JPH0620175Y2 - In-vehicle control unit constant voltage circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a constant voltage circuit for a vehicle-mounted control unit that reduces the current consumption that is taken from a vehicle-mounted battery when the vehicle engine is stopped. .

(Prior Art) In recent years, a microcomputer is mounted on an automobile, and various microcomputers mounted on a vehicle, such as an engine, are controlled to perform desired operations by the microcomputer.

By the way, depending on the device to be controlled, this type of microcomputer protects the stored contents of the memory of the microcomputer even when the vehicle battery is not charged, such as when the vehicle engine is not rotating and the vehicle is parked. For some reasons, it is necessary to supply power from a battery.

In such a case, it is preferable to reduce the current consumption as much as possible when the automobile engine is not rotating. When the current consumption is large, there is a problem that the battery is completely discharged in a relatively short period of time, that is, so-called battery exhaustion occurs.

(Purpose of the Invention) The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to define a vehicle-mounted control unit that reduces the current drawn from the battery when the vehicle-mounted battery is not charged. The purpose is to provide a voltage circuit.

Therefore, according to the present invention, a control unit including a power supply terminal and a standby terminal outputs a standby release signal to the standby terminal when the ignition switch is turned on, and outputs the standby signal from the vehicle battery. An on-vehicle system that supplies the operating current of the control unit to the power supply terminal, outputs a standby signal to the standby terminal of the control unit when the ignition switch is off, and supplies a small current for memory backup to the control unit. Is a constant voltage circuit of a control unit for a vehicle, which is connected between a base of the control transistor and a control transistor having a collector and an emitter connected to the output terminal of the vehicle-mounted battery and the power supply terminal of the control section. Tena Tse A gate diode, a current limiting resistor connected between the collector and base of the control transistor, and a switch circuit that outputs the battery output voltage by turning on the ignition switch to release the standby state of the control unit. Between the output side of the switch circuit and the base of the control transistor, a resistor for supplying the Zener current of the Zener diode and a minute current flowing through the current limiting resistor when the ignition switch is turned off is the standby terminal. It is characterized in that a backflow prevention diode for preventing backflow to the side is connected in series.

(Effect of the Invention) According to the present invention, when the ignition switch is turned off, the control unit enters the standby state due to the output of the switch circuit, while the switch circuit causes the reverse current prevention diode and the Zener current from the vehicle-mounted battery. The Zener current that was being supplied to the Zener diode is cut off through the resistor for supply, which allows the so-called discard current (which is supplied to the constant voltage circuit) to flow to the constant voltage circuit of the vehicle control unit when the ignition switch is off. (Idle current consumed) is zero, and the current consumption of the vehicle-mounted control unit is small when the vehicle battery is not being charged, so the vehicle is left for a relatively long period of time with the engine stopped. But eliminate the possibility that the battery will be completely discharged. be able to.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, when the ignition switch Ig is off, the present invention supplies a base current from a vehicle-mounted battery B to the base of the control transistor 2 through a current limiting resistor R ₁ having a high resistance value for control. While supplying a minute current required for the part 1 at the time of standby, when the ignition switch Ig is on, the switch circuit 3 is turned on and the diode 5 and the resistor R
_A base current is supplied to the base of the control transistor 2 via ₂ and a current required for the operation of the control unit 1 is supplied to the control unit 1.

The control transistor 2 has its emitter connected to the power supply terminal V _DD of the control unit 1, its base connected to the cathode of the Zener diode 4, and its collector connected to the vehicle-mounted battery B. The anode of the Zener diode 4 is connected to the ground. On the other hand, between the switch circuit 3 and the cathode of the zener diode 4, the series resistance R ₂ of the zener diode 4 and the diode 5 for preventing backflow are provided.
And are connected in series. The switch circuit 3 is turned on by the ignition switch is turned on Ig, control transistor 2 via the said diode 5 in series with resistor R ₂
Supply base current to the base of.

A resistor R is placed between the anode of the diode 5 and ground.
₃ and R ₄ are connected in series, and the connection point 6 between these resistors R ₃ and R ₄ is connected to the standby terminal SB of the control unit 1.

In FIG. 1, when the ignition switch Ig is turned on, the switch circuit 3 is turned on, the control unit 1 is released from the standby state, and the anode of the diode 5 is connected to the positive electrode of the battery B. As a result, the base current sufficient to supply the current consumed by the control unit 1 in the standby release state is supplied to the control transistor 2 via the diode 5 and the series resistor R ₂ .

Therefore, when the ignition switch Ig is on,
The control transistor 2 can supply the control unit 1 with a current necessary for the operation of the control unit 1 when the standby state is released.

On the other hand, when the ignition switch Ig is turned off, the switch circuit 3 is turned off, the control unit 1 is in the standby state, the anode of the diode 5 is disconnected from the battery B, and the current flowing through the control transistor 2 becomes zero. When the control unit 1 is in the standby state, the control unit 1 consumes a minute current for holding the stored contents of its memory (not shown), and this minute current is supplied to the base of the control transistor 2. It is obtained by supplying a very small base current through the current limiting resistor R ₁ having a high resistance value.

By doing so, the so-called discard current consumed by the Zener diode 4 when the ignition switch Ig is turned off is extremely small, and the current drawn from the battery B is small.

Next, a description will be given of an embodiment in which the present invention is applied to a power seat that automatically sets the position, height and angle of the backrest of a driver's seat of an automobile to a prestored position by a predetermined operation. .

In this embodiment, as shown in FIG.
Of the seat 8 in the front-rear direction indicated by the arrow A ₁ , the backrest 9 in the front-rear swing angle indicated by the arrow A ₂ , and the front portion 8a and the rear portion 8b of the seat 8 indicated by the arrow A ₃ and The vertical heights indicated by A ₄ can be set to optimum values for four drivers including the owner of the vehicle.

A control circuit of the power seat 7 is shown in FIG.

In FIG. 3, the control unit 11 has a function as a control unit of the power seat 7, and is composed of a one-chip microcomputer and its accompanying components.

The control unit 11 includes input terminals P ₁ to P ₂₀ to which various signals described later are respectively input, an output terminal P ₂₁ to output a set end signal of the power seat 7, a seat portion 8 of the power seat 7 and a backrest portion 9 of the power seat 7. Output terminals P ₂₂ to P ₂₇ for outputting drive signals, a reset terminal RST for inputting a reset signal, a standby terminal SB for inputting a standby signal, clock terminals CL ₁ , CL ₂ , a power supply terminal V _DD and a ground terminal GND. I have it.

The control unit 11 has a power supply terminal V
Power is supplied to the _DD from the vehicle-mounted battery B through the control transistor 2.

The control transistor 2 has its emitter connected to the power supply terminal V _DD of the control unit 11, its base connected to the cathode of the Zener diode 4 whose anode is grounded, and its collector connected to the cathode of the reverse voltage blocking diode D _1. ing. The anode of the diode D ₁ is connected to the positive electrode of the battery B whose negative electrode is grounded.

A current limiting resistor R ₁ is connected between the base and collector of the control transistor 2. Further, a DC resistance R ₂ is connected between the base of the control transistor 2 and the collector of the transistor 12.

The transistor 12 and the transistor 13 form the switch circuit 3 shown in FIG. In the transistor 12, the emitter is connected to the cathode of the diode D ₁ , the resistor R ₃ is connected between the base and the emitter, and the resistor R ₄ is connected between the base and the collector of the transistor 13. Has been done.

The transistor 13 has its emitter connected to ground and its base connected to a connection point between resistors R ₅ and R ₆ connected in series between the cathode of the diode D ₂ for blocking reverse voltage and ground.

An ignition switch Ig is connected between the anode of the diode D ₂ and the battery B. Resistors R ₇ and R ₈ are connected in series between the cathode of the diode D ₂ and the ground, and the standby terminal SB of the control unit 11 is connected to the connection point. The standby terminal SB is also connected to the cathode of a Zener diode D ₃ whose anode is grounded.

On the other hand, the seat portion 8 and the backrest portion 9 of the power seat 7 are connected to the input terminals P ₁ to P ₈ of the control unit 11.
A manual setting circuit 18 for setting the position of (1) with the manual setting switches 14, 15, 16 and 17 is connected. Manual setting switch 14 to 1 above
Among them, the manual setting switch 14 is a switch for sliding the seat portion 8 of the power seat 7 back and forth, and the manual setting switch 15 swings the backrest portion 9 of the power sheet 7 back and forth (knuckle). It is a switch for making it. The manual setting switch 16 is a switch for moving the front portion 8a of the seat portion 8 of the power seat 7 up and down, and the manual setting switch 17 is for moving the rear portion 8b of the seat portion 8 of the power seat 7 up and down. It is a switch. Hereinafter, the manual setting switch 14,
Reference numerals 15, 16 and 17 are referred to as a slide switch, a knuckle switch, a front switch and a rear switch, respectively.

The input terminal P ₁ of the control unit 11 and the power source Vc
Resistors R ₁₁ , R ₁₂ and R ₁₃ are connected in series with c, and a capacitor C ₁₁ is connected between the connection point between the resistors R ₁₁ and R ₁₂ and the ground. Also, resistors R ₁₂ and R
The anode of the diode D ₁₁ is connected to the connection point with _13, and the cathode of the diode D ₁₁ is connected to the forward contact 14 f of the slide switch 14. A circuit similar to the above is also connected between the input terminal P ₂ of the control unit 11 and the backward contact 14b of the front switch 14.

In addition, between the input terminal P ₃ of the control unit 11 and the forward contact 15f of the knuckle switch 15, the input terminal P _3
4 and the rear contact 15b of the knuckle switch 15, the input terminal P ₅ and the up contact 16u of the front switch 16
Circuits similar to the above are also connected between the input terminal P ₆ and the down contact 16 d of the front switch 16.

Further, circuits similar to the above are respectively connected between the input terminal P ₇ of the control unit 11 and the up contact 17u of the rear switch 17 and between the input terminal P ₈ and the down contact 17d of the rear switch 17. .

Resistors R ₁₄ and R ₁₅ are connected in series between the input terminal P ₉ of the control unit 11 and the ground, and the resistor R ₁₄
A changeover switch 19 for manual setting and automatic setting of the power seat 7 is connected between a connection point between the R ₁₅ and R ₁₅ and the power source Vcc taken out from the emitter of the control transistor 2.

On the other hand, the input terminal P ₁₀ of the control unit 11
The front and rear positions of the seat 8 of the power seat 7, the swinging position of the backrest 9, and the vertical positions of the front 8a and rear 8b of the seat 8 are detected at P ₁₁ , P ₁₂ and P ₁₃ , respectively. The sensor circuit 21 is connected.

The seat portion 8 of the power seat 7 slides back and forth by the motor M ₁ , and its position is determined by counting the number of output pulses of the seat portion position detection sensor 22 including a reed switch that is turned on and off by the rotation of the motor M _1. Be seen. The seat portion position detection sensor 22 has one end connected to the ground and the other end connected to the cathode of the diode D ₂₁ of the sensor circuit 21. The anode of the diode D ₂₁ is connected to the input terminal P ₁₀ of the control unit 11, and the anode of the diode D ₂₁ and the power source V
R ₂₁ is connected to cc.

Driving the backrest 9 of the power seat 7, the front 8 of the seat 8
a and the rear portion 8b are driven by motors M ₂ , M ₃ and M, respectively.
_The position of the backrest position detecting sensor 23, which is made of a reed switch, is adjusted by the same method as described above.
It is detected by the front seat position detection sensor 24 and the rear seat position detection sensor 25.

One end of each of the backrest position detecting sensor 23, the seat front position detecting sensor 24, and the seat rear position detecting sensor 25 is connected to the ground, and the other end of the backrest position detecting sensor 23 and the input of the control unit 11 are connected. Terminal P
₁₁ , between the other end of the seat front position detection sensor 24 and the input terminal P ₁₂ of the control unit 11, and between the other end of the seat rear position detection sensor 25 and the control unit 1.
Circuits similar to those described above are connected between the first input terminal P ₁₃ and the first input terminal P ₁₃ .

The input terminals P ₁₄ , P _{15 of} the control unit 11,
A memory command circuit 26 is connected to P ₁₆ , P ₁₇ , P _18, and P ₁₉ to command the memory of the set positions of the power seat 7 of a total of 14 drivers including the owners of the vehicle.

In the memory command circuit 26, the switch 27 is a memory protection switch for preventing the optimum seat position of the automobile owner from being accidentally erased, and the switch 27 is normally used. It is set in a position that is hard to see.

The switch 27 has one end connected to the ground and the other end connected to the cathode of the diode D ₂₂ . A resistor R ₂₂ is connected between the anode of the diode D ₂₂ and the power supply Vcc. A resistor R ₂₃ is provided between the anode of the diode D ₂₂ and the input terminal ₁₄ of the control unit 11.
And R ₂₄ are connected in series, and a capacitor C ₂₁ is connected between the connection point of the resistors R ₂₃ and R ₂₄ and the ground.

Between the input terminal P ₁₅ of the control unit 11 and the memory command switch 28, a capacitor C is provided in the same manner as above.
_{A circuit including 21} , a diode D ₂₂ , a resistor ₂₂ , R ₂₃ and R ₂₄ is connected. When the memory command switch 28 is turned on, the memory switches 29, 30, 31 and 3 are turned on.
By 2, the positions of the power seats 7 of four drivers including the owners of the automobile are input.

One end of each of the memory switches 29, 30, 31 and 32 is connected to the ground, and the other end of the memory switch 29 and the input terminal P _{16 of} the control unit 11 and the other end of the memory switch 30 and the input terminal P of the control unit 11 are connected.
₁₇ , between the other end of the memory switch 31 and the input terminal P ₁₈ of the control unit 11, and between the other end of the memory switch 32 and the input terminal P _{19 of the} control unit 11.
A circuit similar to the above is also connected between and.

The memory switch 32 is for the owner of the vehicle. When the power seat 7 is set by the memory switch 32, the above setting cannot be performed unless the switch 27 is turned on. , The memory contents are not changed.

Resistors R ₂₅ , R ₂₆ and R ₂₇ are connected in series between the input terminal P ₂₀ of the control unit 11 and the power source Vcc. The anode of the diode D ₂₃ is connected to the connection point between the resistors R ₂₅ and R _26, and the capacitor C ₂₂ is connected between the connection point between the resistors R ₂₆ and R ₂₇ and the ground. A speed sensor 33 composed of a reed switch is connected between the cathode of the diode D ₂₃ and the ground.

The output terminal P ₂₁ of the control unit 11 is a terminal for outputting a completion signal of the memory of the power seat 7, and resistors R ₂₈ and R ₂₉ are connected in series between the output terminal P ₂₁ and the ground. The base of the transistor 34 is connected to the connection point between the resistors R ₂₈ and R ₂₉ . The transistor 34 has its emitter connected to the ground, resistors R ₃₀ and R ₃₁ connected in series between the collector and the power supply Vcc, and a buzzer 3 for notifying the memory completion at both ends of the resistor R _31.
5 is connected.

On the other hand, the output terminal P ₂₂ of the control unit 11,
_{P 23, P 24, P 25} , P 26 and each relay driving circuit 36,37,38,39,40 and 41 to P ₂₇ are connected.

Resistors R ₃₂ and R ₃₃ are connected in series between the output terminal P ₂₂ of the control unit 11 and the power supply Vcc, and the base of the transistor 42 is connected to the connection point between the resistors R ₃₂ and R _33. There is. The transistor 42 has its emitter connected to the power supply Vcc and resistors R ₃₄ and R ₃₅ connected in series between the collector and ground.

The transistor 43 has its emitter connected to ground, its base connected to the connection point of the resistors R ₃₄ and R _35, and between the collector and the line connected to the cathode of the diode D ₂ indicated by I′g. The relay coil X ₁ is connected. Further, the collector of the transistor 43 is connected to the anode of the diode D ₂₄ for absorbing the back electromotive force of the relay coil X ₁ , and the cathode of the diode D ₂₄ is connected to the line I′g.

The relay drive circuits 37, 38, 39, 40 and 41 also have the same circuit configuration as the relay drive circuit 36.

The normally open relay contacts X ₁ -a and X ₂ -a are connected to the positive electrode of the battery B via the ignition switch Ig, and the normally closed relay contacts X ₁ -b and X ₂ -b are connected to ground. ing.

On the other hand, the normally open relay contacts X ₃ -a, X ₄ -a, X ₅ -a and X ₆ -a are all connected to the movable contact X ₁ -c and the normally closed relay contacts X ₃ -b, X. ₄ -b, X ₅ -b and X ₆ -
b Both are connected to the movable contact X ₂ -c.

A motor M is provided between the movable contact X ₃ -c and the normally closed contact X ₃ -b.
₁ , the motor M ₂ is located between the movable contact X ₄ -c and the normally closed contact X ₄ -b, and the motor M ₃ is located between the movable contact X ₅ -c and the normally closed contact X ₅ -b. , The movable contact X _6- c and the normally closed contact X
_A motor M ₄ is formed between each of them and _6- b.

The reset terminal RST of the control unit 11
A capacitor C ₂₃ is connected between the control transistor 2 and the emitter of the control transistor 2, and a resistor R ₃₆ and a diode D ₂₅ are connected between the reset terminal RST and the ground.

Clock terminals CL ₁ and CL _{2 of the} control unit 11
A resistor R ₃₇ is connected between the
A capacitor C ₂₄ is connected between L ₁ and the ground terminal GND. This ground terminal GND of the control unit 11 is connected to the ground.

Next, the operation of the circuit shown in FIG. 3 whose configuration has been described above will be described.

In FIG. 3, when the ignition switch Ig is turned on, the control unit 11 is released from the standby state, and the transistor 13 is turned on, so that the transistor 12 is also turned on. Therefore,
In the base of the transistor 2 and the Zener diode 4,
Current is supplied from the battery B through the diode D ₁ , the transistor 12 and the series R ₂ , and the Zener diode 4 keeps the base voltage of the control transistor 2 constant.

In the above state, in order for the driver to adjust the power seat 7 to the optimum position, the changeover switch 19 is turned on, and when the movable contact of the slide switch 14 is connected to the forward contact 14f, for example, the output terminal P ₂₂ of the control unit 11 and A "low" level signal is output from P _24, turning on the transistors 42 and 43. As a result, the relay X ₁
And X ₃ are energized, and the movable contact X ₁ -c becomes the normally open contact X ₁
In -a, the movable contact X ₃ -c is respectively connected to the normally open contact X ₃ -a. By this connection, the motor M ₁ rotates normally and the seat portion 8 of the power seat 7 advances. If the movable contact of the slide switch 14 is returned to the neutral position when the power seat 7 reaches the optimum position, the motor M ₁ is short-circuited at both ends and stopped.

On the other hand, the movable contact of the slide switch 14 is set to the backward contact 1
When connected to 4b, a signal of "low" level is output from the output terminal P ₂₃ and P ₂₄ of the control unit 11,
Relay coil X ₂ and relay coil X ₃ is energized, the movable contact X ₂ -c movable contact X ₃ -c normally open contact X ₂ -a is respectively connected to the normally open contact X ₃ -a. As a result, the motor M ₁ rotates in the reverse direction, the seat portion 8 of the power seat 7 retracts, and stops when the movable contact of the slide switch 14 is set to the neutral position.

For the motors M ₂ , M ₃ and M ₄ , the knuckle switch 15, the front switch 16 and the rear switch 17 are also included.
The positions of the backrest portion 9 of the power seat 7, the front portion 8a and the rear portion 8b of the seat portion 8 can be adjusted by operating the.

Relays X ₁ , X ₂ , X ₃ , X ₄ and X ₅ during this adjustment operation
The positions of the movable contacts X ₁ -c, X ₂ -c, X ₃ -c, X ₄ -c and X ₅ -c are shown in the following table.

Next, in order to store the optimum position of the power seat 7 determined as described above, the memory command switch 28 is turned on and within 3 seconds, one of the memory switches 29 to 32 corresponding to the driver is turned on. Then, the optimum position of the power seat 7 is stored in the memory (not shown) in the control unit 11.

However, the above-mentioned optimum position of the owner of the automobile is the switch 27.
When is off, it cannot be stored in the memory, and the optimum position can be changed only by turning on the switch 27.

When the above storage operation is completed, the control unit 1
A storage completion signal is output from the output terminal P _{21 of} No. 1 and the buzzer 35 notifies the completion of storage.

Next, in order to set the power seat 7 to the optimum position for the driver based on the information stored in the memory of the control unit 11, the changeover switch 19 is turned off and, for example, the memory switch 29 corresponding to the driver is turned on. Then, the motors M ₁ , M ₂ , M ₃ and M ₄ rotate to drive the seat portion 8, the backrest portion 9, the front portion 8 a and the rear portion 8 b of the seat portion 8 of the power seat 7. The control unit 11 is
The pulses generated by turning on and off the position sensors 22 to 25 are counted to detect the positions of the seat portion 8, the backrest portion 9, the front portion 8a and the rear portion 8b of the seat portion 8 of the power seat 7. When this position matches the optimum position, the control unit 11 causes the motors M ₁ , M ₂ , M ₃ and M _{4 to} move.
Is stopped and the position setting of the power seat 7 is completed.

Next, in order to drive the automobile, the ignition switch Ig is turned off, and the control unit 11 enters the standby state. When the ignition switch Ig is turned off, the transistor 13 is turned off and the transistor 12 is also turned off. As a result, the transistor 12
Although the current flowing from the control transistor 2 to the base of the control transistor 2 and the Zener diode 4 becomes zero, a very small amount of current consumed by the control unit 11 at the time of standby does not flow from the battery B to the base of the control transistor 2 and the Zener diode 4. It is provided by supplying through a high value current limiting resistor R ₁ . In this case, the wasted current wasted by the Zener diode 4 is extremely small, and the emitter of the control transistor 2 takes out a very small amount of current required for the standby of the control unit 11.

Therefore, in the above embodiment, the ignition switch Ig
The current drawn from the battery B is very small when it is off, and it is possible to prevent the battery B from being completely discharged even when the vehicle is not used for a long time.

The present invention can be applied to not only the power seat 7 of an automobile but also a power seat of a general vehicle, a rearview mirror with a memory function, and the like.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a general configuration of an in-vehicle control unit according to the present invention, FIG. 2 is an explanatory diagram of movements of various parts of a power seat, and FIG. 3 is a control circuit of a power seat to which the present invention is applied. It is a figure. 1 ... control unit, 2 ... control transistor, 3 ... switching circuit, 4 ... Zener diode, R ₁ ... current limiting resistor, R ₂ ... series resistors, B ... battery.

Claims (1)

[Scope of utility model registration request] 1. A control unit having a power supply terminal and a standby terminal, which outputs a standby release signal to the standby terminal when the ignition switch is turned on, and operates the control unit from the vehicle battery to the power supply terminal. A constant voltage circuit for an in-vehicle control unit that supplies a current and outputs a standby signal to the standby terminal of the control unit when the ignition switch is off and also supplies a small current for memory backup to the control unit. And a control transistor having a collector and an emitter connected to the output terminal of the on-vehicle battery and the power supply terminal of the control section, and a Zener diode connected between the base of the control transistor and the ground. The switch includes a current limiting resistor connected between the collector and the base of the control transistor, and a switch circuit that outputs the output voltage of the battery when the ignition switch is turned on to release the standby state of the control unit. Between the output side of the circuit and the base of the control transistor, a small current flowing through the resistor for supplying the Zener current of the Zener diode and the current limiting resistor when the ignition switch is turned off flows backward to the standby terminal side. A constant voltage circuit for a vehicle-mounted control unit, in which a backflow prevention diode for preventing the above is connected in series.