Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to ignition systems, for vehicles,
and more particularly to an improved form of ignition device and
~ system for facilitating the conversion of conventional ignition
- breaker point devices systems to a breakerless electronic system.
Various types of ignition systems and devices are in use today in
vehicles. The most common is the breaker point assembly used in
the distributor of an automobile or truck and which includes a
pair of breaker points which are caused to open and close upon
rotation of a distributor cam in synchronism with engine rotation.
These breaker points are electrically connected to open and close
the primary winding of an ignition coil. A rotor and distributor ~;;;
cap also are used, and the rotor rotates in synchroni;m with the ~ -
distributor cam shaft to distribute suitable firing pulses to the
spark plugsof the engine.
I Various transistor ignition systems have been devised. ~`
`, The early developments utilized a transistor to switch the electri-
cal current through the primary winding of the ignition coil thus ~
~, removing the electrical switching load from the breaker points ~ ;
which resulted in an extended lifetime for the breaker points.
~owever, the breaker points were still retained to provide the
timing synchronism with the engine rotation. The breaker points
controlled the base drive current to the switching transistor to `
cause the transistor to turn on and off in synchronism with the -~
engine rotation.
~' Further improvements replaced the breaker points entirely, ~ ~
~, using magnetic or optical means to generate timing pulses in ~ i"
synchronism with the engine rotation. These electrical timing
pulses were then amplified and used to control the base drive
current to the power switching transistor. These electronically
timed or "breakerless" systems, as they have become to be known,
~ provided improved timing and virtual maintenance-free operation ~-
`1 not afforded by the breaker point controlled transistor systems.
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Optically controlled systems utilized a light source and
light sensor arrangement in conjunction with a light interrupting
device, usually denoted as a shutter wheel, which rotated in syn-
chronism with the engine. Exemplary systems using a light source
and sensor arrangement are shown in United S~ates patent No.
3,581,725 and in United States patent No. 3,23~,742.
Magnetically controlled systems utilized a magnetic
source and magnetic sensor arrangement. The magnetic field imping-
ing on the sensor was caused to change in magnitude in synchronism
1~ with the engine rotation. Two distinct types of magnetically -~
timed systems evolved. The first was a "variable reluctance" type
of sensor. An example is found in Kaisha Japanese Patent
Publication ~o. 13122/1963, published July 24, 1963. In this type
of system the air gap in a magnetic circuit is alternately in-
creased and decreased, in synchronism with the engine rotation, ~;
causing the magnetic flux in the circuit to alternately decrease
and increase respectively. A pick-up coil is so placed in the
, circuit that the magnetic flux in the circuit passes through the
pick-up coil. A voltage is developed across ~he pick-up coil ;-
which is directly proportional to the rate of change of the mag-
netic flux in the circuit. This type of pulse generating system -~
` has one large drawback. The production of timing pulses is not
only a function of engine position but also engine speed. There
is a minimum speed required to generate a timing pulse of suffi-
cient voltage amplitude to operate the electronic amplifier and ;~
transistor switch. Hence, these systems perform poorly, or not
at all, under low speed, starting conditions. Also the timing
pulses generated by some types of systems do not duplicate the
signals produced by the breaker points in that the ratio of "on"
time to "off" time or, "dwell time", varies with engine speed
3Q making it impossible to optimize ignition performance over the
entire engine speed range.
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A second approach to the generating of magnetically ?
yroduced timing pulses is the use of a Hall cell for the magnetic
sensor in place of a pick-up coil. The Hall cell generates a
voltage, -the amplitude of which is directly proportional to the
magnitude of the magnetic flux passing through it and completely
independent of the rate of change of the magnitude of that flux.
Various means were devised to produce a change in the amplitude of
the magnetic flux passing through the Hall cell in synchronism
with the rotation of the engine. An example is found in United
States patent No. 3,297~009.
Thus, the optically timed systems and the Hall cell ~;
magnetically timed systems duplicate the operation of the breaker
point timing function in that they produce electrical pulses which
are dependent only on the engine position whereas the magnetic
pick-up coil systems produce pulses which are a function of both
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` engine speed and position.
From the time that the first breaker point controlled
, transistor systems appeared~ the advantages of a completely `;
`~ electronic "breakerless" system were obvious. However, the
2Q requirement of providing an economical means of installing elec~
tronic pulse generating means in the many types of existing auto- ~ ~
motive distributors was not an easy one. Odd contours and shapes, ~-
;' limited access for electrical connections and stringent size
, limitations hampered the appearance of such "breakerless" systems. `
'i This feat has only recently been accomplished on any kind of com-
mercial scale and that was only on an original equipment basis.
There remains one primary drawback to all of the above
existing systems. All of them, including the breaker point con-
trolled systems, involve the installation, external to the ~;
distributor housing, of the electronics amplifier and transistor
switch package. This package contains virtually all of the
- electronics circuitry with the exception of the pulse generating
means. This package is typically ten to twenty times larger than
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the pulse generating means. ~ conventional breaker point system
cannot be readily converted to any of these systems. The installa-
tion of this electronics package involves considerable effort to
mount it mechanically and involves considerable modification to
the existing vehicle wiring system. Many automotive mechanics are
not capable of making the necessary wiring modifications. The time
involved to install these systems is typically four to five hours.
The labor cost involved and the fact that ordinary mechanics cannot
repair such systems has greatly retarded their acceptance, especi-
ally for retro-fit applications, even though vehicle owners accept
the fact that such installations would significantly reduce fuel
consumption and undesirable exhaust emissions.
The present invention represents a completely new concept
in the configuration of electronic ignition systems. At a time
when the state-of-the-art has just reached the point where
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electronic pulse generating devices can be installed within the
distributor housing, the present invent:ion provides for the
installation of the entire electronics circuitry, pulse generating
means, amplifier and power transistor swi*ch within the distribu-
2Q tor housing. This feature has a substantial impact relative to ~ -
the ease with which it can be installed on a vehicle, both in a
retro-fit and an original equipment situation. The mechanical
installation is identical to installing a new rotor and set of
breaker points, somethingthat every automotive mechanic has done
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many times. The use of adaptor plates of various configurations ~`-
allows the installation of the same module into existing distribu- ~-
tor configurations. The additional electrical hook-up involves a
single wire being connected to a readily recognizable point in
the automotive wiring system. No alterations need to be made to
the existing vehicle wiring. No holes or fastening devices need
to be added to the vehicle. All initial adjustments and timing
are done in the same manner as with conventional breaker point
systems. If desired, the electronic system can be removed and
the breaker points reinstalled with the same effort as ch~mging a
set of breaker points in the conventional system. The entire ~ ~;
s~stem can be installed and adjusted quickly and is a practical
system for installation in existing vehicl~s.
The ability to mount the entire system within the dis-
tributor housing is made possible by imbedding permanent magnets
or "source" elements substantially within the outline dimensions
- of the existing rotor. By doing this, none of the available mount-
ing space, on the existing distributor breaker plate, is used by
the magnetic "source". In conjunction with this, the "sensor", or ; ~-~
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~ Hall cell, is molded into, and made an integral part of, the ;
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electronics module. These features, combined with micro-miniature
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packaging, make possible the installation of the entire system
within the distributor housing.
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Some ignition systems have been described wherein a ~
tIming source and sensor are mounted on a type of adapter plate ; ~-
for facilitating the mounting thereof within the distributor.
Examples are found in United States patents No. 3,581,725, No. `~
;~ 3,272,930, and No. 3,660,623.
The present invention provides an improved distributor
apparatus and system, and one which can be readily substituted
within a conventional distributor for enabling conversion from
the standard breaker point assembly to be made quickly and effi-
ciently. The present apparatus includes a sensor and all associ-
~l ated electronics in a single module connected to a suitable
-` adapter plate, and this assembly is directly substituted for the
conventional breaker points. A two-wire cable is substituted for
;~ the usual single wire in the conventional ignition system, and
provides the switching lead for the primary of the ignition coil -
and provides power from the ignition switch of the vehicle to the
electronics module~ The bracket of the module which is integrally `
connected to the adapter plate provides a ground return. Further,
the apparatus of the present invention includes a new form of
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rotor substantially idcntical to the existing rotor of a given
vehicle, but which includes a plurality of magnets imbedded into
it and equally spaced around the periphery thereof. The number
of magnets is equal to the number of cylinders of the vehicle.
These magnets operate in conjunction with the sensor to provide
timing signals which are a function of rotor position only. The
system of the electronic module includes a sensor in the form of
a Hall cell, a pulse shaping circuit connected therewith for pro-
viding suitably shaped pulses, an amplifier and a solid state power
switch which is connected to the primary of the ignition coil.
In replacing the breaker point assembly of a conventional
ignition sys~em of a vehicle with the electronics module, it is
;` only necessary to remove the breaker points and the existing rotor,
, as well as the wire from the breaker points and the existing rotor.
The sensor and electronics module with the appropriate adapter
plate attached thereto is positioned on the existing advance plate ~
of the distributor in direct replacemen1: of the breaker points. - ~`
The existing ignition capacitor is used in the same manner as
before, and is connected to the electronics module along with one
1 20 wire of the two-wire cable. The other wire of the two-wire cable
is connected to power the electronics module from the ignition
switch of the vehicle. Then, the new rotor is merely inserted in
the same fashion as is a conventional ro~or, the distributor cap
is replaced, and the conversion is complete. The centrifugal and
vacuum advance devices of the distributor function in their usual
` manner, and timing likewise is set in a conventional manner. The
arrangement of the electronics and sensor module on the adapter
plate is such that it can be readily properly positioned and
spaced from the magnets of the rotor.
The entire new apparatus and system is disposed within
the distributor,and no complex or cumbersome rewiring is neces-
sary in accomplishing the conversion. The new form of rotor,
which is substantially identical to the standard rotor for a given
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type of vehicle, but wi*h the addition of the magnets thereto, and the
arrangement of the sensor and electronics circuit~y in a single module on
an adapter plate allows the present apparatus and system to be mounted
entirely within the distributor housing in this simple and efficient manner.
In some cases, as will appear subsequently, the existing rotor is not
; replaced~ but the new form of rotor with magnets is added.
According to the broadest aspect of the invention there is
provided a modular assembly for mounting within a conventional distributor
for providing timing and switching signals for an ignition coil of an
engine, comprising sensor and circuit module means, said module means includ-
- ing a sensor and a switching circuit for generating switching signals for an
ignition coil of an engine, said module means including first and second
power conductors and an output terminal connected with said circuit, and
bracket means attached to said module means for enabling said module means
to be mounted within a distributor of said engine and for providing a heat
sink for said module means, said bracket means including metal tab and
plate means with the tab means being physically connected with said module
means, said plate means of said bracket means having at least an aperture
therein for allowing said plate means to be attached to said distributor.
Figure 1 is an exploded perspective view of a conventional
distributor illustrating the manner in which the breaker points and rotor
thereof are removed and the assembly of the present invention substituted
therefor;
Figure 2 is a top plan view of the distributor with the sensor
~` and electronics module and rotor of the present invention installed therein; ;
Figure 3 is an elevational view of the assembly of Figure 2;
Figure 4 is a circuit diagram of an exemplary circuit of the
present ignition system; and
Figure 5 is an elevational view of another form of rotor according
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to the present invention, and Figures 6 and 7 are additional views thereof.
Turning to Figure 1, a conventional automobile distributor 10 is
shown Iwith distributor cap removed and not shown) having a conventional
vacuum advance plate 11 disposed therein. A conventional breaker point
cam 12 is shown which, in the conventional ignition system, serves to
operate a movable breaker point 13 of a breaker point assembly 14. The
breaker point assembly 14 also includes a stationary breaker point 15~ and
a mounting bracket 16 which normall~ is secured to the advance plate 11 by
means of screws 17 and 18. A key pin 16a facilitates proper alignment of
the bracket 16 with the plate 11. A capacitor 19 used in the conventional
ignition system is shown within the distributor 10, and normally is
physically and electrically
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to the present invention, and Figures 6 and 7 are additional views thereof. -~-
Turning to Figure 1, a conventional automobile distributor 10 is
shown ~with distributor cap removed and not shown) having a conventional
vacuum advance plate 11 disposed ~herein. A conventional breaker point ~ ;
cam 12 is shown which, in the conventional ignition system, serves to operate ~ `
a movable breaker point 13 of a breaker point assembly 14. The breaker point
assembly 14 also includes a stationary breaker point 15, and a mounting
bracket 16 which normally is secured to the advance plate 11 by means of
screws 17 and 18. A key pin 16a facilitates proper alignment of the bracket
16 with the plate 11. A capacitor 19 used in the conventional ignition
System is shown within the distributor 10, and normally is physically and
, electrically connected to a stud 20 of the breaker point assembly 14 along
, with a wire 21 which connects the breaker point assembly 14 to the primary
`~ winding of the ignition coil of the vehicle. Also shown in Figure 1 is the
conventional rotor 22 which normally is disposed on and keyed to the shaft 23 ~ ;
so as to cause the rotor 22 to rotate in synchronism with the engine speed of
~i the vehicle. The exploded view of Figure 1 illustrates the manner in which
the breaker point assembly 14 and the rotor 22 are removed from the distribu~
tor 10 in making the conversion from a breaker point ignition system to that -
j 2Q of the present invention.
In this regard, Figure 1 also illustrates the electronic module 25
' which includes the Hall sensor~ and a suitable adapter plate 26 therefor.
-i The module 25 has a metal tab 25a physically connected thereto, and this tab
~-i is secured to the adapter pla~e 26 by rivets 27 and 28. The tab 25a also
, serves as an electrical conductor for connecting the circuit in the module 25
to ground through ~he adapter plate 26 and plate 11. The tab 25a also serves
to conduct heat generated in the electronics module to the adap~er plate 26
from which it is dissipated. The adapter plate 26 includes apertures 29 and
30 for enabling the same to be mounted in place of the breaker point assembly ~;
14 by the screws 17 and 18, respectively. In some cases, the aperture 30 and
screw 18 are not needed. A key pin 26a facilitates alignment. The sensor
and electronics module 25 which will be described in greater detail subse-
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quently, includes a power input terminal 32 by which operating power is
supplied thereto, and an output terminal 33 which is connected to the primary
winding of the ignition coil and ignition capacitor. A two-wire cable 35
is provided having a first insulated wire 36 which is connected between the
terminal 32 of the module 25 and the ignition switch of the vehicle, and a
second insulated wire 37 which is connected between the output terminal 33 of
the module 25 and the primary winding of the ignition coil of the vehicle.
A suitable grommet 39 also is provided for allowing the cable 35 to be insert-
ed through and be insulated from aperture 40 of the sidewall 41 of the dis- ;
tributor 10 in place of the standard wire 21.
In addition to the foregoing, Figure 1 illustrates the new form of ~ -
rotor 45 of the present invention. This rotor is identical to the standard
rotor 22 of a given vehicle, with the exception of the addition of equally
spaced magnets 46 into the wall 47 thereof. For best performance, these
magnets should produce the strongest magnetic field possible. In a preferred
- embodiment they are rare earth magnets, such as samarium cobalt magnets manu-
factured by Hitachi Magnetics. As will be apparent to those skilled in the
, art, the precise form of the rolor will be different for different vehicles
inasmuch as different rotor configurations are used conventionally. Another
exemplary form of rotor wi71 be discussed later in the discussion of Figures
5 through 7. The rotor 45 ~and also the cam 12) shown in Figure 1 are for ~;
an eight-cylinder vehicle and, thus, eight magnets 46 are equally spaced
about the periphery of the wall 47 of the rotor 45. As will be discussed
later, these magnets, in combination with a Hall cell sensor in the module 25,
serve to provide timing signals as a function of the position of the rotor 45
as the same is rotated by the shaft 23 of the distributor assembly. The
rotor 45 includes a radially disposed contact 48 and a center contact 49 the ~
same as the conventional rotor 22 for distr~buting impulses to the eight spark ~ ;
plugs of the engine through ignition wires and the distributor cap (not shown) ~ ~
in a conventional manner. ~`
Figures 2 and 3 illustrate the module 25, cable 35 and rotor 45
installed within the conventional distributor 10. Installation, and, thus,
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conversion from the breaker point ignition system, merely involves the removal
of the breaker point assembly 14, the standard rotor 22 and the single-wire
21 of the conventional system. The two-wire cable 35 then is inserted through
the aperture 40 in the wall 41 of the distributor 10, and the adapter plate
26 attached to the module 25 is secured to the advance plate 11 in direct
replacement of the breaker point assembly 14. The adapter plate 26 is secured
to the plate 11 by the screws 17 and 18. The wire 50 of the capacitor 19 and
the wire 37 of the two-wire cable 35 are attached to the output terminal 33 of
the module 25. The wire 36 is attached to the terminal 32 of the module.
The other ends of the wires 36 and 37 are respectively connected to the
ignition switch and to the primary of the ignition coil of the vehicle. The
rotor 45 is inserted on to the shaft 23, and the distributor cap (not shown)
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is reattached to the distributor 10 in a conventional manner.
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The module 25 contains the Hall cell sensor 52 as best seen in
' Figures 2 and 3. In an exemplary embodiment, the sensor and entire electronic
` circuit of the present ignition system are encapsulated in a suitable plastic
`~ material to form the module 25. The sensor, in the form of a Hall cell, may
be approximately ten thousandths of an inch square and disposed approximately
thirty-five thousandths of an inch below the inwardly facing surface 53 of the
module 25. The aperture 29 of the adapter plate 26 for the module 25 is
-' elongated to enable adjustment of the position of the sensor 52 with respect
; to the periphery of the magnets 46 of the rotor 45. It is desired that the
periphery of the magnets 46 be as close as possible to the surface 53 (and,
;~ thus, the sensor 52) to maximize timing accuracy but, of course, they should
, not touch. An exemplary spacing between the surface 53 and outer surface of
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the magnets is five thousandths of an inch, and a plastic feeler gauge can be
used to set this spacing.
The magnets 46 may be disposed within the wall 47 of the rotor 45 ~:
-~ in any suitable manner. For example, these magnets 46 may be epoxied within
slots 55 formed in the peripheral wall 47 of the rotor. These magnets likewise
may be imbedded or recessed within the wall 47. Typically, the magnets 46 ~-~
are mounted so as not to protrude more than ten thousandths o~ an inch or to ~ -
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be recessed more than five thousandths o an inch with presently available
rare earth magnets.
The configuration of the adapter plate 26 can be changed to allow
the same to readily fit in place of various different breaker point assem-
blies 14. That isl it may have a different shape, other apertures, and the
like to enable a standard module 25 to be used with different distributors.
In some instances, the plate 26 is omitted and the tab 25a is directly
attached to a breaker plate the same as the plate 11 of the distributor being
connected. In this case, the original plate 11 is removed from the distribu- ;
tor 10 and discarded, and the breaker plate attached to the tab 25a constitutes
both an adapter plate and replacement breaker plate. Likewise, the rotor
configuration can be different as are conventional rotors.
Figure 4 illustrates an exemplary circuit or system for use with a
Hall cell 52 which is an integral element of circuit 60, and rotor 45 having
the magnets 46 thereon. This integrated circuit 60 is similar in function to
that shown and described in United States Patent No. 3,581,725, and serves to ~ ;
convert the slow rise and fall time output of the Hall cell to a square pulse
train having a ~requency and pulse width over the entire operating speed of
the engine down to zero rpm, determined by the timing signals ~rom the Hall '`
cell to, in turn, operate a solid state switch in series with the primary
winding of the conventional ignition coil. Figure 4 diagrammatically illus-
trates the relationship between the rotor 45 and the Hall cell sensor 52. ; -~
This sensor is a silicon Hall generator included within an integrated circuit
i 60. This integrated circuit also includes an amplifier, trigger and output `
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stage integrated with its own voltage regulator onto a monolithic silicon ~-
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' chip, and may be a Sprague ULS 3006M. -
; The integrated circuit 60 receives operating power through a
resistor 61 connected to line 72 which is connected to input terminal 32 of ;
the module 25. This terminal 32 is connected through wire 36 to the ignition
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switch 62 of the vehicle. The circuit 60 is connected to a common conductor
' 63 which, in turn, is connected to ground 64. This ground connection is
-~ provided by the tab 25a and adapter plate 26 connected to the advance plate
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11 of the distributor 10. 'I'he battery ~12 volt) of the vehicle is indicated
at 65 and is connected between ground 6~ and the ignition switch 62 in a
conventional manner. A Zener dioe 67 is connected across the circuit 60 by
connecting the same between the common connection of resistor 61 and circuit
60 and the common conductor 63.
The circuit 60 includes an output driver stage having a pair of
transistors ~only one of which is shown) whose collectors are connected to
output terminals. Either one or both of these output terminals may be used ;~
as output terminal 68 of the circuit 60. This output terminal 68 supplies the
square pulse train and is connected to the base of a transistor amplifier 70.
The base of the arnplifier 70 is connected through a resistor 71 to line 72 ;which is connected to the terminal 32. The collector of the transistor 70 is
connected through a resistor 73 to the line 72. A Zener diode74 is connected
~' between the collector of the transistor 70 and the common line 63. Zener
diode 67 isolates the circuit 60 from wide voltage variations and harmful
transient spikes which appear on line 72, and Zener diode74 performs a similar
function for the transistor amplifier 70.
The emitter of the amplifier 70 is connected to an input terminal
76 of an integrated Darlington power transistor circuit 77. This circuit may
be a TRW SVT 6001, and includes a pair of transistors 78 and 79 connected in a
Darlington configuration. The emit~er of the transistor 79 is connected to
the common conductor 63, and the collectors of the transistors 78 and 79 are
connected together and to the common conductor 63, and the collectors of the
~'~ transistors 78 and 79 are connected together and to output terminal 33 of the ~;
! module 25. This terminal 33 is connected by the line 37 to the primary
winding 81 of the existing ignition coil 82 of the vehicle. Also shown in
series with the winding 81 is the existing ballast resistor of the vehicle
which is connected between the other end of winding 81 and the ignition switch
by means of the existing vehicle wiring. A pair of Zener diodes 85 and 86
are connected in series between the terminal 76 connected to the base of the
transistor 78 and the terminal 33 connected to the collectors of the transis-
tors 78 and 79. The existing capacitor 19 normally used with the breaker
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point assembly 14 is connected across line 63 and terminal 33, and a diode 87
is connected in parallel between the line 63 and the terminal 33. ~ener diode
85 and 86 clip the voltage generated across the switch 77 when it turns off to
maintain the switch 77 within a safe voltage rating and to protect the same
from large voltage transients occasioned by the sudden decrease of current in
the inductance of the primary winding 81 of the ignition coil 82. Diode 87
protects the switch 77 from reverse voltage resulting from the resonant circuit
found by primary winding 81 and capacitor 19 when transistor 77 turns off.
The Hall cell sensor 52 of the circuit 60 provides timing signals
as a function of the position of the rotor 45 by virtue of the provision of
the magnets 46 on the periphery thereof. These timing signals have a relative-
ly slow rise and fall time. The electronics of the circuit 60 function as
a pulse shaper for generating square pulses having a frequency and pulse
width determined by the signals from the Hall cell sensor 52. The square
pulses are necessary to prevent a portion of the energy, stored in the ignition
coil7 from being dissipated as heat in transistor 77 rather than being deliver-
ed to the spark plug. These pulses are amplified by the amplifier transistor
70, and are applied to the output switch 77. This switch functions to switch
, the primary winding 81 of the ignition coil 82. A waveform 90 associated with ~
output terminal 33 illustrates the switching pulses. It should be noted that ~ -
~, the ratio between "on" time B and "off" time A is constant with the present
system, and is equal to the ratio of the distance between the magnets to the
width of the magnets. The waveform of the present system is equivalent to
that of an idealized breaker point system over the entire operation speed
range of the engine.
Considering the circuit operation in more detail, when one of the
magnets is in close proximity to the Hall cell, the output transistor(s),
connected to terminal 68, are turned on, pulling the voltage at the base of ;~
transistor 70 to the ground potential 64. This turns transistor 70 off and,
thus, turns off Darlington power switch 77. The resultant interruption of
current flow in the primary winding 81 of ignition coil 82 causes a high
voltage to be generated in the secondary winding. When the magnet moves away
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from the ~lall cell, the output transistor turns off, base current is supplied
-~ to transistor 70 through resistor 71 and transistors 70 and 77 turn on again.
~hen the next magnet comes into proximity with the llall cell sensor, the cycle
is repeated. For accurate operation, the Hall cell width (the dimension of
the Hall cell in the direction of rotor rotation) must be much smaller than
the distance between adjacent magnets in the rotor. In a preferred embodiment,
the Hall cell operates on only one polarity of magnetic field, thus all of
the magnets must have the same magnetic pole facing outward from the dis- ;
tributor shaft. Alternatively, a bipolar Hall cell and two magnets per ~ ~-
cylinder can be used.
The circuit 60 is available in a package configuration of .25 inch
by .4 inch by eighty thousandths of an inch thick, and the Hall cell sensor
is integral therein approximately twenty-five thousandths of an inch from an
, outer surface thereof. The Hall cell is approximately ten thousandths of an
inch square as noted earlier. The circuit 60 is encapsulated with the other
circuit components of Figure 4 to form the module 25, with the circuit 60 ~`
ten thousandths of an inch below the surface 53 of the module 25. This places
the Hall cell sensor thirty-five thousandths ~ten thousandths plus twenty-five
thousandths) of an inch below the surface 53. Typical spacing between the
~ 20 surface 53 and the outer surface of the magnets 46 is five thousandths o an
;~ inch and, thus, the outer surface of the magnet is approximately forty
thousandths of an inch from the Hall cell sensor 52 of the circuit 60 encapsu-
~, lated within the module 25.
; Figures 5 through 7 illustrate another form of the rotor of the
present invention. Figure 5 illustrates the conventional vacuum advance plate
95, breaker point cam 96, shaft 97 and rotor mounting plate 98 for certain
types of current vehicles, such as certain General Motors vehicles. Also
shown is the conventional capacitor 99. These distributor assemblies use a
cup-shaped rotor ~not shown) which attaches to the top of the rotor mounting
plate 98. Inasmuch as the rotor mounting plate 98, the cam 96 and shaft 97
are secured together, and there is no way of mounting the magnets in the
existing rotor such that they will pass in close proximity to the Hall cell
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censor when the distributor shaft rot~ ~e ~, a~ ~e~ form of rotor 100 is made in
two halves, 101 and 102, to enable the same to be secured about the periphery
of the cam 96 and shaft 97. Thus, the conventional rotor is retained. In
this embodiment, the cam 96 has six faces and is used with a six-cylinder
vehicle. Thus, the rotor 100 includes six magnets 103 mounted in the peri-
pheral wall thereof. These magnets may be mounted in the same manner discuss-
ed previously, and preferably protrude no more than ten thousandths of an
inch or are recessed no more than five thousandths of an inch. Figure 7 shows
one section 101 of the rotor 100, and illustrates the aperture 104 which fits
over the shaft 97 and hex faces 105 which fit over and are a press fit with
the cam 96. The rotor halves 101 and 102 may be secured together in any suit-
able manner, as by an adhesive. Locking arrangements for enabling the two ;~ . -
halves to lock together upon placement thereof on the cam 96 and shaft 97 may ~
be used. An exemplary material for the rotor 100 is glass-filled nylon inas- ~ ;
much as this rotor does not include any high voltage switching contacts ~such
as contacts 48 and 49 of the rotor 45 in Figure 1).
~' As an example of circuit components, other than those described
above, used in the system of ~igure 4, the following have been found to be
suitable:
Battery 65 Standard 12V vehicle battery ;~ ,
Resistor 61 125 ohms
Resistor 71 2.2 K ohms ~ ~
Resistor 73 80 ohms ~ -
Diode 67 6.2 volt Zener
Diode 74 22 volt Zener
Diodes 85 and 86 140 volt Zeners, each
Diode 81 IN4004
The present embodiments of this invention are to be considered in
all respects as illustrative and not restrictive, the scope of the invention
3Q being indicated by the appended claims rather than by the foregoing descrip-
tion or abstract of the disclosure, and all changes which come within the
~: .
- meaning and range of equivalency of the claims, therefore, are intended to be
embraced therein.
- 15 -
,. .. - . :
:.: ~ .... . , . :
