KR940002607Y1 - Power supply for two phase - Google Patents

Abstract

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Description

2-phase voltage generator

1 is a conventional two-phase voltage generation circuit.

2 is a waveform diagram of the main nodes of the circuit of FIG.

3 is a two-phase voltage generator circuit of the present invention.

4 is a waveform diagram of a main node of the second circuit.

The present invention relates to a two-phase voltage generator circuit, and more particularly to a two-phase voltage generator circuit configured to prevent the flow of through current generated through the transistor from the power supply to the ground during phase switching.

The bridge output circuit, which is a conventional two-phase voltage generation circuit, has a power stage bridged with Q1, Q2, Q3, and Q4 for supplying a driving current to the motor M, as shown in FIG. The first control circuits of Q7, Q8, R3, and R4 and the second control circuits of Q5, Q6, R1, and R2 that supply the control bare currents to Q3 and Q4 are symmetrical.

The determination of the voltage direction applied to the motor M is made by the direction setting circuit composed of the first and second inverters G ₁ and G ₂ , the first transistor Q ₉ and the second transistor Q ₁₀ .

The operation of the conventional motor drive circuit is as follows.

When the high signal is inputted to the DIR terminal of the direction setting circuit, the output of G1 goes low and the output of G2 goes high. So Q9 is on and Q10 is off. When Q9 is turned on, current is supplied to the base of Q8, Q8 and Q7 are turned on, and Q4 is turned on. Since Q10 is off, Q6 and Q5 are off and Q3 is also off.

When Q4 is turned on, the base current of Q1 is supplied through R5, so Q1 is also turned on, and a voltage is applied to both ends of motor M so that current I flows and the motor is driven. At this time, since Q3 is off, Q2 cannot be turned on and remains off.

On the other hand, when the DOR terminal goes low, Q9 is turned off, Q10 is turned on, and Q6, Q5, Q3, and Q2 are turned on, and A10, Q8, Q7, Q4, and Q1 are turned off, and a voltage is applied to the motor in a massive direction.

However, in such a conventional circuit, when the direction of voltage applied to the motor is changed, that is, when the DIR signal is changed from high to low or from low to high, Q3 and Q4 are turned on at the same time as the waveform of current I shown in FIG. At the moment, Q1 and Q2 are also turned on at the same time, and large through current flows from the power supply to ground.

The present invention prevents the instant of turning on Q3 and Q4 at the same time by inserting a delay circuit between the direction setting circuit and the control circuit so as to prevent the passage current through the conventional circuit.

3 shows an embodiment of the present invention and FIG. 4 is a waveform diagram thereof.

The two-phase voltage generator circuit of FIG. 3 differs only in that the first and second delay circuits are added in the circuit of FIG.

The transistor function from Q21 to Q30 in FIG. 3 is the same as that of Q1 to Q10 in FIG.

The second delay circuit is composed of Q31, C1, and R25, and the first delay circuit is composed of Q32, C2, and R26. The C ₁ and Q ₃₁ collectors of the second delay circuit are connected to each other and connected to the collector of Q _30. The remaining terminals of C ₁ and the R ₂₅ and Q ₃₁ bases are connected to each other and connected to the collector of Q29. And the other terminal of R25 are grounded.

The first delay circuit is connected to correspond with the second delay circuit.

When explaining the operation of the embodiment of the present invention configured as described with reference to Figure 4 as follows.

If the direction change terminal DIR is high, Q29 is on, Q30 is off, and Q28, Q27, Q24, and Q21 are on, and Q26, Q25, Q23, and Q22 are off.

At this time, 3Vbe is charged to C2 as shown by the waveform shown as VP2 in FIG. 4, and C1 is charged to the ground potential state as shown by VP1.

In this state, if low signal is input to DIR terminal, Q29 is off and Q30 is on. Q31 turns off, Q32 turns on, C1 begins to charge, and C2 discharges momentarily through Q32. When VP1, the charging voltage of C1, that is, the voltage across the collector of Q31, becomes 3Vbe, Q26, Q25, Q23, and Q22 are turned on, and the opposite voltage is applied to the motor. Q28, Q27, Q24 and Q21 are turned off before this reverse voltage is applied.

That is, since Q24 is already off before Q23 is turned on, generation of through current flowing through Q21 and Q23 and through current flowing through Q22 and Q24 is suppressed.

When DIR goes high again, VIP drops to ground potential first and VP2 slowly rises by the second delay circuit, delaying for a predetermined time defined by C2 and R26 and rising to 3Vbe. And Q21 is turned on so that a positive voltage is applied to the motor again. When VP1 falls below 3Vbe, Q26, Q25, Q23 and Q22 are already off, so there is no case that Q24 turns on at the same time as Q23.

Therefore, the generation of through current, which is a problem of the prior art, is suppressed, thereby improving the efficiency of the motor driving circuit, eliminating instantaneous noise, and suppressing the instantaneous rotational speed fluctuation of the motor when the voltage direction is changed.

In the embodiment of the present invention has been described by connecting the motor as a load of the two-phase voltage generator, other power load may be connected instead of the motor.

Claims (3)

A directional circuit for determining the direction of the voltage applied to the motor, a power stage in which four switching transistors are connected in a bridge so as to apply a positive and reverse voltage to the motor, and the power stage receiving the output of the directional circuit. A two-phase voltage generation circuit comprising first and second control circuits for turning on / off a transistor of claim 1, wherein the first delay circuit is connected between the direction setting circuit and the first control circuit, and the direction setting circuit is provided. And a second delay circuit connected between the second control circuit and the second control circuit. The signal delay circuit of claim 1, wherein the first and second delay circuits each include one capacitor, one resistor, and one transistor, the signal for turning on the transistor of the power stage by a predetermined time determined by the capacitor and the resistor. Two-phase voltage generation circuit characterized by delaying the transmission. The method of claim 1, wherein the direction setting circuit comprises: a first inverter connected to the direction setting input terminal DIR, a first transistor connected to a base thereof through the first inverter, and a first inverter connected to an output of the first inverter. A second transistor having a base connected to a second inverter and a second inverter; a collector of the first transistor and an input of the first control circuit are connected; and a collector of the second transistor and an input of the second control circuit. Is connected, the collector of the transistor of the first delay circuit and the capacitor are connected to the input of the first control circuit, the data of the transistor of the first delay circuit is grounded, the base of the transistor of the first delay circuit Is connected to a resistor connected to the other terminal and the ground and is connected to the collector of the second transistor, and the collector and the capacitor of the transistor of the second delay circuit are connected. Ie, connected to the input of the second control circuit, the data of the transistor of the second delay circuit is grounded, and the base of the transistor of the second delay circuit is connected to the other terminal of the capacitor and a resistor connected to ground; A two-phase voltage generator circuit connected to the collector of the first transistor.