US3868628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for indicating disconnection of automobile lamps
Assignee: Denso Corp
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Filing: 1973-11-21
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Granted: 1975-02-25
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Expires: 1993-11-21
Abstract
Abstract A device for indicating disconnection of automotive lamps comprising a current winding energized by a load current of a lamp and a voltage winding phase-inverted from said current winding for generating a small magnetomotive force, said two windings combining to operate the contact of an indicator circuit, whereby disconnection of one of four or more parallelconnected lamps is successfully detected and indicated under widely varying conditions of a source voltage, thus overcoming the limit of detection which is posed by the load characteristic of the lamps.
Inventors
- 👤 Yasuhiko Sakurai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:09
CPC Classifications
B; B60; B60Q; B60Q11/00; B60Q11/005
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
412 words
A system for indicating disconnection of automotive lamps comprising an electric source having a predetermined nominal voltage output, a pluraLity of more than two automotive lamps connected in parallel with each other, disconnection indicating means, a relay having a current winding connected between said electric source and said more than two automotive lamps, for generating a magnetomotive force; said relay having a voltage winding, connected in parallel with the combination of said current winding and said more than two automotive lamps for generating an opposite magnetomotive force to that of said current winding; said voltage winding being connected in series with a resistor and in parallel with a capacitor; said relay further having a relay contact, connected between the junction point of said two windings and said disconnection indicating means, for interrupting the electric current through said disconnection indicating means when the net magnetomotive force of said two windings becomes above a predetermined value; said current and voltage windings of said relay being designed so that the opposite magnetomotive force generated by said voltage winding is a predetermined amount less than the magnetomotive force generated by said current winding when all of said more than two automotive lamps are connected with the net magnetomotive force consisting of said magnetomotive force less said opposite magnetomotive force being sufficient to actuate said relay contact to interrupt current flow, said predetermined amount by which said opposite magnetomotive force is less than said magnetomotive force being determined by requiring the change in net magnetomotive force caused by current reduction through said current coil due to disconnection of one of said more than two automotive lamps to be greater than changes in net magnetomotive force due to a decrease in voltage output of said electric source of predetermined amount from its nominal value or to an increase in voltage output of said electric source a predetermined amount from its nominal value whereby changes in voltage output of said electric source within the predetermined limits which increase the net magnetomotive force are insufficient to increase said net magnetomotive force to a value which would actuate said relay contact if one of said more than two automotive lamps is disconnected and changes in voltage output of said electric source within the predetermined limits which decrease the net magnetomotive force are insufficient to decrease said net magnetomotive force to a value which would prevent actuation of said relay contact when all of said more than two automotive lamps are connected.
Claim 2
Independent Claim
412 words
A system for indicating disconnection of automotive lamps comprising an electric source having a predetermined nominal voltage output, a pluraLity of more than two automotive lamps connected in parallel with each other, disconnection indicating means, a relay having a current winding connected between said electric source and said more than two automotive lamps, for generating a magnetomotive force; said relay having a voltage winding, connected in parallel with the combination of said current winding and said more than two automotive lamps for generating an opposite magnetomotive force to that of said current winding; said voltage winding being connected in series with a resistor and in parallel with a capacitor; said relay further having a relay contact, connected between the junction point of said two windings and said disconnection indicating means, for interrupting the electric current through said disconnection indicating means when the net magnetomotive force of said two windings becomes above a predetermined value; said current and voltage windings of said relay being designed so that the opposite magnetomotive force generated by said voltage winding is a predetermined amount less than the magnetomotive force generated by said current winding when all of said more than two automotive lamps are connected with the net magnetomotive force consisting of said magnetomotive force less said opposite magnetomotive force being sufficient to actuate said relay contact to interrupt current flow, said predetermined amount by which said opposite magnetomotive force is less than said magnetomotive force being determined by requiring the change in net magnetomotive force caused by current reduction through said current coil due to disconnection of one of said more than two automotive lamps to be greater than changes in net magnetomotive force due to a decrease in voltage output of said electric source of predetermined amount from its nominal value or to an increase in voltage output of said electric source a predetermined amount from its nominal value whereby changes in voltage output of said electric source within the predetermined limits which increase the net magnetomotive force are insufficient to increase said net magnetomotive force to a value which would actuate said relay contact if one of said more than two automotive lamps is disconnected and changes in voltage output of said electric source within the predetermined limits which decrease the net magnetomotive force are insufficient to decrease said net magnetomotive force to a value which would prevent actuation of said relay contact when all of said more than two automotive lamps are connected.
Claim 3
Independent Claim
417 words
A system for indicating disconnection of automotive lamps comprising an electric source having a predetermined nominal voltage output, a plurality of more than two automotive lamps connected in parallel with each other, disconnection indicating means, a relay having a current winding connected between said electric source and said more than two automotive lamps, for generating a magnetomotive force, said relay having a voltage winding, connected in parallel with the combination of said current winding and said more than two automotive lamps for generating an opposite magnetomotive force to that of said current winding; said voltage winding being connected in series with a resistor which is in turn connected in parallel with a capacitor; said relay further having a relay contact, connected between the junction point of said two windings and said disconnection indicating means, for interrupting the electric current through said disconnection indicating means when the net magnetomotive force of said two windings becomes above a predetermined value; said current and voltage windings of said relay being designed so that the opposite magnetomotive force generated by said voltage winding is a predetermined amount less than the magnetomotive force generated by said current winding when all of said more than two automotive lamps are connected with the net magnetomotive force consisting of said magnetomotive force less said opposite magnetomotive force being sufficient to actuate Said relay contact to interrupt current flow, with said predetermined amount by which said opposite magnetomotive force is less than said magnetomotive force being determined by requiring the change in net magnetomotive force caused by current reduction through said current coil due to disconnection of one of said more than two automotive lamps to be greater than changes in net magnetomotive force due to a decrease in voltage output of said electric source a predetermined amount from its nominal value or to an increase in voltage output of said electric source a predetermined amount from its nominal value whereby changes in voltage output of said electric source within the predetermined limits which increase the net magnetomotive foroce are insufficient to increase said net magnetomotive force to a value which would actuate said relay contact if one of said more than two automotive lamps is disconnected and changes in voltage output of said electric source within the predetermined limits which decrease the net magnetomotive force are insufficient to decrease said net magnetomotive force to a value which would prevent actuation of said relay contact when all of said more than two automotive lamps are connected.
Claim 4
Independent Claim
417 words
A system for indicating disconnection of automotive lamps comprising an electric source having a predetermined nominal voltage output, a plurality of more than two automotive lamps connected in parallel with each other, disconnection indicating means, a relay having a current winding connected between said electric source and said more than two automotive lamps, for generating a magnetomotive force, said relay having a voltage winding, connected in parallel with the combination of said current winding and said more than two automotive lamps for generating an opposite magnetomotive force to that of said current winding; said voltage winding being connected in series with a resistor which is in turn connected in parallel with a capacitor; said relay further having a relay contact, connected between the junction point of said two windings and said disconnection indicating means, for interrupting the electric current through said disconnection indicating means when the net magnetomotive force of said two windings becomes above a predetermined value; said current and voltage windings of said relay being designed so that the opposite magnetomotive force generated by said voltage winding is a predetermined amount less than the magnetomotive force generated by said current winding when all of said more than two automotive lamps are connected with the net magnetomotive force consisting of said magnetomotive force less said opposite magnetomotive force being sufficient to actuate Said relay contact to interrupt current flow, with said predetermined amount by which said opposite magnetomotive force is less than said magnetomotive force being determined by requiring the change in net magnetomotive force caused by current reduction through said current coil due to disconnection of one of said more than two automotive lamps to be greater than changes in net magnetomotive force due to a decrease in voltage output of said electric source a predetermined amount from its nominal value or to an increase in voltage output of said electric source a predetermined amount from its nominal value whereby changes in voltage output of said electric source within the predetermined limits which increase the net magnetomotive foroce are insufficient to increase said net magnetomotive force to a value which would actuate said relay contact if one of said more than two automotive lamps is disconnected and changes in voltage output of said electric source within the predetermined limits which decrease the net magnetomotive force are insufficient to decrease said net magnetomotive force to a value which would prevent actuation of said relay contact when all of said more than two automotive lamps are connected.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |