JPH08207663A - Electric retractable mirror control device - Google Patents

Abstract

(57) [Abstract] [Purpose] The control device for the drive motor that tilts the electric retractable mirror has been improved so that when the rotation of the drive motor is blocked by an external cause, the motor is automatically de-energized. The electric circuit having the function of preventing motor burnout due to lock current is made non-contact. [Configuration] FE is provided between the power input terminal 1 and the DC motor M.
FET (T2) is connected between the power input terminal 2 and the DC motor M, and T (T1)
The means for turning on each of the FETs (for example, the gate resistors R3 and R4) and the above-mentioned 2 by detecting an excessive current.
Means for turning off the respective FETs (for example, the transistors T3 and T4, and the overcurrent detection resistor R3.
R4) is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is, for example, in a door mirror of an automobile, rotated from a normal posture in which the mirror protrudes to the side of the vehicle body (a posture which functions as a door mirror) to a storage posture which is substantially parallel to the side surface of the vehicle body. The present invention relates to a device for controlling a drive motor for causing the drive motor to rotate or to rotate so as to return to the normal posture again.

[0002]

2. Description of the Related Art Generally, an electric retractable mirror of this type uses a DC motor as a drive source, is rotated by energization, is stopped by stopping the current, and is rotated in the opposite direction. Let However, in the present invention, the forward rotation direction of the motor is a direction arbitrarily determined for convenience, and rotation in the opposite direction is called reverse rotation. That is, the forward rotation does not always mean rotation in the normal direction, and the reverse rotation does not mean "rotation in the abnormal direction". In this type of electric retractable mirror, when the mirror is rotated from the normal posture to the retracted posture or returned from the retracted posture to the normal posture, the mirror reaches the pivot stroke end and the stopper acts. When you have to turn off the power. The reason for this is that if the power supply is continued, an overload current will flow through the motor, causing a problem such as burnout. When this electric retractable mirror was developed,
Generally, an electric brush that moves with the rotation of the mirror,
The energization control (the cutoff of the motor current at the end of the rotation stroke) is performed by using a switch pattern that is brought into contact with the electric brush to make it conductive (for example, the actual fair 5-445).
Issue). However, if the mechanically sliding contact structure as described above is provided, the entire electric retractable mirror device becomes large in size and weight, and the sliding contact portion is abraded or the conductive failure is caused by stain. In addition, there is a problem that the motor is not energized even if the rotation of the mirror is blocked for some reason during the rotation stroke, and there is a risk of burning. In order to eliminate such problems,
When an excessive current flows through the motor, a technique has been proposed in which the excessive current is immediately detected so as to prevent the burnout and the relay is actuated to interrupt the energization of the motor (for example, Japanese Utility Model Laid-Open No. 4-76196). Switch circuit in drive device).

[0003]

The above-mentioned known device "switch circuit in a driving device" has an excellent effect in that troubles related to the slide switch pattern are completely prevented. However, since a mechanically actuated relay is used, there is a risk of trouble such as wear of the relay contact over time and incomplete contact conduction. The present invention has been made in view of the above circumstances, and when the rotation of the electric retractable mirror is blocked, the drive motor is automatically de-energized regardless of whether it is at the stroke end or not. It is an object of the present invention to provide a control device having a complete contactless structure that can be manufactured.

[0004]

In order to achieve the above object (complete contactlessness), the structure of the control device for the electric retractable mirror according to the present invention is a DC motor in which the rotating direction is reversed when the energizing directions are reversed. And a pair of power supply input terminals whose positive and negative applied voltages are reversed by a manual operation, and an excessive current generated when the rotation of the DC motor is locked, and the energization of the DC motor is cut off. In a control device for an electric retractable mirror including an electric circuit, one each is provided between the DC motor and each of a pair of power input terminals,
Two FETs in total are connected, and the above two FEs are connected.
Each of the Ts is connected so that the source faces the power input terminal side and the drain faces the DC motor side, and when a voltage is applied to the pair of power input terminals, the positive and negative polarities are set. Accordingly, a means for applying an ON voltage to only one specific FET of the two FETs is provided, and when the rotation of the DC motor is blocked and an excessive current flows, the specific one FET is turned off. It is characterized in that means for applying a voltage is provided. The two FETs may use members having the same specifications, and there is no essential difference between them. Therefore, one specific FE
Regarding T, the ON-voltage applying means may be provided in any one of the two FETs. However, an off-voltage applying means must be provided for the FET (FET that applies the on-voltage). That is, in the present invention, the "specific one FET" may be any arbitrary one, but the specific FET should not be changed in the entire circuit configuration. It should be noted that one of the two FETs has a specific F
When ET is set to apply the on-voltage and the off-voltage, it is not necessary to provide the other FET with the on-voltage applying means and the off-voltage applying means, but unnecessary on-voltage applying means and unnecessary off-voltage applying means Even with the provision, it is not possible to escape from the technical scope of the present invention.

[0005]

According to the above construction, the two FETs are symmetrically interposed between the motor for driving the electric retractable mirror and each of the pair of power supply input terminals. Therefore,
When positive and negative voltages are switched and applied to the pair of power supply input terminals, either one of the two FETs becomes in charge of controlling the energization depending on the positive and negative polarities, The other FET is in a state in which the passage of current is allowed uncontrolled. Therefore, the FET positioned in the above control state is named a specific FET, and when an ON voltage is applied to the FET, the motor is energized and the mirror is rotated. When the energization flow rate of the motor is detected and an off voltage is applied to the specific FET when it exceeds a predetermined value, the energization of the motor is cut off and the rotation of the mirror is stopped. This eliminates the possibility that the motor will be burned due to overcurrent. However, the motor of the electric retractable mirror is switched between positive and negative polarities of voltage application so that the mirror is reciprocally rotated between the energized posture and the retracted posture. That is, the polarities of the pair of power input terminals are inverted between positive and negative depending on the driver's operation. When the positive and negative of the power input terminal are inverted, the specific FET of the two FETs is replaced. From this point of view, the circuit configuration of the present invention is provided with two FETs because it is provided with a control FET for forward rotation of the DC motor and a control FET for reverse rotation. The rotation control FET is provided with a forward rotation on-voltage application means and a forward rotation off-voltage application means, and the reverse control FET is provided with a reverse rotation on-voltage application means and a reverse rotation off-voltage application means. As a result, when an excessive current flows through the motor both during forward rotation and during reverse rotation, the motor can be operated instantaneously and the power supply to the motor can be cut off before burning. Moreover, as is clear from the above-mentioned configuration, the contact is completely non-contact, so that the trouble caused by the mechanical contact can be prevented before and completely. Moreover, the control device is compact and lightweight, and there is no risk of poor conduction due to contact contamination, which is excellent in durability and reliability.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, referring to FIGS.
An embodiment of the present invention will be described. FIG. 1 is a wiring diagram of a control circuit in an embodiment of a control device for an electric retractable mirror according to the present invention. Reference numeral M in the drawing denotes a driving DC motor, which is positively or negatively rotated depending on whether the voltage applied to its input terminal is positive or negative, and causes the mirror to reciprocally tilt between the normal posture and the retracted posture. Reference numerals 1 and 2 are a pair of power input terminals, and the voltage of the battery (not shown) is positive,
Negative switching is applied. The structure of this embodiment will be described below, and the functions required for the apparatus of this embodiment will be described before the operation is further described. a. When a voltage with a certain polarity is applied between the power supply input terminals 1 and 2, it is conducted to the DC motor M, and the DC motor M rotates. b. When the rotation of the DC motor M is externally blocked, the conduction is cut off. c. When a voltage having a polarity opposite to that in the item a is applied between the power supply input terminals 1 and 2, the DC motor M reverses as compared with the case a. d. When the reverse rotation of the DC motor M is externally blocked, the DC motor during the reverse rotation is de-energized. In order to perform the on / off control as in the above a to d, the motor drive FET (T1) is connected between the terminal m ₁ of the DC motor M and the power input terminal, and the terminal m ₂ and the power input are also connected. Motor drive FE between terminal 2
T (T2) is connected. Both of the motor drive FETs (T1, T2) are connected so that the source S faces the power input terminal and the drain D faces the DC motor M. Since the FETs are connected as described above, for example, a positive potential is applied to the power input terminal 1 and a negative potential is applied to the power input terminal 2.
When applied respectively, motor drive FET (T1)
Conducts the energization control action, but the motor drive FET (T
2) allows energization without control. When the polarities of the power input terminals 1 and 2 are switched, the above two FETs (T1, T2)
The roles and roles of are exchanged. As described above, the power source input terminal 1 to the source S of the motor drive FET (T1) S to the drain D thereof to the DC motor M to the motor drive FE.
Drain D of T (T2) -Same source S-Power input terminal 2
The main path is the current path, but the above two FETs
A circuit configuration for turning on / off (T1, T2) is attached to or inserted in the main energizing path.

Since the circuit configuration of FIG. 1 is vertically symmetrical with the capacitor C1 sandwiched between them, the upper half will be mainly described in detail and the corresponding lower half configuration will be additionally described. The motor drive FET (T1 In order to turn on the FET (T1) by setting the gate G of (1) to a negative potential than the source S, a gate resistor R5 is connected between the power input terminal 1 and the gate G, and the bipolar electrolytic capacitors C1 and the gate are connected. It is connected to the power supply input terminal 2 via the resistor R6. A PNP transistor T3 is provided to turn off the FET (T1) by short-circuiting the gate resistor R5 so that the gate G and the source S of the motor drive FET (T1) have the same potential, and the emitter of the transistor T3 is provided. E is connected to the source S of the FET (T1), and the collector C of the transistor T3 is connected to the gate G of the FET (T1). Similarly, PNP transistor T
4 is also connected. R1 and R2 are transistors T3
Base resistors R3 and R4 of T4 are overcurrent detection resistors for detecting an overcurrent and turning on the PNP transistors T3 and T4.

The mirror storing operation and the mirror returning operation will be described separately. For convenience of explanation, the terminal m of the DC motor M
_It is assumed that when a positive potential is applied to ₁ and a zero potential (GND) is applied to the terminal m ₂ , the DC motor M is normally rotated to store the mirror. On the contrary, when a potential is applied, the DC motor M rotates in the reverse direction and the mirror is restored. [Retracting operation] When the operator operates the operation switch (not shown) to "retract" in the driver's seat, a positive 12 volts is applied to the power input terminal 1 and a zero voltage is applied to the power input terminal 2. As a result, a charging current flows to the bipolar electrolytic capacitor C1 via the gate resistors R5 and R6. The time constants of the resistor / capacitor are set to be sufficiently larger than the storage operation required time and the return operation required time of the electric storage mirror. As a result, a current flows through the gate resistor R5 from the upper side to the lower side in the figure, and the motor drive FET
The gate G of (T1) has a lower potential than the source S, and the motor drive FET (T1) is turned on. The motor drive FET (T2) remains in the off state, but does not block the energization in the direction from the terminal m ₂ of the DC motor M to the power supply input terminal 2. As a result, the power input terminal 1 → motor drive FET (T1) → overcurrent detection resistor R3 → DC motor M → overcurrent detection resistor R4 → motor drive FE
A path of T (T2) → power input terminal 2 is energized in the direction of the arrow to rotate the DC motor M in the normal direction, and the storing operation is performed.

When the storage rotation of the mirror reaches the stroke end, or when the storage rotation of the mirror is blocked for some reason, an overcurrent called a lock current flows through the DC motor M. This causes a large voltage drop in the overcurrent detection resistor R3. Due to the above voltage drop,
The potential of the base B of the PNP transistor T3 is the emitter E
Of the PNP transistor T3 and the PNP transistor T3 is turned on. When the PNP transistor T3 is turned on, the gate resistor R5 is short-circuited and the motor drive FET (T
In 1), the electric potential of the gate G becomes equal to the electric potential of the source S, the motor drive FET (T1) is turned off, and the direct current motor M is cut off from the energization path and stopped. In this way, the overcurrent of the DC motor m is immediately detected, and the power supply is cut off before the time until the burnout elapses, so that the risk of burnout is eliminated.

[Return Operation] The return operation is performed by the motor drive FET (T2) performing the same action as the motor drive FET (T1) in the above-described storing operation. That is, when plus 12 volts is applied to the power input terminal 2 and zero volt is applied to the power input terminal 2, the voltage drop of the gate resistor R6 is given to the gate G and the source S of the motor drive FET (T2) to cause the motor Drive FE
T (T2) is turned on, the DC motor M is energized, the DC motor M is rotated in the reverse direction, and the mirror is rotated to return. When the return rotation reaches the stroke end or is blocked for some reason and an overcurrent is generated, the voltage drop of the overcurrent detection resistor R4 increases and the PNP transistor T4.
4 is turned on, the gate resistor R6 is short-circuited, the motor drive FET (T2) is turned off, the energization of the DC motor M is blocked, and burnout is prevented. FIG. 2 is an electrical wiring diagram showing an embodiment different from the embodiment shown in FIG. The difference from the embodiment of FIG. Motor drive FET (T5) and T6
An n-channel type FET was used as. and,
B. NPN is used as the transistors T7 and T8 for giving the off voltage to the motor drive FETs (T5 and T6).
Type transistor was used. The operation of the embodiment of FIG. 2 operates vertically symmetrically as compared with the case of FIG. 1 described above.

[Storing operation] Power source input terminal 1 plus 12
When zero volt is applied to the power input terminal 2 and the bipolar electrolytic capacitor C1 is charged, the gate resistors R5 and R6 act as voltage dividing resistors, and the voltage generated by the gate resistor R6. The drop is given to the motor drive FET (T6), its gate G becomes higher potential than the source S, and the motor drive FET (T6)
6) turns on. When the motor drive FET (T6) is turned on, the current input terminal 1 → motor drive FET (T
5) → Overcurrent detection resistor R3 → DC motor M → Overcurrent detection resistor R4 → Motor drive FET (T6) → Power input terminal 2 The operation is performed. DC motor M
When the forward rotation of the NPN transistor T8 is blocked by an external force, an excessive lock current flows, causing a large voltage drop across the overcurrent detection resistor R4.
The potential becomes higher than that and the transistor T8 is turned on.

Thus, the motor drive FET (T
Since the gate resistor R6 of 6) is short-circuited and the gate G of the motor drive FET (T6) is at the same potential as the source S, the motor drive FET (T6) is turned off and the DC motor M due to excessive current flows. Burnout is prevented. The returning operation also acts vertically symmetrically as compared with the case of FIG.

[Restoration operation] Power source input terminal 2 plus 12
If zero volt is applied to the power input terminal 1 and the voltage drop generated in the gate resistor R5 due to the charging current of the bipolar electrolytic capacitor C1 is applied to the motor drive FE.
The T (T5) is turned on, and the DC motor M rotates in the reverse direction. When this reverse rotation is blocked externally, the overcurrent detection resistor R3 causes a large voltage drop according to the lock current, and turns on the NPN transistor T7. When the transistor T7 is turned on, the motor drive FET (T5) is turned off to cut off the energization of the DC motor M. As a result, overheating and burning of the DC motor M is prevented. FIG. 3 is a wiring diagram showing a control device for an electric retractable mirror according to an embodiment different from the above. The embodiment of FIG. 2 described above is further improved to prevent damage to electronic parts due to surges from a power source and high voltage noise. It is configured to prevent. D1 shown in FIG. 3 is a bipolar overvoltage protection zener diode, which is connected between the power input terminals 1 and 2. D2 and D3 are FET control Zener diodes, and each is a motor drive FE.
It acts to give an ON voltage to T (T5) and T (T6). C2 and C3 are transistor delay capacitors (the operation of which will be described later). R7 is a resistor for limiting the Zener current of the Zener diodes D2 and D3.

[Storing operation] Power source input terminal 1 plus 12
When zero volt is applied to each of the volt and the power input terminal 2, a voltage is applied between both terminals of the Zener diode D3, and the ON voltage is given to the motor drive FET (T6).
As a result, the motor drive FET is turned on and the DC motor M is normally rotated. If the normal rotation is blocked externally, an excessive lock current is generated, and the motor drive FET (T
The internal resistance of 6) increases the potential difference between the drain D and the source S, and turns on the NTN transistor T8 for overcurrent control. When the transistor T8 is turned on, the gate G of the motor drive FET (T6) becomes equipotential with the source S, and the motor drive FET (T6)
Is turned off, and the energization of the DC motor M is cut off to prevent burning due to the lock current. [Restoration operation] When positive 12V is applied to the power input terminal 2 and zero volt is applied to the power input terminal 1,
The operation is as follows in a vertically symmetrical manner with respect to the storing operation described above. That is, the motor drive FET (T5) is turned on by the Zener voltage of the Zener diode D2, and the DC motor M is rotated in reverse. When this reverse rotation is blocked externally, the voltage drop caused by the internal resistance of the motor drive FET (T5) turns on the NPN transistor T7, which turns off the motor drive FET (T5) to turn on the DC motor M. Power is cut off.

In the operation described above with reference to FIG. 3, when the DC motor M starts normal rotation or reverse rotation in a normal state, an initial current larger than that in the steady state flows.
At this time, it is inconvenient if the above-mentioned NPN transistor is turned on in response to an excessive current (normal storage and recovery operations stop immediately after starting). Therefore, the transistor delay capacitors C2 and C3 change the ON voltage of the transistors T7 and T8. Absorbs temporarily and delays its on-operation. Since the initial current (current at the start of rotation of the DC motor M) does not last forever, the capacitances of the delay capacitors C2 and C3 may be set so that they can cover the transient state time in which the initial current is generated. Further, even if a pulsed high voltage (surge, noise) is mixed in the power supply input terminals 1 and 2, it is absorbed by the bipolar overcurrent protection zener diode D1, so that the electronic component is prevented from being damaged by the overvoltage. This improves the reliability and durability of the control device. FIG. 4 is a wiring diagram of a control device for an electric retractable mirror according to another embodiment different from the embodiments shown in FIGS.

Comparing the embodiment of FIG. 4 with the embodiment of FIG. 3, the bipolar overvoltage protection zener diode D1 connected between the power supply input terminals 1 and 2 is omitted, and the motor drive FETs (T5) and ( Between the drain D and the source S of T6), the overvoltage protection zener diodes D4 and D
5 is connected. R3 and R4 are overcurrent detection resistors.

[Storing operation] Power source input terminal 1 plus 12
When zero volt is applied to each of the volt and the power input terminal 2, the motor drive FET (T6) is turned on and the direct-current motor M is normally rotated in the same manner as in the embodiment of FIG.
When this normal rotation is blocked externally, an overcurrent is generated, the voltage drop of the overcurrent detection resistor R4 increases, and the NPN transistor T8 is turned on by this potential difference, and the motor drive F
Turn off ET (T6). As a result, the energization of the DC motor M is cut off to prevent burning. The operation of the transistor delay capacitors C2 and C3 in the embodiment of FIG.
The operation is the same as that of the transistor delay capacitors C2 and C3 in the embodiment shown in FIG. Further, even if a pulsed excessive voltage is applied to the power supply input terminals 1 and 2, it is absorbed by the overvoltage protection zener diodes D4 and D5, so that the motor drive FETs (T5) and
For 6), an excessive voltage higher than the Zener voltage is not applied.

[Restoring Operation] When zero volt is applied to the power input terminal 1 and plus 12 volt is applied to the power input terminal 2, the DC motor M is rotated in the reverse direction as in the embodiment of FIG.

When the above reverse rotation is blocked externally, a large voltage drop occurs in the overcurrent detection resistor R4 due to the lock current, the NPN transistor T8 is turned on, and the gate voltage of the motor drive FET (T6) is almost zero. Then, the motor drive FET (T6) is turned off, the energization of the DC motor M is cut off, and the motor burnout is prevented. Note that the rotation of the motor is blocked externally means that the rotation of the motor is mechanically stopped by an external force acting on a member driven by the motor.

[0020]

When the present invention is applied, two FETs are symmetrically interposed between the electric storage mirror driving motor and each of the pair of power supply input terminals.
Therefore, when the positive and negative voltages are switched and applied to the pair of power supply input terminals, two Fs are provided according to the positive and negative polarities.
One of the ETs is in a state of taking charge of the function of controlling energization, and the other FET is in a state of allowing uncontrolled passage of current. Therefore, F which is in the above control state
When ET is named as a specific FET and an ON voltage is applied to it, the motor is energized to rotate the mirror. When the energization flow rate of the motor is detected and an off voltage is applied to the specific FET when it exceeds a predetermined value, the energization of the motor is cut off and the rotation of the mirror is stopped. This eliminates the possibility that the motor will be burned due to overcurrent. However, the motor of the electric retractable mirror is
The negative polarity is switched to switch between positive and reverse, whereby the mirror is reciprocally rotated between the energized posture and the retracted posture. That is, the polarities of the pair of power input terminals are inverted between positive and negative depending on the driver's operation. When the positive and negative of the power input terminal are inverted, a specific F of the two FETs is
ETs are swapped. From this point of view, the circuit configuration of the present invention is provided with two FETs because it is provided with a control FET for forward rotation of the DC motor and a control FET for reverse rotation. A forward rotation ON voltage applying unit and a forward rotation OFF voltage applying unit are provided in the FET for controlling rotation, and a reverse rotation ON voltage applying unit is provided in the FET for controlling reverse rotation.
A reverse rotation off-voltage applying means is provided, and when an excessive current flows through the motor during forward rotation and reverse rotation,
Before the burnout occurs, the motor can be instantly activated to cut off the power supply to the motor. Moreover, as is clear from the above-mentioned configuration, the contact is completely non-contact, so that the trouble caused by the mechanical contact can be prevented before and completely. Moreover, the control device is compact and lightweight, and there is no possibility of poor continuity due to contact contamination, which is excellent in durability and reliability. A great deal contributes to the improvement.

[Brief description of drawings]

FIG. 1 is a wiring diagram of a control circuit in one embodiment of a control device for an electric retractable mirror according to the present invention.

FIG. 2 is an electric wiring diagram showing an embodiment different from the above-mentioned embodiment shown in FIG. 1 according to the present invention.

FIG. 3 is a wiring diagram showing a control device for an electric retractable mirror according to an embodiment different from the above, in which the embodiment of FIG. 2 described above is further improved to damage electronic parts due to surges from a power source and high voltage noise. It is configured to prevent the above.

FIG. 4 is a wiring diagram of a control device for an electric retractable mirror according to an embodiment different from the embodiment shown in FIGS. 1 to 3 above.

[Explanation of symbols]

1, 2 ... power input terminal, C1 ... bipolar electrolytic capacitor,
C2, C3 ... transistor delay capacitor, D1 ... bipolar overvoltage protection zener diode, D2, D3 ... FET control Zener diode, D4, D5 ... overvoltage protection Zener diode, M ... DC motor, m _1, m ₂ ... DC motor terminals , R1, R2 ... Base resistor, R3, R4 ... Overcurrent detection resistor, R5, R6 ... Gate resistor, R7 ... Zener current limiting resistor, T1, T2 ... P-type FET (motor drive FET), T3 T4 ... PNP transistor, T5
T6 ... n type FET (motor drive FET), T7, T
8 ... NPN transistor.

Claims (9)

[Claims] 1. A DC motor whose rotation direction is reversed when the energization direction is reversed, a pair of power input terminals whose positive and negative applied voltages are manually reversed, and rotation of the DC motor is locked. A control device for an electric retractable mirror, comprising: an electric circuit that detects an excessive current that sometimes occurs to cut off the energization of the DC motor, wherein the DC motor and the pair of power input terminals are respectively connected to each other. , One each, a total of two FETs are inserted and connected, and each of the two FETs is connected so that the source faces the power input terminal side and the drain faces the DC motor side, and When a voltage is applied to the pair of power input terminals,
Means is provided for applying an ON voltage to only one specific FET of the two FETs according to the positive and negative polarities, and when the rotation of the DC motor is blocked and an excessive current flows, A control device for an electric storage mirror, characterized in that means for applying an off-voltage to one specific FET is provided. 2. A transistor is provided as a means for detecting the excessive current and applying an off-voltage to one specific FET, and the collector of the transistor is connected to the gate of the specific one FET. At the same time, the emitter of the transistor is
The control device for the electric retractable mirror according to claim 1, being connected to a power input terminal connected to a source of the electric power storage mirror. 3. A pair of power supply inputs comprising two resistors and one capacitor as means for applying an on-voltage to a specific one FET when a voltage is applied to the pair of power supply input terminals. They are connected in series between the terminals, and the connection order is one capacitor placed between two capacitors, in the order of resistor, capacitor, resistor. , The two FETs, respectively
2. The gate of claim 1, which is connected to
Alternatively, the control device for the electric retractable mirror according to claim 2. 4. Two Zener diodes and one resistor are arranged as a means for applying an ON voltage to one specific FET when a voltage is applied to the pair of power input terminals. The connection order is such that one resistor is placed between two Zener diodes and the order is Zener diode, resistor, Zener diode, and both ends of the resistor are the gates of the two FETs. The control device for the electric retractable mirror according to claim 1, wherein the control device is connected to 5. The FET is provided with an on-voltage when the rotation of the DC motor is blocked,
As a means for turning off the FET by reducing the electric resistance between the gate of the FET and the power input terminal,
Control of the electric retractable mirror according to claim 2, characterized in that the internal resistance of the ET is utilized and the base of the transistor is connected to the drain of the FET via a base resistor in series. apparatus. 6. The FET is provided with an ON voltage when rotation of the DC motor is blocked.
A resistor is provided as a means for turning off the FET by reducing the electric resistance between the gate of the FET and the power input terminal, and the resistor is interposed between the drain of the FET and the DC motor. The base of the transistor is connected to the FE through a base resistor in series.
The control device for the electric retractable mirror according to claim 2, wherein the control device is connected to the drain of T. 7. A capacitor for preventing the FET from being turned off in response to a large current at the time of starting the operation of the DC motor by delaying the ON operation of the transistor, a capacitor for preventing the FET from turning off and the base of the transistor. The control device for the electric retractable mirror according to claim 5, wherein the control device is connected between the FET and the source. 8. A Zener diode for protecting the FET from a high noise voltage contained in a power supply is connected between the pair of power supply input terminals. The control device for the electric retractable mirror according to claim 7. 9. A Zener diode for protecting the FET from a high noise voltage contained in a power supply is
The control device for the electric retractable mirror according to any one of claims 1 to 7, which is connected between the drain and the source of the ET.