CN211995170U - A circuit in which a single winding generates positive and negative voltages - Google Patents

Abstract

The utility model relates to a circuit for generating positive and negative voltages by a single winding, comprising: a precision voltage-stabilizing source circuit, which is used for converting an input voltage into required positive-phase voltage and negative-phase voltage; The pull circuit includes a first transistor and a second transistor, the emitters of the two transistors are connected and connected to a ground terminal; the bases of the two transistors are connected and connected with the precision voltage regulator source circuit, the first transistor The base of the transistor is connected to the positive-phase voltage input terminal, the base of the second triode is connected to the negative-phase voltage input terminal; the collector of the first transistor is connected to the positive-phase voltage input terminal and the positive-phase voltage required for output The positive phase voltage output terminal of the second triode is connected to the negative phase voltage input terminal and the negative phase voltage output terminal for outputting the required negative phase voltage. The utility model realizes stable positive and negative voltage output through a precise voltage-stabilizing source circuit and a push-pull circuit, and has the characteristics of simple structure and low cost.

Description

A circuit in which a single winding generates positive and negative voltages

technical field

The utility model relates to the technical field of vehicle motor control, in particular to a circuit for generating positive and negative voltages by a single winding.

Background technique

In the field of on-board motor controllers, considering the safety mode after the motor controller fails, it is required that the motor controller can enter an active short-circuit state and then perform emergency discharge. Active short-circuit and emergency discharge both require the high-side flyback power supply to generate positive and negative voltages to supply power to the drive, so the number of transformer windings will increase, increasing the volume and cost of the transformer. In addition, a single winding can also generate positive and negative voltages through two LDOs, but the cost is high.

Utility model content

The purpose of this utility model is to overcome the defects of the prior art, to provide a circuit for generating positive and negative voltages by a single winding, to solve the problem that the existing positive and negative voltages need to increase the number of windings and increase the volume and cost of the transformer, and to solve the problem that a single winding passes through There is a problem of high cost of generating positive and negative pressures by two LDOs.

The technical solution to achieve the above purpose is:

The utility model provides a circuit for generating positive and negative voltages by a single winding, comprising:

A precision voltage regulator circuit connected to the positive-phase voltage input terminal and the negative-phase voltage input terminal for converting the input voltage into the required positive-phase voltage and negative-phase voltage; and

A push-pull circuit connected to the positive-phase voltage input terminal and the negative-phase voltage input terminal and connected in parallel with the precision voltage regulator source circuit, the push-pull circuit includes a first transistor and a second transistor,

The emitter of the first triode is connected to the emitter of the second triode and is connected to a ground terminal;

The base of the first triode is connected to the base of the second triode and is connected to the precision voltage regulator source circuit, and the base of the first triode is input with the positive phase voltage terminal is connected, and the base of the second triode is connected to the negative-phase voltage input terminal;

The collector of the first triode is connected to the positive-phase voltage input terminal and the positive-phase voltage output terminal for outputting the required positive-phase voltage, and the collector of the second triode is connected to the negative-phase voltage Input terminal and negative phase voltage output terminal for outputting the required negative phase voltage.

The utility model adopts a precise voltage regulator circuit to convert the input voltage into the required positive-phase voltage and negative-phase voltage, and outputs the required positive-phase voltage at the positive-phase voltage output terminal through the push-pull circuit, and outputs the required positive-phase voltage at the negative-phase voltage output terminal. Negative phase voltage required, using push-pull circuit to ensure stable output voltage. The utility model realizes stable positive and negative voltage output through a precision voltage-stabilizing source circuit and a push-pull circuit, has the characteristics of simple structure and low cost, and solves the problems of increasing the volume and cost of the transformer caused by increasing the number of windings in the prior art , and also solves the problem of high cost caused by the generation of positive and negative voltages by a single winding through two LDOs in the prior art.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that the push-pull circuit further comprises a first diode and a second diode;

The anode of the first diode is connected to the base of the first triode and the positive-phase voltage input terminal, and the cathode of the first diode is connected to the cathode of the second diode. The anode is connected and connected with the precision voltage regulator circuit;

The cathode of the second diode is connected to the base of the second triode and is connected to the negative-phase voltage input terminal.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that a first resistor is connected between the anode of the first diode and the positive-phase voltage input terminal;

A second resistor is connected between the cathode of the second diode and the negative-phase voltage input terminal.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that the forward voltage drop of the first diode is smaller than the voltage drop of the base and the emitter of the first triode;

The forward voltage drop of the second diode is smaller than the voltage drop between the base and the emitter of the second triode.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that the precision voltage regulator circuit comprises a three-terminal adjustable shunt reference source, a third resistor, a fourth resistor and a fifth resistor;

The three-terminal adjustable shunt reference source includes a first pin, a second pin and a third pin, and the first pin is connected to the positive-phase voltage input end;

the third resistor, the fourth resistor and the fifth resistor are connected in series, the third resistor is connected to the positive-phase voltage input terminal, and the fifth resistor is connected to the negative-phase voltage input terminal;

the second pin is connected between the third resistor and the fourth resistor;

The third pin is connected between the fourth resistor and the fifth resistor, and is connected to the cathode of the first diode and the anode of the second diode.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that the collector of the first triode is connected to a sixth resistor, and the sixth resistor is connected to the positive-phase voltage input end and the required output The positive-phase voltage output terminal of the positive-phase voltage is connected;

The collector of the second transistor is connected to a seventh resistor, and the seventh resistor is connected to the negative-phase voltage input terminal and the negative-phase voltage output terminal for outputting the required negative-phase voltage.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that a first capacitor is connected between the positive-phase voltage input terminal and the negative-phase voltage input terminal.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that a second capacitor is connected between the positive-phase voltage output terminal and the ground terminal;

A third capacitor is connected between the negative-phase voltage output terminal and the ground terminal.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that the positive-phase voltage input terminal and the negative-phase voltage input terminal are connected to a transformer with a single winding.

A further improvement of the circuit for generating positive and negative voltages by a single winding of the present invention is that the positive-phase voltage output terminal and/or the negative-phase voltage output terminal is connected to a load.

Description of drawings

FIG. 1 is a circuit diagram of a circuit for generating positive and negative voltages by a single winding of the present invention.

Detailed ways

The present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

Referring to FIG. 1 , the present invention provides a circuit for generating positive and negative voltages by a single winding, which is used to solve the problem of increasing the volume and cost of a transformer by generating positive and negative voltages by two windings. The utility model collects a single winding to form an input voltage after rectifying and filtering, provides a precise required positive-phase voltage through a precise voltage-stabilizing source circuit, and outputs stable positive-phase voltage and negative-phase voltage through a push-pull circuit. The negative power supply is loaded or the positive and negative power supplies are loaded at the same time, which can ensure the stability of the output positive phase voltage. The circuit for generating positive and negative voltages by a single winding of the present invention will be described below with reference to the accompanying drawings.

Referring to FIG. 1 , there is shown a circuit diagram of a circuit for generating positive and negative voltages by a single winding of the present invention. The circuit for generating positive and negative voltages by a single winding of the present invention will be described below with reference to FIG. 1 .

As shown in FIG. 1 , the circuit for generating positive and negative voltages by a single winding of the present invention includes a precision voltage regulator circuit S1 and a push-pull circuit S2, wherein the precision voltage regulator circuit S1 is connected to the positive-phase voltage input terminal I1 and the negative-phase voltage input terminal I1. The voltage input terminal I2, the precision voltage regulator circuit S1 is used to convert the input voltage into the required positive phase voltage and negative phase voltage; the push-pull circuit S2 is also connected to the positive phase voltage input terminal I1 and the negative phase voltage input terminal I2 , the push-pull circuit S2 is connected in parallel with the precision voltage regulator source circuit S1, the push-pull circuit S2 includes a first triode Q1 and a second triode Q2, and the first triode Q1 and the second triode Q2 both include Collector c, base b and emitter e, the emitter e of the first transistor Q1 and the emitter e of the second transistor Q2 are connected and connected to a ground terminal GND; the base of the first transistor Q1 b is connected to the base b of the second transistor Q2 and is connected to the precision voltage regulator circuit S1, the base b of the first transistor Q1 is connected to the positive-phase voltage input terminal I1, and the second transistor Q2 The base b is connected to the negative-phase voltage input terminal I2; the collector c of the first transistor Q1 is connected to the positive-phase voltage input terminal I1 and the positive-phase voltage output terminal O1 for outputting the required positive-phase voltage, and the second triode The collector c of the tube Q2 is connected to the negative phase voltage input terminal I2 and the negative phase voltage output terminal O2 for outputting the required negative phase voltage.

The input voltage at the positive-phase voltage input terminal I1 and the negative-phase voltage input terminal I2 is converted into the required positive-phase voltage and negative-phase voltage by the precision voltage regulator circuit S1, and then a stable positive-phase voltage is output by the push-pull circuit S2. Phase voltage and negative phase voltage. The push-pull circuit S2 of the present invention adopts two triode elements, and has the characteristics of simple structure and low cost.

In a specific embodiment of the present invention, the push-pull circuit S2 further includes a first diode D1 and a second diode D2;

The anode of the first diode D1 is connected to the base b of the first transistor Q1 and is connected to the positive-phase voltage input terminal I1, and the cathode of the first diode D1 is connected to the anode of the second diode D2 and is connected to the positive voltage input terminal I1. Precision voltage regulator circuit S1 connection;

The cathode of the second diode D2 is connected to the base b of the second transistor Q2 and is connected to the negative-phase voltage input terminal I2.

Further, a first resistor R1 is connected between the anode of the first diode D1 and the positive-phase voltage input terminal I1; a second resistor R2 is connected between the cathode of the second diode D2 and the negative-phase voltage input terminal I2. The first resistor R1 and the second resistor R2 provide bias current for the first diode D1 and the second diode D2 at the input of the push-pull circuit S2 and establish the quiescent current on that side.

Preferably, the forward voltage drop of the first diode D1 is smaller than the voltage drop of the base b and the emitter e of the first transistor Q1; the forward voltage drop of the second diode D2 is smaller than that of the second transistor Q1. The voltage drop between the base b and the emitter e of the tube Q2. In this way, it can be ensured that no current flows through the two triodes when there is no load.

In a specific embodiment of the present invention, the precision voltage regulator circuit S1 includes a three-terminal adjustable shunt reference source U1, a third resistor R3, a fourth resistor R4 and a fifth resistor R5;

The three-terminal adjustable shunt reference source U1 includes a first pin 1, a second pin 2 and a third pin 3, and the first pin 1 is connected to the positive-phase voltage input terminal I1;

The third resistor R3, the fourth resistor R4 and the fifth resistor R5 are connected in series, and the third resistor R3 is connected to the positive-phase voltage input terminal I1, and the fifth resistor R5 is connected to the negative-phase voltage input terminal I2;

The second pin 2 is connected between the third resistor R3 and the fourth resistor R4;

The third pin 3 is connected between the fourth resistor R4 and the fifth resistor R5, and is connected to the cathode of the first diode D1 and the anode of the second diode D2.

Preferably, the three-terminal adjustable shunt reference source U1 adopts TL431, which can provide an accurate positive-phase voltage. The three-terminal adjustable shunt reference source U1 converts the input voltage Uin into precise positive-phase voltage Up and negative-phase voltage Un, wherein the positive-phase voltage Up is the pair of the first pin 1 of the three-terminal adjustable shunt reference source U1 to the second The voltage of the third pin 3, the negative phase voltage Un is the voltage across the fifth resistor R5. The positive-phase voltage Up can be precisely adjusted according to actual needs, and the negative-phase voltage Un is a negative value, which is equal to the positive-phase voltage Up minus the input voltage Uin.

In a specific embodiment of the present invention, the collector c of the first transistor Q1 is connected to a sixth resistor R6, and the sixth resistor R6 is connected to the positive-phase voltage input terminal I1 and the positive-phase voltage required for the output. The positive phase voltage output terminal O1 is connected;

The collector c of the second transistor Q2 is connected to a seventh resistor R7, and the seventh resistor R7 is connected to the negative phase voltage input terminal I2 and the negative phase voltage output terminal O2 for outputting the required negative phase voltage.

The set sixth resistor R6 and seventh resistor R7 can effectively limit the output current when overload or short circuit occurs, and play the role of overload protection, so that the devices in the circuit will not be damaged.

In a specific embodiment of the present invention, a first capacitor C1 is connected between the positive-phase voltage input terminal I1 and the negative-phase voltage input terminal I2.

Further, a second capacitor C2 is connected between the positive-phase voltage output terminal O1 and the ground terminal GND;

A third capacitor C3 is connected between the negative-phase voltage output terminal O2 and the ground terminal GND.

Still further, the positive-phase voltage input terminal I1 and the negative-phase voltage input terminal I2 are connected to a transformer having a single winding. The transformer of a single winding provides the input voltage for the precision voltage regulator circuit S1 after being rectified and filtered.

Furthermore, the positive-phase voltage output terminal O1 and/or the negative-phase voltage output terminal O2 are connected to the load. The second capacitor C2 and the third capacitor C3 provide instantaneous peak current to the load.

The working principle of the circuit for generating positive and negative voltages by a single winding of the present invention will be described below.

When only the positive-phase voltage output terminal O1 is connected to the load, the load, the second transistor Q2 and the seventh resistor R7 form a loop, and the second transistor Q2 dynamically adjusts the output current to make the output voltage of the positive-phase voltage output terminal O1 Stable, the first transistor Q1 is in an off state. The actual positive-phase voltage output by the positive-phase voltage output terminal O1=Up-VF_D2+VBE_Q2, where Up is the positive-phase voltage (that is, the required voltage) converted by the precision voltage regulator circuit, and VF_D2 is the second diode D2 The forward voltage drop of , VBE_Q2 is the be voltage drop of the second transistor Q2 (the voltage drop between the base b and the emitter e). There is a certain error between the actual output voltage and the required voltage, and the error range is determined by the forward voltage drop of the diode and the voltage drop of the triode.

When only the negative phase voltage output terminal O2 is connected to the load, the load, the first transistor Q1 and the sixth resistor R6 form a loop, and the first transistor Q1 dynamically adjusts the output current to make the output voltage of the positive voltage output terminal O1 Stable, the second transistor Q2 is in an off state. The actual positive-phase voltage output by the positive-phase voltage output terminal O1=Up+VF_D1-VBE_Q1, where Up is the positive-phase voltage (that is, the required voltage) converted by the precision voltage regulator circuit, and VF_D1 is the first diode D1 The forward voltage drop of , VBE_Q1 is the be voltage drop of the first transistor Q1 (the voltage drop between the base electrode b and the emitter electrode e). Similarly, there is a certain error between the actual output voltage and the required voltage, and the error range is determined by the forward voltage drop of the diode and the voltage drop of the triode.

When the positive voltage output terminal O1 and the negative voltage output terminal O2 are connected to the load at the same time, if the output current of the positive power supply is greater than the output current of the negative power supply, the current flowing through the second transistor Q2 is the positive power supply current minus the negative power supply current , the first transistor Q1 is in the cut-off state, and the output voltage is the same as the output voltage when only the positive-phase voltage output terminal O1 is connected to the load. If the output current of the negative power supply is greater than the output current of the positive power supply, the current flowing through the first transistor Q1 is the negative power supply current minus the positive power supply current, the second transistor Q2 is in the off state, and the output voltage is the same as the output voltage of only the negative phase voltage. The output voltage is the same when the load is connected to the terminal O2. If the output current of the positive power supply is equal to the output current of the negative power supply, both the first transistor Q1 and the second transistor Q2 are in an off state, and the output voltage is Up.

The circuit for generating positive and negative voltages by a single winding provided by the present invention can be used to provide positive and negative voltage driving power supply for the motor controller. Preferably, the input voltage Uin generated by a single winding is 15V. Through), without damaging the IGBT, it needs to generate a stable positive phase voltage of +10V and negative phase voltage of -5V. When selecting a diode and a triode, the forward voltage drop of the diode should be slightly smaller than the BE voltage drop of the triode, and the difference between the two voltage drops is the error between the actual output forward voltage and the required forward voltage.

The present invention has been described in detail above with reference to the embodiments of the accompanying drawings, and those of ordinary skill in the art can make various modifications to the present invention according to the above description. Therefore, some details in the embodiments should not be construed to limit the present invention, and the present invention will take the scope defined by the appended claims as the protection scope of the present invention.

Claims (10)

1. A circuit for generating positive and negative voltages with a single winding, comprising:

the precise voltage-stabilizing power supply circuit is connected to the positive-phase voltage input end and the negative-phase voltage input end and is used for converting the input voltage into the required positive-phase voltage and negative-phase voltage; and

a push-pull circuit connected to the positive phase voltage input end and the negative phase voltage input end and connected in parallel with the precision voltage regulator circuit, wherein the push-pull circuit comprises a first triode and a second triode,

the emitter of the first triode is connected with the emitter of the second triode and is connected with a grounding end;

the base electrode of the first triode is connected with the base electrode of the second triode and is connected with the precision voltage-stabilizing source circuit, the base electrode of the first triode is connected with the positive-phase voltage input end, and the base electrode of the second triode is connected with the negative-phase voltage input end;

the collector of the first triode is connected with the positive phase voltage input end and the positive phase voltage output end for outputting the required positive phase voltage, and the collector of the second triode is connected with the negative phase voltage input end and the negative phase voltage output end for outputting the required negative phase voltage.

2. The circuit for generating positive and negative voltages with a single winding according to claim 1, wherein the push-pull circuit further comprises a first diode and a second diode;

the anode of the first diode is connected with the base electrode of the first triode and the positive-phase voltage input end, and the cathode of the first diode is connected with the anode of the second diode and the precision voltage-stabilizing source circuit;

and the cathode of the second diode is connected with the base electrode of the second triode and the negative phase voltage input end.

3. The circuit for generating positive and negative voltages with a single winding as claimed in claim 2, wherein a first resistor is connected between the anode of said first diode and said positive voltage input terminal;

and a second resistor is connected between the cathode of the second diode and the negative phase voltage input end.

4. The circuit for generating positive and negative voltages with a single winding as claimed in claim 2, wherein the forward voltage drop of the first diode is smaller than the voltage drop of the base and the emitter of the first triode;

and the forward voltage drop of the second diode is smaller than the voltage drop of the base electrode and the emitter electrode of the second triode.

5. A circuit for generating positive and negative voltage by a single winding as claimed in claim 2 or 3, wherein said precision regulator circuit comprises a three-terminal adjustable shunt reference source, a third resistor, a fourth resistor and a fifth resistor;

the three-terminal adjustable shunt reference source comprises a first pin, a second pin and a third pin, and the first pin is connected with the positive-phase voltage input end;

the third resistor, the fourth resistor and the fifth resistor are connected in series, the third resistor is connected with the positive phase voltage input end, and the fifth resistor is connected with the negative phase voltage input end;

the second pin is connected between the third resistor and the fourth resistor;

the third pin is connected between the fourth resistor and the fifth resistor and is connected with the cathode of the first diode and the anode of the second diode.

6. The circuit for generating positive and negative voltages with a single winding as claimed in claim 1, wherein the collector of the first transistor is connected to a sixth resistor, and the sixth resistor is connected to the positive phase voltage input terminal and the positive phase voltage output terminal for outputting the required positive phase voltage;

and the collector of the second triode is connected with a seventh resistor, and the seventh resistor is connected with the negative phase voltage input end and the negative phase voltage output end for outputting the required negative phase voltage.

7. The circuit for generating positive and negative voltages with a single winding as claimed in claim 1, wherein a first capacitor is connected between said positive phase voltage input terminal and said negative phase voltage input terminal.

8. The circuit for generating positive and negative voltages with a single winding as claimed in claim 1, wherein a second capacitor is connected between said positive voltage output terminal and said ground terminal;

and a third capacitor is connected between the negative phase voltage output end and the grounding end.

9. The circuit for generating positive and negative voltages with a single winding of claim 1, wherein the positive phase voltage input terminal and the negative phase voltage input terminal are connected to a transformer with a single winding.

10. The circuit for generating positive and negative voltages with a single winding as claimed in claim 1, wherein said positive phase voltage output terminal and/or said negative phase voltage output terminal is connected to a load.

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