Note: Descriptions are shown in the official language in which they were submitted.
W 0 93/17481 C A 2 1 1 7 6 0 2 PCT/N Z93/00009
AUTOMOTIVE POWER DISTR-~UTION AND SWITCIIIN('I SYSTEM
TECHNI~'~I FlF.I.n
The present invention relates to Automobile Electrical Power Distribution and Switching
Systems.
5 BACK(.ROUND ART
The prior art discloses ~,u--vc,,~ional Al-tnmnhih-c utilizing internal ,....,l...~l;.... engines
started by electric starter motors. The starter motor cranks the engine and an electrical
ignition system. Power for cranking and ignition is provided by a lead acid storage
battery commonly referred to as a Staning, Lighting and Ignition (SLI) Battery. After the
engine starts, the vehicle's battery is recharged by a power generator driven by the
internal ~ l;n~ engine. The power generator in modem vehicles utilizes altemating
current for efficiency. The alternating current is "rectified" to provide direct current to
most electrical consumers throughout the vehicle. The direct current also is used to re-
charge the battery. The charging unit of a modern vehicle is commonly referred to as the
Alternator.
The alternator usually provides sufficient current to run the electrical consumers when the
engine is operating. The battery acts as a "load levelling" device to ensure smooth and
constant direct current throughout the vehicle's electrical network.
When the vehicle's engine is not operating, power to the various electrical consumers
must be provided by the SLI battery. For safety and other reasons, the SLI battery
should provide a minimum amount of reserve power to operate the headlights, ignition
and window wipers. For example, if the alternator of the vehicle should fail at night,
while it is raining, the vehicle's SLI battery should provide a minimum amount of power
to operate the vehicle's lights, wipers, and ignition system for a specified period of time.
Preferably, the user should be able to drive the vehicle for between 30 and 100 minutes
with a failed alternator.
Worldwide standards have been ~ hli~ d to measure an SLI battery's "reserve
capacity" for supplying electrical power to important consumers when the alternator
system fails. Generally, the vehicle ..-~.ur.l~,u-c. chooses a particular SLI battery based
30 upon r~ h d standards applied to a particular vehicle's full ~ ,ific~.~i.,..s and
electrical load ~C~IUilCl~
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An important safety . ..~ ;.. regarding the vehicle's battery capacity is the amount
of power provided by the battery during times of emergency. In times of emergency, the
vehicle user will normally activate park lights or hazard lights as a warning to oncoming
traffic. The vehicle's engine may not be operable at this time. The SLI battery must
5 therefore be capable of providing electric power ;...1. ~.. 1. 1 of the altemator for safety
functions.
Another aspect of modern vehicle electric power 1~;4~ results from an everincreasing demand for "key off' power to low current consumers. The SLI battery is
subjected to an increasingly higher power discharge, '~, I of operation of the
10 engine, because modern vehicles use an ever increasing array of electronic devices ("key
off').
Cu..~. 1 batteries are often damaged by slow, long discharges caused by the ever
increasing number of key off loads. An extended period of slow discharge may force the
battery into a state of deep discharge which in turn may cause i--~ il,le damage to the
15 electrode plates because they are designed for short shallow discharge.
Due to an increase in electric power demand, c~....~..1iv.,.ll vehicle electrical systems are
poorly suited for modern vehicle use. Indeed, worldwide statistics indicate that battery
failure is the most common cause of vehicle breakdown. SLI battery failure causes
between 20% to 50% of all emergency breakdown incidences throughout the world. The
20 next most common breakdown cause represents less than 11% of all emergency
breakdown incidences.
Clearly, the ~ Liullal SLI battery is ~ hl. for safety reasons, and must be re-
designed in order to be made more compatible with modern ~ nm nhil~ demands. It is
possible to provide a battery with reserve back-up power to re-start a vehicle in an
25 emergency. These batteries, known as "dual", "switch" or "2 in 1 batteries", provide
emergency back-up power in the form of a reserve battery. However, dual batteries do
not solve the problem of battery i~ i1.;1iry with modern vehicles' electrical
' 1 ~,IIl~lIL~. Most dual battery systems are designed to provide cranking power in an
emergency only. u-.r~ Iy, such batteries are inefficient unless integrated into the
30 vehicles' electrical network.
The conventional SLI battery is in fact a design culll~ e. Although it is able to
provide some reserve power at a slow rate of discharge for ~ , i.e., when there
is alternator failure, the SLI battery is primarily designed for short rapid discharge as is
required for starting. Deep discharge of the cu,. ~ ~,lldu~lal battery results in damage to the
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electrode plates which may become permanent.
Under some crm~ nc an ' 1~'5 electrical system is incapable of supplying
sufficient power to service the ever increasing number of electrical consumers. Although
it is possible to increase the output of the alternator, inevitably the increased capacity of
5 the alternator is consumed by the addition of more electrical loads. Such a condition is
known as "deficit charging." Deficit charging occurs when the alternator is unable to
provide sufficient power to re-charge the battery. Due to low engine speed and high
electrical consumer demand, the battery must provide back-up power. If deficit charging
continues for too long of a time period, the state of charge of the battery falls and a
10 consequent voltage drop results in engine stalling.
Another example of the inromr~ihili~y between modern vehicle power ~ic~ihll~inn
switching systems and battery chardng systems is .L .~ n..~. :I by the IGl~lliu...l.i
between alternator and battery. Modem L ' 'les employ chardng systems using
alternators that are integrated with a rectifying diode system and a voltage regulator. The
15 alternator is driven by the vehicle's internal ~ "".h...~...,. endne and is located relatively
remotely from the battery. As the alternator's ~ increases due to the running
endne, the efficiency of the voltage regulator is reduced. The rectifier and the voltage
regulator ~~ ,.aLu-~ eventually shift out of :~...,LIu~ Liull with the el~,L.,
IU.~uilGll~ lts of the battery due to a variation in t~ ,.,l d~ul ~, between the voltage regulator
20 and battery electrolyte. This ~' results in sulphation of the electrodes and a
lower state of charge.
Many attempts have been made to provide an improved vehicle battery and electrical
power system. Since am~mrlhil~-c have relied on batteries to provide power for lighting,
and later starting, ~llr~m~hil~ batteries have been continually refined. N~ by
25 safety and reliability concerns, electrical networks and switching systems have continued
to expand providing more power to more consumers. What were once luxury items are
now standard equipment. The electrical harness has a~,~,u.,lhl~ly become more complex
and expensive. Demands on the SLI battery have increased ~ Iy. As a result,the battery is unable to cope with increased power demands and now represents the
30 weakest component in terms of emergency breakdown incidences.
Attempts to overcome the problem of "accidental battery discharge" are made by Pacific
Dunlop's GNB Switch Battery and Johnson Controls' Dual Start, USA Patent
No. 5,002,840. Both the Switch t~,~,L~ulo~y and the Johnson Controls dual start
systems only provide emergency starting capability. These systems cannot be relied
35 upon to solve the long term problems associated with the , ' ' y between vehicle
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battery design and electrical system demand.
Electricai power ii~t~ih~ti. n systems in ~ ;l, have evolved around the limitations
of the SLI battery and charging systems. This has resulted in very complex, expensive
and heavy electtical networks which are inefficient and inr~mp~tihlf~ with battery
S cl~ .ucl.~ .;, al reactions. Therefore, there exists a need for a longer lasting battery
system for modern vehicles which includes a ~yllulllulliG~I power generator and load
- shedding system.
Under certain conditions, e.g., when the altemator has failed, it is necessary for an
improved battery system to provide emergency power to the vehicle. Under these
10 conditions the battery must be capable of ~ ul~neuu~l~ providing both high current,
rapid discharge power and lower current, slow discharge power to the vehicle. Short
duration, high current discharge of electrical power is necessary to crank an internal
r.~, .h I i. .1 . engine under emergency starting conditions. Al ~,ly, a long duration,
low current discharge capability is ~r~ ,t. di by an ever increasing number of low
15 current electrical consumers.
Additionally, the voltage output of the altemator charging system must be ~ ' u..;~l
with the electrical and chemical reactions of the battery. To prevent battery failure, it is
necessary to prevent charging the battery when it reaches excessive t~,...l,, .,~.
Therefore, the sensor that detects battery t~,lll~l~liUI~ should be located in close proximity
20 with the battery.
Under some c;.. ~ , it is necessary to isolate the battery terminals to facilitate
improved vehicle operation. For example, when the battery power is drained from
misuse or overuse, it is necessary to shed one terminal from the normal electrical loads,
saving that terminal for emergency starting only. In addition, when the voltage produced
25 by the battery falls below a certain threshold, it is necessary to shed low current loads to
prevent permanent battery damage. The shedding of low current electrical consumers
protects the battery from long term irreversible damage occasionally caused by accidental
deep discharge. Finally, the ultra low current electrical consumers should be
~m~ tl~ connected to the battery so that critical low current functions are
30 The long lasting battery system of the present invention including a load shedding system
is necessary to meet the needs of mociem vehicles.
Dlscl.o.sllRr~ oP JNvRNTION
The automotive battery system of the present invention comprises a battery including at
least two discharge . I ~ ,.. tl . ;~li. ', one capable of short high current discharge of electric
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powcr for cranking an intemal .. ,., .1,.. 1;1 ,., engine, and the other capable of providing a
lower rate of current discharge as required for vehicle auxiliary power. The battcry
system of the present invention operates in c~.mhin~ti(~n with an integrated power
switching system that provides protection to the battery system by s.~ ulll~ g the
5 battery's discharge rate with the cl~,~l., ' I reactions of the battery system.
Preferably, the battery system utilizes cL,~ ulll~l6..~,liu switches that open and close
according to a pre~ r~minc~1 voltage and current level. The cl~l.u.ll.,6..~,~ic switches
,LvlulliL~, the battery's discharge rate with the cl~,~,llu.,l.~,.ll;~,dl reactions of the
integrated battery.
10 A preferrcd ~ ~ ' of the invention utilizes a binary battery of the type described in
U.S. Application Serial No. 524,325, filcd May 16, 1990, herein hl~,UI~)UI~IL~I. Other
battery ~ ~ ~" r~ could be substituted without departing from the spirit or essential
l; , of the invention.
The binary battery discloscd by U.S. Application Serial No. 524,325, comprises a15 negative terminal grounded to the ~ a first positive tcrminal connected to a
series of cells which are capable of rapid discharge and recharge, as opposed to a sccond
positive terminal connected to a series of cells which are capable of slower, deeper
discharge and recharge. The two sets of cells are arranged in series parallel, thus
providing dual or multi-current variations at the positive terminals. The series of cells
20 connectcd to the frst positive temminal have thinly layered positive plates providing high
current for short durations. The cells connected to the second positive temminal have
thickly layered positive plates providing lowcr current for longcr durations.
The invention also consists of an automobile electrical powem' ' system that, byUl.,.l~UI~ of the clc~ vlll.~6...,~i., reactions of the integrated battery, is able to
25 ;---1. ~ ly shed any loads across the integrated battcry according to an optimizcd
voltage or current that is ~Il.,Llull;~l with the cle~,llu~ ,.llh,.ll reactions of the battery.
The invention further consists of an :iv~ electrical power ' I and
switching system which includes a battery and an altemator, means for rectifying the
alternating current provided by the altemator, and a means for regulating the voltage
30 produced by the altemator. The voltage regulator preferably includes a Zener diode, a
~lu~ ulc sensitive resistor, and a transistor. Preferably, the voltage regulator is
located within the battery in order to achieve a more accurate reading of the battery
t~Ul~ UlC;. The voltage output of the altemator charging system is thereby more
accurately ~ ,hlu~ J with the cle~,~lu~ ,.llh,~l reactions of the battery based on the
35 actual intcmal L~ ul~ and chemical conditions of the battery.
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In another clllbol of the present invention, the improved power ~ , . ;1 i ... and
switching system is integrated with a manual switching and signalling system and a
series of sensor controllers and decoders attached to each of the electrical loads. The
manual switching and signalling systems of the present invention accepts switch data
S from either the automobile itself or a user. The switch data indicates wmch loads require
power and is fed by the switching and signalling system to a digital code generator. The
binary code generator sends binary coded signals to a series of sensor controls and
decoders. The decoders analyze the binary signals and transfer power to electrical
consumer loads c~,llc~ lJi.lg to the decoded binaty signals.
10 A power bus, separate from the binary signal line, delivers power to requesting users.
The power bus is tapped off at suitable locations in order to provide power to electrical
consumers with varying current lc.~uilclll.,llls. Separaling the binary signal line and
swilching system from the power bus reduces the size and weight of the electrical
hamess for a given number of electrical loads and functions.
15 The present invention provides an optimized ~uLu~ Li~, power ~lictrihmion andswitching system that is totally integrated and s,~ ' u.-i~d with the ele.,u~ ,al
reactions of a preferred power supply battery. Together with a charging system, also
integrated and ~ h, ' to the CI~L u-,L~ ,l reactions of the preferred battery
system, the invention provides a safe and reliable power dictrihll*~'n system.
20 BRlEFDEscr~lpTloN OF DRAWINGS
Fieure I is a simplified schematic of a typical ~llloLivc electrical power
rlictrihlltinn system.
Fieure 2 is a schematic diagram of a preferred power rlictrihl!tion and switching
system of the present invention.
25 Fieure 3 is a graph illustrating the effect of removing loads from a typical SLI
battery.
Fieure 4 is a simplified schematic diagram illustrating another preferred
~.,.~1~1;~.~ " of the power switching system of the present invention.
BEST MODF..C FQR CARRYING OUT THE INVENTION
30 The present invention comprises a power ~ictrihlltir~n and switching system for an
automobile that includes a binary battery system comprising a series of cells optimized
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for deep cycle discharge, and cells optimized for rapid shallow discharge. The
d~ and switching system includes an altemator that is similar to the alternator
used in W~ Liu~ ' ' The alternator includes an integrated rectifying circuit
providing direct current to a voltage regulatûr that is remote to the alternator. An integral
5 switching system comprises both electronic and ~ c I ;. switches that are uscd to
the charging of the battery with the clc~ .ol conditions of the battery
and the i r 1~ variation in the remote voltage regulator.
Figure 1 illustrates a simplified schematic of a typical automotive power d
system of the prior art which includes a cc,.~ io..al SLI battery 1, an alternator
10 generator 2, an ~,I~,.,IIUI.~ switch 3 used to connect the starter motor 4, the ignition
system 5, the key switch (or ignition switch 6), and electric power consumer loads 7, 8,
9 and 10, such as lights, wipers, etc. The electric power consumer loads 7-10 can be
switched on by switches 11, 12, 13 and 14. Switches 11 -14 are positioned at either the
negative or positive sides of the loads in series. Accessory load 15 can be operated only
when the key switch 6 is moved to a l,l,.L .. ,.. ;.. ~I position 60. Load 15 typically is a
radio device which is powered on by switch 16. An additional accessory load 17 is
similarly powercd on when the key switch is moved to the same p.~ position
60. Load 18 may be an ultra low current load that is powered on by switch 22 according
to a ~ .L l.. ;. d event, such as a remote electronic signal. Both loads 19 and 20
20 r ~y consume ultra low current regardless of the position of the key switch 6.
These ultra low current consumers may include clocks and memory devices. The ground
connection 21 of the power ~' ' system is grounded to the vehicle body.
The ~ ,..iiunal key switch 6 may be operated remotely by low current or an electronic
signal; however, the functions are the same as outlined in the simplified ~
illustration of Figure 1. As illustrated in Figure 1, a moving conductor 23 may rotate
through positions 60-62 by the turn of the vehicle's key once it is inserted into the
ignition lock. In the illl~ctrAtjnn, when the key is turned to the left into position 60, the
conductor 23 ftrst engages line 26 which switches current to the accessory loads 15 and
17, such as a radio or cigarette lighter. When the key is further tumed to the left into
position 61, the conductor 23 engages line 25 which conducts current to the ignition
system 5 and engine IIIA~_C~ ''I' ''I systems (not shown), or any other systems which
consume power only while the engine is running. A further turn of the key to the left
into position 62 engages the conductor 23 with line 24 which powers starter switch 3.
The last turn position 62 of the key switch 6 requires that the key switch 6 be held against
a bias away from position 62. If the key switch 6 is released, conductor 23 will spring
back away from the contact of line 24. Line 27 provides the power from the vehicle's
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battery to conductor 23.
Tuming now to Figure 2, a simplified schematic is shown illustrating a preferredL ' of the: ~ 8~ power .I;~I.il...li.... and switching system of the present
invention, which includes a preferred binary battery 100 of the present invention. The
binary battery 100, of the type described in U.S. Application Serial No. 524,325, filed
May 16, 1990, herein i..~,UI~ ' It preferably includes a first terminal cell 137 that is a
series of thickly layered positive plates that are optimized for deep cycle discharge. A
second temlinal ceD 136 is a series of thinly layered positive plates that are optimized for
rapid shaDow discharge as is typical in CO....,.I~iolldl SLI batteries.
The binary battery 100 is grounded from a single negative terminal 138 to the vehicle
chassis at temoinal 121. A heavy current capacit,v line 139 is connected to temlinal 136,
which connects a starter switch 103 to temminal 136. When starter switch 103 is closed a
starter motor 104 is activated. The starter motor 104 cranks the vehicle's internal
... engine (not shown).
Preferably, the series of cells at terminal 136 which are optimized for high current
discharge are able to provide at least 250 amps of discharge for a period of at least 30
seconds while under load at 18 C. In addition, the voltage at the terminal 136 must not
drop below 6.5 volts during the 30-second period of discharge at 250 amps. Preferably,
the voltage at terminal 136 starts at between 12.4 and 12.8 volts before the load is
applied. The series of cells at terminal 137 that are optimized for slow, deep discharge
preferably are able to provide one amp of current for a period in excess of 25 hours while
under load at 25 C without the voltage dropping below 10.5 volts. The voltage attemlinal 137 starts at between 12.2 and 12.6 volts before the load is applied. The overall
capacit,v of the combined cells of the binary battery 100 based on a 20-hour discharge rate
should be between 50 and 60 amp hours, down to a nominal voltage of 10.5 volts.
The present invention includes a switch 128 that, when activated, connects temlinals 136
and 137 of the battery system together. Power to activate switch 128 is provided frrst
from tem~inal 137 via line 135 and 141 from alternator 102. The altemator 102 includes
a voltage regulator 129 which is remote from the altemator 102. The voltage regulator
129 is preferably placed on, into or within the battery 100, and is directly connected to
the altemator 102. Preferably, the voltage regulator 129 is set inside the cover of the
battery 100.
The voltage regulator 129 includes a Zener Diode 156 of a specified rating that allows
voltage to pass above a minimum charging level, a t~ LIllc; sensitive resistor 157 that
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sets the passing voltage at a minimum level and a transistor 130 that controls the
operation of switch 128 The prefetred minimum charging voltage level that is able to
pass through the Zener Diode 156 is selected to prevent deficit charging of the high
discharge rate battery cells at terminau 136 when the autemator 102 is producing less tban
5 a ~IIG 1~ minimum voltage. The minimum voltage is chosen such that the high
discharge rate cells are not p~ damaged during charging. Preferably, the value
of the t~ ; sensitive resistor 157 is chosen such that when the t~ Lb.c; of the
resister increases above a preferred threshold level, where the battery will no longer
perform as designed, an above t~,lUy~ tul~; warning will be delivered to the remainder of
10 the voltage regulator circuitry 129 which prevents the charging of both cells of the battery
100.
More specifically, when the t~ ,l.-Lu.~, increases above the preferred threshold level, the
t~ UI~ sensitive resistor 157 causes the voltage delivered to transistor 130 to be
below the minimum turn-on level for the transistor 130 This causes transistor 130 to
15 turn "off' which causes switch 128 to open, thus preventing charging of both cells of the
battery 100 at excessive t~,...l,.,.~Lu~
By ~ g the t~ .-,Lb,~; sensitive resistor 157 inside the cover of the battery 100,
the voltage regulator 129 is able to regulate the voltage output of the alternator 102 in
reference to the actuad t~,lll~lUtUlC of the battery 100 rather than by using the t~ Lu c~
20 of the alternator 102 as in prior art battery systems A more accurate reading of the
battery t~ ,.alUI~ allows charging of the battery 100 by the altemator 102 to be closely
I--u..;~ with the actuau clc~,LIu~ l conditions of the battery 100
The Zener diode 156 is provided to prevent The Zener diode 156 prevents the voltage
from the alternator 102 from passing to the transistor 130 unless it is above the specific
25 r~r~rrrric-irS of the diode If the voltage is passed to the transistor 130 the transistor
will turn "on" and enable the closing of switch 128 The closing of switch 128 connects
battery terminals 136 and 137 together, thus connecting both terrninals 136 and 137 to
the alternator 102. By isolating terminal 136 from the main electrical system of the
a--tnmnhilr, terminal 136 is prevented from d;~,Lal~;h-g as the demands on the electricau
30 system increase Instead, the cells of terminal 136 are saved for emergency cranking of
the starter 104, as described in more detail below
For example, if the Zener diode 156 is specified at 12 5 volts, the transistor 130 will turn
on when the alternator 102 is producing more than 12.5 volts However, if the
L-.llJ-, dtu.~ of the battery 100 is above the specified threshold, the t~ LI..~, sensitive
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resistor 157 will prevent the delivery of the alternator voltage to the transistor 130. If the
alternator 102 is producing more than 12.5 volts, i.e., the vehicle engine is running, and
the t~,.lllJ-,l.l~L.C of the battery 100 is below the given threshold, the transistor 130 turns
"on," thereby activaing switch 128. Switch 128 connects terminals 136 and 137 of the
battery 100 together, and enables both portions of the battery 100 to be charged.
Further, switch 128 ~llt()m:~ti('~lly opens when excess t~ Ul~,S are reached, asdetermined by the t~,lll~J-,I.~lUUC sensitive resistor 157, protecting the battery from damage
caused when the t~,lll,U.,I~lUlC shifts out of ~ .w~i~ution with the cle~llu~,h~.lli.,~l
.c . ~,mc..t~ of the battery. In this manner, the battery 100 and altemator 102 supply a
10 more reliable and energy efficient charging system than those of the prior art.
Turning to the operation of the remainder of the switching system of the presentinvention, the key switch 106 operates in the same manner as the cu..~.,...iu..al key
switch 6 described above. Current is provided to the key switch 106 and conductor 123
from terminal 137 via lines 141, 142 and 127. When the key switch 106 is turned to the
left one position, call the "auxiliary" position 160, the conductor 123 is connectcd to line
126. Line 126 is in turn connected to switch 132 which controls the connection of
auxiliary loads 117 and 115 to the battery system 100. Application of auxiliary load 115
is further controlled by switch 116. Switch 132 is provided to protect the battery 100
from excessive drainage in the event that the conductor 123 is left in the "auxiliary"
position when the engine is not running. The operation of switch 132 is described in
more detail below.
When the key switch 106 is turned to the left to a second position, called the "ignition"
position 161, the conductor 123 is connected to line 125. Line 125 connects the
vehicle's ignition system to the battery system 100. All other loads which are relevant to
ignition are connected to the battery 100 through line 125.
When the key switch 106 is turned to the left to a third position or "start" position 162,
the conductor 123 is connccted to 1ine 124. The starter switch 103 is closed and current
is provided to the starter 104. As before, the last tum position of the key switch 106 to
the "start" position 162 requires that the key switch 106 be held against a bias away from
position 162. If the key switch 106 is released, conductor 123 will spring back away
from contact with line 124. When the key switch 106 is held in the "start" position 162,
current flows through conductor 123 to lines 144 and 124. The current to line 124 closes
switch 103, which enables the high level current from terminal 136 to flow to the starter
104 via high current line 139. The high level current from terminal 136 is required only
when the starter 104 is being cranked.
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In a preferred ~ ".1.".1;,.,. of the automobile switching system, when the engine is being
started, i.e., key switch 106 is in the "start" position 162, connecting line 127 to line
144, the current along line 144 closes switch 128 by bypassing voltage regulator system
129; thus, switch 128 is activated at a lower voltage than the pre-set "engine running"
voltage, i.e. 12.5 volts. Current along line 144 will continue during cranking and will
energize the coil of switch 131, thereby latching switch 131 into the "on" position.
Current is thereby provided to loads 107- 110.
Switch 113 controls current to load 107, switch 114 controls current to load 108, switch
112 controls current to load 109, and switch 111 controls current to load 110. These
loads are typical electrical consumer loads such as wipers, lights, etc. A resistor 154 is
provided for protection of transistor 130 due to the wide voltage range that can be applied
to turn transistor 130 on. In another ~ l ,o.l;~ this step is bypassed to avoid closing
switch 128 during engine cranking by ~ ;"g the connection of resistor 154 to thebase of transistor 130, and ~ ' g usage of these loads while the engine is starting.
After the engine is started, conductor 123 is moved away from the "start" position 162 to
the "ignition" position 161, and no longer connects terminal 137 to line 124 via line 144.
Diode 140 is provided to prevent current flow back along line 144 to line 124 and
ultimately to switch 103 after conductor 123 has moved away from the "start" position
162. With the conductor 123 in the "ignition" position 161 the power to hold switch 131
in the "on" state is provided from terminal 137 via lines 141, 142 and 133. Therefore,
switch 131 will remain closed until the voltage at tcrminal 137 falls to the specified "drop
out" voltage.
The "drop out" voltage is ~' ' by the resistance value of variable resistor 155 and
the internal resistance of the coil of the cle~,l-u~ 6~ ic switch 131. For a nominal 12
25 volt ~tnmnhil~ electrical system, the preferred "drop out" voltage is ideally 10.5 volts.
The effect of the voltage dropping below the "drop out" level at switch 131 is that all
consumer loads connected to switch 131, i.e., loads 107, 108, 109 and 110, will be shed
from terrninal 137. Switch 132 is designed to open when the voltage at terminal 137
drops below the "drop out" voltage. Thus, the "auxiliary" loads 117 and 115 are shed
when the voltage reaches the "drop out" voltage. Preferably, switches 131 and 132
utilize a coil of a specified resistance that gradually reduces the cl~ u~ 6~ il, force of
the switch in ~...,hluni~d~iull with the voltage at terminal 137 in order to prevent darnage
to the switches 131 and 132 caused by fast removal of el~,.,L,u.. ~,.. ,,~i., force.
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By opening switch 131 when the drop-out voltage is reached, the voltage at temlinal 137
will ~ ' 'y begin to climb from the drop out voltage, i.e., 10.5 volts, to a level very
close to the nominal battery voltage, i.e., between 11.5 and 12 volts. The voltage climbs
after the loads are removed because the natural cle~,lJu-,h~ ,dl diffusion of the electrolyte
5 from within the active material of the electrode plates is slower than cutrent . . ~ . q .~ ;- ,
Therefore, when current CUIl~ullllJliull is t~in~ l, the diffusion process continues,
resulting in a build-up of electrons on the surface of the electrode plates, thereby
increasing the voltage at the battery temminal 137. The graph in Figure 3 illustrates this
Typically, the increase in voltage at terrninal 137 would cause the electromagnetic
switches 131 and 132 to oscillate until the voltage at temlinal 137 see-saws up and then
gradually down to below the "cut in" voltage of the e,le~llu-lla~;---,ii-, switches. The
present invention avoids this I ' by supplying current to hold switch 131 and
132 on only when the voltage supplied from temminal 137 is higher than the "drop out"
voltage of the coil. Once the voltage decreases to the "drop out" level, switch 131 opens
and current is removed from line 133. Therefore, both switches 131 and 132 remain
open until the key switch 106 is again tumed to the "start" position 162, which connects
conductor 123 with the terminals of lines 124, 125, 126 and 144 and delivers current
once against to line 133. Because voltage at terminal 137 begins to ;11111 ' Iy climb,
due to the opening of switches 131 and 132, the voltage at temlinal 137 quickly reaches
the el~ lu.ll&~ ,Lic cut-in voltage of switches 131 and 132, thereby closing the switches
again during the starting operation. After the engine is started, switches 131 and 132 will
be held closed.
In addition, the ultra low current loads 118, 119 and 120, such as clocks, memory
devices and electronic signals, are connected to the battery temminal 137 via line 135, and
therefore are always provided with power i_ ~_r ' of key switch 106. The
connection of the ultra low current load 118 is controlled by switch 122, and therefore is
not always demanding cutrent from temminal 137.
The effect of the preferred power di~ttih--ti~n and switching system results in a number
of desirable conditions that provide for optimized vehicle safety and reliability. The first
advantage of the preferred power distribution and switching system is that the battery 100
is protected from long-term irreversible damage caused by accidental deep discharge, and
is further protected by the s~ ,hlu~ ic n of the ele~ "1 reactions of the
battery with the consumer loads of the vehicle. Secondly, the important ultra low current
consumers, such as the vehicle's electronic memory devices and the vehicle clock, are
S U B S TIT U T E S H E E T
W 0 93/17481 C A2j jl 7602 P~r/N Z93/00009
protected from loss of power as they are p~ a~ ly connected to the battery 100, and
can therefore remain operating for long periods.
Thirdly, the preferred binary battery 100 can provide power from terminal 137 for
emergency purposes without allowing the cells to drain. The user can therefore use
S .c-,l~,aliu"àl or emergency lighting without risk of either long-term battery damage or
- battery drain. Lastly, in the event that the power at temminal 136 is drained, the car is
started in the normal way, by turning the key switch 106, because power is A ~ 8~ ~lly
provided to crank the engine from temminal 137. The operation of the powe ml; l, ;1"";,- .
and switching system of the present invention is therefore completely transparent to the
10 vehicle user.
In addition, the preferred ~ ..,1~,.1;"~. ~ of the powem'~ ' ' and switching system of
the present invenion provides for a more efficient use of the altemator and battery. The
system of the present invention enables the battery to more rapidly recover fromdischarge. Switch 128 prevents discharge from temminal 136 to low current loads while
15 the altemator is not operating. Recovery from discharge after cranking is therefore
relatively fast and without voltage drop across switch 128, as would be the case if a
diode was altematively used. The cells of temminal 137, that are designed to shallow
cycle, may be maintained at a state of charge on average 50% below the cells of temlinal
136 due to the load shedding capability inherent to switches 131 and 132. Therefore, the
20 electric energy available throughout the ~' ' ~ network can be applied to more
consumers without affecting the safety and reliability of the ~ r~mj hil.-
The present invention provides for a ~yll-,h,vld~-,l power switching system that enables
the additional of such devices as linear electric drivers to replace cv..~ hydraulic
power steering systems of prior art ~-ltrm~hilrc Indeed, linear electtic drivers, or
25 electtic motor drives for power steering systems, facilitate safer driving than do the
cu,,~, I systems because electric drivers, integrated with the system of Figure 2,
continue to operate safely after engine failure. Similarly, power assisted electtic brakes
may also be integrated with the system of Figure.2, further adding to vehicle safety. An
electric heat exchanger system may also replace the present m--rh~nir~llly driven
30 C~ VI of air c~ ;--; e systems. Mechanically driven devices such as the
~,VIII~ .VI and hydraulic pump can be removed and replaced with a more efficientaltemator that is integrated with the ~ ,;.,v..i~,J power switching and ~ictrihlltirm and
optimized battery system.
In anothem; L ' of the present invention, as illustrated in Figure 4, a simplified
35 automotive power .1;~ and switching system includes a preferred binary battery
SUBSTITUTE SHEE~
WO 93/17481 CA 2 i 1 7 6 02 PCI/NZ93/00009
100 as described above. Further, a first positive terminal 236 of the battery 100 is
connected to a senes of high current discharge cells, also as previously described, and
then to line 239, that connects to the vehicle's starter switch. A second positive terminal
237 of the preferred battery 100 is connected to a series of cells ~ .r;~ cd to
5 ~ ;. ,..; suitable for slow but long, shallow discharge and recharge cycles.
Preferably, the series of cells at terminal 236 which are optimized for high current
~ discharge are able to provide at least 250 amps of discharge for a period of at least 30
seconds while under load at 18-C. In addition, the voltage at the terminal 236 must not
drop below 6.5 volts during the 30-second period of discharge at 250 amps. Preferably,
the voltage at terminal 236 starts up between 12.4 and 12.8 volts before the load is
applied, The series of cells at terminal 237 that are optimized for slow, deep discharge,
preferably are able to provide one amp of current for a period in excess of 25 hours while
under load at 25-C without the voltage dropping below 10.5 volts. The voltage atterminal 237 starts at between 12.2 and 12.6 volts before the load is applied. The overall
capacity of the combined cells of the binary battery 100 based on a 20-hour discharge rate
should be between 50 and 60 amp hours, down to a nominal voltage of 10.5 volts.
In the ( ,~ of the present invention as illustrated in Figure 4, switch 228 (not
shown) is provided first from terminal 237 via line 235 (not shown) and line 241 from
alternator 202 (not shown). The alternator 202 includes a voltage regulator 229 (not
20 shown) which is remote from the alternator 202 and which functions similarly to the
voltage regulator 129 as described in reference to Figure 2. The voltage regulator 229 is
preferably placed on, into, or within the battery 100 and is directly connected to the
altemator 202.
The (,.llbod of the present invention illustrated in Figure 4 also includes load25 shedding switches similar to those described in Figure 2. For example, the ~
illustrated in Figure 4 includes a transistor 230 (not shown) which operates similarly to
transistor 130 as described in reference to Figure 2. This transistor causes switch 228
(not shown) to open which prevents charging of both cells of the battery 100 at excessive
battery le~ ,.dl(..cl. In addition, the ~ 1 illustrated in Figure 4 similarly
includes a key switch 206 (not shown) which is operated similarly to key switch 106 as
described above. When key switch 206 is in the "start" posirion 262, switch 231 will be
latched into the on position. Similar to switch 131, switch 231 will remain closed until
the voltage at terminal 237 falls to the specifled "drop out" voltage. The "drop out"
voltage is determined by the resistance value of vatiable resistor 255 (not shown) and the
internal resistance of the coil of the ~le~ UII~ , switch 231.
14
SUBSTITUTE SHEET
WO93/17481 CA2 i i 7602 PCT/I~IZ93/00009
The remainder of the switching system of the - . . ho~ l; ~ . .~ .,1 illustrated in Figure 4 operates
similarly to the switching system described above in connection with Figure 2. Current
is provided to a key switch 206 (not shown) and conductor 223 (not shown) from
terminal 237 via line 241, 242 and 227 (not shown). The key switch 206 is operated
S through an "auxiliary" position, a "start" position, and an "ignition" position, as
described above with operation of key switch 106.
A first negative terminal 238 of the battery 100 is grounded to the body of the vehicle at
221. Loads 207, 208, 209, 210, and 215, are also grounded at 221. Power to all loads,
except the very high current starter motor, is provided from terminal 237 via line 241
from the vehicle altemator and through line 242, which includes a main safety fuse 245.
Terminal 237 is connected to loads 207-210 and load 215 when switch 231 is closed.
The switching of the power consumer loads as illustrated by Figure 4 is :~f ~ by
an ultra-low current sensor signalling scheme. Sensor controllers and decoders, of a
type well known in the art, are illustrated at 246, 247, 248, 249 and 250. Figure 4 is a
IS simplified illustration of the ultra-low current sensor signalling scheme. Any number of
sensor controllers and decoders may be i...,u.l,, ' into the distribution network.
Although Figure 4 illustrates that the control sensors and decoders are positioned on the
positive side of the loads, the devices may also be positioned on the negative side of the
power consumer loads.
A manual switching and signalling system 251 is powered from terminal 236 through
line 252. All manual switching is l~ t~,d by system 251. System 251 consists of a
digital binary code generator, well known in the art, and each switch of system 251
sends a signal to each of the sensor controllers and decoders 246-250, when activated by
the vehicle user. Of course, those of ordinary skill in the art will be familiar with binary
code g, , decoders, controllers and equivalent devices. The decoders of the
sensor controllers analyze the binary signals and switch power to the power consumer
loads that correspond to the decoded binary signals. The signals ~ n~l from
switching system 251 may be in the form of sound waves, direct current pulses sent
along line 253, or infrared light pulses transmitted through air space or along a fiber optic
line.
The power d ' and switching system of Figure 4 greatly reduces the weight and
~ u---} L".ily of an :Intnmflhil~'s electrical power distribution system. The power
.l;~n;l,..~ and switching system of Figure 4 may be integrated with the system of
Figure 2. For example, switching system 251 of Figure 4 may control the closure of
SUBSTITUTE SHEET
W O 93/17481 C A 2 1 1 7 6 0 2 PC~r/N Z93/00009
load switches 113, 114, 112, 111 and 110 of Figure 2. Using the load shedding and
switching systems of Figure 2, in cullju~ iun with the ultra-low current sensor
signalling scheme of Figure 4, greatly enhances the safety, reliability and c~ ,n;~ of
the amc~mf~hil
S The altemate ...,ho.l;,.,..,l illustrated in Figure 4, is adv~ ,uus over the prior art
because it eliminates the need for the .,ullv~,uliul.dl "wire hamess" of an ~n-nml~hil~ The
cu.~ ic)lldl wire harness evolved throughout a period of rapid changes in vehicle
electrical powemcu,uiu~ s. However, the CUIIV~ " I wire hamess was restricted bythe limitations of a conventional single current source battery system. Indeed, the
10 electrical hamess of ~u~ iu~ automobile design is, to a large extent, built around the
limitations of a battery and altemator which are not syn~ u--i~l in either function or
p ~,.rc,l.l.a.."c. By utilizing the bus system line 242, power di:~llibu~iu~ circulates the
automobile and is tapped off at suitable locations, providing power to electrical
consumers of varying current lc.~uh-,lll.,.ll~. The switching of power to the consumers,
15 separate from the bus hamess, provides for the low current switching system described.
The present invention may be embodied in other specific fomms without departing from
itsspiritoressential~ l;, Thedescribed . ,lY,,I; ". ,aretobeconsideredin
all respects only as illustrative and not restrictive. The scope of the invention is,
therefore, indicated by the appended claims rather than the foregoing .1~ 5~iptj~n All
20 changes which come within the meaning and range of c4uiv ' ~ of the claims are to be
embraced within their scope.
16
SUBSTITUTE SHEET
