U.S. patent application number 10/602332 was filed with the patent office on 2003-12-18 for methods for eliminating power drainage in power sources used with starter-generators.
This patent application is currently assigned to Club Car, Inc.. Invention is credited to Bobbitt, John T. III, McLeod, Paul W..
Application Number | 20030232697 10/602332 |
Document ID | / |
Family ID | 25502799 |
Filed Date | 2003-12-18 |
United States Patent
Application |
20030232697 |
Kind Code |
A1 |
McLeod, Paul W. ; et
al. |
December 18, 2003 |
Methods for eliminating power drainage in power sources used with
starter-generators
Abstract
Methods for eliminating inadvertent power drain from an
electrical power source coupled to a starter-generator. In one
embodiment, a multiple-position key switch and bypass rectifier
configuration is implemented. The multiple-position key switch is
coupled to the power source. The key switch's start terminal is
coupled to a solenoid for starting, while a bypass rectifier is
coupled in parallel to the solenoid to provide a circuit path for
recharging the electrical power source. When either a
closed-in-neutral gear shift switch is open or the key switch is in
a run/accessory power position, the solenoid is de-energized. This
leaves the bypass rectifier as the remaining circuit path through
which the power source is recharged. The bypass rectifier allows
current flow in a single direction, thereby preventing discharge of
the power source.
Inventors: |
McLeod, Paul W.; (Martinez,
GA) ; Bobbitt, John T. III; (Evans, GA) |
Correspondence
Address: |
MICHAEL BEST & FRIEDRICH LLP
3773 CORPORATE PARKWAY
SUITE 360
CENTER VALLEY
PA
18034-8217
US
|
Assignee: |
Club Car, Inc.
|
Family ID: |
25502799 |
Appl. No.: |
10/602332 |
Filed: |
June 24, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10602332 |
Jun 24, 2003 |
|
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|
09960108 |
Sep 21, 2001 |
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6616573 |
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Current U.S.
Class: |
477/99 |
Current CPC
Class: |
F02N 11/04 20130101 |
Class at
Publication: |
477/99 |
International
Class: |
F16H 059/74 |
Claims
What is claimed is:
1. A method of starting an engine with a first switch, the method
comprising: turning the first switch to a starting position;
energizing a second switch using an electrical power source;
closing the second switch; energizing a starter-generator; turning
the first switch to a running position; and charging the electrical
power source using the starter-generator.
2. A method as in claim 1, further comprising keeping a
transmission in a neutral position.
3. A method of controlling a starter-generator using a first
switch, the method comprising: providing a circuit path from a
battery to the first switch; providing a switched circuit path from
a shifter to the first switch; energizing a second switch by moving
the first switch to a predetermined position; providing current
from the battery through the second switch to the
starter-generator; and providing a rectified circuit path from the
starter-generator to the battery.
4. A method of controlling a starter-generator as claimed in claim
3, the method further comprising de-energizing the second switch by
moving the key switch to a second predetermined position.
5. A method of controlling a starter-generator as claimed claim 3,
the method further comprising configuring the rectified circuit
path and the second switch in parallel.
6. A method of controlling a starter-generator as claimed claim 3,
the method further comprising de-energizing the second switch by
opening the switched circuit path.
7. A method of controlling electrical power drainage of a
starter-generator circuit, the method comprising: providing a
bypass rectifier for charging an electrical power source; providing
a multiple position switch for de-energizing a solenoid; and
providing a shifter-controlled switch for de-energizing a solenoid.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 09/960,108, filed Sep. 21, 2001.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to starter-generators. More
specifically, the invention relates to a starter-generator circuit
that eliminates inadvertent power drainage from a power source.
[0003] Starter-generators are used in utility vehicles and
equipment having internal combustion engines. Starter-generators
are electromagnetic machines that combine the functions of a
starter motor and a generator in a single device. A
starter-generator is responsible for starting an engine and, once
the engine is running, operating as a generator of electrical
power. The electrical power is often used to recharge a starting
battery and to power devices within or connected to the vehicle or
equipment containing the starter-generator. Starter-generators are
usually controlled by starter-generator circuits. Often the
starter-generator circuit includes a voltage regulator to control
the voltage level of generated electrical power.
[0004] Starter-generator circuits may also interact with components
of the vehicle or devices in which they are installed. For example,
known utility vehicles are equipped with
pedal-actuated-starter-generator circuits, such as the circuit 110
shown in FIG. 1. The circuit 110 includes a ground or ground node
111, a battery 112 with a positive terminal 114, and a two-position
key switch 118. The switch 118 includes a ground terminal 120, a
magneto terminal 124, a battery terminal 126, and an accessory
terminal 128. The switch can be placed in one of two positions--an
off/magneto kill position and a run/accessory power position. When
in the off/magneto kill position, the switch 118 couples the
magneto terminal 124 to the ground terminal 120. When in the
run/accessory power position, the switch 118 couples the battery
terminal 126 to the accessory terminal 128. In this position, power
from the battery may be supplied to accessories (such as lights, a
radio, etc. in the vehicle or device) and to a starter-generator
(discussed below).
[0005] A pedal activated switch 132 is connected to the accessory
terminal 128. When the pedal activated switch 132 is closed (such
as when a driver steps on an accelerator pedal of a utility
vehicle), a coupling is established between the battery terminal
126 and a first inductor coil terminal 140 of a solenoid 142.
[0006] The solenoid 142 has a second inductor coil terminal 144 and
an open-in-neutral gearshift switch 152 is coupled to the terminal
144. When the open-in-neutral gearshift switch 152 is closed (such
as when a driver places a utility vehicle in gear) a coupling is
established between the second inductor coil terminal 144 and
ground 111. This energizes the solenoid 142 such that a solenoid
switch 148 is closed. When closed, the solenoid switch 148 couples
the positive terminal 114 of the battery 112 to a node 155. The
node 155 is coupled to an inductor 160. The inductor 160 is coupled
to a terminal 161 of a starter-generator 162. The starter-generator
162 is coupled to an engine (not shown). When the engine is off,
the starter-generator acts as a starter and uses power supplied
from the battery to start the engine. Once the engine starts and
the engine speed reaches a certain level, the starter-generator
acts as generator and generates current that may be used to
recharge the battery 112.
[0007] The starter-generator 162 is coupled to a transistor
terminal 170 of a voltage regulator 172. The voltage regulator 172
is coupled to the node 155 and regulates the voltage applied to the
battery 112 by selectively creating a path between the terminal 161
and the ground.
[0008] Another example of a starter-generator circuit is a key
actuated starter-generator circuit. Like a
pedal-actuated-starter-circuit, a key actuated starter-generator
circuit has a multi-position switch coupled to a solenoid relay, a
voltage regulator, and a starter-generator. However, a key-actuated
starter generator circuit lacks a pedal activated switch and may or
may not include a gearshift switch.
SUMMARY OF THE INVENTION
[0009] The inventors have discovered that a problem with the
pedal-actuated-starter-generator circuit 110 and key-actuated
starter generator circuits is that so long as the key switch (such
as switch 118) remains in the run/accessory power position,
accessories can continue to draw power from the battery. In
addition, if the engine stalls (in which case the switches 132 and
152 may remain closed in the circuit 110) or operates in such a way
that the voltage at the starter-generator is less than the voltage
at the positive terminal of the battery, power may be drawn from
the battery. In some circumstances it is possible that these
demands may deplete the battery. Once depleted, starting the
vehicle or device in which the starter-generator is located is
impossible until the battery is replaced or recharged with an
another mechanism. Accordingly, there is a need for an improved
starter-generator circuit such that inadvertent power drainage can
be eliminated or reduced.
[0010] Embodiments of the invention provide a system for preventing
power drain of a battery and utilizes a key actuated
starter-generator circuit. The circuit includes a key switch with a
plurality of predetermined positions to provide a connection
between an electrical power source and a solenoid, and a bypass
rectifier to prevent inadvertent drainage of an electrical power
source. The solenoid couples the electrical power source to a
starter-generator. The circuit also includes a starter-generator to
start an engine and to generate power to charge the electrical
power source and a voltage regulator to regulate a predetermined
voltage applied to the electrical power source. The system may also
include a gear-controlled neutrally closed switch to provide a
ground for the solenoid.
[0011] The inventors also devised methods of starting an engine
with a key switch. One method involves turning a key switch to a
starting position and energizing a solenoid by an electrical power
source. The closing of the solenoid energizes a starter-generator.
The method also involves turning the key switch to a running
position, and charging the electrical power source by the
starter-generator. The method further involves de-energizing the
solenoid by moving the key switch to a second predetermined
position, or by opening the switched circuit path. The method may
further involve keeping a gear in a neutral position. By
configuring a rectified circuit path and the solenoid in parallel,
and with either the key switched to the second predetermined
position or the switched circuit path opened, the electrical power
source is recharged by the generator through the rectified circuit
path.
[0012] Other features and advantages of the invention will become
apparent to those skilled in the art upon review of the following
detailed description, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the drawings:
[0014] FIG. 1 is a schematic diagram of a prior-art pedal actuated
starter-generator circuit.
[0015] FIG. 2 is a schematic diagram, partially in block form, of a
key actuated starter-generator circuit with a bypass rectifier
embodying the invention.
[0016] FIG. 3 is a detailed schematic diagram of the key actuated
starter-generator circuit with the bypass rectifier shown in FIG.
2, along with electrical system components found in a typical
utility vehicle.
[0017] FIG. 4 is a schematic diagram of one preferred embodiment of
the bypass rectifier. FIG. 4A is a schematic diagram of another
preferred embodiment of the bypass rectifier.
[0018] FIG. 5 is a flow chart depicting a method of preventing
power drain utilizing a circuit embodying the invention.
DETAILED DESCRIPTION
[0019] Before embodiments of the invention are explained, it is to
be understood that the invention is not limited in its application
to the details of the construction and the arrangements of the
components set forth in the following description or illustrated in
the drawings. The invention is capable of other embodiments and of
being practiced or being carried out in various ways. Also, it is
to be understood that the phraseology and terminology used herein
is for the purpose of description and should not be regarded as
limiting.
[0020] FIG. 2 illustrates an improved key actuated
starter-generator circuit 210 with bypass rectifier (discussed
below). The circuit 210 includes a ground or ground node 211 and a
battery 212 having a positive terminal 214. The circuit 210 also
includes a three-position key switch 218. The key switch 218 has a
ground terminal 220, a kill or magneto terminal 222, a battery
terminal 226, a start terminal 227, and an accessory terminal 228.
The key switch 218 can be placed in one of three positions--an
off/magneto kill position (not shown), a start position (not
shown), and a run/accessory power position (also not shown). In the
off/magneto kill position, the key switch 218 couples the magneto
terminal 222 to the ground terminal 220. In the start position, the
key switch 218 couples the battery terminal 226 to the start
terminal 227. In this position, power from the battery is supplied
to a starter-generator (discussed below). In the run/accessory
power position, the key switch 218 couples the battery terminal 226
to the accessory terminal 228. In this position, power from the
battery 212 may be supplied to accessories (such as lights, a
radio, etc. in the vehicle or device). The start terminal 227 is
coupled to a first solenoid inductor coil terminal 240 of a
solenoid 242. The solenoid 242 also has a second solenoid inductor
terminal 244.
[0021] The second solenoid inductor terminal 244 is connected to a
closed-in-neutral gearshift switch 252. When the closed-in-neutral
gear shift switch 252 is closed, (such as when a transmission is in
neutral) a coupling is established between the second solenoid
inductor coil terminal 244 and ground 211. This energizes the
solenoid 242 such that a solenoid switch 248 is closed. This
further couples the battery terminal 214 to a first inductor coil
terminal 260 of an inductor 261. The inductor 261 is coupled to a
starter-generator 262 at a node 263. The starter-generator 262 is
coupled to a transistor terminal 270 of a voltage regulator 272,
which is coupled to the first inductor coil terminal 260 or the
battery terminal 214 (the preferred coupling is shown with a solid
line while the alternative connection is shown with a dashed line).
The voltage regulator 272 regulates the voltage applied to the
battery 212 by selectively creating a path from the node 263 to
ground 211.
[0022] A bypass rectifier 280 having a positive terminal 282 and a
negative terminal 284 is coupled in parallel to the solenoid 242 to
provide a circuit path 285 for recharging the battery 212. The
rectifier allows current flow in a single direction to the positive
terminal of the battery and prevents or reduces current flow from
the positive terminal of the battery along path 285. When the
closed-in-neutral gear shift switch 252 is open (for example, while
the vehicle is in gear and moving), the solenoid 242 is
de-energized. This opens the solenoid switch 248, leaving the
bypass rectifier 280 as the remaining circuit path through which
the battery 212 is recharged. The positive terminal 282 is also
coupled to the first inductor coil terminal 262 and the negative
terminal 284 is coupled to the positive terminal 214 of the battery
212.
[0023] FIG. 3 is a detailed schematic diagram of the key actuated
starter-generator circuit 210 in conjunction with components
commonly found in a utility vehicle (not shown). The components
include a left head light 301, a right head light 302, a dashboard
303, and an electrical component box 304. The utility vehicle also
includes components such as the battery 212, the bypass rectifier
280, and the starter-generator 262.
[0024] The dashboard 303 includes a light switch 320, an oil light
325, a meter gauge 327, a reverse buzzer 330, and the
three-position key switch 218. The light switch 320 couples the
left head light 301 and the right head light 302 to the positive
terminal 214 of the battery 212 through a fuse block 334. The
solenoid 242, which is embedded in the electrical component box
304, is coupled to the fuse block 334. The left headlight 301 and
the right headlight 302 are also coupled to a second rectifier unit
335, which is coupled to the ground 211. The oil light 305 is
coupled to an oil sensing unit 340 and the meter gauge 307. The
meter gauge 307 is further coupled to a fuel tank sensing unit 345.
The accessory terminal 228 of the three-position key switch 218 is
coupled to the meter gauge 307. The reverse buzzer 308 is coupled
to a reverse limit switch 353 and the ground 211. A forward limit
switch 354 is also coupled to the positive terminal 214 of the
battery 212 through the fuse block 334 and the solenoid 242.
[0025] As should be apparent, since FIG. 3 simply includes more
details of the circuit 210 plus additional well-known components,
the operation of the circuit shown in FIG. 3 need not be addressed
herein. However, FIG. 3 does illustrate that the closed-in-neutral
gearshift 252 can be implemented using the limit switches 353 and
354. In addition, FIG. 3 shows additional details regarding the
construction of one preferred embodiment of the bypass rectifier
280. For even further clarity, the preferred embodiment of the
rectifier shown in FIG. 3 is reproduced in FIG. 4.
[0026] FIG. 4 is a schematic diagram of one preferred bypass
rectifier 400. The rectifier 400 includes a first diode 402 in a
first circuit path 404 and a second diode 406 in a second circuit
path 408 that is parallel to the first circuit path 410. The
rectifier 400 also includes a third diode 410 coupled in series to
the first diode 402 in the first circuit path 404 and a fourth
diode 408 coupled in series to the second diode 406 in the second
path 408. FIG. 4A is a schematic diagram of another preferred
embodiment of the bypass rectifier 450. The rectifier 450 includes
a first diode 452 in a first circuit path 454 in parallel to a
second diode 456 in a second circuit path 458. The rectifier 450
further includes a third diode 462 in a third circuit path 466. The
third diode 462 in the third circuit path 466 is parallel to both
the first circuit path 454 and the second circuit path 458.
[0027] Although other rectifiers including a single diode or other
diode combinations beyond what is shown could be used, the
arrangement shown in FIG. 4 has several advantages. Diodes arranged
in a series configuration increase the reverse voltage blocking
capability of the diode combination. (While the forward current
flows remain the same, the reverse breakdown voltage is the maximum
of the two individual breakdown voltages.) Further, connecting
diodes in parallel increases the current rating of the rectifier.
Therefore, connecting diodes-in-series and then in parallel
increases both the reverse blocking capability and the current
rating. FIG. 4A shows yet another embodiment of three diodes in
parallel. This arrangement increases the current rating of the
rectifier as described earlier.
[0028] A method for preventing power drain of a battery utilizing a
control circuit embodying the invention is illustrated in a flow
chart 500 shown in FIG. 5. The method begins at a starting step
502. Whether a transmission is in neutral is determined at a first
decision 504. If the transmission is not in neutral, no action
occurs. Once in neutral, whether the key is at a start position is
determined at step 508. (However, it should be noted that the
invention may be implemented in devices without gear-controlled
switches and step 504 may be eliminated.) If the key is not at a
start position, no further action is taken.
[0029] If the key is at a start position, the battery is coupled to
the solenoid as shown in a coupling step 512. Thereafter, the
solenoid is energized by the battery at step 516. The solenoid
switch is then closed at step 520. The starter generator inductor
is then energized at step 524.
[0030] Whether the key is at a run position is determined at step
528. If the key is not at the run position, the circuit continues
to apply a start current to the starter-generator. Once the key is
in the run position, the engine status is checked at step 530. If
the engine is not running, no recharging will take place (step
548). Otherwise, the starter-generator begins to act as a generator
at step 532. The rectifier path is then enabled at step 536. The
battery is then recharged at step 540. The key position is then
checked at step 544. If the key is at a stop position, the engine
is shut off and recharging of the battery stops (step 548).
Otherwise, the engine continues to run and recharge the battery so
long as the battery is not fully charged.
[0031] As can be seen from the above, the invention provides a
method and apparatus for eliminating inadvertent power drain from a
power source used with a starter-generator. Various features and
advantages of the invention are set forth in the following
claims.
* * * * *