JPS58116080A - Control circuit for drive of motor - Google Patents

Abstract

PURPOSE:To prevent the flowing of abnormal large currents through a switching element by providing a circuit bypassing transient currents based on the inductance of the motor generated in case of the changeover of circuits. CONSTITUTION:When transistors 1, 6 are turned ON and 3, 4 OFF, the motor 9 is turned forward. The terminal voltage of a resistor 8 is detected at that time, and the transistor 1 is ON-OFF controlled by a chopper control section based on the voltage. When the transistors 1, 6 are turned OFF, transient currents based on the inductance of the motor 9 flow in the path of a diode 11, a power supply 7, a diode 14 and the motor 9. The transistor 6 is left as it is turned OFF because currents do not flow through the resistor 8 at that time. When the transistors 3, 4 are turned OFF, the motor 9 is reversed. Accordingly, circuits can rapidly be changed over smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical field of the invention The present invention relates to a drive control circuit.
A control circuit that enables quick and smooth motor drive control, especially in circuits that allow the motors used in printers such as dot printers and kanji printers to maintain a constant printing speed to be rotated in forward and reverse directions using a single power source. Regarding.

(2) Technical background Data processing by data processing equipment 1! For example, a printer such as a dot printer or a kanji printer is used to print the results. In such a printer, the printing bar is moved in the printing direction and vice versa,
Furthermore, constant speed control is performed to keep the printing speed constant. The motor used to move the print bar is controlled to switch forward, reverse, and N rotations, and is also controlled by constant current to control the print bar at a constant speed.

(3) US-based technology and problems Conventionally, the circuit shown in Figure 1 has been used to perform the above-mentioned control. This circuit turns on the transistor Tr-1f to cause the motor M@ to rotate in the forward direction and causes a current to flow from the power source E1 in the direction of the solid arrow, and to rotate the motor Me f in the reverse direction, the transistor Tr-1f is turned on. The current ffI flows in the direction of the dotted arrow on r -2+
t. Then, the terminal voltage is detected by the current observation resistor R, and the on period of the transistor T data 1 (or T data 2) is adjusted and controlled accordingly, thereby enabling constant current control. It's in control. However, this circuit configuration.

Since separate power supplies E1 and Em are required depending on the current in the forward and reverse directions, there is a problem in that the cost is high.

Therefore, the circuit shown in Figure 2 is used.

This circuit illustrates a series circuit of transistor 1-diode 2-transistor 3 and a series circuit of transistor 4-diode 5-transistor 6.

Connect between points. In addition, the positive terminal of the power source 7 is connected to the 6 points, a resistor 8 for current observation is connected to the & point, and the negative terminal of the power source 7 is connected to the resistor 8. Then, a transistor (M9) is connected between the output terminals of the diode 2 and the diode 5, and a diode L is connected in parallel to the series circuit of the transistor L and the diode 2.
A diode 11 is connected in parallel with a series circuit of transistor 4 and diode 5. Here, the transistor 1 has a built-in diode 16 with the polarity shown, and similarly, the transistors 3, 4, and 6 have diodes 3-14 and 6 built-in, respectively. Also resistance 8
One end is grounded, and the other end is connected to the device control section.

In this circuit, when transistor 1.6t is on and transistor 3.4 is off, the current flows from power supply 7 - transistor l - diode 2 - motor 9 - transistor 6 -
The current flows through the resistor 8-power supply 7 path, and the resistor 9 rotates in the forward direction.

Conversely, transistor 1. 6 off and transistor 3.4 on, the current flows from power supply 7 - transistor 4
- Diode 5 - Tally transistor 3 - Resistor 8 -
It flows through the path of the power source 7, and the motor 9 rotates in the opposite direction. At this time, the terminal voltage of resistor 8 is detected, and this detected value is sent to the chip control section, where transistor 6 (forward rotation) or transistor 3 (reverse rotation) is controlled on and off to perform constant current control. The motor 9 is controlled at a constant speed.

By the way, when the motor 9 is rotated from normal rotation to reverse rotation as described above, the transistor 1.6 is controlled from on to off, but at this time, since the motor 9 has an inductance, the transient current flows between the motor 9 and the diode. 11-Power supply 7-
The current flows through the path of resistor 8 and diode 3G. Therefore, due to the voltage drop caused by the resistor 8, the emitter voltage of the transistor 6 becomes lower than the ground voltage, and the transistor 6 may be turned on. In this state, transistor 3.4
When turned on, current flows through the path of power supply 7 - transistor 4 - transistor 6 - power supply 7.

A large current flows through transistor 4.6. As a result, these transistors 4.6 may be destroyed. Therefore, the current based on the above inductance is F
The turn-on operation of transistor 3.4 had to be delayed until it was small enough to turn it off, making it impossible to quickly and smoothly switch the rotation of the motor. It should be noted that when the hepteater 9 is rotated from reverse rotation to forward rotation, the transistor 3 is turned on due to the voltage drop caused by the resistor 8 in the same manner as described above, and the transistor 1. 3 may be destroyed.

The above applies when the motor 9 is rotated in forward and reverse directions, but when the motor 9 is decelerated from a constant speed or put into a pure state, one transistor L,
3 or 4.6 may be on at the same time.

For example, if we look at this with regard to the rotation of the motor 9 in the forward direction, it will be as shown in FIG. Here, the motor 9 rotates at a constant speed due to the on/off combination of each transistor shown in tkl, and the current path. Theft.

From this state, the electric brake is applied to the motor 9 through the current flow when all the transistors are on, indicated by FJn2, and then the current flow due to the combination of on/off transistors indicated by Nn3, whereby the motor 9 is rapidly decelerated. Finally, the motor 9 is rotated at a constant speed due to the combination of on/off of the transistors shown in the diagram 5 and the constant current generated by operating the transistor 6.
When transitioning from Nn3 to Nb2, all transistors are turned off as shown by Nn4. At this time, the transient current of the motor 9 flows through the resistor 8, which may turn on the transistor 6. When the state shifts to Nn5 in this state, the transistors 4 and 6 turn on at the same time, and as described above, the transistor 6 turns on. .6 may be destroyed. When the motor 9 is stopped from a constant speed, a reverse current flows through the motor 9 due to the on/off combination of the transistors shown as Nn7, but when the state changes from FkLl to Nn7, the current is shown on the 0th floor 6. All transistors are turned off. At this time, resistor 8 as above
A transient signal flows through transistor 3, transistor 3 is turned on, and in this state, when the transition is made to N+17, transistor 1. 3
may turn on at the same time, destroying these transistors. Note that when the electric brake is applied to the motor 9 in step 3 above, the current flows through the diode 3.
Since this is a built-in diode in the transistor, it has a large resistance and therefore reduces the current flowing to the motor, making the brakes less effective. Also, since the capacity is small, it has the disadvantage of being prone to over-wattage.

(4) Purpose of the Invention As stated above, the purpose of the present invention is to quickly and smoothly switch circuits due to transient current caused by motor inductance when conventionally driving a motor in forward and reverse rotation with a single power source. In order to improve the problem that the above-mentioned inductance-induced current is bypassed, the present invention provides a motor drive control circuit that is provided with a circuit that bypasses the current caused by the inductance.

(5) Structure of the invention and to achieve this object, in the motor drive control circuit of the present invention, switching means series circuits each configured by connecting at least two switching means in series are connected in parallel, and one of the switching means series circuits is connected in parallel. In a motor drive control circuit in which a power source is connected to a connecting portion, the other connecting portion is connected to the power source through a resistor, and a motor capable of forward and reverse rotation is connected between the switching means of each of the series circuits. .

It is characterized in that unidirectional conductive elements are connected from both ends of the motor to both ends of the electrical connection part, respectively.

(6) Examples of the invention Next, one embodiment of the present invention will be described based on FIG. 4.

FIG. 4 is a circuit diagram of an embodiment of the present invention.

In the figure, the same reference numerals as in other figures indicate the same components, and 21 diode 2 and second diode 5 in FIG.
Remove f and also diode 12゜13.14.15'
).

The diode 12 has its input terminal connected to the connection point between the -77 terminal of the diode 9 and the collector terminal of the transistor l, and its output terminal connected to the collector terminal of the transistor 3. Similarly to the diode 12, the diode 13 has its input terminal connected to the connection point between the other terminal of the motor 9 and the collector terminal of the transistor 4, and its output terminal connected to the collector terminal of the transistor 6.

The diode 14 bypasses transient current based on the inductance of the motor 9.

The diode 14 has its input terminal connected to the power supply 7 and its output terminal connected to one terminal of the motor 9. The diode 15 also has the same function as the diode 14, and its input terminal is connected to the power supply 7, and its output terminal is connected to the other terminal of the motor 9.

Note that the diodes 10, 11, 14, and 15 are as follows.

A shield diode with low internal resistance is used.

Further, the transistor 1 or 4 is controlled to be turned on or off by a chipper control section, and also functions as a chopper selectively.

Next, the operation of the embodiment of the present invention shown in FIG. 4 will be described.

When transistor 1.6') is turned on and transistor 13°4 is turned off, the current flows from power supply 7 - transistor l - resistor 9 - diode 13 - transistor 6 - resistor 8 - power supply 7
The motor 9 rotates in the forward direction. At this time, resistance 8
terminal voltage is detected.

Based on this, the transistor l is controlled on and off by the chip control section, and a constant current flows through the motor 9.

Next, when transistor 1.6t is turned off and all transistors are turned off, the transient current based on the inductance of 9 is caused by
- flows in the path of the motor 9;

At this time, since no current flows through the resistor 8, the emitter voltage of the transistor 6 does not become lower than the ground voltage and the transistor 6 remains off. In this way, transistor 1.
Transistor 6 is kept off even immediately after transistor 6 is turned off, so transistor 3.4 is connected to transistor 1.
．． Even if the transistor 6 is turned off and turned on at the same time, the transistor 4.6
are not turned on at the same time, and as a result, the current is
)') Transistor 3.4 in the path of transistor 4 - resistor 9 - diode 12 - transistor 3 - resistor 8 - power supply 7
The motor 9 flows smoothly from the beginning when it is turned on, and the motor 9 is switched to the reverse rotation direction. In order to control the Tanabata 9 with a constant current in this reverse rotation state, it is sufficient to control the transistor 4 in a constant current state.If the motor 9 is to be rotated from this reverse rotation to a forward rotation, the star 1.6f can be controlled in the same way as above. Just turn it on.

In addition, based on the on/off combinations of transistors corresponding to Figure 3 when Tanabata is decelerated from a constant speed or stopped, and based on these (current path f shown in Figure 5), As is obvious, when slowing down the motor from a constant speed.

Motor 9 immediately without turning off all transistors.
It is possible to apply a dynamic brake to the vehicle, and similarly, it is possible to control the transistor 1 to a predetermined constant speed without turning off all the transistors.

When the dynamic brake is applied, the current flows through the diodes 11 and 14, but since these are switching barrier diodes, their resistance is smaller than that of a diode connected to a transistor, and the current flowing to the motor 9 is There will be more. As a result, the force of the power generation brake is improved, and overage is less likely to occur.

Note that the above is a case where the motor 9f is rotated in the forward direction.

The same applies to the case of reverse rotation.

Note that in the above description, diodes 10, 11. 14°1
Although we have explained an example in which a shut-off barrier diode is used for the transistor 1, 3.4°6, etc., it is of course not limited to this.
Although the example using the iIl has been described, it is of course not limited to this.

(7) As described in detail, according to the present invention, a circuit is provided to bypass the transient current based on Tanabata inductance that occurs when switching one circuit, so a constant current control resistor is connected to the switching element. It is possible to prevent current from flowing through this resistor even if the resistor is connected. This prevents switching elements from turning off from being on.

For example, when a large current flows through a transistor used as a switching element,
Furthermore, if the on/off of the switching element is not affected by the transient current, one circuit can be switched quickly and smoothly.

[Brief explanation of drawings]

Figure 2 is a conventional motor drive control circuit diagram, Figure 3 is an explanatory diagram of the operation of the circuit in Figure 2, Figure 4 is the circuit configuration of this actual example, and Figure 5 is the diagram in Figure 4. FIG. 2 is an explanatory diagram of the operation of the circuit. In the figure, 1, 3, 4.6 are transistors, 11.3.
. 4g, 6. are diodes that are attached to the respective transistors 1, 3, 4, 6, 2, 5, 10, 11.12゜1
3.14.15 is a diode, 7 is a power supply, and 8 is a resistor. 9 is a motor. Patent Applicant Fujitsu Co., Ltd. Representative Patent Attorney Akira Yamatani Figure 1 Figure 2

Claims (1)

[Claims] (1) Switching means series circuits each consisting of at least 21 m of switching means connected in series are connected in parallel, a power supply is connected to one of the connections, and the other power connection is connected to the upper power distribution via a resistor. At the same time, in the drive control circuit of the seven-star tanabata in which a motor capable of forward and reverse rotation is connected between the switching means of each of the series circuits, unidirectional conductive elements are connected from both ends of the tanabata to both ends of the power supply section, respectively. A Tanabata drive control circuit characterized by being connected.