JPH0787713B2 - Motor forward / reverse device - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention is a method for controlling a motor mounted on an automobile,
More specifically, the present invention relates to a control method of a motor such as a power window driving motor in which stop and forward / reverse rotation are freely selected.

[Prior art]

FIG. 3 shows an example of a conventional method of controlling the motor M that requires such a forward / reverse rotation function. One of the contact terminals of a double-pole double-throw switch S having a neutral point is used to control the motor M. The positive and negative power supply lines are connected, and this contact terminal and the other one of the contact terminals are connected in a shunted manner, and the motor M is rotated in the normal direction by making it any contact terminal side connected to the closing terminal. Alternatively, reverse rotation is performed, and the motor M is stopped by setting the closing terminal at a neutral point, that is, a position not connected to any contact terminal.

[Problems to be Solved by the Invention]

However, the above-mentioned conventional method has a problem that it is difficult to deal with the above-mentioned conventional method because the control by the motor is highly sophisticated, and for example, automation or high precision by the stepping motor includes mechanical parts. Secondly, the wiring is becoming more and more congested with the increasing sophistication of electronic control of automobiles in recent years, and thus it is becoming impossible in space to route two power lines in this way. It was an issue.

[Means for Solving the Problems]

The present invention comprises, as a concrete means for solving the above-mentioned problems that occur in the prior art, a microcomputer, a modulation circuit, a comparison circuit, a motor drive circuit and a motor, and the microcomputer outputs an output terminal for outputting a forward rotation command. And a pair of resistance elements connected in series to the power supply voltage so that the modulation circuit has a midpoint that divides the power supply voltage into approximately two, and an output terminal that outputs a reverse rotation command, and each of the resistance elements. And a switching element connected in parallel, the comparison circuit includes two voltage comparison circuits connected to the midpoint, and one voltage comparison circuit has a power supply voltage of approximately 3/4 higher than the midpoint voltage. Is set to a reference voltage, and an output is generated when the reference voltage is higher than this reference voltage, and the other one of the voltage comparison circuits has the reference voltage set to approximately 1/4 power supply voltage lower than the voltage at the midpoint. , Shall produces an output when the reference voltage below the output terminals of the microcomputer is connected to said switching element of said modulation circuit, an output terminal of the modulation circuit is connected to s the voltage comparing circuit respectively,
The motor drive circuit is connected to the output terminals of the two voltage comparison circuits, and when neither of the voltage comparison circuits produces an output, the motor is stopped, and when one of the voltage comparison circuits produces an output. The motor forward / reverse rotation device is characterized in that the motor is rotated in a predetermined direction and the motor is rotated in the reverse direction when an output is generated in the other one of the voltage comparison circuits. The present invention solves the above-mentioned conventional problems by making it possible to control a motor with a single motor.

【Example】

Next, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is an electric circuit diagram of a motor forward / reverse rotation device according to the present invention, which is an example of a device for correcting an optical axis of a headlight that changes depending on a load such as a load. Reference numeral 1 in the figure is a transmitter, and this transmitter 1
Is a modulation circuit that is composed of a microcomputer CPU and resistance elements R ₁ and R ₂ and switch elements Q ₁ and Q ₂ such as transistors connected to the output of this microcomputer CPU.
There is a MOD, and one receiving unit 2 has voltage comparison circuits CMP ₁ and CMP ₂ connected to the modulation circuit MOD and the voltage comparison circuit.
There is a motor drive circuit MD and a motor M connected to CMP ₁ and CMP ₂ . The adjustment amount of the optical axis is given to the input terminals s1 to s4 of the microcomputer CPU of the transmitter 1 as, for example, a 4-bit signed digital amount, and the microcomputer CPU inputs this input to the motor M. On the other hand, if it is determined that clockwise rotation is necessary, output is performed from the output terminal cw1, and if it is determined that counterclockwise rotation is required, output is performed from the output terminal ccw1. It is the modulation circuit MOD that receives this output, and the resistance element R ₁ and the resistance element R ₂ are connected in series to the modulation circuit MOD so as to divide the power supply voltage Vcc into approximately two. Switch element Q ₁ , so as to be in parallel with R ₁ and R ₂ ,
Q ₂ is connected to the output terminals cw1 and c
cw1 is connected to the control terminals of the switch elements Q ₁ and Q ₂ , respectively. Here, when the switch elements Q ₁ and Q ₂ are specifically transistors, collectors and emitters are connected to both ends of the resistance elements R ₁ and R ₂ , respectively, and the output terminals cw 1 and ccw 1
The base will be connected to. In addition, reference numerals in the figure
The resistance elements indicated by R ₃ and R ₄ are for protecting the switching elements Q ₁ and Q ₂ , and here, for ease of understanding, R ₁ >>
It is assumed that R ₃ and R ₂ >> R ₄ and the influence can be ignored. Further, a transistor Q ₃ for extracting the midpoint voltage is connected to the midpoint where the resistance elements R ₁ and R ₂ are connected. Here, the operation of the modulation circuit MOD will be described. First, when no output is generated to the microcomputer CPU, neither of the switch elements Q ₁ and Q ₂ is conductive, and this modulation circuit MOD The output of Z ₁ is shown in Fig. 2.
It will be stable at a voltage of approximately 1/2 Vcc as shown in the range. Next, when an output is generated at the output terminal cw1, one of the switching elements Q ₁ becomes conductive in response to this output, so that the resistance element R ₁ becomes short-circuited, and this modulation circuit MOD the output voltage range of approximately 1 / 2Vcc from substantially Vcc as shown by the range of Z ₂ in FIG. 2, the one that responds to the output of the microcomputer CPU. Similarly, when an output is generated at the output terminal ccw1, the other one of the switching elements Q ₂ becomes conductive in accordance with this output, so that the other one of the resistance elements R ₂ is short-circuited, Similarly, the output responds to the output of the microcomputer CPU in the voltage range of about 1/2 Vcc to about 0 V as shown in the range of Z ₃ in FIG. As is clear from the above description, the reference voltage is set in one of the voltage comparison circuits CMP ₁ provided in the receiving section 2 so as to generate an output when the voltage is approximately 3/4 Vcc or higher, and the other voltage comparison circuit CMP ₁ is compared. By setting a reference voltage in the circuit CMP ₂ so that an output is generated when the voltage is approximately 1/4 Vcc or less, the input terminals cw2 and ccw2 of the motor drive circuit MD are connected in the rotation direction of the motor M. A corresponding control signal is applied. It should be noted that the signal line 3 connecting the transmitting unit 1 and the receiving unit 2 will be particularly described here, and this signal line 3 needs to transmit only the voltage as is clear from the above description. Therefore, the problem of current capacity does not occur, and therefore, an extremely thin object can sufficiently attain the purpose. In the figure, reference numeral F is a filter for removing the alternator noise and the like on the signal line 3,
For the same reason, a small capacity will serve the purpose. Further, in the above description, the transmitter 1 and the receiver 2 are operated with the same power supply voltage for the sake of easy understanding, but there is a difference in this voltage depending on the standard of the electronic parts used. Can also be implemented, and at this time, the values of the resistance elements R ₁ and R _{2 and} the like may be appropriately adjusted according to the voltage of the receiving unit 2.

【The invention's effect】

As described above, according to the present invention, a pair of resistance elements connected in series to the power supply so as to have a midpoint that divides the power supply voltage into approximately two, and a switching element connected in parallel to each of the resistance elements. And a voltage comparison circuit that is connected to the midpoint and determines whether the midpoint voltage rises or falls from the set voltage.The motor is stopped at the set voltage and the voltage rises from the set voltage. The motor forward / reverse rotation device sometimes rotates the motor in a predetermined direction and reverses the motor when the voltage drops from the set voltage, so that the power line between the transmission unit and the reception unit, that is, the operation unit and the motor. It has an excellent effect that it solves the problem of the space inside the car by making it possible to control with a very thin signal line and with one line, and furthermore, mechanical parts are abolished and all are placed in electronic parts. Effect called also to place automation is also intended to achieve combined.

[Brief description of drawings]

FIG. 1 is a wiring diagram showing an embodiment of a motor forward / reverse rotation device according to the present invention, FIG. 2 is a graph showing the action of the transmitter of the same embodiment in terms of voltage, and FIG. 3 is a wiring diagram showing a conventional example. is there. 1 …… Sending unit CPU …… Microcomputer cw1 …… Clockwise output terminal ccw1 …… Counterclockwise output terminal MOD …… Modulation circuit R ₁ , R ₂ …… Resistor element Q ₁ , Q ₂ …… Switch element 2 ... Receiver CMP ₁ , CMP ₂ ...... Voltage comparison circuit MD …… Motor drive circuit cw2 …… Clockwise input terminal ccw2 …… Counterclockwise input terminal M …… Motor 3 …… Signal line

Claims (1)

[Claims] 1. A microcomputer comprising a microcomputer, a modulation circuit, a comparison circuit, a motor drive circuit and a motor, the microcomputer having an output terminal for outputting a forward rotation command and an output terminal for outputting a reverse rotation command, and the modulation circuit. A pair of resistance elements connected in series to the power supply voltage so as to have a midpoint that divides the power supply voltage into approximately two, and a switch element connected in parallel to each of the resistance elements, wherein the comparison circuit is It is composed of two voltage comparison circuits connected to the middle point, and one of the voltage comparison circuits has a reference voltage set to about 3/4 power supply voltage higher than the voltage obtained by dividing the power supply voltage into about two, and this reference voltage or more The output voltage is generated at the time of, and the other one of the voltage comparison circuits has a reference voltage set to about 1/4 power supply voltage lower than the voltage obtained by dividing the power supply voltage into about two, and when the voltage is less than or equal to this reference voltage. output The output terminal of the microcomputer is connected to the switch element of the modulation circuit, the output terminal of the modulation circuit is connected to each of the voltage comparison circuits, and the motor drive circuit is connected to each of the two voltage comparison circuits. Connected to the output terminal, when no output is generated in either of these voltage comparison circuits, the motor is stopped, and when an output is generated in the one voltage comparison circuit, the motor is rotated in a predetermined direction, A motor forward / reverse rotation device, wherein the motor is rotated in the reverse direction when an output is generated in the other voltage comparison circuit.