Vehicle condition monitoring system
First Claim
1. In a vehicle having a plurality of variable condition devices and a plurality of condition monitoring transducers for said devices, a condition monitoring system comprising:
- (i) a central control unit;
(ii) a plurality of remote data acquisition modules, each having a plurality of inputs responsive to said condition monitoring transducers and data storing means for storing data representing data signals received at said inputs; and
(iii) a single communication wire for each data acquisition module and connecting the respective data acquisition module to the central control unit;
(iv) the central control unit further comprising means for prompting each data acquisition module in turn over the respective single communication wire; and
(v) each data acquisition module comprising means responsive to said prompting for transmitting the data stored in the respective data storing means to the central control unit over the respective single communication wire wherein an input of at least one data acquisition module is an analogue input, and said one data acquisition module comprises an analog-to-digital converter connected to said analog input, said converter comprising;
a capacitor,a reference resistor,a first current path including said reference resistor for modifying the charge on said capacitor from a first predetermined level to a second predetermined lever,a transducer of variable resistance responsive to said analogue input,a second current path including said transducer for modifying the charge on said capacitor from said first predetermined level to said second predetermined level, control means for modifying the charge on said capacitor through each of said first and second current paths and for resetting said capacitor to said first predetermined level after each charge modification, andmeans for determining and comparing respective time periods taken for the charge on said capacitor to change from said first predetermined level to said second predetermined level along said first and second current paths, respectively, to provide a digital representation of the transducer resistance.
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Accused Products
Abstract
A condition monitoring system for a vehicle comprises a central control unit and a plurality of remote data acquisition modules, each of the modules being connected to the central control unit over a single wire and having a plurality of inputs connected to local condition-sensing transducers. Each data acquisition module serves to store data representing signals received at its inputs. The central control unit prompts the modules in turn and each module, when prompted, transmits its stored data to the central control unit over the respective single wire. This system provides a simplification of the wiring and connectors required between the various transducers and the central control unit, which drives displays displaying the conditions of the transducers.
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Citations
10 Claims
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1. In a vehicle having a plurality of variable condition devices and a plurality of condition monitoring transducers for said devices, a condition monitoring system comprising:
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(i) a central control unit; (ii) a plurality of remote data acquisition modules, each having a plurality of inputs responsive to said condition monitoring transducers and data storing means for storing data representing data signals received at said inputs; and (iii) a single communication wire for each data acquisition module and connecting the respective data acquisition module to the central control unit; (iv) the central control unit further comprising means for prompting each data acquisition module in turn over the respective single communication wire; and (v) each data acquisition module comprising means responsive to said prompting for transmitting the data stored in the respective data storing means to the central control unit over the respective single communication wire wherein an input of at least one data acquisition module is an analogue input, and said one data acquisition module comprises an analog-to-digital converter connected to said analog input, said converter comprising; a capacitor, a reference resistor, a first current path including said reference resistor for modifying the charge on said capacitor from a first predetermined level to a second predetermined lever, a transducer of variable resistance responsive to said analogue input, a second current path including said transducer for modifying the charge on said capacitor from said first predetermined level to said second predetermined level, control means for modifying the charge on said capacitor through each of said first and second current paths and for resetting said capacitor to said first predetermined level after each charge modification, and means for determining and comparing respective time periods taken for the charge on said capacitor to change from said first predetermined level to said second predetermined level along said first and second current paths, respectively, to provide a digital representation of the transducer resistance. - View Dependent Claims (2, 3, 4, 5)
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6. An analogue-to-digital converter, comprising:
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an input, a variable-resistance transducer connected to said input, a reference resistor, a capacitor, a first current path including said reference resistor for modifying the charge on said capacitor from a first predetermined level to a second predetermined level, a second current path including said variable-resistance transducer for modifying the charge on said capacitor from said first predetermined level to said second predetermined level, control means for modifying the charge on said capacitor through each of said first and second current paths and for resetting said capacitor to said first predetermined level after each charge modification, and means for determining and comparing respective time periods taken for the charge on said capacitor to modify from said first predetermined level to said second predetermined level along said first and second current paths, respectively, and providing a digital representation of the transducer resistance.
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7. A data acquisition module, comprising a plurality of data signal inputs and an input/output terminal for connecting to a single communication wire, the module comprising:
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means for reading signals received at said signal inputs, a data storing means for storing data representing said signals, and a transmitting means, responsive to a prompt signal received at said input/output terminal over said single communication wire, for transmitting over said wire the data stored in said data storing means wherein one of said data signal inputs comprises an analogue input, and said signal reading means comprises an analog-to-digital converter responsive to said analogue input, said converter comprising; a capacitor, a reference resistor, a first current path including said reference resistor for modifying the charge on said capacitor from a first predetermined level to a second predetermined level, a transducer of variable resistance responsive to said analogue input, a second current path including said transducer for modifying the charge on said capacitor from said first predetermined level to said second predetermined level, control means for modifying the charge on said capacitor through each of said first and second current paths and for resetting said capacitor to said first predetermined level after each charge modification, and means for determining and comparing respective time periods taken for the charge on said capacitor to change from said first predetermined level to said second predetermined level along said first and second current paths, respectively, to provide a digital representation of the transducer resistance. - View Dependent Claims (8, 9, 10)
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Specification