JP3557301B2 - Motor drive circuit - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a drive circuit for selectively driving a plurality of motors using a motor drive IC.
[0002]
[Prior art]
For example, many motors are used in automobiles. In general, these motors can control forward and reverse rotation and also need a protection function in the event of a short circuit or locking of the load circuit. Controlled by a motor drive IC having terminals and having a protection function when the motor is short-circuited or locked is mainly used. For this reason, a motor drive IC is required for each motor, which has been a factor that increases the overall cost of the motor drive circuit.
[0003]
[Problems to be solved by the invention]
However, in an application in which only one of a plurality of motors is selectively driven, it is not always necessary to use a motor drive IC for each motor. In view of this point, the present invention has been made to realize a predetermined function at a low cost by controlling a plurality of motors with one motor drive IC and minimizing necessary circuit elements. Things.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, in the motor drive circuit of the first invention, the first motor having the highest operation frequency is connected to the normally closed contact of the first relay, and the operation frequency is set to the normally open contact. The next highest second motor is connected via the normally closed contact of the second relay, and a plurality of motors with the higher operation frequency are connected to the normally closed contact side while combining with the relay in the same manner. Connect the motors one after another according to the operation frequency so that the lower one is connected to the normally open contact side. together constitute a circuit which is to connect the parallel connection circuit of the motor between the output terminals of a pair of motor drive IC, when driving the second following motor is driven from the first relay The relay just before the given motor to be And so as to operate only the corresponding motor by an operation in.
[0006]
In the second invention, a plurality of motors are connected in series between a pair of output terminals of the motor drive IC, and a connection point of each motor is independently conducted in either the forward direction or the reverse direction. A common terminal of the plurality of semiconductor switches is connected to each of the semiconductor switches, and a positive terminal of each semiconductor switch is connected to one output terminal of the motor drive IC via a forward diode, and a reverse terminal is connected to a reverse diode. Connected to the other output terminal of the motor drive IC via a common terminal, and only the semiconductor switch whose common terminal is connected to the predetermined motor to be driven is made conductive so that only the corresponding motor is operated. are doing.
[0007]
In the third invention, one terminal of each of the plurality of motors is connected to one output terminal of the motor drive IC, and one of the forward and reverse directions is independently conducted to the other terminal of each motor. The common terminals of a plurality of semiconductor switches are connected to each other, the positive terminal of each semiconductor switch is connected to one output terminal of the motor drive IC via a forward diode, and the reverse terminal is connected to the reverse terminal. By connecting only the semiconductor switch connected to the other output terminal of the motor drive IC via the diode and the common terminal to the predetermined motor to be driven to the conductive state, only the corresponding motor is operated. I am.
[0008]
[First Embodiment of the Invention]
Next, the embodiment of the first invention will be described for a case where there are three motors. In the circuit diagram of FIG. 1, reference numeral 1 denotes a control unit including a microcomputer or a control IC, and 2 denotes a pair of output terminals 2a and 2b capable of reversing the polarity such as TA8080K. Are known motor drive ICs having the above protection function, 3 is a motor parallel connection circuit, M1, M2 and M3 are first to third motors provided for various operations, and R1 and R2 are relays. The motor drive IC 2 is connected to the control unit 1, and a drive voltage having a predetermined polarity is output from output terminals 2 a and 2 b according to a control signal of the control unit 1.
[0009]
Here, the motor M1 is used for the application with the highest operation frequency among the three units, the motor M2 is used for the application with the highest operation frequency after the motor M1, and the motor M3 is used for the application with the lowest operation frequency. I have. Further, C1, NC1 and NO1 are a common contact, a normally closed contact and a normally open contact of the relay R1, respectively. Similarly, C2, NC2 and NO2 are a common contact, a normally closed contact and a normally open contact of the relay R2, respectively.
[0010]
As shown in the figure, the parallel connection circuit 3 of the motor includes a normally closed contact NC1 of the relay R1, one end of the motor M1 connected to the normally open contact NO1, a common contact C2 of the relay R2 connected, and a normally closed contact of the relay R2. One end of a motor M2 is connected to NC2 and one end of a motor M3 is connected to a normally open contact NO2. A common contact C1 of a relay R1 is connected to one output terminal 2a of a motor drive IC2. The other end of each motor is connected to the other output terminal 2b. The driving transistors T1 and T2 are connected to the relays R1 and R2, respectively, and are turned on in response to a control signal output from the control unit 1 to the respective bases, so that the relays R1 and R2 operate. The common contacts C1 and C2 are switched to the normally open contacts NO1 and NO2.
[0011]
Next, the operation will be described. First, when operating the motor M1, the relays R1 and R2 are not operated, and a drive voltage having a predetermined polarity is simply output from the motor drive IC. As a result, the motor M1 is driven to rotate forward or reverse. When the motor M2 is operated, the drive transistor T1 is turned on to operate the relay R1, the common contact C1 is switched to the normally open contact NO1, and a drive voltage having a predetermined polarity is output from the motor drive IC. As a result, the motor M2 is driven to rotate forward or reverse. Further, when the motor M3 is operated, the driving transistors T1 and T2 are both turned on, the relays R1 and R2 are operated to switch the common contacts C1 and C2 to the normally open contacts NO1 and NO2, and at the same time, to the predetermined polarity. The drive voltage is output from the motor drive IC, which drives the motor M3 to rotate forward or reverse.
[0012]
As described above, the operation frequency of the motor M1 is the highest and the motor M3 is the lowest, and when the motor M1 driven at a high frequency is driven, it is only necessary to operate the motor drive IC2. When the motor M3 is driven, both the relays R1 and R2 need to be operated, but the frequency is the lowest. When the motor M2 is driven, the relay R1 needs to be operated. It is intermediate between the cases of M1 and M3. In other words, the higher the frequency of operation of the motor, the easier the control because the number of relays to be operated is smaller, and the overall control procedure is simpler than when a relay is provided for each of the motors M1, M2, M3. Become. In addition, a drive circuit can be configured at a lower cost than when a motor drive IC is provided for each motor.
[0013]
In FIG. 1, T1 ', T2', and T3 'are braking transistors. That is, when the motor is not driven, these transistors are turned on by the control signal from the control unit 1, and the respective motors M1, M2, M3 are brought into a braking state. It is also possible to switch the motor after braking by the output, and leave the motor circuit open when not controlling. Accordingly, in this case, a braking circuit using the transistor T1 'or the like is unnecessary, and this control circuit is not shown in FIGS.
[0014]
In the present invention, the number of required relays may be one less than the number of motors. Therefore, especially when there are only two motors M1 and M2, the relay R2 is unnecessary, and the motor is connected to the normally open contact NO1 of the relay R1. What is necessary is just to connect M2 directly. Therefore, the circuit configuration becomes simple and the control procedure becomes extremely simple. When the number of motors is four or more, a motor having a high operating frequency is connected to the normally closed contact side of the relay and a motor having a low operating frequency is connected to the normally open contact side according to FIG. A plurality of motors may be connected in parallel in the order of operation frequency in combination with a relay, and this parallel connection circuit may be connected between output terminals of the motor drive IC.
[0015]
[Second Embodiment of the Invention]
Next, an embodiment of the second invention will be described. FIG. 2 shows an example in which there are n motors, where M1, M2,..., Mn are the first to nth motors, and S1, S2,. The switches D1, D2, D3, and D4 are diodes, and the semiconductor switches S1 to Sn-1 are each configured by combining two power transistors TR1 and TR2.
[0016]
As shown in the figure, the motors M1 to Mn are connected in series between the output terminals 2a and 2b of the motor drive IC2, and the collector side of the transistors TR1 and TR2 of the semiconductor switches S1 to Sn-1 is a common terminal. They are sequentially connected to motor connection points. Further, the emitter side of each transistor TR1 is connected to the output terminal 2a or 2b of the motor drive IC2 via a diode D1 or D2 in the reverse direction, respectively, and the emitter side of each transistor TR2 is connected via a diode D4 or D3 in the forward direction, respectively. Connected to the output terminal 2a or 2b of the motor drive IC2. Although not shown, the bases of the transistors TR1 and TR2 of each semiconductor switch are connected to the control unit 1, and the conduction is controlled by a control signal from the control unit 1.
[0017]
Next, the operation will be described assuming that the case where the motor current flows in the direction of the solid line arrow in the drawing is normal rotation and the case of the broken line arrow is reverse rotation. First, when the motor M1 is rotated forward, the terminal 2a outputs a positive drive voltage from the motor drive IC2, and at the same time, only the transistor TR2 of the semiconductor switch S1 is turned on. Thus, a circuit including the terminal 2a, the motor M1, the transistor TR2, the diode D3, and the terminal 2b is formed, and the motor M1 rotates forward. In the case of reverse rotation, the polarity of the drive voltage of the motor drive IC2 is reversed, and only the transistor TR1 is turned on. As a result, a circuit including the terminal 2b, the diode D2, the transistor TR1, the motor M1, and the terminal 2a is formed, and the motor M1 rotates reversely.
[0018]
Next, when the motor M2 is rotated forward, the terminal 2a outputs a positive drive voltage from the motor drive IC2, and at the same time, the transistor TR1 of the semiconductor switch S1 and the transistor TR2 of the semiconductor switch S2 are turned on. Thus, a circuit including the terminal 2a, the diode D1, the transistor TR1 of the semiconductor switch S1, the motor M2, the transistor TR2 of the semiconductor switch S2, the diode D3, and the terminal 2b is formed, and the motor M1 rotates forward. In the case of reverse rotation, the polarity of the drive voltage of the motor drive IC2 is reversed, and the transistor TR2 of the semiconductor switch S1 and the transistor TR1 of the semiconductor switch S2 are turned on. As a result, a circuit including the terminal 2b, the diode D2, the transistor TR1 of the semiconductor switch S2, the motor M2, the transistor TR2 of the semiconductor switch S1, the diode D4, and the terminal 2a is formed, and the motor M2 rotates reversely.
[0019]
As described above, a drive voltage of a predetermined polarity is output from the motor drive IC2, and at the same time, in the case of the motor M1 or Mn at both ends, the transistors TR1 and TR2 of either the semiconductor switch S1 or Sn-1 are selectively turned on. In the case of other motors, by selectively turning on one of the transistors TR1 and TR2 of the two semiconductor switches connected to both sides thereof, one desired motor can be rotated forward or reverse. You can.
[0020]
Therefore, a plurality of motors M1 to Mn can be controlled by one motor drive IC, and the number of semiconductor switches is one less than the number of motors, so that a drive circuit can be formed at low cost. Also, since the diode is inserted in series in the energizing circuit, no reverse voltage is applied to the power transistor, and the semiconductor switch is not damaged by the reverse voltage.
[0021]
[Third Embodiment]
According to the second aspect of the invention, in the case other than the motors M1 and Mn at both ends, since two power transistors are inserted in the energizing circuit, the loss increases by that amount. The third invention solves this point, and an embodiment thereof will be described with reference to FIG.
[0022]
Here, one terminal of each of the plurality of motors M1 to Mn is connected to one output terminal 2a of the motor drive IC 2, and semiconductor switches S1 to Sn are provided for each motor, and the common terminal is connected to the other terminal of each motor. And the emitter side of each transistor TR1 is connected to the output terminal 2a or 2b of the motor drive IC2 via the reverse diode D1 or D2, respectively, and the emitter side of each transistor TR2 is connected to the forward diode D3. Alternatively, it is connected to the output terminal 2b or 2a of the motor drive IC 2 via D4.
[0023]
With the above-described configuration, for example, when a current in the direction of the solid line arrow is supplied to the motor M1 to perform forward rotation, the terminal 2a side outputs a positive drive voltage from the motor drive IC2, and at the same time, the transistor TR2 of the semiconductor switch S1 is activated. Turn on. Thus, a circuit including the terminal 2a, the motor M1, the transistor TR2, the diode D3, and the terminal 2b is formed, and the motor M1 rotates forward. In the case of reverse rotation, the polarity of the drive voltage of the motor drive IC2 is reversed, and the transistor TR1 is turned on. As a result, a circuit including the terminal 2b, the diode D2, the transistor TR1, the motor M1, and the terminal 2a is formed, and the motor M1 rotates reversely. The other motors can be rotated forward or reverse according to this.
[0024]
As described above, a drive voltage having a predetermined polarity is output from the motor drive IC2, and at the same time, one of the transistors TR1 and TR2 of the semiconductor switch connected to the motor to be driven is selectively turned on, so that the desired motor is driven. Only one unit can be rotated forward or reverse.
[0025]
Therefore, a plurality of motors M1 to Mn can be controlled by one motor drive IC, and a drive circuit can be formed at low cost. Also, no reverse voltage is applied to the power transistor due to the diodes D2 and D3 inserted in series in the energizing circuit and the diodes D1 and D4 connected in parallel to the series circuit of the motor and the semiconductor switch. Therefore, the semiconductor switch is not damaged.
[0026]
【The invention's effect】
As is apparent from the above description, the motor drive circuit according to the first aspect of the invention connects a motor with a high operation frequency to the normally closed contact side of the relay and connects a motor with a low operation frequency to the normally open contact side. In this way, a plurality of motors are connected in parallel in the order of operation frequency in combination with a relay, and this parallel connection circuit is connected between output terminals of the motor drive IC.
[0027]
Therefore, the number of required relays is one less than the number of motors, and moreover, one motor drive IC can control a plurality of motors, so that the cost is lower than when a motor drive IC is provided for each motor. A drive circuit can be configured. In addition, the motor with the highest operation frequency is always connected to the motor drive IC, and the other motors with higher operation frequency require fewer relays to operate at the time of driving. It's easy.
[0028]
According to a second aspect of the present invention, a plurality of motors are connected in series between output terminals of the motor drive IC, and a semiconductor switch is connected to a connection point of each motor. At the same time, the conduction of either the forward direction or the reverse direction of each semiconductor switch is controlled.
[0029]
Therefore, a plurality of motors can be controlled by one motor drive IC, and the number of semiconductor switches is one less than the number of motors. Therefore, a drive circuit can be formed at low cost. Further, the diode inserted in the energizing circuit prevents the semiconductor switch from being damaged by the reverse voltage.
[0030]
According to a third aspect of the present invention, a plurality of circuits in which a motor and a semiconductor switch are connected in series between output terminals of a motor drive IC are connected in parallel, and a drive voltage of a predetermined polarity is output from the motor drive IC and any one of them is simultaneously output. Of the semiconductor switch in the forward or reverse direction.
[0031]
Therefore, it is possible to configure a drive circuit at a low cost, in which a plurality of motors can be controlled by one motor drive IC, and no loss is caused by inserting two semiconductor switches into the power supply circuit. Further, the diode inserted in the energizing circuit prevents the semiconductor switch from being damaged by the reverse voltage.
[Brief description of the drawings]
FIG. 1 is a basic circuit diagram showing an example of a drive circuit according to the first invention.
FIG. 2 is a basic circuit diagram showing an example of a drive circuit according to a second invention.
FIG. 3 is a basic circuit diagram showing an example of a drive circuit according to a third invention.
[Explanation of symbols]
1 control unit 2 motor drive IC
2a, 2b Output terminal 3 Motor parallel connection circuit M1 to Mn Motor R1, R2 Relay C1, C2 Common contact NC1, NC2 Normally closed contact NO1, NO2 Normally open contact S1 to Sn Semiconductor switch TR1, TR2 Power transistor D1 to D4 Diode

Claims (4)

Multiple motors are connected to one motor drive IC that has a pair of output terminals capable of reversing the polarity and has a protection function when the motor is shorted or locked, and only one of these motors is selected. Is a circuit that is dynamically driven,
The first motor with the highest operation frequency is connected to the normally closed contact of the first relay, and the second motor with the next highest operation frequency is connected to the normally open contact via the normally closed contact of the second relay. In the same manner, a plurality of motors are sequentially connected in accordance with the operation frequency such that the higher operation frequency is connected to the normally closed contact side and the lower operation frequency is connected to the normally open contact side while being combined with the relay in the same manner, lowest motor operation frequency, along with constituting the circuit normally open plurality of motors connected directly to the contacts are substantially connected in parallel immediately before the relay 1 a parallel connection circuit of the motor of the motor drive IC When connecting between the pair of output terminals and driving the second or lower motor, only the corresponding motor is operated by operating from the first relay to the relay immediately before the predetermined motor to be driven. To let Driving circuit of the motor, characterized in that form. 2. The motor drive circuit according to claim 1, wherein three or more motors are connected to one motor drive IC . Multiple motors are connected to one motor drive IC that has a pair of output terminals capable of reversing the polarity and has a protection function when the motor is shorted or locked, and only one of these motors is selected. Is a circuit that is dynamically driven,
A plurality of motors are connected in series between a pair of output terminals of the motor drive IC, and a plurality of semiconductor switches are connected in common in a forward direction or a reverse direction independently to a connection point of each motor. Terminals are connected to each other, and the positive terminal of each semiconductor switch is connected to one output terminal of the motor drive IC via a forward diode, and the reverse terminal is connected to the motor drive IC via a reverse diode. The semiconductor device is connected to the other output terminal, and is configured to operate only the corresponding motor by turning on only a semiconductor switch having a common terminal connected to a predetermined motor to be driven. Motor drive circuit. Multiple motors are connected to one motor drive IC that has a pair of output terminals capable of reversing the polarity and has a protection function when the motor is shorted or locked, and only one of these motors is selected. Is a circuit that is dynamically driven,
One of the output terminals of the motor drive IC is connected to one terminal of each of the plurality of motors, and the other terminal of each of the plurality of semiconductor switches is independently conductive in either the forward or reverse direction. A common terminal is connected to each of the semiconductor switches. A positive terminal of each semiconductor switch is connected to one output terminal of the motor drive IC via a forward diode, and a reverse terminal is connected to a motor drive IC via a reverse diode. Connected to the other output terminal of each of the first and second terminals, and only the corresponding motor is operated by turning on only a semiconductor switch having a common terminal connected to a predetermined motor to be driven. Motor drive circuit.

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