Patent Grant
6943532
The present invention relates to a voltage control apparatus for a vehicle generator wherein an ignition switch and a charge lamp are connected in series so that a single input terminal is commonly used for these elements.
As a voltage control apparatus for a vehicle generator which has an input terminal for inputting a battery voltage through an ignition switch and a charge lamp and starts the operation when the voltage at the input terminal exceeds a predetermined value, there is known one disclosed in Japanese Patent No. 2707616.
The voltage control apparatus 1 shown in
To be more concrete, the voltage control apparatus 1 shown in
The transistor 14 and a transistor 152 are connected to a comparator 15 through transistors 141, 151, respectively. When the vehicle generator 2 starts the electric power generation operation, the voltage generated by the generator exceeds a constant voltage V3, so that the comparator 15 turns off the transistors 14, 152. In the figure, reference numerals 22, 23 depict the stator coil and the full-wave rectifier of the vehicle generator 2 respectively. A resistor 144 provided between the input terminal L and the ground serves to lower the voltage at the input terminal L to the ground level upon the normal opening operation of the ignition switch 3.
During the electric power generation operation, the power transistor 11 is turned on and off in response to a transistor 1111. A zener diode 1113 is provided on the base side of the transistor 1111.
An example of the conventional voltage control apparatus for a vehicle generator is shown in
However, when the current limit resistor is mounted on the vehicle side, the arrangement of the apparatus on the vehicle side becomes complicated. Further, even in the case where the current limit resistor is inserted on the vehicle side, there arises a problem that, when a high voltage such as a battery voltage etc. is directly applied to the input terminal L due to the abnormality of the vehicle wiring etc., the transistor for driving the light emitting element (light emitting diode etc.) driven with a low dissipation power may be broken by an overcurrent.
Further, there is a problem that a dedicated element such as a transistor etc. for lightening the light emitting element is required and that the light emitting element may always be kept in a lightened state by a current flowing into the input terminal L for starting the operation of the voltage control apparatus.
Accordingly, the present invention has been made in order to obviate the aforesaid problems of the prior art, and an object of the present invention is to provide a voltage control apparatus for a vehicle generator having a stable starting circuit which can start the voltage control circuit without breaking the voltage control apparatus even in an abnormal case that a high voltage is directly applied to the input terminal L of the voltage control apparatus.
Further, another object of the invention is to provide a voltage control apparatus for a vehicle generator which eliminates a dedicated element such as a transistor etc. which has been employed merely to turning on and off the light emitting element and can turn on and off the light emitting element with a simple circuit arrangement.
Furthermore, still another object of the invention is to provide a voltage control apparatus for a vehicle generator which can prevent the occurrence of such a phenomenon that the light emitting element is always kept in a lightened state by a current for starting the operation of the voltage control apparatus which flows into the voltage control apparatus from the input terminal L through the light emitting element.
The invention according to aspect 1 is characterized in that in a voltage control apparatus for a vehicle generator which has an input terminal for inputting the voltage of a battery through an ignition switch and a light emitting element connected in series with the ignition switch and driven by a low dissipation power and which starts the excitation of the rotor coil of the vehicle generator when the voltage at the input terminal exceeds a predetermined value, wherein a resistor for limiting the current flowing through the light emitting element is disposed between an element within the voltage control apparatus for driving the light emitting element and the input terminal.
The invention according to aspect 2 is characterized in that in a voltage control apparatus for a vehicle generator which has an input terminal for inputting a voltage of a battery through an ignition switch and a light emitting element connected in series with the ignition switch and driven by a low dissipation power and which starts excitation of a rotor coil of the vehicle generator when a voltage at the input terminal exceeds a predetermined value, wherein the light emitting element is lightened by a current itself which is inputted into the input terminal for starting the operation of the voltage control apparatus.
The invention according to aspect 3 is characterized, in the voltage control apparatus for a vehicle generator according to aspect 2, in that the light emitting element is coupled through the ignition switch to the base terminal of an NPN transistor for starting the operation of the voltage control apparatus so that the light emitting element is turned on by a current flowing into the base terminal. The invention according to aspect 4 is characterized in that in a voltage control apparatus for a vehicle generator which has an input terminal for inputting a voltage of a battery through an ignition switch and a light emitting element connected in series with the ignition switch and driven by a low dissipation power and which starts excitation of a rotor coil of the vehicle generator when a voltage at the input terminal exceeds a predetermined value, wherein a circuit for detecting the voltage of the input terminal and starting the voltage control apparatus is arranged to be shutdown or inoperable after the vehicle generator starts the electric power generation operation.
The invention according to aspect 5 is characterized, in the voltage control apparatus for a vehicle generator according to aspect 4, in that after the circuit for detecting the voltage of the input terminal and starting the voltage control apparatus is shutdown after the vehicle generator starts electric power generation operation, the operation of a starting circuit for the voltage control apparatus is maintained by the output of one phase of the vehicle generator.
The invention according to aspect 6 is characterized in that in a voltage control apparatus for a vehicle generator which has an input terminal for inputting a voltage of a battery through an ignition switch and a light emitting element connected in series with the ignition switch and driven by a low dissipation power and which starts excitation of a rotor coil of the vehicle generator when a voltage at the input terminal exceeds a predetermined value, wherein a circuit for detecting the voltage of the input terminal and starting the voltage control apparatus includes a field effect transistor.
The invention according to aspect 7 is characterized in that a light emitting diode is used as the light emitting element.
The voltage control apparatus 1 includes a current limit resistor 115 connected in series with a transistor 114 between the input terminal L and the collector of the transistor 114 for lightening the light emitting diode 4.
The voltage control apparatus 1 further includes a comparator 108 having a negative “−” terminal to which the voltage of the input terminal L is applied and a positive “+” terminal to which a constant voltage Vy is inputted.
When the ignition switch 3 is closed, the battery voltage is applied to the negative terminal of the comparator 108 through the light emitting diode 4 thereby to change the output of the comparator 108 from a high level to a low level, so that a transistor 110 is turned on. When the transistor 110 is turned on, the voltage control apparatus 1 is started. Thus, a transistor 101 is supplied with a base current through a resistor 104 and hence a rotor coil 201 is supplied with a field current, whereby the vehicle generator 2 is placed in a state of capable of generating electric power.
When the vehicle generator 2 is in a state of before starting an electric power generation operation, a comparator 109 is supplied at its positive “+” terminal with zero voltage, so that the comparator 109 outputs a low level thereby to turn off a transistor 103. Thus, the transistor 114 for driving the light emitting diode 4 is supplied with a base current through a resistor 116 and turned on, whereby the light emitting diode 4 is turned on by the current flowing through the resistor 115.
In this case, since the voltage of the input terminal L of the voltage control apparatus 1 is kept at almost same voltage as that of the battery 5 by the resistor 115, the negative terminal of the comparator 108 is kept to be supplied with a voltage higher than the voltage Vy, so that both the transistors 101 and 114 are surely kept to be supplied with the base current.
Further, even when the input terminal L is directly applied with the voltage of the battery 5 due to the abnormality of the wiring of the input terminal L, the short-circuit of the light emitting diode 4 etc. of the voltage control apparatus 1, since the current flowing into the collector of the transistor 114 is limited by the resistor 115, the transistor 114 is prevented from being broken.
When the vehicle generator 2 starts the electric power generation operation, since both a diode 111 and a capacitor 112 receive the output voltage of one phase of the generator, the voltage of the positive terminal of the comparator 109 becomes larger than the voltage Vx of the negative terminal thereof. Thus, since the output of the comparator 109 is changed from a low level to a high level, the transistor 113 is tuned on and so the transistor 114 is turned off thereby to turn off the light emitting diode 4.
Since a transistor 103 and the transistor 101 are switched in response to a predetermined voltage which is obtained by dividing the output voltage of the vehicle generator 2 by resistors 106, 107 and a zener diode 105, the current flowing through the rotor coil 201 is intermittently controlled and so controlled to a predetermined value.
When the current limit resistor 115 is disposed in a manner as shown in
As described above, according to the voltage control apparatus for a vehicle generator of the first embodiment, in a case where the light emitting element such as the light emitting diode driven by a low dissipation power is employed as the charge lamp, the resistor for limiting the current flowing through the light emitting element is disposed between the input terminal and the element for driving the light emitting element within the voltage control apparatus. Thus, the voltage control circuit is prevented from being broken even in an abnormal case that the output voltage of the battery is directly applied to the input terminal, and the stable starting circuit for the voltage control circuit can be arranged with the simple configuration.
The second embodiment is arranged in a manner that in the voltage control apparatus for a vehicle generator which has an input terminal L for inputting the voltage of a battery through an ignition switch and a light emitting element (light emitting diode etc.) connected in series with the ignition switch and driven by a low dissipation power and which starts its operation when the voltage at the input terminal L exceeds a predetermined value, the light emitting element is lightened by the current itself which is inputted into the input terminal L for starting the operation of the voltage control apparatus thereby to eliminate a dedicated element for lightening the light emitting element.
Further, the light emitting diode 4 is lightened by the base current of the transistor 122 which is supplied to the input terminal L through the ignition switch 3 for driving the transistor 122.
When the vehicle generator 2 starts the electric power generation operation, like the first embodiment, since the output of a comparator 109 is changed from a low level to a high level, a transistor 121 is tuned on, so that a transistor 123 is also turned on. Thus, since the battery voltage is applied to the collector terminal of the transistor 123, the current having been supplied to the light emitting diode 4 is cut off, whereby the light emitting diode 4 is turned off.
Further, since the transistor 122 is supplied with the base current due to the turning-on of the transistor 123, the circuit for supplying the base current for the transistor 101 is prevented from being shut down or inoperable.
Since the voltage control operation of the voltage control apparatus of this embodiment is same as that of the first embodiment, the explanation of the voltage control operation of the voltage control apparatus of this embodiment will be omitted.
As described above, according to the voltage control apparatus for a vehicle generator of the second embodiment, the element such as a dedicated transistor etc. which has been employed merely to turning on and off the light emitting element driven with a low dissipation power can be eliminated and the light emitting element can be turned on and off with the simple circuit arrangement.
The third embodiment is arranged in a manner that in the voltage control apparatus for a vehicle generator which has an input terminal L for inputting the voltage of a battery through an ignition switch and a light emitting element (light emitting diode etc.) connected in series with the ignition switch and driven by a low dissipation power and which starts its operation when the voltage at the input terminal exceeds a predetermined value, the circuit for detecting the voltage of the input terminal L and starting the voltage control apparatus is arranged to be shutdown or inoperable after the vehicle generator starts the electric power generation operation.
In
In this case, the light emitting diode 4 is lightened by the base current of the transistor 122 flowing through the resistor 146 and the collector current of the transistor 133 flowing through a resistor 147.
When the vehicle generator 2 starts the electric power generation operation, like the first embodiment, since the output of a comparator 109 is changed from a low level to a high level, a transistor is turned on, so that a transistor 133 is turned off. Thus, since the transistor 144 is also turned off, the current having been supplied to the base electrode of the transistor 122 is cut off, whereby the light emitting diode 4 is turned off.
Further, when the transistor 122 is turned off, the transistor 110 is also turned off, whereby the circuit for supplying the base current for the transistor 101 is shut down or made inoperable. Thus, after the vehicle generator 2 starts the electric power generation operation, a transistor 131 is turned on by the output of the comparator 109 thereby to turn on the transistor 110, whereby the circuit for supplying the base current for the transistor 101 is kept to be operable to maintain the supply of the base current.
Since the voltage control operation of the voltage control apparatus of this embodiment is same as that of the first embodiment, the explanation of the voltage control operation of the voltage control apparatus of this embodiment will be omitted.
As described above, according to the voltage control apparatus for a vehicle generator of the third embodiment, the circuit for detecting the voltage of the input terminal L and starting the voltage control apparatus is arranged to be shutdown or inoperable after the vehicle generator starts the electric power generation operation. Thus, this embodiment can prevent the occurrence of such a phenomenon that the light emitting element is kept in a lightened state by the current for starting the operation of the voltage control apparatus which flows into the voltage control apparatus from the input terminal L through the light emitting element driven with a low dissipation power.
The fourth embodiment is arranged in a manner that in the voltage control apparatus for a vehicle generator which has an input terminal L for inputting the voltage of a battery through an ignition switch and a light emitting element (light emitting diode etc.) connected in series with the ignition switch and driven by a low dissipation power and which starts its operation when the voltage at the input terminal L exceeds a predetermined value, the circuit for detecting the voltage of the input terminal L and starting the voltage control apparatus includes a field effect transistor.
In
When the vehicle generator 2 starts the electric power generation operation, like the first embodiment, since the output of a comparator 109 is changed from a low level to a high level, a transistor 113 is tuned on, so that the transistor 114 is turned off. Thus, since the current having been supplied to the light emitting diode 4 is cut off, the light emitting diode 4 is turned off.
The starting circuit for the voltage control circuit 1 of the vehicle generator 2 includes the field effect transistor (FET) 151. Since the FET 151 does not require any current to be supplied to the gate circuit thereof, the FET 151 keeps the conductive state whilst the current does not flow through the resistor 152. Thus, the operation of the starting circuit can be maintained without erroneously lightening the light emitting diode 4.
Since the voltage control operation of the voltage control apparatus of this embodiment is same as that of the first embodiment, the explanation of the voltage control operation of the voltage control apparatus of this embodiment will be omitted.
As described above, according to the voltage control apparatus for a vehicle generator of the fourth embodiment, the circuit for detecting the voltage of the input terminal L and starting the voltage control apparatus includes the field effect transistor. Thus, this embodiment can prevent the occurrence of such a phenomenon that the light emitting element is kept in a lightened state by the current flowing into the voltage control apparatus from the input terminal L.
As described above, according to the invention in aspects 1 and 7, the resistor for limiting the current flowing through the light emitting element (light emitting diode etc.) driven with a low dissipation power is disposed between the input terminal and the element for driving the light emitting element within the voltage control apparatus.
Thus, the voltage control circuit is prevented from being broken even in an abnormal case that the output voltage of the battery etc. is directly applied to the input terminal, and the stable starting circuit for the voltage control circuit can be arranged with the simple configuration.
According to the invention in aspects 2, 3 and 7, the light emitting element (light emitting diode etc.) driven with a low dissipation power is lightened by a current itself which is inputted into the input terminal for starting the operation of the voltage control apparatus. Thus, a dedicated transistor etc. which has been employed merely to turning on and off the light emitting element can be eliminated and the light emitting element can be turned on and off with the simple circuit arrangement.
According to the invention in aspects 4, 5 and 7, the circuit for detecting the voltage of the input terminal and starting the voltage control apparatus is arranged to be shutdown or inoperable after the vehicle generator starts the electric power generation operation. Thus, the light emitting element can be prevented from being kept in a lightened state by the current for starting the operation of the voltage control apparatus which flows into the voltage control apparatus from the input terminal L through the light emitting element (light emitting diode etc.).
According to the invention in aspects 6 and 7, the circuit for detecting the voltage of the input terminal and starting the voltage control apparatus includes the field effect transistor. Thus, there is no current for starting the operation of the voltage control apparatus which flows into the voltage control apparatus from the input terminal L through the light emitting element (light emitting diode etc.). Accordingly, the light emitting element is prevented from being kept in a lightened state by the current flowing into the voltage control apparatus from the input terminal.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2000-109030 | Apr 2000 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4275344 | Mori et al. | Jun 1981 | A |
| 4295087 | Morishita et al. | Oct 1981 | A |
| 4306184 | Iwaki et al. | Dec 1981 | A |
| 4309648 | Morishita | Jan 1982 | A |
| 4336487 | Tanaka et al. | Jun 1982 | A |
| 4379990 | Sievers et al. | Apr 1983 | A |
| 4381483 | Muto et al. | Apr 1983 | A |
| 4418311 | Torii et al. | Nov 1983 | A |
| 4549128 | Morishita et al. | Oct 1985 | A |
| 4642548 | Mashino | Feb 1987 | A |
| 4658200 | Kouge | Apr 1987 | A |
| 4665354 | Sada et al. | May 1987 | A |
| 4687983 | Beyn | Aug 1987 | A |
| 4755737 | Komurasaki et al. | Jul 1988 | A |
| 4914374 | Iwatani et al. | Apr 1990 | A |
| 5266882 | Morishita | Nov 1993 | A |
| 5280232 | Kohl et al. | Jan 1994 | A |
| 5563497 | Iwatani et al. | Oct 1996 | A |
| 5581172 | Iwatani et al. | Dec 1996 | A |
| 5719487 | Sato et al. | Feb 1998 | A |
| 5780995 | Maggioni et al. | Jul 1998 | A |
| 6313613 | Iwatani et al. | Nov 2001 | B1 |
| Number | Date | Country |
|---|---|---|
| 1603886 | Dec 1981 | GB |
| 52-068911 | Jun 1977 | JP |
| 61-046200 | Mar 1986 | JP |
| 402036734 | Feb 1990 | JP |
| 06 237541 | Aug 1994 | JP |
| HEI 07-15886 | Jan 1995 | JP |
| 7-298515 | Nov 1995 | JP |
| 09-047091 | Feb 1997 | JP |
| 2707616 | Oct 1997 | JP |
