JP2009126461A - Control circuit for setting destination point - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control circuit for setting a destination point capable of certainly operating a micro-computer mounted on a vehicle. <P>SOLUTION: The control circuit for setting the destination point includes the micro-computer 21 for storing inherent characteristic data in each different specification by the destination point and having at least one of input terminals 42-46 for setting the characteristic data; pull-up resistances 48-52 connected to a vehicle power source line of the input terminals 42-46; and pull-down resistances 53-57 connected to an earth line of the input terminals 42-46. A voltage value in which a voltage fed from the vehicle power source 47 is divided by the pull-up resistances 48-52 and the pull-down resistances 53-57 is inputted to the input terminals 42-46. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a destination setting control circuit provided in a microcomputer mounted on a vehicle.

  A vehicle such as a car in recent years generally includes an electronic device, and the electronic device is controlled by an ECU on which a microcomputer is mounted. For example, when a ignition switch is operated to the ON position, a vehicle air-conditioning control device is already known in which a microcomputer for controlling air conditioning of a vehicle is supplied with power through the ignition switch and air-conditioning control is performed according to a changeover switch operation. The vehicle air-conditioning control device using a microcomputer automatically detects the temperature change inside and outside the vehicle and the influence of solar radiation when the passenger sets the temperature inside the vehicle to the desired temperature. There are a full auto control type that automatically adjusts the wind direction and automatically controls the cabin temperature to the set temperature, and a semi-auto control type that manually adjusts the temperature and switches the air volume and direction.

  In such a vehicle air-conditioning control apparatus using a microcomputer, when the ignition switch is operated to the ON position, the microcomputer power circuit and the battery mounted on the vehicle are connected via the ignition switch, and the microcomputer is connected to the power circuit. Power is supplied by the output voltage of the air conditioner and air conditioning control becomes possible.

  By the way, if the specification of the electronic device varies depending on the destination, the vehicle stores characteristic data for each destination in the microcomputer instead of changing the microcomputer for each destination, and prepares for setting each specification. The specifications are determined by setting external input conditions to the input terminals.

  In other words, prepare multiple input terminals for specification setting in the microcomputer, change the resistance value of the pull-up resistor or pull-down resistor installed in the destination setting control circuit electrically connected to each input terminal, and input each By changing the voltage value input to the terminal, the input voltage value is detected and the execution function of the microcomputer is changed. Therefore, when the input voltage value is detected by either High or Low, two execution functions can be selected for each input terminal. These two execution functions are set as a basic specification and an extended specification, for example.

Japanese Patent Laid-Open No. 04-126625

  In the control circuit for setting the destination of the microcomputer as described above, if there is a defect such as a pull-up resistor or pull-down resistor that determines the microcomputer specification for some reason, the microcomputer specification is changed. There was a problem that it could not be set.

  More specifically, if a pull-up resistor or pull-down resistor that determines the specifications of the microcomputer is removed from the substrate forming the destination setting control circuit, an electromagnetic wave such as a mobile phone is transmitted to a device including the microcomputer. When the device approaches, the voltage value input to the microcomputer specification setting input terminal fluctuates due to electromagnetic noise, and the input state becomes unstable when the microcomputer reads the voltage value of the input terminal. For this reason, it cannot be determined whether the specification is set to the basic specification or the extended specification, and the microcomputer may fall into a state in which it does not operate normally. When the microcomputer cannot determine the specification in this way, a phenomenon occurs in which the display lamp of the electronic device controlled by the microcomputer repeatedly blinks, which may cause discomfort to the passenger.

  In view of the above circumstances, the present invention is directed to a reliable operation of a microcomputer even when a defect such as a pull-up resistor or a pull-down resistor that determines the specification of the microcomputer for some reason is disconnected from the substrate. An object is to provide a ground setting control circuit.

  In order to achieve the above object, in the present invention, unique characteristic data is stored for each specification different depending on the destination, and the microcomputer has at least one input terminal for setting the characteristic data, and the input terminal In the destination setting control circuit comprising a pull-up resistor connected to the vehicle power supply line and a pull-down resistor connected to the ground line of the input terminal, the input terminal is supplied from the vehicle power supply A destination setting control circuit is proposed in which a voltage value obtained by dividing a voltage by the pull-up resistor and the pull-down resistor is input.

  The destination setting control circuit of the present invention described above is a pull-up resistor even when a defect such as one of the pull-up resistor or the pull-down resistor that determines the specifications of the microcomputer is disconnected from the substrate due to some cause. Since one of the pull-down resistors is mounted, it is possible to prevent the input value from becoming unstable due to the voltage value input to the input terminal that determines the specifications of the microcomputer due to electromagnetic noise, The microcomputer can be operated reliably.

Next, an embodiment in which a destination setting control circuit of the present invention is applied to a vehicle air conditioning control device will be described with reference to the drawings.
FIG. 1 is a front view of an operation panel provided with an operation knob and a push knob of a vehicle air-conditioning control device, FIG. 2 is a block diagram showing a device circuit of the vehicle air-conditioning control device, and FIG. 3 shows a main part of the present invention. It is a circuit diagram of a control circuit for setting a destination.

As shown in FIG. 1, this vehicle air-conditioning control device includes a temperature control operation knob 11, an air volume adjustment operation knob 12, and a wind direction adjustment operation knob 13, which are dial-type operation knobs, on the operation panel 10. Further, the operation panel 10 includes a push knob 14 of a rear differential switch RrDEF for energizing a heat wire of the rear window, a push knob 15 of an air conditioner switch A / C for switching on / off of the air conditioner, and an internal air circulation. A push knob 16 of an inside / outside air changeover switch REC / FRS for switching between outside air introduction is provided.
The push knobs 14, 15 and 16 are provided with optical indicator lamps 14a, 15a and 16a made of LEDs or the like indicating the operation of each switch.

  The temperature adjusting operation knob 11 and the airflow direction adjusting knob 13 have a known configuration in which the control wire is pushed out and pulled back to mechanically control the air conditioner. .

  The operation knob 12 for adjusting the air volume is interlocked with a fan switch having a rotary switch structure by rotating the operation knob, and as shown in FIG. 2, a switch signal is inputted to a microcomputer (controller) and electrically processed. Similarly, switch signals of the rear differential switch RrDEF, the air conditioner switch A / C, and the inside / outside air changeover switch REC / FRS are also inputted to the microcomputer and processed electrically. Thus, in the vehicle air-conditioning control apparatus according to the present embodiment, the vehicle occupant manually operates the temperature adjustment and the wind direction adjustment, and the microcomputer 21 performs ON / OFF switching between the air conditioner and the rear differential, and the internal air circulation. This is a so-called semi-automatic air conditioner that electrically controls switching of outside air introduction.

FIG. 2 is a block diagram showing a device circuit of the vehicle air conditioning control device.
As shown in the figure, the microcomputer 21 of the device circuit 20 is connected to a battery 23 mounted on the vehicle with the ignition switch 22 closed, and is supplied with power by the battery 23.
That is, when the ignition switch 22 is closed and the engine is started, the battery power supply voltage (for example, 12V) is converted into a voltage by the voltage conversion circuit 24, and the converted voltage (for example, 5V) is applied to the microcomputer 21. .

At this time, the capacitor of the charge / discharge circuit 25 is charged by receiving the power supply voltage of the battery 23.
The charge / discharge circuit 25 prevents the output voltage of the voltage conversion circuit 24 from being lowered due to chattering of the ignition switch 22 and the like, and prevents the microcomputer 21 from being reset. In addition, the signal power supply circuit 26 is released when the ignition switch 22 is opened. The signal power supply voltage is supplied to the changeover switch signal circuit 27 via the.

As described above, the fan switch 28 is turned ON / OFF by rotating the operation knob 12, and this ON / OFF signal is input to the microcomputer 21 via the changeover switch signal circuit 27.
The microcomputer 21 recognizes ON / OFF of the fan switch 28, and controls an air conditioning mechanism such as an air conditioner when an ON signal is input.
As will be described later, the blower motor is started by the ON operation of the fan switch 28, and the selection resistor is selected according to the turning operation of the operation knob 12 interlocking with the fan switch 28, and the rotational speed control of the blower motor 48 is controlled. Done.

In addition, in FIG. 2, the block 29 is a push switch collectively showing a rear differential switch RrDEF, an air conditioner switch A / C, and an inside / outside air changeover switch REC / FRS.
These RrDEF, A / C, and REC / FRS switch signals are input to the microcomputer 21 via the SW signal input circuit 30.
In addition, an indicator LED circuit 31 is provided for turning on the above-described indicators 14a, 15a, and 16a in accordance with the operation of each switch of RrDEF, A / C, and REC / FRS.

That is, if the push knob 15 is operated to operate the air conditioner switch A / C, the microcomputer 21 to which the switch signal is input is in an air conditioner mode in which the air conditioner output circuit 32, the control unit 33, and the compressor 34 are operated.
In this case, the indicator lamp 15a is turned on.

When the rear differential switch RrDEF is operated by operating the push knob 14, the microcomputer 21 to which the switch signal is input operates the rear differential output circuit 35 and the rear differential relay 36 to energize the heat wire of the rear window.
In this case, the indicator lamp 14a is turned on.

Further, when the push knob 16 is operated to operate the inside / outside air changeover switch REC / FRS, the microcomputer 21 receiving the switch signal operates the inside / outside air actuator driving circuits 37 and 38 and the inside / outside air actuator 39, It becomes an operation mode of inside air circulation or outside air introduction.
In this case, the indicator lamp 16a is turned on.

  Further, the block 40 is a voltage drop reset watchdog timer that resets the microcomputer 21 when the power supply voltage of the microcomputer 21 becomes a predetermined value or less, or when the program runs away, and the block 41 is a right handle. This is a destination setting circuit for setting circuit conditions that change depending on whether the left handle is used.

FIG. 3 is a circuit diagram specifically showing the destination setting control circuit 41 described above.
As shown in the figure, the microcomputer 21 is provided with five input terminals 42 to 46 for setting the destination, and the input terminals 42 to 46 are connected to the vehicle power supply 47 via the pull-up resistors 48 to 52, respectively. At the same time, the input terminals 42 to 46 are grounded via pull-down resistors 53 to 57, respectively.

  Among the input terminals 42 to 46 of the microcomputer 21, one pull-up resistor 48 and one pull-down resistor 53 are connected to the input terminal 42. Similarly, the input terminal 43 has a pull-up resistor 49 and a pull-down resistor 54, the input terminal 44 has a pull-up resistor 50 and a pull-down resistor 55, and the input terminal 45 has a pull-up resistor 51 and a pull-down resistor 56. 46, one pull-up resistor 52 and one pull-down resistor 57 are connected to each other.

  By the way, depending on the destination of the vehicle, the specification of the electronic device connected to the microcomputer 21 is different, so the setting of the microcomputer 21 needs to be changed according to the specification. In this embodiment, the resistance values of the pull-up resistors 48 to 52 and the pull-down resistors 53 to 57 are set to different values according to specifications. That is, pull-up resistors 48 to 52 and pull-down resistors 53 to 57 having different resistance values according to specifications are mounted on the substrate. By changing the resistance value, the voltage value input to the input terminals 42 to 46 changes, and the microcomputer 21 can select the execution function according to the specification.

  The microcomputer 21 of the present embodiment detects whether the voltage value input to the input terminals 42 to 46 is High level or Low level. That is, two execution functions are selected for each input terminal. For example, a description will be given of a case where the position of the steering handle differs depending on the destination. The specifications of the vehicle air-conditioning control device are also different, and the execution function of the microcomputer 21 needs to be changed. Here, assuming that the specification of the right-hand drive vehicle is the basic specification and the specification of the left-hand drive vehicle is the extended specification, the arrangement of the push switch differs between the basic specification and the extended specification. Specifically, in the basic specification, as shown in FIG. 1, the push switches are arranged in order from left to right, such as a rear differential switch 14 and an indicator lamp 14a, an inside / outside air changeover switch 16 and an indicator lamp 16a, an air conditioner switch 15 and an indicator lamp 15a. Has been placed. In the extended specification, this is the arrangement of the air conditioner switch 15 and the indicator lamp 15a, the inside / outside air changeover switch 16 and the indicator lamp 16a, the rear differential switch 14 and the indicator lamp 14a. The display needs to be changed.

  The specification change when the steering handle is different on the left and right is set using the input terminal 42 of the microcomputer 21. The microcomputer 21 reads the state of the input terminal 42 and determines the specification. When the detected voltage value is High level, the microcomputer 21 determines the basic specification, and when the detected voltage value is Low level, the specification is determined. Here, if the vehicle power supply 47 is set to 5 (V), the resistance value of the pull-up resistor 48 is set to 1 (Ω), and the resistance value of the pull-down resistor 53 is set to 10 (Ω), the microcomputer 21 The voltage detected at the input terminal 42 is V = {10 / (1 + 10)} × 5≈4.5 (V), and the microcomputer 21 detects the high level voltage value. Is determined.

  When the resistance value of the pull-up resistor 48 is set to 10 (Ω) and the resistance value of the pull-down resistor 53 is set to 1 (Ω), the voltage V detected by the microcomputer 21 at the input terminal 42 = {1 / (10 + 1) )} × 5≈0.45 (V), and the microcomputer 21 detects the low-level voltage value, and therefore determines that the left handle specification is an extended specification. As described above, the voltage divided by the pull-up resistor 48 and the pull-down resistor 53 is input to the input terminal 42.

  As described above, since both the pull-up resistor 48 and the pull-down resistor 53 are connected to the input terminal 42, the voltage value input to the input terminal 42 is stable, and the vehicle air-conditioning control apparatus including the microcomputer 21 is provided. Even when a device such as a mobile phone that emits electromagnetic waves approaches, the voltage value input to the specification setting input terminal 42 of the microcomputer 21 does not fluctuate due to electromagnetic noise. Therefore, when the microcomputer 21 reads the voltage value of the input terminal 42, there is no possibility that the input state becomes indefinite, and it can be accurately determined whether the basic specification or the extended specification is set. .

  On the other hand, a case where the pull-up resistor 48 is detached from the substrate for some reason will be described. When the pull-up resistor 48 is disconnected and opened, the input terminal 42 has the same potential as the ground voltage. Therefore, the voltage V≈0 (V) detected by the microcomputer 21 at the input terminal 42, and the microcomputer 21 is at the low level. The voltage value will be detected. Thus, although the microcomputer 21 has a disadvantage that it is not the basic specification that should be originally determined but the left handle specification that is an extended specification, the pull-down resistor 53 is connected to the input terminal 42. Even when a device for transmitting electromagnetic waves, such as a mobile phone, approaches the vehicle air conditioning control device including the microcomputer 21, the microcomputer 21 sets the voltage value of the input terminal 42 at a low level. There is no possibility that the input state becomes indefinite when read, and it is impossible to determine whether the input is set to the basic specification or the extended specification, so that the microcomputer 21 falls into a state in which it does not operate normally. Status can be avoided, and the display lamps of the electronic devices controlled by the microcomputer blink repeatedly. There is no what happens unpleasant phenomenon in the car ride's called.

  On the other hand, a case where the pull-down resistor 53 is detached from the substrate for some reason will be described. When the pull-down resistor 53 is disconnected and opened, the voltage from the vehicle power supply 47 is applied to the input terminal 42 as it is, and the voltage V≈5 (V) detected by the microcomputer 21 at the input terminal 42 becomes high. In order to detect the voltage value of the level, it is determined that the specification is the right handle specification which is the basic specification. In this case, although the pull-down resistor 53 is disconnected, since the pull-up resistor 48 is connected to the input terminal 42, the voltage value input to the input terminal 42 is stabilized at the high level, and similarly the microcomputer. Even when a device for transmitting electromagnetic waves, such as a mobile phone, approaches the vehicle air conditioning control device including the input device 21, the input state may be undefined when the microcomputer 21 reads the voltage value of the input terminal 42. It is possible to reliably determine that the basic specification is set.

  In the present embodiment, the vehicle air-conditioning control device in which the position of the steering handle is different between the right handle and the left handle according to the destination has been described, but as another example, an operation knob for adjusting the wind direction of the vehicle air-conditioning control device When there is a linked function that turns on the air conditioner and forcibly switches to the inside air circulation mode when 13 is operated to the DEF position, or a timer function that automatically turns off after a predetermined time has elapsed when the rear differential switch 14 is turned on. The presence / absence and presence / absence of a function for controlling the luminance of night illumination of other electronic devices controlled by the microcomputer 21 in accordance with the operation of the push buttons 14 to 16 can be mentioned. In the present embodiment, since the microcomputer 21 has five input terminals 42 to 46, the input terminals 42 to 46 can be assigned corresponding to a maximum of five functions that differ for each specification described above.

  It can be used as a control device for an electronic device including a microcomputer mounted on a vehicle such as an automobile.

It is a front view of the operation panel provided with the operation knob and operation button of the control apparatus for vehicle air conditioning. It is the block diagram which showed the apparatus circuit of the control apparatus for vehicle air conditioning. It is a circuit diagram of the control circuit for destination setting which showed the principal part of this invention.

Explanation of symbols

20 Device Circuit 21 Microcomputer 42-46 Input Terminal 47 Vehicle Power Supply 48-52 Pull-up Resistor 53-57 Pull-down Resistor

Claims (1)

  Characteristic data unique to each specification depending on the destination is stored, a microcomputer having at least one input terminal for setting the characteristic data, and a pull-up resistor connected to the vehicle power line of the input terminal And a pull-down resistor connected to a ground line of the input terminal, wherein a voltage supplied from the vehicle power source is applied to the input terminal by the pull-up resistor and the pull-down resistor. A destination setting control circuit, wherein a divided voltage value is inputted.

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