Electrical distribution system for vehicle

Abstract

An electrical arrangement is disclosed for use in supplying electrical power to the units in a motor vehicle. The arrangement comprises a battery, and an inverter to receive power from the battery and to generate a high frequency signal at an intermediate voltage higher than the voltage of the battery. There is a distribution network to distribute the high frequency signal to the units in the vehicle. At least some of the units supplied with electrical power are provided with step-up transformers to step-up the intermediate voltage to a higher voltage, that higher voltage being used by the units.

What is claimed is: 
     
       1. An electrical arrangement for use in supplying electrical power to units in a motor vehicle, the arrangement comprising a battery, an inverter to receive power from the battery and to generate a high frequency signal at an intermediate voltage higher than the voltage of the battery, and a distribution network to distribute the high frequency signal to the units in the vehicle, the distribution network including a current regulator for establishing a constant current loop, the constant current loop containing the primary winding of two or more transformers, each transformer for activating and deactivating a unit associated therewith. 
     
     
       2. An arrangement according to claim 1 wherein at least some of the units supplied with electrical power are provided with step-up transformer means adapted to step-up the intermediate voltage to a higher voltage. 
     
     
       3. An arrangement according to claim 2 wherein the transformer is a current transformer. 
     
     
       4. An arrangement according to claim 1 wherein the distribution network is in the form of a ring main. 
     
     
       5. An arrangement according to claim 1 wherein the one or more transformers each associated with a unit includes a secondary winding, the output of which is connected to the unit, there being a saturable core operatively located between the primary winding and the secondary winding, there being a control winding associated with the core adapted to substantially saturate the core so that, insufficient power is supplied to the unit to activate the component, and to un-saturate the core so that sufficient power is supplied to the unit to activate the unit. 
     
     
       6. An arrangement according to claim 1 wherein a unit to receive power from the distribution network comprises a discharge lamp, the discharge lamp being provided with respective transformer means associated with each of the electrodes of the discharge lamp. 
     
     
       7. An arrangement according to claim 1 wherein a unit to receive power from the distribution network comprises a discharge lamp of the type which requires a high voltage to re-strike the lamp when the lamp is hot, the lamp being associated with a further arrangement adapted to provide an additional voltage across the lamp when the lamp is to be "struck" when hot, comprising second transformer means having a primary winding adapted to receive current from the distribution network and third transformer means having a secondary winding in series with the lamp. 
     
     
       8. An arrangement according to claim 7 wherein means are provided between the second transformer means having the primary winding associated with the distribution network and the third transformer means having the secondary winding in series with the lamp adapted to step-up the voltage. 
     
     
       9. An arrangement according to claim 1 wherein means are provided to monitor the current and/or voltage conditions prevailing when any unit is activated, and for determining whether those conditions fall within predetermined limits. 
     
     
       10. An arrangement according to claim 9 wherein display means are provided to provide a display when the operating conditions do not fall within predetermined limits. 
     
     
       11. An arrangement according to claim 9 wherein means are provided to deactivate a component if the operating conditions of that unit are determined not to fall within said predetermined limits. 
     
     
       12. An arrangement according to claim 1 wherein earth leakage detection means are provided to determine when an earth leakage current flows, means being provided to deactivate at least part of the arrangement where an earth leakage current is occurring in response to the detection of such earth leakage current. 
     
     
       13. An arrangement according to claim 12 wherein means are provided to determine an open-circuit fault, and to terminate the flow of power to the part of the arrangement having the open-circuit fault. 
     
     
       14. An arrangement according to claim 13 wherein the means to determine an open-circuit fault comprise back-to-back diodes extending from a high tension lead of a component and extending to earth to enable an open-circuit fault to simulate an earth leakage current. 
     
     
       15. An arrangement according to claim 1 wherein the said units comprise one or more lights for the vehicle. 
     
     
       16. An arrangement according to claim 1 wherein the units comprise in-car entertainment. 
     
     
       17. An arrangement according to claim 1 wherein the said units comprise spark plugs or other ignition devices. 
     
     
       18. An arrangement according to claim 1 wherein the distribution network comprises a cable including at least two cores being adapted to carry the output of the inverter, and at least one core being adapted to carry control signals. 
     
     
       19. An arrangement according to claim 18 wherein the said cable is of substantially rectangular cross-section, adhesive being applied to one face of the cable to enable the cable to be located easily in position. 
     
     
       20. An arrangement according to claim 1 wherein a "stand by" inverter is provided, means being provided to activate the "stand by" inverter should the said inverter fail.