Lamp failure warning system

Claim 2

A warning system for checking failure of a lamp comprising a lamp, a source of electrical energy, means coupled to said source of electrical energy, and said lamp for intermittently energizing said lamp, a warning means, a solid state switching device having output electrodes and an input electrode, means coupling said output electrodes, said warning means and said source of electrical energy, means coupling said lamp and said input electrode of said solid state switching device to a condition in which said warning means is energized when said lamp is in an open circuited condition, a second solid state switching device having output electrodes and an input electrode, said input electrode being coupled to said means coupled to said source of electrical energy and said lamp for intermittently energizing said lamp, and means coupling said output electrodes of said second solid state sWitching device and the input electrode of said first mentioned solid state switching device for preventing said first solid state switching device from being switched to a state where it energizes said warning means when said means coupled to said source of electrical energy and said lamp for intermittently energizing said lamp is energized from said source of electrical energy.

Claim 3

The combination of claim 1 in which said means coupling said lamp and said input electrode of said solid state switching device includes a voltage divider connected between one terminal of said source of electrical energy and the input electrode of said first mentioned solid state switching device, said lamp being connected to an intermediate point of said voltage divider whereby electrical current is shunted around a portion of said voltage divider through said lamp and whereby current flows through the portion of the voltage divider connected to the input electrode of said solid state switching device when said lamp is open circuited, the resistance of the portion of the voltage divider connected between said source of electrical energy and said intermediate point being sufficient to prevent current flow through said lamp to bring it to a level where it reaches incandescence.

Claim 4

A turn signal and brake lamp failure warning system for an automotive vehicle comprising, a source of electrical energy, a plurality of signal lamps, a warning means, a turn signal switching means coupled to said source of electrical energy and to said signal lamps for intermittently energizing selected groups of said signal lamps from said source of electrical energy when said turn signal switching means is actuated, a brake lamp switch means coupled to said source of electrical energy and certain of said signal lamps for energizing said certain signal lamps from said source of electrical energy when said brake lamp switch means is actuated, a plurality of voltage dividers, one for each of said lamps, one terminal of each of said voltage dividers being coupled to said source of electrical energy, a solid state switching device having a control electrode and a pair of output electrodes, the other terminal of each of said voltage dividers being coupled to said control electrode, each of said lamps being connected to an intermediate point on its corresponding voltage divider, the change in current to said control electrode when any one of said lamps is open circuited being sufficient to switch said solid state switching device from one state to another state, and circuit means coupled to said source of electrical energy, said warning means and said output electrodes for energizing said warning means when said solid state switching device is switched from one state to the other state.

Claim 5

A turn signal and brake lamp failure warning system for an automotive vehicle comprising, a source of electrical energy, a plurality of signal lamps, a warning means, a turn signal switching means coupled to said source of electrical energy and to said signal lamps for intermittently energizing selected groups of said signal lamps from said source of electrical energy when said turn signal switching means is actuated, a brake lamp switch means coupled to said source of electrical energy and certain of said signal lamps for energizing said certain signal lamps from said source of electrical energy when said brake lamp switch means is actuated, a plurality of voltage dividers, one for each of said lamps, one terminal of each of said voltage dividers being coupled to said source of electrical energy, a solid state switching device having a control electrode and a pair of output electrodes, the other terminal of each of said voltage dividers being coupled to said control electrode, each of said lamps being connected to an intermediate point on its corresponding voltage divider, the change in current to said control electrode when any one of said lamps is open circuited being sufficient to switch said solid state switching device from one state to another state, and circuit means coupled to said source of electrical energy, said warning means and said output electrodes for energizing said warning means when said solid state switching device is switched from one state to the other state.

Claim 6

The combination of claim 3 and further comprising disabling means coupled to said turn signal switching means, to said brake lamp switch means and to said control electrode of said solid state switching device for preventing operation of said solid state switching means and energization of said warning means when said turn signal switching means or said brake lamp switch means is actuated.

Claim 7

The combination of claim 4 in which said disabling means comprising a second solid state switching device having a switching electrode connected to said turn signal switching means and said brake lamp switch means, and a pair of output electrodes connected in shunt with the control electrode of said first solid state switching device.

Claim 8

A warning system for checking failure of a lamp comprising a lamp, a source of electrical energy, means coupled to said source of electrical energy and said lamp for intermittently energizing said lamp, a warning means, a solid state switching device having output electrodes and an input electrode, means coupling said output electrodes, said warning means and said source of electrical energy for controlling the energization of said warning means, means coupling said lamp and said inPut electrode of said solid state switching device for switching said solid state switching device to a condition in which said warning means is energized when said lamp is in an open circuited condition, said last mentioned means including a voltage divider having one terminal connected to one terminal of said source of electrical energy and the other terminal connected to the input electrode of said solid state switching device, said voltage divider having an intermediate junction connected to said lamp, the resistance of said voltage divider between said one terminal of said source of electrical energy and said junction being sufficient to prevent current flow of a magnitude to energize said lamp to a level where it reaches incandescence.

Claim 9

A warning system for checking failure of a lamp comprising a lamp, a source of electrical energy, means coupled to said source of electrical energy and said lamp for intermittently energizing said lamp, a warning means, a solid state switching device having output electrodes and an input electrode, means coupling said output electrodes, said warning means and said source of electrical energy for controlling the energization of said warning means, means coupling said lamp and said inPut electrode of said solid state switching device for switching said solid state switching device to a condition in which said warning means is energized when said lamp is in an open circuited condition, said last mentioned means including a voltage divider having one terminal connected to one terminal of said source of electrical energy and the other terminal connected to the input electrode of said solid state switching device, said voltage divider having an intermediate junction connected to said lamp, the resistance of said voltage divider between said one terminal of said source of electrical energy and said junction being sufficient to prevent current flow of a magnitude to energize said lamp to a level where it reaches incandescence.