Information
-
Patent Grant
-
6616573
-
Patent Number
6,616,573
-
Date Filed
Friday, September 21, 200122 years ago
-
Date Issued
Tuesday, September 9, 200320 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Estremsky; Sherry
- Lewis; Tisha D.
Agents
- Michael Best & Friedrich LLP
-
CPC
-
US Classifications
Field of Search
US
- 477 99
- 477 101
- 290 30 R
- 290 30 A
- 290 31
- 290 32
- 290 33
- 290 34
- 290 35
- 290 36 R
- 290 37 R
- 290 37 A
- 290 38 R
-
International Classifications
- F16H5974
- F02N1104
- H02K2352
- H02P904
-
Abstract
A method and apparatus for eliminating inadvertent power drain from an electrical power source coupled to a starter-generator. 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.
Description
BACKGROUND OF THE INVENTION
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.
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.
Starter-generator circuits may also interact with components of the vehicle or device 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).
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
.
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
.
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.
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
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.
The invention provides 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.
The inventors also devised a method of starting an engine with a key switch. The 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.
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
In the drawings:
FIG. 1
is a schematic diagram of a prior-art pedal actuated starter-generator circuit.
FIG. 2
is a schematic diagram, partially in block form, of a key actuated starter-generator circuit with a bypass rectifier embodying the invention.
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.
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.
FIG. 5
is a flow chart depicting a method of preventing power drain utilizing a circuit embodying the invention.
DETAILED DESCRIPTION
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.
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
.
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
.
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
.
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
.
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
.
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
.
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
.
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.
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.
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
.
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.
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.
Claims
- 1. A key actuated starter-generator circuit comprising:a key switch with a plurality of predetermined positions to provide a connection between an electrical power source and a solenoid; a solenoid to provide a connection between the electrical power source and a starter-generator; a starter-generator to start an engine and to generate power to charge the electrical power source; a voltage regulator to regulate a predetermined voltage applied to the electrical power source; and a bypass rectifier to prevent inadvertent drainage of the electrical power source when the starter-generator is stalled.
- 2. A circuit as in claim 1, wherein the key switch includesan input for the electrical power source; a starter output to provide the electrical power source to the solenoid: an input for a ground; an accessory power output; and a kill output.
- 3. A circuit as in claim 2, further comprising a gear-controlled neutrally closed switch to provide a ground for the solenoid.
- 4. A key actuated starter-generator circuit comprising:a key switch with a plurality of predetermined positions to provide a connection between an electrical power source and the solenoid; a solenoid to provide a connection between the electrical power source and a starter-generator; and a bypass rectifier to prevent inadvertent drainage of the electrical power source when the starter-generator is stalled.
- 5. A circuit as in claim 4, further comprising a gear-controlled switch to provide a ground for the solenoid.
- 6. A starter-generator circuit comprising:a multiple position switch operable to be coupled to a power source; a relay coupled to the multiple position switch, having a switching element, and operable to be coupled to a starter-generator; and a rectifier coupled in a parallel circuit path to the switching element to prevent inadvertent drainage of the electrical power source when the starter-generator is stalled.
- 7. A starter-generator circuit as claimed in claim 6, wherein the multiple position switch is a key switch.
- 8. A starter-generator circuit as claimed in claim 7, wherein the multiple position switch has a start position, a kill position, and an accessory position.
- 9. A starter-generator circuit as claimed in claim 6, wherein the rectifier is a diode.
- 10. A starter-generator circuit as claimed in claim 6, wherein the rectifier includes a diode in a first circuit path and a second diode in a second circuit path that is parallel to the first circuit path.
- 11. A starter-generator circuit as claimed in claim 10, further comprising a third diode coupled in series to the diode in the first circuit path and a fourth diode coupled in series to the diode in the second path.
- 12. A starter-generator circuit as claimed in claim 6, the rectifier includes a diode in a first circuit path, a second diode in a second circuit path that is parallel to the first circuit path, and a third diode in a third circuit path that is parallel to the second circuit path.
- 13. A starter-generator circuit as claimed in claim 6, wherein the relay includes a solenoid.
- 14. A starter-generator circuit as claimed in claim 6, the circuit further comprising a shifter-controlled switch coupled to the relay.
- 15. A starter-generator system comprising:a starter-generator; a voltage regulator coupled to the starter-generator; a multiple position switch operable to be coupled to a power source; a relay coupled to the multiple position switch, having a switching element, and operable to be coupled to a starter-generator; and a rectifier coupled in a parallel circuit path to the switching element to prevent inadvertent drainage of the electrical power source when the starter-generator is stalled.
- 16. A starter-generator system as claimed in claim 15, wherein the multiple position switch is a key switch.
- 17. A starter-generator system as claimed in claim 16, wherein the key switch has a start position, a kill position, and an accessory position.
- 18. A starter-generator system as claimed in claim 15, the rectifier is a diode.
- 19. A starter-generator system as claimed in claim 15, wherein the rectifier includes a diode in a first circuit path and a second diode in a second circuit path that is parallel to the first circuit path.
- 20. A starter-generator system as claimed in claim 19, further comprising a second diode coupled in series to the diode in the first circuit path and a fourth diode coupled in series to the diode in the second path.
- 21. A starter-generator system as claimed in claim 15, the rectifier includes a diode in a first circuit path, a second diode in a second circuit path that is parallel to the first circuit path, and a third diode in a third circuit path that is parallel to the second circuit path.
- 22. A starter-generator system as claimed in claim 15, the system further comprising a shifter-controlled switch coupled to the relay.
US Referenced Citations (14)
Foreign Referenced Citations (1)
Number |
Date |
Country |
4120066 |
Jan 1992 |
DE |