KR100859016B1 - Power folding mirror and operating circuits for the same - Google Patents

Abstract

An electric folding mirror and a circuit for operating the same are provided to prevent a motor from being damaged by shortening the time taken to operate a switch. A circuit(1) for operating an electric folding mirror comprises a first trigger signal unit(30) for generating a first trigger signal, a relay operating unit(40), a relay unit(45) regulated by the relay operating unit, a motor unit(50), a current detection unit(60), and a relay cutoff unit(70). The relay operation unit includes a first subsidiary unit including a first transistor(T1), a seventh resistor(R7), a third diode(D3), a second subsidiary unit including a second transistor(T2), an eighth resistor(R8), and a fourth diode(D4). The second subsidiary unit is biased by the first subsidiary unit and biases the first subsidiary unit. The current detection unit detects current applied to the motor. The relay cutoff unit cuts off operation of the relay unit if current exceeds a level of cutoff current.

Description

Power Folding Mirror and Operating Circuits

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power folding mirror and a driving circuit thereof, and more particularly, to a power folding mirror and a driving circuit which can prevent burnout of a motor and operate reliably.

In general, vehicle side mirrors are provided at predetermined portions of the left and right sides of the vehicle body, respectively. The driver may adjust the side mirrors at a predetermined angle to grasp the situation of the rear and left and right sides of the vehicle when the vehicle is driven.

However, there are times when the side mirror becomes an obstacle, such as when parking on a narrow street. In this case, when the side mirror becomes an obstacle, a power folding mirror has been developed that allows the driver to operate the switch in the driver's seat to fold the side mirror and re-open it during driving.

As a circuit for driving a power folding mirror, a circuit using a PTC (Positive Temperature Coefficient) element and a fold-back circuit using a resistor have been proposed. Here, the PTC element is an element whose resistance value increases as the temperature rises.

In the process of operating the motor to fold or unfold the power folding mirror, if the power folding mirror rotates to the stop position, the gears stop and the power folding mirror can no longer be rotated. The current continues to flow in the motor, but because the motor is forcibly stopped, the motor is overloaded and an overcurrent flows. This is called a stall current.

In a circuit using the PTC element, the PTC element has a high temperature due to heat generated by the stall current, and the impedance value is increased to block the flow of current. In other words, the circuit is cut off using the switch characteristic of the PTC element. On the other hand, in a fold-back circuit using a resistor to detect the stall current flowing through the resistor to cut off the circuit.

The circuit using the PTC element has a long time for increasing the impedance value of the PTC element to a value at which the current flowing through the PTC element is cut off, and thus has a long switching time. In addition, even when the current flowing through the PTC element is cut off, when the temperature of the PTC element drops due to the current interruption and the impedance value decreases, the current flows again to the PTC element. In other words, since the current is cut off and the conduction is repeated, the switching process is repeated. Since the circuit using the PTC element has a long switching time and repeats the switching process, the stall current flows repeatedly for a long time. Therefore, the motor may be burned out.

In the fold-back circuit using the resistor, the current driving the motor changes in proportion to the voltage value supplied to the power folding mirror driving circuit. Therefore, the voltage value for driving the fold-back circuit does not change in proportion to the voltage value supplied to the power folding mirror driving circuit, so that the fold-back circuit may malfunction.

Accordingly, an object of the present invention is to provide a power folding mirror driving circuit that prevents burnout of a motor and operates reliably.

Accordingly, an object of the present invention is to provide a power folding mirror that prevents burnout of a motor and operates reliably.

Problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to another aspect of the present invention, there is provided a power folding mirror driving circuit including a first trigger signal part for generating a first trigger signal, a first sub part triggered by the first trigger signal, and A motor driver including a relay driver including a second sub part biased by the triggered first sub part and biasing the first sub part, a relay part intermittent by the relay driver, and a motor driven by the relay part And a current detecting unit detecting a current flowing in the motor, and a relay blocking unit to block driving of the relay when the current is greater than or equal to the blocking current.

According to another aspect of the present invention, there is provided a power folding mirror comprising: a first trigger signal unit for generating a first trigger signal; a first sub unit triggered by the first trigger signal; And a second sub part biased by the triggered first sub part to bias the first sub part, a motor part including a motor driven by the biased first sub part, and a current flowing through the motor. A power folding mirror driving circuit including a current sensing unit configured to perform a current sensing unit, and a relay blocking unit to block relay driving when the current is greater than or equal to a breaking current, a motion transfer unit transferring a rotational movement of the relay driven motor, and the movement A mirror that is rotated by the delivery unit.

Specific details of other embodiments are included in the detailed description and the drawings.

According to the power folding mirror and the driving circuit thereof according to the present invention, the following effects are obtained.

First, since the switching speed is short, the burnout of the motor due to the stall current can be prevented. In other words, even if a stall current occurs in the motor, the circuit is cut off within a short time, thereby protecting the motor.

Second, even if the driver operates the switch again while the driver operates the switch to fold or unfold the power folding mirror, the power folding mirror driving circuit operates normally.

Third, since the voltage value for driving the circuit which blocks the relay drive changes proportionally with respect to the change in the voltage value input to the power folding mirror driving circuit, it is possible to reduce the malfunction of the power folding mirror driving circuit, thereby operating the power folding mirror. It can increase the reliability of.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the present embodiments merely make the disclosure of the present invention complete, and are common in the art to which the present invention pertains. It is provided to fully inform those skilled in the art of the scope of the invention, which is to be defined only by the scope of the claims. Like reference numerals refer to like elements throughout. "And / or" also includes each and all combinations of one or more of the items mentioned.

Although the first, second, etc. are used to describe various elements, components and / or sections, these elements, components and / or sections are of course not limited by these terms. These terms are only used to distinguish one element, component or section from another element, component or section. Therefore, the first element, the first component or the first section mentioned below may be a second element, a second component or a second section within the technical spirit of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and / or “comprising” refers to the presence of one or more other components, steps, operations and / or elements. Or does not exclude additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. In addition, the terms defined in the commonly used dictionaries are not ideally or excessively interpreted unless they are specifically defined clearly.

First, a power folding mirror according to an embodiment of the present invention will be described with reference to FIG. 1. 1 is a perspective view schematically showing the structure of a power folding mirror according to an embodiment of the present invention.

Referring to FIG. 1, the power folding mirror includes a mirror 9, a power folding mirror drive circuit including a motor M (see 1 in FIG. 2), a door bracket 7, a door hinge 2, and motion transfer. Section 3, 5; The motion transmission part 3, 5 here comprises a first gear 5 and a second gear 3.

The motor M is installed in the interior space of the mirror 9, and the 1st gear 5 is axially installed in the shaft end. The mirror bracket 2 is attached to the door bracket 7, and the second gear 3 is shaft-mounted at the shaft end thereof. Here, the first gear 5 and the second gear 3 are provided to mesh with each other.

When the motor M is rotated forward or reversely by the power folding mirror driving circuit, the mirror 9 is forward or reversed through the first gear 5 and the second gear 3 engaged with each other. It works. In other words, the mirror 9 performs the forward (folding) or reverse (unfolding) operation with the mirror hinge 2 as the central axis. Then, when the mirror 9 rotates to the stop positions P1 and P2 by performing the forward operation or the reverse operation, the gears are stopped so that the mirror 9 can no longer be rotated and the motor M is forcibly stopped.

Hereinafter, a power folding mirror driving circuit according to an embodiment of the present invention will be described with reference to FIG. 2. 2 is a circuit diagram illustrating a power folding mirror driving circuit according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the power folding mirror driving circuit 1 may include a power supply unit 10, an abnormal signal blocking unit 20, first and second trigger signal units 30 and 35, a relay driver 40, and a relay unit. 45, a motor unit 50, a current sensing unit 60, and a relay blocking unit 70.

The power supply unit 10 includes a first power supply terminal IN1 and a second power supply terminal IN2, and supplies power to the power folding mirror driving circuit 1. The power folding mirror driving circuit 1 may be supplied with a DC power supply, for example, a battery voltage Vb of an automobile. When the battery voltage Vb is applied to the first power supply terminal IN1 and the second power supply terminal IN2 is grounded, the motor M may operate in the forward direction. On the contrary, when the first power supply terminal IN1 is grounded and the battery voltage Vb is applied to the second power supply terminal IN2, the motor M may operate in the reverse direction.

The abnormal signal blocking unit 20 may include a varistor ZNR and / or a first capacitor C1. The abnormal signal blocking unit 20 blocks a surge signal and / or a noise signal introduced into the power folding mirror driving circuit 1 from the outside. Here, a surge signal refers to a transient signal that changes badly within a short time. Such a surge signal may occur in the process of turning on / off a switching circuit or interrupting an inductive load such as a relay.

The varistor ZNR protects a surge signal that may be generated externally and flow into the power folding driving circuit 1. Varistor (ZNR) is a two-terminal semiconductor device having a property that the resistance value is changed non-linearly by the voltage. The varistor ZNR has a very large resistance value up to the threshold voltage, and if it exceeds the threshold voltage, the varistor ZNR has a very small resistance value.

Therefore, when a surge signal flows into the power folding mirror driving circuit 1, the resistance value of the varistor ZNR becomes very small, so that a current flows toward the varistor ZNR, thereby absorbing the surge signal. Thus, elements such as transistors T1, T2, T3, T4, T5, and T6 in the power folding mirror driving circuit 1 can be protected from surge signals.

The first capacitor C1 blocks noise that may be generated from outside and flow into the power folding driving circuit 1. When an AC signal that is noise is applied to the first capacitor C1, the first capacitor C1 may act as a short circuit to the noise. Therefore, it is possible to absorb the noise and to prevent the noise from flowing into the power folding drive circuit 1.

The trigger signal unit 30 includes a second capacitor C2 and a first resistor R1. The trigger signal unit 30 applies a trigger signal to the relay driver 40 to cause an initial operation of the relay driver 40. In other words, the trigger signal unit 30 triggers the relay driver 40. The detailed configuration and role of the trigger signal section 30 will be described later with reference to the operation of the power folding mirror driving circuit 1.

The relay driver 40 may include a first sub part T1, R7 and D3, a second sub part T2, R8 and D4, a third sub part T3, R3, R5 and D1, and a fourth sub part ( T4, R4, R6, D2). The relay drive unit 40 intercepts the relay unit 45. In other words, the on / off of the relay unit 45 is controlled.

The first sub parts T1, R7, and D3 include a first transistor T1, a seventh resistor R7, and a third diode D3. Cathodes of the eleventh resistor R11, the seventh resistor R7, and the third diode D3 are respectively connected to the emitter, the base, and the collector of the first transistor T1.

The second sub units T2, R8, and D4 include a second transistor T2, an eighth resistor R8, and a fourth diode D4. An anode of the eleventh resistor R11, the eighth resistor R8, and the fourth diode D4 is connected to the emitter, the base, and the collector of the second transistor T2, respectively.

The third sub part T3, R3, R5, and D1 includes a third transistor T3, a third resistor R3, a fifth resistor R5, and a first diode D1. The first power supply terminal IN1, the third resistor R3, and the fifth resistor R5 are respectively connected to the emitter, the base, and the collector of the third transistor T3, and the fifth resistor R5 is connected to the first power terminal IN1, the third resistor R5, and the fifth resistor R5. The anode of one diode D1 is connected.

The fourth sub part T4, R4, R6, and D2 includes a fourth transistor T4, a fourth resistor R4, a sixth resistor R6, and a second diode D2. The first power supply terminal IN1, the fourth resistor R4, and the sixth resistor R6 are respectively connected to the emitter, the base, and the collector of the fourth transistor T4, and the sixth resistor R6 is connected to the first power terminal IN1, the fourth resistor R4, and the sixth resistor R6. The cathode of two diodes D2 is connected.

In the relay driver 40, the first sub-parts T1, R7, D3 and the third sub-parts T3, R3, R5, D1 operate in forward operation. The second sub units T2, R8, and D4 and the fourth sub units T4, R4, R6, and D2 operate in the reverse operation.

Here, the first to fourth transistors T1 to T4 may be BJTs, the first and fourth transistors T1 and T4 are npn transistors, and the second and third transistors T2 and T3 are pnp transistors. Can be.

The first and second diodes D1 and D2 control the direction in which current flows in the power folding mirror driving circuit 1. That is, the flow of current that may leak to the second sub-parts T2, R8 and D4 and the fourth sub-parts T4, R4, R6 and D2 in the forward operation is suppressed, and the first sub in the reverse operation. The flow of current that may leak to the sections T1, R7, and D3 and the third sub sections T3, R3, R5, and D1 is suppressed.

The third and fourth diodes D3 and D4 allow the power folding mirror driving circuit 1 including the first and second zener diodes Z1 and Z2 to operate normally. Specifically, if there is no fourth diode D4 in the forward operation, the second zener diode Z2 is conductive. Therefore, the first transistor T1 does not operate, and the power folding mirror driving circuit 1 does not operate normally. Similarly, if there is no third diode D3 in the reverse operation, the first zener diode Z1 becomes conductive. Therefore, the second transistor T2 does not operate, and the power folding mirror driving circuit 1 does not operate normally.

In addition, the seventh resistor R7, the eighth resistor R8, the third resistor R3, and the fourth resistor R4 are the first transistor T1, the second transistor T2, and the third transistor ( T3) and the current flowing through the base of the fourth transistor T4 is limited. Meanwhile, the third resistor R3 and the fourth resistor R4 may also serve to block a surge voltage generated from the relay coil Rc. The surge voltage generated in the relay coil Rc will be described later.

Meanwhile, the relay driver 40 may further include first and second zener diodes Z1 and Z2. The first and second zener diodes Z1 and Z2 are connected in parallel to the first and second transistors T1 and T2, respectively.

When the relay unit 45 is interrupted, a sudden current change occurring in the relay coil Rc induces a surge voltage in the relay coil Rc. When the surge voltage is equal to or higher than the breakdown voltage (for example, 40 V) of the first and second zener diodes Z1 and Z2, the first and second zener diodes Z1 and Z2 are turned on. Thereafter, the first and second zener diodes Z1 and Z2 maintain the breakdown voltage, thereby keeping the voltages applied to the first and second transistors T1 and T2 below the breakdown voltage. Therefore, the first and second transistors T1 and T2 can be protected from the surge voltage.

The detailed configuration and role of the other relay driver 40 will be described later with reference to the operation of the power folding mirror driving circuit 1.

The relay unit 45 includes a relay coil Rc and a relay contact Ry. The relay unit 45 drives the motor M so that the motor M operates in the forward or reverse direction.

Referring to the operation, when a current flows through the relay coil Rc by the relay driver 40, a voltage is induced in the relay coil Rc. As a result, when the relay driving voltage is secured to the relay coil Rc, the relay contact Ry may be closed to supply power to the motor M. FIG. In FIG. 2, the switch SW connected to the relay contact Ry in a dotted line is for explaining that the relay contact Ry is switched to the relay coil Rc by being closed or opened.

The motor unit 50 includes a motor M and a fourth capacitor C4. The motor is a DC motor, and the fourth capacitor C4 is an example of an electromagnetic interference (EMI) reduction circuit, and reduces electromagnetic waves, that is, noise generated from the motor. The principle is the same as the principle in which the first capacitor C1 described above operates.

The current sensing unit 60 includes an eleventh resistor R11. When the motor is forcibly stopped, the current detector 60 detects a stall current flowing through the eleventh resistor R11. The detailed configuration and role of the current sensing unit 60 will be described later with reference to the operation of the power folding mirror driving circuit 1.

The relay blocking unit 70 includes a fifth transistor T5, a sixth transistor T6, a tenth resistor R10, a fifth capacitor C5, and an eleventh resistor R11. When the stall current flows, the relay cutoff unit 70 cuts off the power supplied to the motor, thereby preventing motor burnout by the stall current.

An eleventh resistor R11, a fifth capacitor C5, and a first trigger node Vt are connected to the emitter, the base, and the collector of the fifth transistor T5, respectively. An eleventh resistor R11, a fifth capacitor C5, and a second trigger node Vt ′ are respectively connected to the emitter, the base, and the collector of the sixth transistor T6. The base and emitter of the fifth and sixth transistors T5 and T6 are connected to each other, and the fifth capacitor C5 is connected between the base and emitter of the fifth and sixth transistors T5 and T6. The detailed configuration and role of the relay interrupting unit 70 will be described later with reference to the operation of the power folding mirror driving circuit 1.

Hereinafter, the operation of the power folding mirror driving circuit in the forward operation mode will be described with reference to FIGS. 2 and 3A to 3E. 3A to 3C are diagrams for describing an operation of a circuit in a normal operation mode and in a situation where a motor is normally driven. 3D and 3E are diagrams for explaining the operation of the circuit in the forward operation mode and the motor is forcibly stopped.

First, referring to FIG. 3A, when the battery voltage Vb is applied to the first power supply terminal IN1, the second capacitor C2 of the first trigger signal part 30 is momentarily short-circuited, and thus, the first trigger node. The battery voltage Vb is applied to Vt. The battery voltage Vb is applied to the base of the first transistor T1 to trigger the first transistor T1.

Thus, when the first transistor T1 operates, the first power supply terminal IN1, the relay coil Rc, the third diode D3, the first transistor T1, the eleventh resistor R11, and the second A closed loop including the power supply terminal IN2 is formed. Therefore, a momentary current flows in the relay coil Rc, voltage is induced in the relay coil Rc, the third transistor T3 is biased, and the third transistor T3 is operated.

Subsequently, referring to FIG. 3B, when the third transistor T3 operates, the first power supply terminal IN1, the third transistor T3, the fifth resistor R5, the first diode D1, and the first resistor A closed loop including R1 and a second power supply terminal IN2 is formed. As a result, the battery voltage Vb of the first power supply terminal IN1 is divided by the fifth resistor R5 and the first resistor R1 and applied to the first trigger node Vt.

The voltage applied to the first trigger node Vt is applied to the base of the first transistor T1 so that the first transistor T1 is continuously biased. Therefore, a closed loop including the first power supply terminal IN1, the relay coil Rc, the third diode D3, the first transistor T1, the eleventh resistor R11, and the second power supply terminal IN2. Is formed, and current may continuously flow through the relay coil Rc.

Subsequently, referring to FIG. 3C, a current continuously flows through the relay coil Rc, thereby securing a relay driving voltage in the relay coil Rc. Then, the relay contact Ry is closed to the relay coil Rc and the relay switch SW is closed. As a result, a closed loop including the first power supply terminal IN1, the motor M, the relay switch SW, the ninth resistor R9, and the second power supply terminal IN2 is formed. Therefore, power is supplied to the motor M, so that the motor rotates in the forward direction.

Next, referring to FIG. 3D, when the motor M is forcibly stopped, the stall current flows. Stall current flows through the ninth resistor R9, so that a voltage is generated across the ninth resistor R9, and the tenth resistor R10, the fifth capacitor C5, the eleventh resistor R11, and the second power source. The fifth capacitor C5 is charged by the closed loop including the terminal IN2.

When the fifth capacitor C5 is charged and the voltage applied to the blocking node Vp becomes equal to or higher than the driving voltage of the fifth transistor T5, the fifth transistor T5 is biased to operate the fifth transistor T5. do. When the fifth transistor T5 is operated, a bypass path formed of the first trigger node Vt, the fifth transistor T5, the eleventh resistor R11, and the second power supply terminal IN2 is formed. Is formed. As a result, the first trigger node Vt is grounded.

Here, the fifth transistor T5 corresponds to the product (time constant) of the capacitance of the fifth capacitor C5 plus the value of the resistance of the tenth resistor R10 and the resistance of the eleventh resistor R11. Delayed operation For example, if the time constant is 400 ms, the fifth transistor T5 operates after power is supplied to the motor M for approximately 400 ms.

The above time delay has the following effects. Although the mirror (see 9 in FIG. 1) does not rotate to the stop position (see P1 and P2 in FIG. 1), a situation may occur in which the mirror fails to rotate and the power supplied to the motor M is cut off. For example, foreign matter caught in the power folding mirror may prevent the mirror from rotating. In such a situation, the mirror may rotate by supplying power to the motor M for a time corresponding to the time constant.

Subsequently, referring to FIG. 3E, when the first trigger node Vt is grounded, the first transistor T1 is unbiased. As a result, the relay driving voltage secured to the relay coil Rc disappears, the relay coil Rc and the relay contact Ry open, and the relay switch SW opens. Therefore, the power supply to the motor M is stopped, and the stall current no longer flows to the motor M. FIG.

Hereinafter, the operation of the power folding mirror driving circuit in the reverse operation mode will be described with reference to FIGS. 2 and 4A to 4E. 4A to 4C are diagrams for describing an operation of a circuit in a reverse operating mode and in a situation where a motor is normally driven. 4D and 4E are diagrams for describing an operation of a circuit in a reverse operating mode and in a situation where a motor is forcibly stopped. Here, the operation principle is the same as the operation principle of the power folding mirror driving circuit in the forward operation mode, detailed description thereof will be omitted.

First, referring to FIG. 4A, the battery voltage Vb is applied to the second power supply terminal IN2, and the first power supply terminal IN1 is grounded. At this time, the third capacitor C3 is momentarily shorted to trigger the second transistor T2. As a result, voltage is induced to the relay coil Rc in an instant, and the fourth transistor T4 is biased.

4B, when the fourth transistor T4 operates, the battery voltage Vb of the second power supply terminal IN2 is divided by the second resistor R2 and the sixth resistor R6. It is applied to the second trigger node Vt '. This voltage continuously biases the second transistor T2 so that a current can continuously flow through the relay coil Rc.

Subsequently, referring to FIG. 4C, when a current continuously flows through the relay coil Rc and the relay driving voltage is secured, power is supplied to the motor M, and the motor rotates in the reverse direction.

Subsequently, referring to FIG. 4D, when the motor M is forcibly stopped, the stall current flows through the ninth resistor R9 so that a voltage is generated across the ninth resistor R9 and the fifth capacitor C5 Is charged. When the voltage applied to the blocking node Vp becomes equal to or higher than the driving voltage of the sixth transistor T6, the sixth transistor T6 is operated. When the sixth transistor T6 is operated, a bypass path is formed so that the second trigger node Vt 'has a battery voltage Vb.

Subsequently, referring to FIG. 4E, when the second trigger node Vt 'has the battery voltage Vb, the second transistor T2 is unbiased. As a result, the relay driving voltage secured to the relay coil Rc disappears, and the relay switch SW opens. Therefore, the power supply to the motor M is stopped, and the stall current no longer flows to the motor M. FIG.

According to the above-described power folding mirror and its driving circuit, the switching speed is relatively short, so that the burnout of the motor due to the stall current can be prevented. In other words, even if a stall current occurs in the motor, the circuit is cut off within a short time, thereby protecting the motor.

Further, even when the driver operates the switch again while the driver operates the switch to fold or unfold the power folding mirror, the power folding mirror driving circuit may operate normally.

In addition, the malfunction of the power folding mirror driving circuit 1 can be reduced, and the reliability of the operation of the mirror (see 9 in FIG. 1) can be improved. This will be described in detail below.

In a situation where the motor is normally driven, the voltage value applied to the first power supply terminal IN1 may vary. As the voltage value increases, the current flowing through the motor M also increases, and the voltage applied to the ninth resistor R9 also increases. Therefore, the voltage applied to the fifth capacitor C5, that is, the voltage biasing the fifth transistor T5 may increase.

In this way, the voltage applied to the fifth capacitor C5 is increased, so that the fifth transistor T5 may be driven even though the motor M is normally driven. In particular, at a high temperature, the voltage capable of biasing the fifth transistor T5 is lowered. As a result, in spite of the situation in which the motor M should be driven normally, the relay driving is interrupted, and the motor M can be stopped.

However, according to the above-described power folding mirror and its driving circuit, the above-described malfunction can be reduced for the following reason.

In a situation where the motor M is normally driven, a closed circuit including a first power supply terminal IN1, a relay coil Rc, a third diode D3, a first transistor T1, and an eleventh resistor R11. A loop is formed. When the voltage is applied to the eleventh resistor R11 in the closed loop, the voltage increases proportionally when the voltage value applied to the first power supply terminal IN1 increases.

Therefore, even if the voltage applied to the first power supply terminal IN1 is increased and the voltage applied to the ninth resistor R9 is increased, the voltage applied to the ninth resistor R9 is applied to the eleventh resistor R11. The voltage dropped by the voltage applied to the fifth capacitor C5 is applied. Here, the voltage applied to the eleventh resistor R11 increases proportionally as the voltage value applied to the first power supply terminal IN1 increases. Accordingly, the voltage applied to the fifth capacitor C5, that is, the voltage biasing the fifth transistor T5 may be smaller than the driving voltage of the fifth transistor T5.

As described above, a voltage value biasing the fifth transistor T5, that is, a voltage value driving the relay blocking unit 70, changes proportionally with respect to a change in the voltage value input to the power folding mirror driving circuit 1. . As a result, the malfunction of the power folding mirror driving circuit 1 can be reduced, and the reliability of the operation of the mirror (see 9 in FIG. 1) can be improved.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

1 is a perspective view schematically showing the structure of a power folding mirror according to an embodiment of the present invention.

2 is a circuit diagram illustrating a power folding mirror driving circuit according to an exemplary embodiment of the present invention.

3A to 3C are diagrams for describing an operation of a circuit in a normal operation mode and in a situation where a motor is normally driven.

3D and 3E are diagrams for explaining the operation of the circuit in the forward operation mode and the motor is forcibly stopped.

4A to 4C are diagrams for describing an operation of a circuit in a reverse operating mode and in a situation where a motor is normally driven.

4D and 4E are diagrams for describing an operation of a circuit in a reverse operating mode and in a situation where a motor is forcibly stopped.

(Description of the main parts of the drawing)

10: power supply unit 20: abnormal signal blocking unit

30: first trigger signal portion 35: second trigger signal portion

40: relay drive unit 45: relay unit

50: motor unit 60: current sensing unit

70: current interruption

Claims (13)

A first trigger signal unit for generating a first trigger signal; A relay driver including a first sub-part triggered by the first trigger signal and a second sub-part biased by the triggered first sub-part to bias the first sub-part; A relay unit intermittent by the relay driving unit; A motor unit including a motor relayed by the relay unit; A current sensing unit sensing a current flowing in the motor; And And a relay blocking unit to block the relay drive when the current is greater than or equal to the blocking current. According to claim 1, The power folding mirror driving circuit further includes a power supply unit for supplying DC power, including a first power supply terminal and a second power supply terminal, And the first trigger signal unit includes a first capacitor and a first resistor connected between the first power terminal and the second power terminal. According to claim 1, The relay driver may include a second trigger signal unit generating a second trigger signal; And a third sub portion triggered by the second trigger signal, and a fourth sub portion biased by the triggered third sub portion to bias the third sub portion. The method of claim 3, wherein The power folding mirror driving circuit further includes a power supply unit for supplying DC power, including a first power supply terminal and a second power supply terminal, The first sub-unit includes a first transistor and a first resistor, wherein the emitter, base, and collector of the first transistor are connected to the second power supply terminal, the first resistor, and the relay unit, respectively. The second sub-unit includes a second transistor, a second resistor, and a third resistor, wherein the emitter, the base, and the collector of the second transistor are respectively the first power supply terminal, the second resistor, and the second resistor. 3 resistors are connected, The third sub-unit includes a third transistor and a fourth resistor, and the emitter, the base, and the collector of the third transistor are connected to the second power supply terminal, the fourth resistor, and the relay unit, respectively. The fourth sub-unit includes a fourth transistor, a fifth resistor, and a sixth resistor, and the emitter, the base, and the collector of the fourth transistor include the first power terminal, the fifth resistor, and the fifth resistor, respectively. 6 Power folding mirror drive circuit to which resistors are connected. The method of claim 4, wherein And the first and fourth transistors are npn transistors, and the second and third transistors are pnp transistors. The method of claim 4, wherein The first sub unit further includes a first diode having a cathode connected to the collector of the first transistor, And the second sub unit further comprises a second diode having an anode connected to the collector of the second transistor. The method of claim 4, wherein The relay driver further includes first and second zener diodes connected in parallel to the first and third transistors, respectively. The third sub unit further includes a third diode having an anode connected to the collector of the third transistor, And the fourth sub-part further comprises a fourth diode having a cathode connected to the collector of the fourth transistor. According to claim 1, And a current resistor connected to the motor and including a first resistor through which a current flowing in the motor flows. According to claim 1, And the relay blocking unit includes a fifth transistor biased when the current becomes greater than or equal to the blocking current to unbias the first sub-unit. The method of claim 9, The relay driver may include a second trigger signal unit generating a second trigger signal; And a third sub portion triggered by the second trigger signal, and a fourth sub portion biased by the triggered third sub portion to bias the third sub portion, And the relay blocking unit further includes a sixth transistor biased when the current becomes greater than or equal to the blocking current to unbias the third sub unit. The method of claim 10, The power folding mirror driving circuit further includes a power supply unit for supplying DC power, including a first power supply terminal and a second power supply terminal, The relay blocking unit further includes a first resistor and a first capacitor connected in parallel with the current sensing unit, An emitter, a base, and a collector of the fifth transistor are connected to a node biasing the second power supply terminal, the first capacitor, and the first sub-part, respectively, An emitter, a base, and a collector of the sixth transistor are respectively connected to a node biasing the second power terminal, the fourth capacitor, and the third sub-part, And a base and an emitter of the fifth and sixth transistors are connected to each other, and the first capacitor is connected between the base and the emitter of the fifth and sixth transistors. The method of claim 11, wherein The relay blocking unit further includes a second resistor connected between the emitters of the fifth and sixth transistors, the node to which the fifth capacitor is connected, and the second power supply terminal. A first trigger signal part generating a first trigger signal, a first sub part triggered by the first trigger signal, and a first sub part triggered by the triggered first sub part to bias the first sub part; A motor unit including a second sub-unit, a motor driven by the biased first sub-unit, a current sensing unit sensing a current flowing through the motor, and blocking the relay drive when the current exceeds a breaking current A power folding mirror driving circuit including a relay blocking unit; A motion transmission unit for transmitting a rotational motion of the relay driven motor; And And a mirror that rotates by the motion transfer unit.

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