means, said failure sensing means and said ring-back means being arranged in cooperative relation with one another to energize said audible alarm device when connected to said collector only when a control signal is generated while only being energized in the absence of a control signal when connected to said ring-back circuit.
Claim 2
Dependent Claim
229 words
Lamp failure detector for monitoring at least one pilot lamp arranged to show the state of a transducer, said detector comprising at least one lamp to be monitored; switching means connected to said lamp for controlling the magnitude of a signal current flowing through said lamp between two levels, one level being sufficient to visibly light the lamp and another level insufficient to visibly light the lamp; control means for sensing the level of current flow through said lamp and for generating a control signal when current flow through said lamp is interrupted; failure sensing means comprising a transistor having a base connected to said control means for receiving said control signal; indicator means comprising an audible alarm device connected to the collector of said transistor for providing an indication when current flow is interrupted in said lamp and a signal is received at said base of said transistor; ring-back means connected to said collector of said transistor; and movable contact means for switching said audible alarm device to said collector of said transistor and to ring-back means, said failure sensing means and said ring-back means being arranged in cooperative relation with one another to energize said audible alarm device when connected to said collector only when a control signal is generated while only being energized in the absence of a control signal when connected to said ring-back circuit.
Claim 3
Dependent Claim
18 words
Lamp failure detector as defined in claim 1, wherein said indicator means further comprises a failure indicator lamp.
Claim 4
Dependent Claim
68 words
Lamp failure detector as defined in claim 1, wherein said ring-back means comprises a transistor, first and second series-connected voltage divider resistors having a center tap, said resistors being connected between said collector of said failure sensing means transistor and the emitter of the latter, said ring-back transistor having a base connected to said center tap and a collector to which said audible alarm device can be switched.
Claim 5
Dependent Claim
93 words
Lamp failure detector as defined in claim 3, further comprising a two-position switch having a movable contact connected to said audible alarm device, a first fixed contact connected to said collector of said failure sensing transistor means, and a second fixed contact connected to said collector of said ring-back means, said audible alarm device being arranged to be energized only when connected to said first contact in the presence of a control signal while being arranged to be energized only when connected to said second contact in the absence of a control signal.
Claim 6
Dependent Claim
199 words
Lamp failure detector for monitoring at least one pilot lamp arranged to show the state of a transducer, said detector comprising at least one lamp to be monitored; switching means connected to said lamp for Controlling the magnitude of a signal current flowing through said lamp between two levels, one level being sufficient to visibly light the lamp and another level insufficient to visibly light the lamp; control means for sensing the level of current flow through said lamp and for generating a control signal when current flow through said lamp is interrupted; failure sensing means connected to said control means for receiving said control signal; indicator means connected to said failure sensing means for providing an indication when current flow is interrupted in said lamp; ring-back means connected to said failure sensing means; and movable contact means for switching said indicator means to said failure sensing means and to said ring-back means, said failure sensing means and said ring-back means being arranged to energize said indicator means when connected to said failure sensing means only when a control signal is generated while only being energized in the absence of a control signal when connected to said ring-back means.
Claim 7
Dependent Claim
199 words
Lamp failure detector for monitoring at least one pilot lamp arranged to show the state of a transducer, said detector comprising at least one lamp to be monitored; switching means connected to said lamp for Controlling the magnitude of a signal current flowing through said lamp between two levels, one level being sufficient to visibly light the lamp and another level insufficient to visibly light the lamp; control means for sensing the level of current flow through said lamp and for generating a control signal when current flow through said lamp is interrupted; failure sensing means connected to said control means for receiving said control signal; indicator means connected to said failure sensing means for providing an indication when current flow is interrupted in said lamp; ring-back means connected to said failure sensing means; and movable contact means for switching said indicator means to said failure sensing means and to said ring-back means, said failure sensing means and said ring-back means being arranged to energize said indicator means when connected to said failure sensing means only when a control signal is generated while only being energized in the absence of a control signal when connected to said ring-back means.