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Description  |
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FIELD OF THE INVENTION
The present invention relates to a circuit board for the control and/or
power supply of electrical function devices of a vehicle. The expression
"function device" is to be understood to mean any electrical device that
may be found in a vehicle, such as lights, indicators, windshield wipers,
radio, window heaters, heating systems, and so on.
More particularly, the invention is directed to the realisation of the
concept whereby certain functions are regrouped together, in such a way
that protective devices (such as fuses), electrical connections, and
electrical distribution means, are integrated together so that they
constitute a cabin computer in modular form.
The circuit board of the invention is connected between a source of
electrical energy and a source of control signals, on the one hand, and
the function devices themselves on the other hand.
BACKGROUND OF THE INVENTION
In the prior art, it has already been proposed to provide systems in which
the electrical energy coming from a supply source is distributed towards
the electrical loads as a function of commands given, typically by the
driver of the vehicle. However, these prior art arrangements have a
certain number of drawbacks which the present invention proposes to
overcome.
In the prior art arrangements for power supply in vehicles, the number of
power supply and control wires is high, and this imposes a considerable
penalty, in terms of both the overall cost of the electrical parts of the
vehicle and to the technical complexity of the power supply system.
In addition, the prior art arrangements require to be perfectly matched
with the various electrical function devices in the particular vehicle in
which they are installed. For this reason, in the prior art, power supply
arrangements are in general designed specifically for only one type of
vehicle. In particular it is often necessary to redesign a large part of
the electrical supply system, even when, in a vehicle of one given type or
model, equipment options are only slightly different from the arrangements
provided in the basic model.
Furthermore, the prior art vehicle electric supply arrangements usually
include, starting from a circuit board, a certain number of plug-in
components, and require a large number of connections for distribution in
the system. This proliferation of connections is a major cause of the high
cost of the system, and in addition it leads to a reduction in its
reliability.
In the specification of European published patent application EP 0 181
534A, a system has been described which includes a central electrical unit
for the centralised connection of electrical components such as cable
harnesses, plug-in connectors, fuses and interruptors, these latter being
typically in the form of relays, which are connected together through
appropriate connecting layers. However, distribution of the power supply,
or interconnection between specific modules linked to a circuit board, is
not made possible by such an arrangement.
DISCUSSION OF THE INVENTION
An object of the present invention is to provide a remedy for the above
mentioned drawbacks.
According to the invention, a circuit board for the control and/or power
supply of electrical function devices of a vehicle, the circuit board
being connected between at least one source of electrical power and a
source of control signals on the one hand, and the said electrical
function devices on the other hand, and comprising a support inside which
there is disposed at least one layer of connecting means which will be
referred to herein as a connecting (or connection) layer, with, disposed
on at least one said layer, an electronic part which integrates together a
plurality of associated protective devices, with power and logic control
circuits for the said function devices, in such a way as to constitute a
vehicle cabin computer, the circuit board being adapted to carry at least
one plug-in module on a face of the said support, the said electronic part
containing an electrical means associated with the control and/or power
supply for at least one electrical function device of a given vehicle, is
characterised in that it further includes a means for distribution of the
electrical power supply and/or for interconnection between two plug-in
modules.
Further features and advantages of the present invention will appear more
clearly on a reading of the detailed description which follows, and in
which, with reference to the accompanying drawings, a number of preferred
embodiments of the present invention are described by way of example only,
and compared with prior art arrangements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a very basic arrangement in accordance
with the prior art, of a power supply system for an electrical function
device on board a vehicle.
FIG. 2 is a similar diagram illustrating a modified version of the same,
again in the prior art.
FIG. 3 is a diagrammatic perspective view showing a circuit board in one
form known from the prior art.
FIG. 4 shows a circuit board in a first embodiment of the present
invention.
FIG. 5 shows a circuit board in a second embodiment of the present
invention.
FIG. 6 is a simplified cross sectional view of a circuit board in another
embodiment of the present invention.
FIG. 7 is a simplified cross sectional view of a circuit board in a further
embodiment of the present invention.
FIG. 8 is another simplified cross sectional view, showing a further form
of circuit board in accordance with the present invention and having at
least two separate modules.
FIG. 9 shows a further embodiment of a circuit board according to the
present invention, in simplified form and in cross section, this circuit
board having a single connection layer without any external connections.
FIG. 10 is a similar view of yet another circuit board in accordance with
the invention, this time having two connection layers without any external
connections.
FIG. 11 is a similar view showing part of a circuit board in a further form
in accordance with the invention, this board having two interconnecting
layers, together with external connections.
FIG. 12 is a scrap view showing a detail of a removable module in one form
in accordance with the invention.
FIG. 13 is a simplified cross sectional view showing a circuit board
according to the invention which includes connecting means in a modified
form.
FIG. 14 is a plan view showing a circuit board according to the invention
having a modified form of connecting means.
FIG. 15 is a block circuit diagram showing one example of an application of
the concept of the invention.
FIG. 16 is a diagrammatic plan view showing an arrangement of components of
the circuit shown in FIG. 15.
FIG. 17 is a block circuit diagram showing another example of the
application of the concept of the invention.
FIG. 18 is similar to FIG. 16, but relates to the circuit shown in FIG. 17.
DESCRIPTION OF SOME PRIOR ART ARRANGEMENTS
Reference is first made to FIG. 1, which shows a first embodiment of a
power supply system for fitting on a vehicle in accordance with known
principles. This system comprises a power supply unit 1 consisting of a
battery and an alternator which is connected to the battery, these being
carried on the vehicle. The output of the power supply unit 1 is
transmitted to a selection module 3, on which certain means 4 are
disposed. The means 4 may for example consist of an anti-theft device, or
a key-operated ignition switch, or both.
A power supply function selection line 5 leads from the output of the
selection module 3. This line 5 is connected to a protection module 6
which includes, mainly, a plurality of fuses or similar protective devices
to provide protection against over-voltages and/or excessive currents. The
output of the module 6 is taken through a line 7 to a control device 8,
typically a manually-operated switch. This has a command device 8a such as
an actuating lever for operating the switch 8, operated by the driver of
the vehicle from the fascia of the latter, thereby imposing a command on
the system.
The control device 8 has an output line 9 connected to an electronic unit
10 for electrical energy generation. This in turn is connected through a
line 11 to the vehicle ground or earth M. The unit 10 is also connected,
through an output line 12, to a load 13 in the form of a function device
(as defined above) of the vehicle. As shown in FIG. 1, this function
device is a lamp of one of the vehicle lights. The load 13 is also
connected to ground M through a line 14.
In an arrangement such as that shown in FIG. 1, the number of function
devices which are connected through electrical conductive lines or wires,
or other energy carrying paths, is considerable. For this reason the
manufacturing cost is high while the reliability of the system is low.
In order to remedy these drawbacks to some extent, it has also been
proposed in the past to group the electronic unit 10 and the protective
module 6 together in a single unit. Such an arrangement is shown in FIG.
2, in which the same elements as are represented in FIG. 1 carry the same
reference numerals and need not be described here in any greater detail.
The integrated module is indicated at 15 in FIG. 2, and includes the
protective devices 16 such as fuses, together with an electronic unit 17
similar to the unit 10 in FIG. 1. The control device 8, with its manual
switch lever or similar command device 8a, is connected to the integrated
module 15 through two input lines 18 and 19. The module 15 is also
connected through a line 20 to ground M, and through an output line 22 to
the load 13, whereby power is distributed to the latter from the
integrated module 15. The latter is also connected through a line 21 to an
indicating device 23 such as a warning lamp, which in turn is connected to
ground through another line 24. The grouping together of the electronic
distribution unit and the protective devices eliminates some connections,
such as the line 9 in FIG. 1, between the electronic unit and the control
means for the system, which were present in the arrangement shown in FIG.
1.
Referring now to FIG. 3, this shows a prior art arrangement in which the
various components are physically grouped together on a circuit board, as
can for example be done with the integrated module 15 of FIG. 2. The
circuit board comprises a housing 25 made of a suitable plastics material,
for example in two halves, namely an upper half and a lower half, with at
least one electrical connecting layer 26 arranged between the two halves.
In FIG. 3 this connection layer is indicated in broken lines. On the upper
surface 27 of the circuit board 25 there are connection zones 28 and 29,
for connection to the electrical supply source and to the function
devices, respectively.
In addition, the upper surface 27 of the circuit board 25 has a plurality
of connectors 30a, 30b, . . . 30n, into which electronic units or relays
31a, 31b, . . . 31n can be plugged. Similarly, a plurality of fuses are
arranged on the connectors 30a to 30n, these being indicated at 32a, 32b,
. . . 32n.
This compact arrangement has the advantage that all of the protective
devices and electronic modules are assembled together on a single circuit
and in one place, so that a single accessible location can be provided for
mounting the circuit board. Maintenance can then easily be carried out,
such as the changing of a blown fuse or replacement of a plug-in relay or
plug-in electronic device. However, the plug-in units 31a to 31n typically
contain a number of electronic components, such as capacitors,
transistors, resistors and so on. Each of these is intended to perform a
simple electrical function, which is carried out according to
predetermined electronic circuit diagrams, which are completed in the
usual way by the conductive paths of the circuits of which these various
components form part. These electrical paths are defined on the connection
layer 26. There will be one electronic circuit corresponding to each of
the loads or function devices of the vehicle that are connected through
the connector 29. However, the internal connecting layer 26 has only one
electrical layout, specifically designed so that it is adapted to provide
distribution networks which include the protective devices and their
required interconnections for application to a particular type or model of
vehicle. With this concept, it is necessary to modify, in particular, the
connecting layer 26 every time any modification has to be made to the
electrical system of the vehicle.
In addition, a large number of connections are still required for
connecting the function devices of the vehicle to the circuit board.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
Reference is accordingly now made to FIG. 4, which shows a first means in
accordance with the present invention for providing a remedy to this
drawback of the prior art. FIG. 4 shows modules 33, 34 and 35, but there
may be any required number of these modules.
A certain number of electrical and electronic supply and/or control
functions are grouped in these various modules, either as a function of
electrical or electronic requirements linked to the way in which the
electrical circuits operate, or as a function of electrical function
devices or groups of electrical function devices forming part of a
vehicle.
As a general rule, the "architectural" design of the invention tends to
optimise a group of functions with a view to minimising the external
interconnections. In particular, the modules 33 to 35 are adapted to be
plugged in to connectors similar to the connectors 30a to 30n in FIG. 3,
but with each one including all of the electronic, electrical and
protective functions which are provided for the purpose of providing
connection to a group of electrical function devices, or at least one
electrical function device, of a given vehicle.
When, in any given vehicle, some change is to be made in the electrical
function device or devices, it is merely necessary to change the
appropriate module 33, 34 or 35. Similarly, in the event of a fault, this
can simply be rectified by removing and replacing the faulty module.
Finally, whereas in the prior art a module was associated with one specific
type, or even one specific model, of vehicle, the invention makes it
possible, instead, to associate a module with the type of function device
itself, since this latter is generally suitable for use in various types,
makes and models of vehicles.
Each module, for example the module 33, has a connector 36 through which it
can be connected, firstly to the electrical load and secondly to the
electrical supply source. It also includes a plurality of fuses 37 which
are plugged in to an upper surface 38 of the module. And, as will be shown
in greater detail later on in this description, the electronic means
necessary for carrying out the control and/or power supply functions
mentioned above are all arranged within the module 33.
Referring now to FIG. 5, this shows another embodiment of the invention. In
this arrangement, all of the electronic functions are grouped in a single
plug-in module 40 having connecting fingers, such as the finger 41, which
plug in to a connecting zone 42 on the upper surface 43 of a circuit board
44. The circuit board 44 comprises a body or support, within which a
number of electrical connecting layers (not shown) are disposed. These
connecting layers receive the connecting fingers such as the fingers 41 of
the electronic module 40, the connecting fingers of a set of fuses 45, and
the terminals of the electronic or electrical connections for connection,
firstly to the power supply source through connector 46, and secondly to
the loads through connectors 47 and 48.
In the modular design of FIG. 4, each module can be optimised as a function
of:
requirements expressed in terms of the levels of equipment required for
each vehicle or each type of vehicle; and
cost and reliability criteria compatible with the operating requirements
and acceptable manufacturing cost.
Reference is now made to FIG. 6, which shows a first form of a circuit
board into which the electronic module has been integrated in a
non-removable way. This circuit board, indicated at 50, comprises a
support which is in two halves, namely an upper half 51 and a lower half
52, which are connected together by means of a suitable fastening device
(not shown). This may for example be a screw and gasket system between the
opposed terminal edges 53 and 54 of the two halves 51 and 52. The upper
surface 55 of the support 51, 52 includes at least one connector, such as
the connector 56 which comprises a set of contact pins 57, 58, 61. These
pins are part of respective cross-connecting elements, i.e. electrically
conductive elements disposed transversely to the connecting layer or
layers contained within the support or base of the circuit board. In the
rest of this description, any cross-connecting element, as thus defined,
will for brevity be referred to as a "pin", whether or not it includes a
contact pin of a plug-in connector.
The pins 57 are connected to a first connection layer 58; the pins 61 are
connected to both the first connection layer 58 and a second connection
layer 60; and the pins 61 are connected only to the second connection
layer 60. The pins 61 are insulated from the first connection layer 58, so
as to constitute, for example, an electrical ground or earth.
A module 62 is disposed on the first connection layer 58. All of the power
circuits for management of the power supply of the circuit board, or which
(for example in the form of shunts) provide control for the current
consumed, are integrated into the module 62. This integrated module may be
provided with means for removing heat, such as a radiating means (not
shown), which may for example project above the upper surface 55 of the
support in the raised zone indicated at 63.
The upper surface 55 of the support also includes two female clip-type
connectors 64 and 65. The connector 64 includes a base pin connected
directly to the power connection layer 58, while the connector 65 has a
base pin 66 which is connected to the ground connection layer 60. A fuse
69 has plug-in fingers 67 and 68 which are plugged into the connectors 64
and 65 respectively. It will be understood that the circuit board of FIG.
6 has a number of these fuses 69 with their associated clip-type
connectors 64 and 65.
Inside the support 51, 52 there is also a third connecting layer 70. This
carries, in the conventional way already known from the prior art, a
number of electronic components such as the components 71, 72, 73, 74 and
75, thus grouping together the electronic functions performed by the
resulting module incorporated on the circuit board. A conductive pin 76
connects the three layers 70, 60 and 58 electrically together, while other
connections are also provided, such as to enable only a limited number of
layers to be connected together depending on the requirements of the
particular application.
The power supply module 62 has to have regard to the various levels of
power supply available in the vehicle. In addition, the protective
devices, such as the fuse 69, may be integrated within the interior of the
circuit board, while remaining accessible for replacement purposes. It can
be seen that the electronic functions are grouped and integrated on at
least one internal connecting layer of the circuit board. The control
signals can have only a low interrupting power, since the power control
signal is relayed. The control signals are therefore transmitted at low
current on the connector 56.
Finally, the arrangement of FIG. 6 may include diagnostic means for taking
into account the identification of the functions being controlled, and
this can be made comprehensive.
Reference will now be made to FIG. 7, which shows a second form of circuit
board according to the invention. FIG. 7 shows a module which is adapted
to be placed on a support or base plate, the function of which is, in
general, purely mechanical with respect to the plug-in modules, but which
may also have a thermal function. This module comprises a housing 80,
having a connector 81 similar to the connector 56 described above with
reference to FIG. 6, together with a series of protective elements 82
similar to the fuse 69 in FIG. 6, and three internal connection layers 83,
84 and 85. The purpose of the connection layer 83 is power management,
while that of the layer 84 is power distribution. The layer 84 defines a
connecting plane. The electronic module is integrated on to the layer 85.
An integrated power generating module 86, connected on to the connection
layer 83, is also shown. The component 86 is a transistor or an
intelligent power component, which makes use of part of the first layer to
make the power connections and to serve as a cooler, together with part of
the second layer to carry the control signals. This modular design enables
the electronic circuits, which are separate from each other in
conventional arrangements, to be integrated with each other. In addition
it enables a common electronic "heart" to be used. The modular design of
this arrangement also enables each sub-assembly to be designed in the form
of a station which is compatible with multiplexing.
The power module 86 is also connected to conventional protective fuses 82,
and/or to other suitable devices giving protection against over-voltages.
The power distribution layer 84 enables the need for power connections to
be reconciled with the need for low power level connections for control
purposes. The power connections are made firstly at the input, to power
supply sources such as the battery, and also at the output to the loads,
which consist of the various electrical function devices of the vehicle.
The low power level connections are made firstly at the control signal
inputs, for the signals coming from the control devices such as those on
the fascia, and secondly at the control signal outputs leading to the
electrical loads. The electronic layer, such as the layer 85, which
carries the electronic heart of the module, provides the power control
signals, and thus provides the control and detection functions in the
circuit board itself. It also provides the function of communication
between the circuit board and the various function devices of the vehicle.
It performs a number of integrated functions, such as generation of time
delays. Finally, it carries out all the control logic functions from which
logic states can be computed.
The supply connector, such as the connector 81 in FIG. 7 or 56 in FIG. 6,
carries the polarities of the positive terminals of the battery, the
"+ACC" terminal of an anti-theft device, the starter, headlamps, and so
on.
In the power portion of the module, measurement of the current can be
coupled with relaying by means of power relays, whether these be of an
electromagnetic or static type.
The module also includes, in its various connecting means, connectors which
not only provide interconnection but which also carry control signals.
There are thus signal links and interconnections with other units and
function indicators.
In a modular design in accordance with the invention, it is necessary to
provide an electrical supply to each module, and to provide it with its
necessary electronic means, which is normally of a different type for each
module. It is also necessary to provide outputs for connection between
modules. On the other hand it is possible to adapt the circuit board to
various equipment levels. In addition, high reliability is obtained with
power which is integrated by distribution over several modules.
Implementation is thus made easier. It is also possible to use the modules
in other vehicles.
Reference is now made to FIG. 8, which shows another embodiment of a
circuit board according to the invention. This circuit board comprises a
support 90, in the form of a housing which may for example be of a
plastics material. Modules 92 and 93 are fixed on an upper wall 91 of the
housing.
The support 90 has a single power supply distribution layer 94, which
provides the power supply and interconnections between the modules. This
connection layer 94 enables signals and energy to be exchanged between the
two modules 92 and 93. The modules in FIG. 8 have two layers. The main
elements of the module 92 are a connector 95, a means 96 for providing
protection against excessive voltages and currents, and an integrated
electronic circuit module 97 for producing power. This power circuit is
connected on a connecting layer 98, and, through its integrated output 99,
to a further connecting layer 100 which carries the electronic part of the
module 92. The connecting layer 98 also carries a conductive
cross-connecting pin 101, which has a first end fixed to the connecting
layer 98, for example by being soldered on to a conductive part of the
latter. The pin 101 has an elongated body which passes through a sealed
passage 102, and a second end which is held in a female clip fitted on a
conductive portion of the connecting layer 94 on the other side of the
upper wall 91 of the support housing 90. A plug-in connection for the
modules is thus provided on the support housing 90.
The module 93 is substantially identical with the module 92, and in FIG. 8
the same components are indicated on the module 93 with the same reference
numerals as for the module 92, but with the suffix "a".
The support 90, with its single connecting layer 94, enables the circuit
board to be easily adapted to the various levels of equipment in a given
vehicle. It also facilitates adaptation of the circuit board with other
modules for use in other vehicles. It gives good reliability due to the
integration of the power supply. The circuit board enables the power
supplies to be grouped together, while the inter-module connections are
integrated in it. A common electronic module can be incorporated on the
connection layer 94 of the support housing.
Referring now to FIGS. 9 to 11, these show three embodiments of the
integration scheme provided by the invention. In these three Figures,
those elements which are identical or similar to each other carry the same
reference numerals as each other.
In FIG. 9, the module comprises a housing 110, within which there is a
single connection layer 111, on which the connecting means, consisting
mainly of conductive strips, are disposed on a substrate of insulating
material which is conductive to heat. On the upper face of the module, a
connector 112 is arranged, having three conductive pins connected to the
connection layer 111. The upper face also includes two inserted female
contacts 116b and 117b, which receive the connecting fingers 116a and 116b
of a fuse, for example the fuse 113. The connecting layer 111 also carries
the power circuits 114 and 115, together with components such as the
components 128 and 129 which constitute the integrated electronic part of
the module.
In FIG. 10, the housing 120 of the module has two connecting layers, 123
and 124 respectively. In this arrangement, the layer 124 carries the power
circuits, together with any heat radiating means associated with them, for
disposal of heat by radiation at the free upper face of the housing 120.
The layer 123 carries the logic circuits and the various low-power
components. The situation is reversed if the power components have means
for disposing of heat by convection, these being arranged to be thermally
coupled with, for example, the chassis of the vehicle which serves as a
heat sink.
FIG. 11 shows a module on part of a circuit board which includes a base 133
and a housing 131, in which a connecting layer 132 is mounted. The
connection layer 132 enables external connections to be made between the
modules disposed on the circuit board. In this case, each module, for
example the module 130, includes a snap connector 134, for engagement on
the upper surface of the circuit board 131 to 133. The snap connector 134a
has a set of conductive pins, for example the pin 134a, the end 134b of
which makes contact with a conductive zone of the connecting layer 132.
Referring now to FIG. 12, this shows one form which may be taken by the
side walls of the modules, for the purpose of facilitating the insertion
of several modules on a common circuit board. FIG. 12 shows part of two
modules 140 and 141 in top plan view and in cross section. The modules
have side walls 142 and 143, which are in contact with each other when the
modules are suitably installed on the upper surface of the circuit board.
The wall 142 of the module 140 is formed with guide and securing slots
into which corresponding tongues 146 and 145, carried by the corresponding
wall 143 of the module 141, are inserted. The other side wall 144 of the
module 141, which is not in contact with any other module if the module
141 is at the end of the group, is formed with guide slots 147 and 148.
Turning now to FIG. 13, this shows one form of a module 150 having a single
connecting layer 160. The module 150 has three connectors 152, 154 and 156
on its upper surface. The connector 152 connects to the electronic unit
that provides the control function and interconnects between modules, and
which brings the control signal transmissions together. The connector 154
is for connection to the electrical supply source, while the connector 156
is for power distribution towards the various electrical loads.
The connecting layer 160 is connected to the connectors 152, 154 and 156
through conductive pins, which are joined to sets of mating conductive
elements. These latter are carried on respective connector pieces 151, 153
and 155. The pattern of each set of conductive elements in the connector
pieces 151, 153 and 155 is matched to that of the conductive elements in
the corresponding connectors 152, 154 and 156.
In one embodiment, the connecting layer 160 carries the electronic power
components such as a circuit 158, and electronic processing circuit
components such as the component indicated at 159. Fuses, such as that
indicated at 157, are also arranged to plug in to the upper part of the
module.
In a preferred arrangement, at least two of the three connector pieces 151,
153 and 155 are in the form of rigid bars, so that the associated
connecting wires can be grouped together, and so that these bars can be
fitted by simple insertion on the corresponding connectors 152, 154 or 156
so as to assemble the various modules together. This arrangement is
particularly suitable if the modules have their side walls configured in
the way described above with reference to FIG. 12.
FIG. 14 is a top plan view which shows three modules 160, 161 and 162
respectively, associated together through two electrical and mechanical
coupling bars 163 and 164.
The coupling bar 164 provides the connection of the modules to the
electrical power supply. It accordingly includes electric wires 166 to 170
which carry the earth connections and the various electrical voltages
required, together with the battery connection, and so on. The coupling
bar 164 overlies the three modules 160 to 162. These latter may or may not
be mounted on a suitable flat support base, or plate (not shown), arranged
under the modules. The sole purpose of such a support plate would be to
provide a mechanical connection, and if necessary to act as a means for
dissipating heat produced by the modules. If such a support is provided,
it accordingly carries means for fastening mechanically to the modules, as
well as heat transfer means for thermal coupling with those components
integrated in each module which generate heat.
In another embodiment, the coupling bar 164 is made of a rigid material and
is constructed in the form of a rigid beam, which may for example have a
C-shaped cross section and which is coupled to U-shaped elements, so as to
give a snap-fitting engagement, for example, on the upper surface of each
module 160 to 162.
Each of these modules carries a connector 173a, 174a and 175a in a
selected, accessible, part of the top surface of the module. The coupling
bar 164 carries corresponding connectors 173b, 174b and 175b respectively,
in corresponding positions. These connectors carried by the coupling bar
are fitted in the respective connectors 173a to 175a. The top face of each
module also carries fuses 176a, 176b, 176c and 176d, together with
connectors 177a, 177b and 177c. The references for these various
components are indicated in FIG. 14 only in respect of the module 162. The
connectors 177a to 177c connect the corresponding module to each of the
electrical loads, or to each group of electrical loads, which is to be
controlled and supplied with power through that module.
Each module 160 to 162 also includes two connectors 178a and 179a, seen in
the lower part of FIG. 14, which connect the module with the other
coupling bar 163. The coupling bar 163 is of course provided with
corresponding connectors 178b and 179b, and contains a set of wires for
the electrical connection at low power levels for the logic part of the
modules, so as to provide the interconnection 172 between the modules and
such electrical function devices of the vehicle that are energised
directly at low power levels.
Within each module 160 to 162, in at least one of the various embodiments
described above, there is at least one connecting layer which includes an
electronic "heart". In particular, this may comprise circuitry (indicated
in broken lines at 180 in FIG. 14) providing a relay facility and power
circuitry, and which includes electromagnetic and/or transistor relays. In
the latter case these consist of power transistors, in particular of the
MOS type, or again intelligent power components. Another logic part,
indicated in broken lines at 181 in the module 162 in FIG. 14, contains
the low-power electronic components which carry out the processing
operations (mainly on the logic signals).
Reference is now made to FIGS. 15 and 16, which show the first of two
examples of how the concept of the present invention can be applied. FIG.
16 is a diagrammatic top plan view of a module incorporating the circuit
shown in FIG. 15. Here, an input 200 is connected to the positive terminal
(the "+ battery" terminal), and also to a first terminal of a protective
device such as a fuse 190, the other terminal of which is connected to a
first terminal of a power relay in the form of an electromagnetic relay,
having a contractor 195 and a relay coil 212. The other terminal of the
relay is connected to the respective inputs of the first and second
circuits 192 and 193, for measuring current flowing in the line connecting
the terminal 200 to the relay.
A second input 201 is | | |
