KR100334571B1 - Apparatus of Controlling Voltage from Generator of Vehicle - Google Patents

Abstract

The present invention relates to a voltage generator of a vehicle generator that can be used adaptively to the temperature gradient characteristics of the electrical load of the vehicle.

The voltage control device for a vehicle generator includes a generator for generating a voltage by the rotational force of the engine, a power switching means for switching the current path of the generator, a reference voltage generating means for generating a reference voltage, and an output voltage of the generator. And a switching control means having a comparison means having a first transistor to compare with a second transistor and a second transistor for controlling a switching operation of the power switching means in accordance with the comparison result of the comparison means. At least one constant voltage device connected between the two transistors and a resistor voltage divider having a voltage divider point connected in series with the constant voltage device and connected to the second transistor to generate the reference voltage, the reference voltage being the first and second voltages; The threshold voltages of the second transistors and the turn-on voltage of the constant voltage device vary with temperature, thereby varying with temperature. The temperature gradient characteristic changes, and the temperature gradient characteristic is determined by the partial pressure ratio of the resistance voltage divider.

Description

Voltage generator of vehicle generator {Apparatus of Controlling Voltage from Generator of Vehicle}

The present invention relates to an apparatus for controlling a voltage to be supplied to an electrical load including a capacitor from a generator of a vehicle, and in particular, voltage control of a vehicle generator for controlling a voltage to be supplied to an electrical load of a vehicle including a battery from the generator according to a temperature. Relates to a device.

In general, a generator of a vehicle generates electricity, that is, a voltage by using a rotational force of an engine included in the vehicle. The voltage generated by the generator of such a vehicle not only varies with the rotational speed of the engine, but also changes with the temperature. Accordingly, a voltage control device called a "regulator" for maintaining a constant voltage to be supplied from the vehicle generator to the electrical load including the storage battery is used at the output stage of the generator of the vehicle.

On the other hand, the electrical load in the vehicle including the storage battery changes the voltage response characteristics according to the temperature. For example, a battery has a fast voltage charging speed as the temperature increases, while a slow charging speed as the temperature decreases. In other words, the electrical load of the vehicle including the storage battery has different charging characteristics depending on the temperature. Further, the temperature gradient characteristic varies slightly depending on the storage battery, and also depends on the position on the vehicle in which the storage battery is mounted. For this reason, the characteristics of the voltage control device of the vehicle generator is inevitably changed according to the automobile manufacturer.

However, since the voltage control devices of the existing vehicle generators have a temperature gradient characteristic that is fixed in a circuit to suit the characteristics required by the car maker, respectively, there is no expandability in use. In addition, the voltage control device of the existing vehicle generator had to be newly designed whenever a new temperature gradient characteristic is required. Against this background, it is to provide a new vehicle generator voltage control device which can change the temperature gradient characteristic to improve the expandability in use and to prevent the design change.

Accordingly, an object of the present invention is to provide a voltage generator of a vehicle generator that can be adaptively used in the temperature gradient characteristics of the electrical load of the vehicle.

1 is a view schematically showing an electric system of a vehicle to which a voltage control device for a vehicle generator according to an embodiment of the present invention is applied.

<Description of Symbols for Main Parts of Drawings>

10 vehicle generator 12 storage battery

14 electrical load 16 voltage control device

20: power switch 22: voltage detector

C1 to C4: Capacitors D1, D2: Diode

Q1 to Q5: transistors R1 to R10: resistors

ZD: Zener Diode

In order to achieve the above object, the voltage control device for a vehicle generator according to the present invention is a generator for generating a voltage by the rotational force of the engine, power switching means for switching the current path of the generator, and a reference voltage for generating a reference voltage A switching means having a generating means, a comparing means having a first transistor for comparing the output voltage of the generator with a reference voltage, and a second transistor for controlling the switching operation of the power switching means in accordance with the comparison result of the comparing means; And the reference voltage generating means includes at least one constant voltage element connected between the first transistor and the second transistor, and a resistor voltage divider having a voltage divider point connected in series with the constant voltage element and connected to the second transistor. The reference voltage is the threshold voltage of the first and second transistors and before the turn-on of the constant voltage device. By varying according to the temperature, and have a variable temperature gradient characteristic with temperature, the temperature gradient characteristic is characterized in that which is determined by the partial pressure ratio of the resistive voltage divider.

The voltage control device for a vehicle generator according to the present invention includes a generator for generating a voltage at each of the first and second terminals by the rotational force of the engine, a power switching means for switching the current path of the generator, and a reference for generating a reference voltage. A switching means having a voltage generating means, first and second transistors for selectively comparing voltages on the first and second terminals of the generator with a reference voltage, and switching operation of the power switching means in accordance with the comparison result by the comparing means; And a switching control means for switching the third transistor, wherein the reference voltage generating means connects at least one constant voltage element connected between the common connection point of the first and second transistors and the third transistor in series with the constant voltage element. And a resistor voltage divider having a voltage divider point connected to the third transistor to generate a reference voltage, the reference voltage being the first and second transistors. The threshold voltage of any one of the stators and the turn-on voltage of the third transistor and the constant voltage element vary with temperature, and thus have a temperature gradient characteristic that varies with temperature. Characterized in that it is determined.

Other objects and features according to the present invention in addition to the above objects will become apparent from the detailed description of the following embodiments with reference to the accompanying drawings.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to FIG. 1.

1 is a diagram illustrating an electric system of a vehicle to which a voltage control device for a vehicle generator according to an exemplary embodiment of the present invention is applied. 1, the vehicle electrical system includes a storage battery 12 and an electrical load 14 connected in parallel between the first terminal 10A of the vehicle generator 10 and the ground voltage line 11. Also shown is a voltage controller 16 of a vehicle generator according to an embodiment of the present invention, which is connected between the first to third terminals 10A to 10C and the ground voltage line 11 of the vehicle generator 10. . The vehicle generator 10 includes a field coil FC connected between the second and third terminals 10B and 10C. The vehicle generator 10 having the field coil FC generates a voltage between the first to third terminals 10A to 10C by repeatedly switching the current path of the field coil FC. The battery 12 charges the voltage from the first terminal 10A of the generator 10 and also supplies the charged voltage to the electrical load 14 when no voltage is supplied from the generator 10. The electrical load 14 driven by the voltage from the first terminal 10A or the battery 12 of the generator 10 represents an electrical system installed in a vehicle.

The voltage controller 16 has a power switch 20 which repeatedly opens and closes a current path between the third terminal 10C of the generator 10 and the base voltage line 11 in response to the voltage on the first node n1. ) Will be included. The power converter 20 connects the third terminal 10C of the generator 10 to the base voltage line 11 when the voltage on the first node n1 becomes higher than its threshold voltage (for example, 0.7V). On the other hand, when the voltage on the first node n1 becomes lower than its threshold voltage, the third terminal 10C of the generator 10 is opened with the base voltage line 11. The power converter 20 includes a first transistor Q1 connected between the third terminal 10C of the generator 10, the first and second nodes n1 and n2, and a third of the generator 10. The second transistor Q2 is connected between the terminal 10C, the second node n2, and the base voltage line 11. In addition, the power converter 20 includes a resistor R1 connected between the base terminal and the emitter terminal of the first transistor Q1, that is, the first and second nodes n1 and n2, and the second transistor Q2. Has a resistor (R2) connected between the base terminal and the emitter terminal, i.e., the second node (n2) and the base voltage line (11). On the other hand, at the first node n1, the voltage on the second terminal 10B of the generator 10 appears through the resistor R3. A resistor R4 and two capacitors C1 and C2 are connected in series between the third terminal 10C and the first node n1 of the generator 10. The resistor R4 and the capacitor C1 determine the on-off period of the power converter 20, and the capacitor C2 is used as a phase guarantee capacitor to prevent oscillation. The diode D1 connected between the second and third terminals 10B and 10C of the generator 10 prevents reverse electromotive force from flowing from the second terminal 10B toward the third terminal 10C.

The voltage control device 16 also includes a voltage detector 22 connected between the first and second terminals 10A and 10B, the first node n1 and the ground voltage line 11 of the generator 10. do. The voltage detector 22 switches the voltage on the first node n1 to the ground voltage source GND in response to the voltage on the first terminal 10A and / or the second terminal 10B of the generator 10. The voltage on the first terminal 10A and the second terminal 10B of (10) is kept constant. In detail, the voltage detector 22 bypasses the voltage on the first node n1 toward the base voltage line 11 when the voltage on the first terminal 10A of the generator 10 rises above a predetermined level. By doing so, the power converter 20 opens the current path between the third terminal 10C of the generator 10 and the ground voltage line 11. At this time, the generator 10 stops generating power and the voltages on the first and second terminals 10A and 10B drop. In contrast, when the voltage on the first terminal 10A of the generator 10 falls below the set voltage, the voltage detector 22 short-circuits the current path between the first node n1 and the base voltage line 11. The power converter 20 causes the current path between the third terminal 10C of the generator 10 and the ground voltage line 11 to be interrupted. In this case, since the generator 10 generates power, voltages on the first and second terminals 10B and 10C are increased. As such, the voltage detector 22 opens and closes the current path between the first node n1 and the base voltage line 11 in accordance with the voltage level on the first terminal 10A of the generator 10. The voltage of the phase is kept constant. In addition, the voltage detector 22 has a voltage level at which the voltage on the first terminal 10A of the generator 10 is constant so as to be suitable for the charging speed of the battery 12 and the response voltage of the electrical load 14 that vary with temperature. Change in range. That is, the voltage detector 22 has a temperature gradient characteristic of the voltage such that the voltage on the first terminal 10A of the generator 10 varies in a constant voltage level range according to the temperature.

In order to perform these functions, the voltage detector 22 may include a third transistor Q3 connected between the first and third nodes n1 and n3 and the base voltage line 11, a third node n3 and A fifth resistor R5 connected between the base voltage line 11, a sixth resistor R6 and a fourth connected in series between the second terminal 10B and the third node n3 of the generator 10; A transistor Q4, a seventh resistor R7, a zener diode ZD1, and an eighth resistor R8 are provided. In addition, the voltage detector 22 includes the ninth and tenth resistors R9 and R10 connected in series between the first terminal 10A of the generator 10 and the base voltage line 11, and the generator 10 of the generator 10. Eleventh and twelfth resistors R11 and R12 connected in series between the two terminals 10B and the base voltage line 11, and a fifth transistor Q5 connected in parallel with the fourth transistor Q4. Furthermore, the voltage detector 22 further includes a sixth transistor Q6 connected between the seventh resistor R7 and the third node n3. The ninth and tenth resistors R9 and R10 divide the voltage on the first terminal 10A of the generator 10 and divide the divided voltage Vn4 through the fourth node n4 to the fourth transistor Q4. It is supplied to the base terminal of. The voltage appearing on the fourth node n4 is expressed by Equation 1 below.

In Equation 1, Va is a voltage on the first terminal 10A of the generator 10. The third capacitor C3 connected in parallel with the tenth resistor R10 bypasses the noise of the high frequency component included in the divided voltage Vn4 on the fourth node n4 toward the base voltage line 11. The fourth transistor Q4 is turned on when the voltage Vn4 on the fourth node n4 becomes higher than the reference voltage Vref to turn on the sixth resistor R6 from the second terminal 10B of the generator 10. The third transistor Q3 is turned on by applying a voltage input via the third node n3. At this time, the power switch 20 is turned off and the generator 10 also stops generating power. As a result, the voltage on the first terminal 10A of the generator 10 drops. As the fourth transistor Q4 is switched according to the voltage Vn4 on the fourth node n4, the voltages on the first and second terminals 10A and 10B of the generator 10 are kept constant. However, when the connection between the first terminal 10A of the generator 10 and the ninth resistor R9 is opened or the fourth transistor Q4 is broken, the output voltage of the generator 10 continues to rise to the vehicle. There is a risk of damaging the electrical equipment of the product. When this situation occurs, the fifth transistor Q5 is used to adjust the output voltage of the generator 10 in response to the voltage Vb on the second terminal 10B of the generator 10. The eleventh and twelfth resistors R11 and R12 also divide the voltage on the second terminal 10B of the generator 10 and divide the divided voltage Vn5 through the fifth node n5 to the fifth transistor Q5. It is supplied to the base terminal of. The divided voltage Vn5 appearing on the fifth node n5 is expressed by Equation 2 below.

In Equation 2, Vb is the voltage on the second terminal 10B of the generator 10. The fifth transistor Q5 is turned on when the voltage Vn5 on the fifth node n5 is higher than the reference voltage Vref to turn on the sixth resistor R6 from the second terminal 10B of the generator 10. The third transistor Q3 is turned on by applying a voltage input via the third node n3. At this time, the power switch 20 is turned off and the generator 10 also stops generating power. As a result, the voltages on the first and second terminals 10A and 10B of the generator 10 fall. In addition, the voltage divider ratios of the eleventh and twelfth resistors R11 and R12 cause the fifth transistor Q4 to be turned on at a voltage level lower by a predetermined voltage than the voltage level at which the fourth transistor Q4 is turned on. Since it does not affect the detection operation of the fourth transistor (Q4). The fourth capacitor C4 connected in parallel with the twelfth resistor R12 bypasses the noise of the high frequency component included in the divided voltage Vn5 on the fifth node n5 toward the base voltage line 11.

The reference voltages Vref provided to the fourth and fifth transistors Q4 and Q5 are determined by Equation 3 below.

In Equation 3, "Vbe" is a potential difference between a base terminal and an emitter terminal when the third to sixth transistors Q3 to Q6 are turned on, that is, a threshold voltage, and "Vz" is a zener diode (ZD). ) Is the turn-on voltage. The reference voltage Vref set in this way has a temperature gradient characteristic that varies with temperature. This is because the threshold voltages of each of the zener diodes ZD and the third to sixth transistors Q3 to Q6 vary by a constant voltage depending on the temperature. The voltage change rate at which the reference voltage Vref changes with temperature may be expressed as shown in Equation 4.

In Equation 4, "∂Vd / ∂T", "∂Vbe / ∂T", and "∂Vz / ∂T" are constant values, and R9 / R10 are values for adjusting the output voltage of the generator 10. It is determined by the adjustment voltage to be set. "(∂Vbe / ∂T) · (R8 / R5)" is adjusted according to the value of the variable (R8 / R5) so that the reference voltage Vref is set to a temperature gradient characteristic desired by the user or the manufacturer. In other words, since the threshold voltage Vbe of the third transistor Q3 appears at both ends of the fifth resistor R5, the change caused by the temperature of the threshold voltage of the third transistor Q3 is changed from the fifth resistor R5. This is indicated by a change in current flowing through the eighth resistor R8 connected in series. This current change is represented by the difference between the voltages across the eighth resistor R8, and the voltage difference is determined according to the resistance ratios of the fifth and eighth resistors R5 and R8. Therefore, the overall system has a temperature gradient characteristic that varies by (∂Vbe / ∂T) · (R8 / R5) · (1 + R9 / R10) in accordance with the resistance ratios of the fifth and eighth resistors R5 and R8. Will have

On the other hand, in the conventional technology, since the elements of the input stage that set the adjustment voltage are all composed of constant voltage generators, the average current value generated at the input stage changes according to the load change of the generator 10 (the power converter 20). Although the output voltage of the generator 10 is hardly affected even when the switching period of the switch is changed, in the present invention, the amount of current passing through the eighth resistor R8 is changed so that the adjustment voltage is changed. In order to prevent this, the seventh resistor R7 and the sixth transistor Q6 are used. The sixth transistor Q6 senses the amount of current to flow through the eighth resistor R8 by the seventh resistor R7 so that a constant current flows in the eighth resistor R8 at all times. The change (increase) of the base current is passed through its base and the collector. As a result, a constant voltage always appears in the eighth resistor R8.

As described above, in the voltage control device of the generator according to an embodiment of the present invention, the output voltage of the generator is temporarily stopped by temporarily stopping the power generation of the generator so that the voltage output of the generator is constantly maintained. It has a gradient characteristic.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (5)

A generator for generating a voltage by the rotational force of the engine, Power switching means for switching the current path of the generator; Reference voltage generating means for generating a reference voltage; Comparison means having a first transistor for comparing an output voltage of the generator with a reference voltage; A switching control means having a second transistor for controlling a switching operation of the power switching means in accordance with a comparison result of the comparing means, The reference voltage generating means Generate the reference voltage including at least one constant voltage device connected between the first transistor and the second transistor, and a resistor voltage divider having a voltage divider point connected in series with the constant voltage device and connected to the second transistor; , The reference voltage has a temperature gradient characteristic that varies with temperature by changing the threshold voltages of the first and second transistors and the turn-on voltage of the constant voltage device according to temperature, and the temperature gradient characteristic of the resistor voltage divider. Voltage generator of a vehicle generator, characterized in that determined by the partial pressure ratio. The method of claim 1, And the at least one constant voltage device comprises at least one of a diode and a zener diode. A generator for generating a voltage at each of the first and second terminals by the rotational force of the engine, Power switching means for switching the current path of the generator; Reference voltage generating means for generating a reference voltage; Comparison means having first and second transistors for selectively comparing voltages on the first and second terminals of the generator with the reference voltage; A switching transistor for switching a third transistor for controlling the switching operation of said power switching means in accordance with a comparison result by said comparing means, The reference voltage generating means At least one constant voltage device connected between the common connection point of the first and second transistors and the third transistor, and a resistor voltage divider having a voltage divider point connected in series with the constant voltage device and connected to the third transistor; Generating the reference voltage, The reference voltage has a temperature gradient characteristic that varies according to temperature by changing one of the first and second transistors, the threshold voltage of the third transistor and the turn-on voltage of the constant voltage device according to temperature, The temperature gradient characteristic of the generator for a vehicle, characterized in that determined by the partial pressure ratio of the voltage divider. The method of claim 3, wherein And the at least one constant voltage element comprises at least one of a diode and a zener diode. The method of claim 3, wherein And the second transistor is responsive to a second terminal of the generator when the first transistor cannot respond to a voltage on the first terminal of the generator.