Multiplexed D.C. electrical systems for automotive vehicles
First Claim
1. In an automotive vehicle signal lamp system which comprises respective right and left signal lamp loads of given continuous D.C. voltage and illumination ratings on respective right and left sides of a vehicle for providing visible signals on the right and left sides of a vehicle, a D.C. power supply for energizing said lamp loads, and circuit means operatively coupling said D.C. power supply with said lamp loads, said circuit means including switch means for selectively energizing said lamp loads from said D.C. power supply to produce said signals, the improvement which comprises said power supply comprising means providing a lamp-load-energizing D.C. voltage the magnitude of which is essentially twice the given continuous D.C. voltage rating of said lamp loads, and said circuit means comprising means for operating said switch means to cause said lamp-load-energizing D.C. voltage to be duty-cycle applied to said lamp loads in such a manner that the time average value of voltage which is applied to said lamp loads is substantially the same as the given continuous D.C. voltage rating of said lamp loads and said lamp loads are caused to emit substantially their rated illumination without any perceptible flickering.
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Accused Products
Abstract
In a "two-wire" multiplexed lighting system, a square wave voltage alternating between positive and negative polarities is delivered by the two wires to both right and left lamps. Each lamp includes a diode, and the diodes are oppositely pulled with respect to each other so that one of the lamps is energized by one polarity of the square wave while the other lamp is energized by the opposite polarity. The magnitude of each polarity relative to ground is twice the continuous D.C. voltage rating of each lamp so that the average voltage applied to each lamp can be equal to the load'"'"'s maximum continuous rating to thereby provide full intensity illumination. The lamps provide different signaling functions, such as turn signal, emergency warning, brake lamp and running lamp signals by the operation of corresponding command switches acting through a control logic circuit, including multiplexing, configured to assign a priority to the commands such that the highest priority command will override any others and produce the corresponding operation of a lamps. In the "three-wire" embodiment of a multiplexed vehicle lighting system, the two lamps have a common ground but each is supplied by its own individual wire. The control circuit further includes a novel circuit for performing the marker lamp function that is commonly used in large trucks and highway tractors.
43 Citations
37 Claims
- 1. In an automotive vehicle signal lamp system which comprises respective right and left signal lamp loads of given continuous D.C. voltage and illumination ratings on respective right and left sides of a vehicle for providing visible signals on the right and left sides of a vehicle, a D.C. power supply for energizing said lamp loads, and circuit means operatively coupling said D.C. power supply with said lamp loads, said circuit means including switch means for selectively energizing said lamp loads from said D.C. power supply to produce said signals, the improvement which comprises said power supply comprising means providing a lamp-load-energizing D.C. voltage the magnitude of which is essentially twice the given continuous D.C. voltage rating of said lamp loads, and said circuit means comprising means for operating said switch means to cause said lamp-load-energizing D.C. voltage to be duty-cycle applied to said lamp loads in such a manner that the time average value of voltage which is applied to said lamp loads is substantially the same as the given continuous D.C. voltage rating of said lamp loads and said lamp loads are caused to emit substantially their rated illumination without any perceptible flickering.
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28. In an automotive vehicle signal lamp system which comprises a running lamp load, a D.C. power supply for energizing said running lamp load, and circuit means operatively coupling said D.C. power supply with said running lamp load, the improvement which comprises respective park and interrupt switches which operate on said circuit means such that said running lamp load is energized only if either one, but not both, of said park and interrupt switches is actuated.
- 29. In a lamp system which comprises two separate lamp loads of given continuous D.C. voltage and illumination ratings, a D.C. power supply for energizing said lamp loads, and circuit means operatively coupling said D.C. power supply with said lamp load, said circuit means including switch means for selectively energizing said lamp loads from said D.C. power supply, the improvement which comprises said power supply comprising means providing a lamp-load-energizing D.C. voltage the magnitude of which is essentially twice the given continuous D.C. voltage rating of said lamp loads, and said circuit means comprising means for operating said switch means to cause said lamp-load-energizing D.C. voltage to be duty-cycle applied to said lamp loads in such a manner that the time average value of voltage which is applied to said lamp loads is substantially the same as the given continuous D.C. voltage rating of said lamp loads and said lamp loads are caused to emit substantially their rated illumination without any perceptible flickering, said means for operating said switch means comprises means for causing said lamp-load-energizing voltage to be applied at any given instant in a mutually exclusive manner to said loads such that said lamp-load-energizing voltage is applied to only one of said lamp loads at any given instant, said D.C. power supply and said switch means comprise means for delivering different polarities of said lamp-load-energizing voltage to said lamp loads, and said lamp loads comprise polarity-sensitive means for rendering one of them responsive to only a particular one of said polarities of said lamp-load-energizing voltage and the other of them responsive to only a particular other of said polarities of said lamp-load-energizing voltage.
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34. In an automotive vehicle signal lamp system which comprises respective right and left signal lamp loads of given continuous D.C. voltage and illumination ratings on respective right and left sides of a vehicle for providing visible signals on the right and left sides of a vehicle, a D.C. power supply for energizing said lamp loads, and circuit means operatively coupling said D.C. power supply with said lamp loads, said circuit means including switch means for selectively energizing said lamp loads from said D.C. power supply to produce said signals, the improvement which comprises control logic means for operating said switch means in accordance with signal command inputs to said control logic means to cause said lamps loads to produce different signals corresponding to different signal command inputs, means for according a predetermined priority to said different signal command inputs such that said lamp loads are caused to exhibit the signal commanded by the highest priority signal command which is being input to said control logic means, and in which said signal command inputs include, in decreasing order of priority, hazard warning, right and left turn, and brake lamp commands, and said control logic means comprises means for controlling the operation of said switch means in a particular manner for each command, in which said control logic means comprises means for imposing on said switch means particular duty cycles of operation corresponding to particular ones of said signal command inputs, and including feedback regulator means for monitoring the power flow to said lamp loads for each of the different signal command inputs and for causing the appropriate power flow for each particular signal command input to be maintained to the lamp loads despite variations in the magnitude of said lamp-load-energizing voltage due to variations in the magnitude of said D.C. power supply voltage, in which said feedback regulator means comprises means for varying the duty cycle operation of said switch means in a manner to cause the appropriate power flow for each particular signal command input to be maintained to the lamp loads.
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35. In an automotive vehicle electrical system which comprises respective first and second loads of given continuous D.C. voltage and power ratings, a D.C. power supply for energizing said loads, and circuit means operatively coupling said D.C. power supply with said loads, said circuit means including switch means for selectively energizing said loads from said D.C. power supply to operate said loads at their given continuous D.C. voltage and power ratings, the improvement which comprises said power supply comprising means providing a load-energizing D.C. voltage the magnitude of which is essentially twice the given continuous D.C. voltage rating of said loads, and said circuit means comprising means for operating said switch means to cause said load-energizing D.C. voltage to be duty-cycle applied to said loads in such a manner that the time average value of voltage which is applied to said loads is substantially the same as the given continuous D.C. voltage rating of said loads and said loads are caused to operate substantially at their rated power.
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36. In an electrical system which comprises two separate loads of given continuous D.C. voltage and power ratings, a D.C. power supply for energizing said loads, and circuit means operatively coupling said D.C. power supply with said loads, said circuit means including switch means for selectively energizing said loads for said D.C. power supply, the improvement which comprises said power supply comprising means providing a load-energizing D.C. voltage the magnitude of which is essentially twice the given continuous D.C. voltage rating of said loads, and said circuit means comprising means for operating said switch means to cause said load-energizing D.C. voltage to be duty-cycle applied to said loads in such a manner that the time average value of voltage which is applied to said loads is substantially the same as the given continuous D.C. voltage rating of said loads and said loads are caused to operate substantially at their rated power, said means for operating said switch means comprises means for causing said load-energizing voltage to be applied at any given instant in a mutually exclusive manner to said loads such that said load-energizing voltage is applied to only one of said loads at any given instant, said D.C. power supply and said switch means comprise means for delivering different polarities of said load-energizing voltage to said loads, and said loads comprise polarity-sensitive means for rendering one of them responsive to only a particular one of said polarities of said load-energizing voltage and the other of them responsive to only a particular other of said polarities of said load-energizing voltage.
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37. In an automotive vehicle signal lamp system which comprises respective right and left signal lamp loads of given continuous D.C. voltage and illumination ratings on respective right and left sides of a vehicle for providing visible signals on the right and left sides of a vehicle, a D.C. power supply for energizing said lamp loads, and circuit means operatively coupling said D.C. power supply with said lamp loads, said circuit means including switch means for selectively energizing said lamp loads from said D.C. power supply to produce said signals, the improvement which comprises control logic means for operating said switch means in accordance with signal command inputs to said control logic means to cause said lamp loads to produce different signals corresponding to different signal command inputs, priority according means for according a predetermined priority to said different signal command inputs such that said lamp loads are caused to exhibit the signal commanded by the highest priority signal command which is being input to said control logic means, and in which said signal command inputs include, in decreasing order of priority, hazard warning, right and left turn, and brake lamp commands, and said control logic means comprises means for controlling the operation of said switch means in a particular manner for each command, in which said priority according means comprises plural logic gates which, from those command signals being received by said control logic means, transmit to said switch means the one command signal which has the highest priority, and in which said logic gates comprise a first set of gates associated with one of said lamp loads and a second set of gates associated with the other of said lamp loads, said hazard warning signal command input being provided through a hazard warning switch to one particular input of both sets of gates, said right and left turn signal command inputs being provided through a turn signal switch selectively to both sets of gates, the right turn signal command to said one particular input of said first set of gates and the left turn signal command to said one particular input of said second set of gates, and said brake command input being provided through a brake switch to another particular input of both sets of gates, and in which said command signal inputs further include a running lamp command input which has a priority lower than the first-three-mentioned command signal inputs, and the running lamp command signal input is provided to both said sets of gates and is conjointly developed by means of respective park and interrupt switches which operate through an EXCLUSIVE OR gate on said control logic means such that said running lamp command signal is transmitted to both said sets of gates only if either one, but not both, of said park and interrupt switches is actuated.
Specification