JPH05191996A - Motor drive circuit - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a motor drive circuit in which a through current does not flow even if reverse operation is performed without time delay. [Structure] Motor drive transistors 1, 2, 3 and 4 have the same conductivity type drive circuit control transistors 10 and 1 in which the base and emitter are commonly connected to each other.
1, 12, 13 are provided, and the collectors of these transistors control the drive circuits 6, 7, 8, 9 for turning on and off the motor drive transistors so that a through current does not flow through the motor drive transistors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in motor drive circuits.

[0002]

2. Description of the Related Art FIG. 2 is a circuit diagram of a conventional motor drive circuit. In FIG. 2, 1 is an emitter of a first power source (Vc).
PNP transistor connected to c), 2 is this PNP
PN with the emitter of the transistor 1 connected to the emitter
The P-transistor 3 is connected to the collector of the PNP transistor 1 and the emitter is the second power source (ground).
The NPN transistor 4 connected to the NPN transistor 4 has the emitter and the emitter of the NPN transistor 3 connected, and the collector and the collector of the PNP transistor 2 connected to each other.
Transistor 5 is a motor connected between collectors of commonly connected transistors 1 and 3, 2 and 4, and 6 is a PN
A first drive circuit connected to the base of the P-transistor 1 to switch the PNP transistor 1, 7 is connected to the base of the PNP transistor 2 and a second drive circuit to switch the PNP transistor 2, 8 is a base of the NPN transistor 3. A third drive circuit connected to switch the NPN transistor 3 and a fourth drive circuit 9 connected to the base of the NPN transistor 4 to switch the NPN transistor 4.

Next, the operation will be described. The first drive circuit 6 and the fourth drive circuit 9 connect the PNP transistor 1 and the NP.
When the N transistor 4 is turned on and the PNP transistor 2 and the NPN transistor 3 are turned off by the second drive circuit 7 and the third drive circuit 8, the current flowing through the PNP transistor 1 passes through the motor 5 and flows into the NPN transistor 4.
The motor 5 rotates. Further, when the PNP transistor 2 and the NPN transistor 3 are turned on by the second drive circuit 7 and the third drive circuit 8 and the PNP transistor 1 and the NPN transistor 4 are turned off by the first drive circuit 6 and the fourth drive circuit 9, respectively. The current flowing through the transistor 2 passes through the motor 5 and then flows through the NPN transistor 3, and the motor 5 rotates in the opposite direction to the above operation.

[0004]

Since the conventional motor drive circuit is constructed as described above, when a collector and a transistor of opposite conductivity type to which the collector is connected are both turned on, a very large through current flows. However, when reversing the direction of rotation, there is a problem that it is necessary to wait for a certain period of time before entering the reverse rotation operation until the transistor that was on is turned off.

The present invention has been made to solve the above problems, and an object thereof is to obtain a motor drive circuit in which a through current does not flow even when a reverse operation is performed without a time delay.

[0006]

A motor drive circuit according to the present invention is provided with a transistor for controlling a drive circuit of the same conductivity type in which a base and an emitter of a motor drive transistor are commonly connected to each other. The collector controls the drive circuit of the motor drive transistor.

[0007]

In the drive circuit controlling transistor according to the present invention in which the motor drive transistor and the base and the emitter are commonly connected, a through current does not flow through the motor drive transistor of the reverse conductivity type in which the collector is connected to the collector of the motor drive transistor. Control.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an emitter having a first power source (Vc
c) Connected PNP transistors, 2 is a PNP in which the emitter of the PNP transistor 1 and the emitter are connected
Transistor 3 is an NPN transistor whose collector and collector are connected to PNP transistor 1 and whose emitter is connected to a second power source (ground). Reference numeral 4 is a collector of PNP transistor 2 whose emitter and emitter are connected. An NPN transistor whose collector is connected to each other. 1 and 3 form a first series connection body composed of two motor driving transistors connected in series, and 2 and 4 form a second series connection body. There is. 5
Is a motor connected between the collectors of commonly connected transistors, that is, between the transistor connection points of the two series-connected bodies, 6 is connected to the base of the PNP transistor 1, and P
A first drive circuit for switching the NP transistor 1,
7 is connected to the base of the PNP transistor 2,
A second drive circuit for switching the transistor 2, 8 is connected to the base of the NPN transistor 3, and a third drive circuit for switching the NPN transistor 3, 9 is an NP
A fourth drive circuit 10 connected to the base of the N-transistor 4 to switch the NPN transistor 4 is a PNP.
A PNP transistor for controlling a drive circuit, in which the base and the emitter of the transistor 1 are commonly connected, and the collector is connected to the third drive circuit 8, and 11 is a base, an emitter, a base and an emitter of the PNP transistor 2, which are commonly connected. The collector is connected to the fourth drive circuit 9, and the drive circuit controlling PNP transistor 12 is connected to the base and emitter of the NPN transistor 3 in common with the base and the emitter, and the collector is connected to the first drive circuit 6. A drive circuit controlling NPN transistor 13 is a drive circuit controlling NPN transistor in which the base and emitter of the NPN transistor 4 are commonly connected and the collector is connected to the second drive circuit 7.

Next, the operation will be described. The first driving circuit 6 and the fourth driving circuit 9 turn on the motor driving PNP transistor 1 and the NPN transistor 4, and the second driving circuit 7 and the third driving circuit 8 turn on the motor driving PNP transistor 2 and the NPN transistor 3. When turned off,
The current flowing through the PNP transistor 1 passes through the motor 5,
It flows to the NPN transistor 4, and the motor 5 rotates. Further, the second driving circuit 7 and the third driving circuit 8 turn on the motor driving PNP transistor 2 and the NPN transistor 3, and the first driving circuit 6 and the fourth driving circuit 9 turn on the motor driving PNP transistor 1 and the NPN transistor. Transistor 4
When is turned off, the current flowing through the PNP transistor 2 passes through the motor 5 and flows through the NPN transistor 3, and the motor 5 rotates in the direction opposite to the above operation. In this operation PN
When the P-transistor 1 is turned on, a current flows through the PNP transistor 10 for controlling the drive circuit, and the third drive circuit 8 controls so that the NPN transistor 3 for driving the motor is not turned on. Similarly, when the motor driving PNP transistor 2 is turned on, the driving circuit controlling PN is
A current flows through the P-transistor 11, and the fourth drive circuit 9 controls so that the motor-driving NPN transistor 4 is not turned on. When the motor driving NPN transistor 3 is turned on, a current flows through the driving circuit controlling NPN transistor 12, and the first driving circuit 6 controls so that the motor driving PNP transistor 1 is not turned on. When the transistor 4 is on, the drive circuit control N
A current flows through the PN transistor 13, and the second drive circuit 7 controls so that the motor driving PNP transistor 2 is not turned on.

In this embodiment as described above, a transistor of the same conductivity type in which the base and the emitter of the motor driving transistor are commonly connected to each other is provided, and the collector of the transistor is used to connect the drive circuit of the motor driving transistor to the through current. Since the control is performed so that the current does not flow, it is possible to obtain the motor drive circuit in which the through current does not flow even if the reverse operation is performed without time delay.

[0011]

As described above, according to the present invention, a transistor for controlling a drive circuit of the same conductivity type in which a base and an emitter of a motor driving transistor are commonly connected to each other is provided, and a collector of the transistor. Since the drive circuit of the motor drive transistor is controlled so that the through current does not flow, there is an effect that a motor drive circuit in which the through current does not flow can be obtained even if the reverse operation is performed without a time delay.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a motor drive circuit according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional motor drive circuit.

[Explanation of symbols]

 1 PNP transistor (for motor drive) 2 PNP transistor (for motor drive) 3 NPN transistor (for motor drive) 4 NPN transistor (for motor drive) 5 Motor 6 1st drive circuit 7 2nd drive circuit 8 3rd drive circuit 9 Fourth drive circuit 10 PNP transistor (for drive circuit control) 11 PNP transistor (for drive circuit control) 12 NPN transistor (for drive circuit control) 13 NPN transistor (for drive circuit control)

Claims (2)

[Claims] 1. A power supply connected between a first power supply and a second power supply,
The first, which consists of two transistors connected in series,
A second series-connected body and four transistor drive circuits for controlling ON / OFF of each transistor of the both series-connected bodies are provided, and drive control of a motor connected between the transistor connection points of the both series-connected bodies is performed. In the motor drive circuit, first control means for controlling the drive circuit of these transistors so that the other transistor does not turn on while one transistor of the first series connection body is on, and the second control means. A motor drive circuit comprising: second control means for controlling a drive circuit for these transistors so that the other transistor is not turned on while one transistor of the series connection body is turned on. 2. The motor drive circuit according to claim 1, wherein the first series connection body includes a first PNP transistor and a first NPN transistor having a collector and a collector connected to the first PNP transistor. The connection body includes a second PNP transistor and a collector of the transistor and a second NPN transistor having a collector connected to each other. Bases of the first and second PNP transistors include first and second drive circuits for switching the respective transistors. Connected to the bases of the first and second NPN transistors are connected third and fourth drive circuits for switching the respective transistors, and the first control means is a base and an emitter of the first PNP transistor. The base and emitter are connected to each other, and the collector is the third A third PNP transistor connected to the drive circuit, a base of the second PNP transistor,
The fourth control means includes a fourth PNP transistor having an emitter, a base, and an emitter connected to each other, and a collector connected to a fourth drive circuit. The second control means connects the base, the emitter, the base, and the emitter of the first NPN transistor, respectively. A third NPN transistor having a collector connected to the first drive circuit, and a fourth NPN transistor having a base and an emitter connected to the second drive circuit and a collector connected to the second drive circuit. A motor drive circuit characterized by being configured.