Load driver and system with fault detection apparatus for providing a sequence of fault detection logic states
First Claim
1. Load driver with fault detection apparatus, comprising:
- semiconductor switch having a control electrode for receiving a switch control signal which determines on and off modes of operation of the switch, said switch having an output electrode for connection to an associated electrical load;
W/R terminal for receiving a write/read control signal;
C/stat terminal for receiving a command signal;
circuit means coupled between said semiconductor switch and said W/R and C/stat terminals for providing said switch control signal to said semiconductor switch in accordance with said write/read signal and said command signal; and
fault diagnostic circuit means coupled to said semiconductor switch and at least one of said W/R and C/stat terminals for monitoring operation of said semiconductor switch and its associated load and for providing, at said one terminal, a timed sequence of at least three predetermined logic states indicative of said monitored switch/load operation, each of said predetermined logic states indicative of, respectively, switch/load operation at sequential times (a) after said switch control signal attempts to turn said switch on and when said switch is supposed to be on, (b) at a first time after said switch control signal attempts to turn said semiconductor switch off, and (c) at a second time when said switch is supposed to be off, later than said first time, after said switch control signal attempts to turn said semiconductor switch off, a particular sequence of said three logic states indicating proper switch/load operation and each of three other sequences of said three logic states indicative of a different operational fault of said switch/load.
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Accused Products
Abstract
Load driver system (10) preferably uses a microprocessor controller (20) to generate write/read signals and command signals received by a circuit at write/read and command/status input terminals (16, 17). The circuit (15) responds to the input signals and controls a semiconductor switch (11) that controls the operative state of a load (14). The circuit (15) includes a load shorted high detector (28), a load shorted low detector (29) and a load open detector (30) which are used to detect various faults and provide a predetermined sequence of logic states at the command/status input terminal (17) during read cycles implemented by the controller (20). Thus one input line (terminal 17) is used to both send commands to the semiconductor switch (11) and receive a sequence of logic states indicative of various fault modes. This permits the controller to determine which of several types of faults, if any, has occurred, while minimizing the number of controller-circuit interconnections.
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Citations
23 Claims
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1. Load driver with fault detection apparatus, comprising:
- semiconductor switch having a control electrode for receiving a switch control signal which determines on and off modes of operation of the switch, said switch having an output electrode for connection to an associated electrical load;
W/R terminal for receiving a write/read control signal; C/stat terminal for receiving a command signal; circuit means coupled between said semiconductor switch and said W/R and C/stat terminals for providing said switch control signal to said semiconductor switch in accordance with said write/read signal and said command signal; and fault diagnostic circuit means coupled to said semiconductor switch and at least one of said W/R and C/stat terminals for monitoring operation of said semiconductor switch and its associated load and for providing, at said one terminal, a timed sequence of at least three predetermined logic states indicative of said monitored switch/load operation, each of said predetermined logic states indicative of, respectively, switch/load operation at sequential times (a) after said switch control signal attempts to turn said switch on and when said switch is supposed to be on, (b) at a first time after said switch control signal attempts to turn said semiconductor switch off, and (c) at a second time when said switch is supposed to be off, later than said first time, after said switch control signal attempts to turn said semiconductor switch off, a particular sequence of said three logic states indicating proper switch/load operation and each of three other sequences of said three logic states indicative of a different operational fault of said switch/load. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- semiconductor switch having a control electrode for receiving a switch control signal which determines on and off modes of operation of the switch, said switch having an output electrode for connection to an associated electrical load;
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13. Load driver system with fault detection apparatus, comprising:
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semiconductor switch having a control electrode for receiving a switch control signal which determines on and off modes of operation of the switch, said switch having an output electrode; a load coupled to said semiconductor switch output electrode; W/R terminal for receiving a write/read control signal; C/stat terminal for receiving a command signal; circuit means coupled between said semiconductor switch and said W/R and C/stat terminals for providing said switch control signal to said semiconductor switch in accordance with said write/read signal and said command signal; and fault diagnostic circuit means coupled to said semiconductor switch and at least one of said W/R and C/stat terminals for monitoring operation of said semiconductor switch and said load and for providing, at said one terminal, a timed sequence of at least three predetermined logic states indicative of said monitored switch/load operation, each of said predetermined logic states indicative of, respectively, switch/load operation at sequential times (a) after said switch control signal attempts to turn said switch on and when said switch is supposed to be on, (b) at a first time after said switch control signal attempts to turn said semiconductor switch off, and (c) at a second time when said switch is supposed to be off, later than said first time, after said switch control signal attempts to turn said semiconductor switch off, a particular sequence of said three logic states indicating proper switch/load operation and each of three other sequences of said three logic states indicative of a different operational fault of said switch/load. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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21. Load driver system with fault detection apparatus, comprising:
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a plurality of semiconductor switches each having a control electrode for receiving a switch control signal which determines on and off modes of operation of the switch, each of said switches having an output electrode; a load associated with and coupled to each of said semiconductor switch output electrodes, respectively; W/R terminal for receiving a write/read control signal; a plurality of C/stat terminals each associated with one of said switches, respectively, and each receiving a command signal; a plurality of circuit means each coupled between said W/R terminal, one of said semiconductor switches and one of said C/stat terminals, respectively, for providing said switch control signal to said one of said semiconductor switches in accordance with said write/read control signal and said command signal provided at said one of said C/stat terminals associated with said one of said semiconductor switches; and a plurality of fault diagnostic circuit means each coupled to and associated with one of said semiconductor switches and each coupled to at least one of said W/R and C/stat terminals associated with said one of said semiconductor switches for monitoring operation of said one of said semiconductor switches and its associated load and for providing, at said one of said W/R and C/stat terminals associated with said one of said switches, a timed sequence of at least three predetermined logic states indicative of said monitored switch/load operation, each of said predetermined logic states indicative of, respectively, switch/load operation at sequential times (a) after said switch control signal attempts to turn said one of said switches on and when said one of said switches is supposed to be on, (b) at a first time after said switch control signal attempts to turn said one of said semiconductor switches off, and (c) at a second time when said one of said switch is supposed to be off, later than said first time, after said switch control signal attempts to turn said one of said semiconductor switches off, a particular sequence of said three logic states indicating proper switch/load operation and each of three other sequences of said three logic states indicative of a different operational fault of said switch/load, whereby said write/read signal is coupled to a plurality of said switches to control the operation thereof and whereby each of said fault diagnostic circuit means monitors the operation of its associated switch and load. - View Dependent Claims (22, 23)
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Specification