GB2205009A

GB2205009A - Power supply for electronic systems on vehicles or vessels

Info

Publication number: GB2205009A
Application number: GB08711179A
Authority: GB
Inventors: Robert Throwell Burton
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1987-05-12
Filing date: 1987-05-12
Publication date: 1988-11-23
Also published as: GB8711179D0

Abstract

The power supply has a main alternator-driven supply 12 which is used to power heavy duty sub-systems 28,30 such as relays, motors, lights and the like, and an auxiliary power supply system working in tandem with the main alternator-driven supply, and having its own engine-driven auxiliary alternator 14 to provide a protected auxiliary power supply for electronic microprocessor control devices 24,26 in the vehicle/vessel independently of the main supply. The two alternators 12,14 can be housed in magnetically and electrically isolated sections of a single tandem alternator unit which share a common engine drive. The auxiliary supply maintains a rechargeable back-up battery system 22. Microprocessors 24,26 may control vehicle braking and suspension systems, 28,30 which receive power from the main supply 18. In the event of failure of the auxiliary supply a warning signal may be given, or fail-safe systems within controllers 24,26 may be initiated, or a temporary supply may be switched in from the main supply. <IMAGE>

Description

POWER SUPPLY FOR AUTOMOTIVE ELECTRONIC SYSTEMS.

The present invention relates to power supplies for automotive electronic systems, and in particular, but not exclusively, to power supplies for automotive microprocessors.

It is a common phenomenon that disturbances in computer power supplies disrupt the computer function causing process failure. In automotive applications, where vehicles now often incorporate a plurality of individual microprocessors, it is usual for each microprocessor to be provided with its own ir.tegral power supply circuit. These circuits provide protective isolation from power supply disturbances such as voltage transients and disturbances caused by heavy current devices, e.g motors and relays.

With the advent of multiple microprocessor applications-in vehicles and vessels, e.g. engine, driveline, driver information displays, vehicle suspension and vehicle braking systems, the use of multiple integral power supplies greatly increases the amount of equipment utilized for the purpose of supplying power to the microprocessors. This increase in the amount of power supply equipment presents problems since it increases the probability of a fault occurring in the power supply components that may have to be replaced during routine maintenance and also increases the physical size of the power supply unit (i.e. the unit producing the "clean" electrical supply, often in the form of a microprocessor control module) and therefore increasing the volume occur wed by the power supply unit.

It is important that the power supply for automotive microprocessors should be clean (free from disturbances) and secure, in order to provide the microprocessors with a continuous power source that will not cause a process failure. It would be logistically, financially and practically advantageous if a single clean and secure power supply, isolated -from other heavy current devices, e.g. motors and relays, could be provided to supply all the automotive microprocessors.

In accordance with the present invention, P power supply for an automotive electronic system comprises, in addition to a main alternator-driven supply which is used to power heavy duty sub-systems such as relays, motors, lights, etc., an auxiliary power supply system working in tandem with the main alternator-driven supply, and having its own enginedriven auxiliary alternator to supply power to electronic devices in the vehicle/vessel independently of the main supply.

In one embodiment of the present invention the main alternator and auxiliary alternator are housed in magnetically and electrically isolated sections of a single tandem alternator unit, and share a common engine drive.

Preferably, the auxiliary power supply maintains its own re-chargable battery system, sufficient to supply all vehicle electronic systems, e.g.

microprocessors, together with their sensor and signalling demands. The power supply for actuators and valves etc. is provided by the main vehicle/vessel electrical supply.

In another embodiment of the present invention the auxiliary power supply unit incorporates an auxiliary power failure warning system whereby, in the event of auxiliary power failure, a signal is generated which either initiates a warning signal, initiates a failsafe system within each controller or switches in a temporary supply from the main vehicle electrical supply system.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawing, which is a schematic diagram of the present invention as applied to automotive microprocessors.

A power supply alternator 10 comprises tandem units 12 and 14, electrically and magnetically isolated by a suitable isolating screen 16. On driving the alternator, one of the isolated alternator units 12 provides a main vehicle electrical power supply 18 and the other isolated unit 14 provides an auxiliary electrical power supply 20. This auxiliary supply 20 maintains a-re-chargeable back-up battery system 22 and provides a power supply 42 for a microprocessor 24 controlling a vehicle suspension system 28, and a power supply 44 for a microprocessor 26 controlling a vehicle braking system 30. The auxiliary supply 20 also provides adequate power for the sensor and signalling demands 34,36 and 32,38 of the microprocessors.

Although the signals 32,38 from the microprocessors 24,26 control the actuators and valves of the suspension system 28 and braking system 30 the power required to drive these. components is provided by the main vehicle electrical power supply 18 via supply route 40.

In the event of an auxiliary power failure the back-up battery system 22 switches in and provides the microprocessors 24,26 with the required electrical power, including the sensor and signalling demands.

Also, an appropriate warning signal, e.g. visual and/or audible, would be given so that an operator of the vehicle in which the system is fitted would be made aware of the presence of a failure.

The invention is not restricted to the details of the foregoing embodiment. For example, the power supply can be utilized for any electronic system, or vehicles or vessels, and the number of microprocessors or electronic systems is not restricted to the number illustrated. The two alternators 12,14 need not be part of a common unit (although this is preferable) but could be physically separate, each with its own drive system.

Claims

1. A power supply for an automotive electronic system comprising, in addition to a main alternatordriven supply which is used to power heavy duty sub-systems, such as relays, motors, lights and the like, an auxiliary power supply system working in tandem with the main alternator-driven supply, and having its own engine-driven auxiliary alternator to provide a protected auxiliary power supply for electronic microprocessor control devices in the vehicle/vessel, independently of the main supply.

2. A power supply as claimed in claim 1, wherein said auxiliary alternator is incorporated in a tandem alternator unit, housing both said auxiliary alternator and said main alternator in electrically and magnetically isolated sections, and sharing a common engine drive.

3. A power supply for automotive electronic systems as claimed in claim 1 or claim 2, wherein said auxiliary power supply maintains a re-chargable battery providing a back-up auxiliary power supply.

4. A power supply for automotive electronic systems as claimed in claim 1, 2 or 3, wherein actuating apparatus controlled by said electronic microprocessor control devices is driven by power from said main vehicle/vessel supply.

5. Apparatus for the supply of power to an automotive electronic system, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.